# New Balmar SmartGuage experience



## Minnewaska (Feb 21, 2010)

Installed this at the beginning of the season and calibrated it to 100% charge and set it to GEL battery type, as the house was fully charged at the slip all week. My first few trips off the dock were short, so the batts never discharged below 80%.

Being away for the weekend more often now, I see discharge levels down in the 50s after a couple of days. But only twice at that level of discharge. 

My odd experience, however, has to do with recharging, which may have nothing to do with the gauge.

Previously, all I had to identify charge was the Xantrex remote panel, which has three idiot lights for Bulk, Absorb and Float.

Now, I'm checking the new toy all the time, to see actual voltage and charge percentage. 

The SmartGuage was not showing much increase in charge level, after running the generator for an hour or two. Previously, that would be about all I felt I needed to recharge a full days usage. It's been showing an increase of maybe 10% of capacity on a 400ah house bank. This is concerning, because I use more than that per day and I wouldn't think I would need to run the generator for more than two hours per day to keep up.

Then I noticed something on the original idiot gauges. They marched their way up from bulk to float, but the SmartGuage still said the bank was only 84% charged. Float should be 98-99, if I understand this correctly. 

Could it be that the SmartGuage hasn't "learned" the house parameters yet? Remember, I've also considered that the idiot lights are wrong too.

Final symptom..... When plugged into the dock, I measure 115volts at the AC receptacles. When running the generator, I only measure 106 volts. However, in both scenarios, the SmartGuage seems out of synch with the idiot lights.


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## Maine Sail (Jan 6, 2003)

How is the generator charging the batteries? 

If it is charging through an inverter/charger or battery charger what make, model and amperage rating?

What is the charge voltage of the batteries?

What is the voltage drop at full charger output between the charger or I/C and battery bank terminals?

What brand and model are the batteries?

How old are the batteries?

From 50% SOC (on SmartGauge) how quickly do they attain target voltage eg: how quickly do they reach 14.1V (typical GEL absorption)?

What is the max charge current when you first fire up the charger? 

How long does full output current last?


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## Minnewaska (Feb 21, 2010)

This is what I can do of the top of my head. I can get the rest this weekend.



Maine Sail said:


> How is the generator charging the batteries? *Inverter/charger*
> 
> If it is charging through an inverter/charger or battery charger what make, model and amperage rating? *Xantrex Freedom 20*
> 
> ...


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> How is the generator charging the batteries? *Inverter/charger*


Good



Minnewaska said:


> If it is charging through an inverter/charger or battery charger what make, model and amperage rating? *Xantrex Freedom 20*


You mentioned the word "idiot lights" and the older Freedom chargers could not be any more "idiot" if they tried. Your charger is _not as "smart" as you think it is_ and usually the absorption charge (time spent at target voltage) is far too short. Without a Link remote these (_we need to know what remote you have_) chargers simply default to what amounts to "_kitchen timers_". With the standard remote the Freedom 20 will only do 1 hour of absorption when set to Flooded or AGM and only three hours when set to GEL. Alternatively if the batteries drop to less than 10A acceptance they can switch to float before the _egg timer_ has run out. It is critical that your charger is set to GEL if you are charging GEL batteries.



Minnewaska said:


> What is the charge voltage of the batteries? *I'm not exactly sure what you're asking. Do you mean the Bulk charge rate? When I press the voltage button on the SmartGuage during bulk, it said 14.something. Will have to confirm.*


Bulk = Constant Current; Bulk it is not a "_voltage limited_" stage of charging it is full bore from the charger with the battery voltage slowly rising to the absorption set point.. If you have a 100A charger then it _*should be_ pumping out 100A (bulk) until the battery voltage rises to 14.1V (GEL absorption voltage). *Many older inverter chargers can not develop full charging output when run off a generator as they can be a bit intolerant of the input from a generator. If yours can only develop 70A, and you are doing the mental math on 100A, then you will be frustrated with charging speeds. Once target voltage has been attained (GEL = 14.1V) the _current_ will begin to cut back as voltage is held steady and SOC rises.

This article, despite being about faster charging AGM batteries, may help explain it a bit further:

*How Fast Can an AGM Battery be Charged?*



Minnewaska said:


> What is the voltage drop at full charger output between the charger or I/C and battery bank terminals? Don't know, not sure I know how to check. Given that the SmartGuage is attached direct to the terminals, does it give the reading?


When the charger is pumping out 100A you need to measure terminal voltage, with a DVM, at the charger end of positive & negative then at the battery end. The best way is to measure the voltage drop of the positive cable & then negative cable but most folks don't have DVM test leads that will reach from the I/C to the battery bank.. There will always be some VD, but too much can dig into your charging speed and cause the charger to hit absorption, and _start the timer_, before the batteries ever obtain the proper target voltage..



Minnewaska said:


> What brand and model are the batteries? It was a quality brand, but can't recall off the top of my head. They are Gel batteries. Four group 34, I believe.


If they are quality GEL batteries such as a Deka or Sonnenschein (Prevailer) then use the GEL charge setting.



Minnewaska said:


> How old are the batteries? *Three years
> *


At three years old they likely have a fair bit of sulfation. A good way to tell how much is by how fast the charging voltage rises to 14.1V from 50% SOC. Your charge rate is .25C (25% of 400Ah) if the charger can develop all 100A off your genset, so from 50% SOC the charger should be in bulk/constant current for approx 45 minutes to 1 hour before the batteries attain 14.1V. If the charger turns on at 50% and the battery voltage climbs to 14.1V quickly (eg: less than 35-40 minutes & don't forget about voltage drop) then the batteries are sulfated and charging will simply take longer than it will with healthy batteries.

The math would look like this

400Ah bank at 50% SOC = -200Ah

1 hour of bulk at 100A = -102Ah or approx 75% SOC

At about 75% SOC your batteries should be at, or approaching, 14.1V (dependent upon state of health) and from here to 100% SOC charging gets slower and slower and slower....



Minnewaska said:


> From 50% SOC (on SmartGauge) how quickly do they attain target voltage eg: how quickly do they reach 14.1V (typical GEL absorption)? *Not sure how I would know this. The idiot light, on the Xantrex panel, took hours. But, the charge rate dropped along the way and the idiot lights saying in float, when the SmartGuage says no where near the upper 90% of charge.*


Ignore the _idiot_ lights on the charger! All they are telling you is what the charger "_thinks_" it should be doing and this may be grossly incorrect and usually is especially with "_egg-timer_" chargers... Do you have a volt meter on-board? If you know your target absorption voltage is 14.1V we need to know how long it took to get there from 50% SOC. If this climb in voltage happens _quickly_ that means the battery health is not good..



Minnewaska said:


> What is the max charge current when you first fire up the charger? *Is this the 14.something you asked above?*


Voltage is voltage, current is current. We need to know if the charger can actually develop it's 100A rating running off your genset. Many can't so this number is important to know. Yopu would need an ammeter on-board or a DC clamp meter capable of measuring DC amperage to at least 100A. These are pretty inexpensive these days and are something every boater should own..

I grabbed one of these for a customer and he loves it. They can be had for less too but this one has a lot of good features.

*UT207 AC/DC Clamp Meter*



Minnewaska said:


> How long does full output current last? *If you're asking how much time I get from the 400ah bank, before reaching 50%, that's about two days, with two fridges running, electric heads, plotters/radios running 4-5 hrs per day, pot of coffee off the invertor, lights, etc. Of course, the engine runs in/out of the harbor for a short bit.*


I am asking how long the charger remains delivering its 100A rating for when started up at 50% SOC.

Bottom line is you're far better to trust the SmartGauge and to ignore the idiot lights. The idiot lights are NOT based on your battery actually being _full_ before switching to float. Switching to float too early, a phenomenon I call "premature floatulation" only serves to dramatically extend the time it takes to fully charge your batteries. At the dock, no big deal, but when running a genset _premature floatulation_ leads to slow charge performance..

Look at the SmartGauge each morning _before charging_ and in the evening before bed. Don't focus on it while it's charging. Once you stop charging it will hone in on SOC.. The longer you use it the better it knows your bank and the faster after charging it will hone in on a more accurate SOC....


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## Minnewaska (Feb 21, 2010)

Thank you very much, MS. If you're ever near RI, I owe you a beer.

Admittedly, I'll need to re-read your post a few times this evening. I have a volt meter, but will get the clamp meter.

To answer one of your questions, this is the remote panel that I have:

https://www.amazon.com/Xantrex-84-2056-01-Freedom-Basic-Remote/dp/B000XBKMC2

What would you recommend for a replacement, if the invertor itself becomes the problem? I know you are no fan of the Xantrex. Remaking the battery cables, doesn't seem like fun. I doubt I'll buy the right tools, so I would probably have them made, if I swap out the unit.


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## olson34 (Oct 13, 2000)

Probably not indicative of the experiences of most users, but a data point all the same...
I installed a new Smartgauge this spring and it did not function. I called the company (up in WA) and their tech guy had me test the supply voltage to the meter with my digital volt meter and he declared it non-working.
He issued a return authorization to their repair facility located in Alabama. The postage to send it in was on me - I do not like that but it's their policy. They did pay shipping to send a new one back.
Seems to work now.
One other caveat: the fellow I spoke to did say that my usual practice of leaving the boat on the shore power charger when in the slip would affect the accuracy by about 10%.

Just another .02 worth, and YMMV.

Loren


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## Don L (Aug 8, 2008)

Starting at 70% SOC charge running a generator for 2 hours wouldn't ever really fully charged a 400AH battery bank (as the OP has now discovered). I don't think one ever really gets their batteries fully charged with a generator unless they are willing to let it run a long time with hardy any load on it (going to charge amps). One of the nice things about Battery Monitors is that they tell you what the batteries are accepting (even if the SOC reading is questionable) and with that and the voltage you can may a pretty reasonable guess at SOC knowing that the source could be putting out a lot more power if it had a load to provide .

In my opinion.


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## Minnewaska (Feb 21, 2010)

olson34 said:


> ....their tech guy had me test the supply voltage to the meter with my digital volt meter and he declared it non-working.....


Could you clarify this test? You tested the actual voltage of the batts, with a separate meter and compared it to the reading on the gauge, presumably with the charger off? If I even have this right, how far off was it?


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> Starting at 70% SOC charge running a generator for 2 hours wouldn't ever really fully charged a 400AH battery bank (as the OP has now discovered)......


I do understand that, but don't think I implied otherwise.

My stated concern is, after a couple of hours of charging (generator powering a battery charger), I don't see much of an increase in stated capacity at all. Sometimes less that a 10 point increase in capacity. That seemed light to me.

More critically, it indicates that we use more than 10 points of capacity per day, so that suggests we can't keep up. That really makes no sense. Even on our power hungry boat, I would think that running the battery charger for two hours per day would keep up.

More testing coming this weekend. Heading out for a two week cruise in a couple of week, with likely no slip power along the way. Need to straighten this out.


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## xort (Aug 4, 2006)

Mainesail does have a donate button on his website. You cant send beer but you can send money. Besides, any beer sent now for his daughters college fund would go very flat by the time she can drink it.


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## Minnewaska (Feb 21, 2010)

xort said:


> Mainesail does have a donate button on his website. You cant send beer but you can send money. Besides, any beer sent now for his daughters college fund would go very flat by the time she can drink it.


I went to look and couldn't find it. It's not on the home page, nor the on the page he linked above. Maybe my ad blocker is hiding it?

Then, it occurred to me. I bought the SmartGauge from MS. 

I've also purchase butyl from him over the years. So, it's really a customer inquiry.


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## olson34 (Oct 13, 2000)

Minnewaska said:


> Could you clarify this test? You tested the actual voltage of the batts, with a separate meter and compared it to the reading on the gauge, presumably with the charger off? If I even have this right, how far off was it?


He asked me to check battery voltage at the terminals and then at the connections at the SmartGuage.The idea was to see just exactly what voltage was being supplied to the instrument. I had about 13 volts at the battery and wiring was new and delivering that to the terminals on the device, but it's screen was displaying 9. something.
The menus were not working right to display anything else, either.

It was good that they honored their warranty, but I admit to being irked that I had to pay rather big $$ to send and insure it to their "service center" when all they were going to do was ship a new one to me anyway. 
This is not an inexpensive item, and IMHO it's more normal for high-end computer and peripheral builders to pay for shipping or even "cross ship" a new device to the customer.

OK time to stop grumbling. At least Now it works.

Loren


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## wsmurdoch (Jan 23, 2007)

There is a newer SmartGauge. It's 119 UKL Vat inc in the UK.

SmartGauge Electronics - Homepage

JG Technologies Dealer Specialist Marine Electronics

I wonder if it is smarter.


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## knuterikt (Aug 7, 2006)

wsmurdoch said:


> There is a newer SmartGauge. It's 119 UKL Vat inc in the UK.
> 
> SmartGauge Electronics - Homepage
> 
> ...


That is the real Smartgauge, Balmar is just putting their own label on it for the US market.


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## Maine Sail (Jan 6, 2003)

knuterikt said:


> That is the real Smartgauge, Balmar is just putting their own label on it for the US market.


Balmar is the North American market distributor for the SmartGauge.


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## wsmurdoch (Jan 23, 2007)

UKL 119 inc 20% VAT would be UKL 99 ex-VAT or $130. The Balmar list price is $400.


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## Minnewaska (Feb 21, 2010)

Update....... still not sure the Smartguage is acting smartly. 

Since my OP, I've changed out my Xantrex inverter charger for a Magnum 2800w inverter/charger. For starters, I love the Magnum so far. Much better inverter, charger and remote. 

Over the winter, I pulled the fuse on the Smartguage to avoid any parasitic load. I don't know if that messed anything up. It no longer reads anything near 100% charge at any time. Not even after plugged in for a week. The Magnum remote reads Full Charge, while the smartgauge will read anything from 70% to maybe 80%. I've also tried to run the batts down, when cruising, to 12.2 volts (as read on the Magnum remote and confirmed on the Smartguage), just to get some range for the gauge to follow and learn. It has read in the 40% capacity range, when I still had 12.2-12.4 volts in the batts. 

Bottom line, it never reads full, when I know it's full and it seems to read much lower capacity than I think it really has.

Is there a hard restart I should do to start over?


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## eherlihy (Jan 2, 2007)

The hard reset on the SmartGauge is to pull the negative wire from the back, wait a minute, and then re-connect. The SmartGauge will display the error message "E01", until you push any button. 
I suggest that you re-program the battery type to match the batteries that you have installed;


> The battery types are numbered 1 to 7 and are as follows:
> • Type 1 - Standard wet cell deep cycle Lead Acid - Use this setting for:-
> 1. Standard vented Lead Acid deep cycle
> 2. Lead acid recombinant (have a catalyzer in the cap to recombine the oxygen and hydrogen back into water that is normally lost during charging in a standard Lead Acid battery). Do not confuse with VRLA (AGM or Gel).
> ...


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## Minnewaska (Feb 21, 2010)

Doesn't pulling the fuse essentially do the same thing, albeit on the positive?


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## eherlihy (Jan 2, 2007)

There are TWO positive leads for two banks. Disconnect one negative or two fuses - same diff.


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## Maine Sail (Jan 6, 2003)

Merely pulling the fuses or negative does not perform a factory reset on the SG. Start with a factory reset...


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> Merely pulling the fuses or negative does not perform a factory reset on the SG. Start with a factory reset...


Roger that. I just looked up how to perform it and will give that a try tonight.

At some point, I did manually adjust the SOC readout and wonder if that messed up it's brains. I bet I set it to 100% SOC when it was plugged in, which would be artificially high voltage at that point. Although, I seem to recall doing so because it never read near 100% right out of the box. This may prove to be a flaw, but I'll try the reset first.


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## knuterikt (Aug 7, 2006)

Minnewaska said:


> Roger that. I just looked up how to perform it and will give that a try tonight.
> 
> At some point, I did manually adjust the SOC readout and wonder if that messed up it's brains. I bet I set it to 100% SOC when it was plugged in, which would be artificially high voltage at that point. Although, I seem to recall doing so because it never read near 100% right out of the box. This may prove to be a flaw, but I'll try the reset first.


The SG need sone time to learn the battery, don't fiddle with the settings.


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## Minnewaska (Feb 21, 2010)

knuterikt said:


> The SG need sone time to learn the battery, don't fiddle with the settings.


Yup, I think when I initially installed it, I didn't spend enough time off the dock with it, before I messed with the settings. We'll see how the reset works.

I trust the Magnum remote to tell me when the batts are actually full this time.


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## jerryrlitton (Oct 14, 2002)

Minnewaska said:


> Installed this at the beginning of the season and calibrated it to 100% charge and set it to GEL battery type, as the house was fully charged at the slip all week. My first few trips off the dock were short, so the batts never discharged below 80%.
> 
> Being away for the weekend more often now, I see discharge levels down in the 50s after a couple of days. But only twice at that level of discharge.
> 
> ...


 I have a Morningstar Duo which charges both banks with a Balmar Smart Guage. I also show the same numbers....no matter what I do 84% seems to be the magic number. Even when I tell it that 84 is really 100% it agrees with me for a few hours and slowly sinks to 84% or a bit lower if there is a load thn climbs again to 84. I was told I need to check battery voltage 30 min after sunset to know the true state of the batteries by comparing the voltage to am chart....


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## Minnewaska (Feb 21, 2010)

I did the factory reset this weekend, then reset the battery type and left it alone. Upon reset, it read 75% SOC as the default the manual said it would. My batts were actually at near 100%, plugged into the dock. I wasn't without power, in some form, for very long this weekend, but tried to run them down as best I could and then plugged back in. This morning, it reads 79%, still plugged in. 

The manual says it takes about 48 hrs to figure things out. I'm beginning to wonder if staying plugged in for those 48hrs gives it a false sense.


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## Don L (Aug 8, 2008)

reading this thread - what good is having a SG other than to spend your money on something?


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## Minnewaska (Feb 21, 2010)

In order to best know when your batts are near 50% SOC, or when you have enough buffer to go to sleep before recharging and not risk a deep discharge overnight. Extends battery life. Pays for the gauge multiple times over. This is supposed to be a better mouse trap than the old shunt and amp counter, if I can get it working properly. The old method wouldn't know when the batts total capacity was degraded, they only count what you tell them. I get approx 8 yrs from my batts. Average is probably 5.

Somehow I suspect you're content not having one.


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## Loki9 (Jun 15, 2011)

When you are plugged in at the dock are your batteries charging/floating? If so, won't that throw off the SG?

My SG will get to 99 or 100% when I plug in and charge using my Xantrex, but I never see much over 90% when charging from my alternator (Balmar with external reg). 

Also, can someone (Maine Sail) confirm that my SG should be set to type 5 for Firefly batteries?


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## Minnewaska (Feb 21, 2010)

Acccording to the manual, type 5 is for Carbon Fibre batteries, which I believe FireFly to be.

With my new Magnum invester-charger, once topped up, the charger alternates between float and full.


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## Don L (Aug 8, 2008)

Minnewaska said:


> In order to best know when your batts are near 50% SOC, or when you have enough buffer to go to sleep before recharging and not risk a deep discharge overnight. Extends battery life. Pays for the gauge multiple times over. This is supposed to be a better mouse trap than the old shunt and amp counter, if I can get it working properly. The old method wouldn't know when the batts total capacity was degraded, they only count what you tell them. I get approx 8 yrs from my batts. Average is probably 5.
> 
> Somehow I suspect you're content not having one.


But I can do all that with my battery monitor. And it's you posting about how your SG isn't accurate so don't make the excuse that BMs aren't accurate. If I know how many AH out and voltage of my batteries I know pretty much their state of charge and how much is left.

Yes I'm content not having a SG. I wanted one once and came close to getting one. But decided I didn't need another magic box to tell me lies.

A smart gage is over half the price of my house bank that I replaced after 6 years of abuse even though they had at least 80% capacity still. So. Don't see how having one would save money.


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## Minnewaska (Feb 21, 2010)

Don, then don't get one and leave the thread to those of us who do. My issue will get resolved, I'm sure.

If you think your amp hr counter is accurately telling you SOC, you clearly don't understand them. Carry on.


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## Don L (Aug 8, 2008)

Minnewaska;3988810
If you think your amp hr counter is accurately telling you SOC said:


> So I guess this is XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
> 
> Personal attack removed per forum rules- Jeff_H SailNet Moderator


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## bristol299bob (Apr 13, 2011)

FWIW I also have a SmartGauge (also bought it from mainsail!). I installed it and a new ProCharge Ultra 1.5 years ago. 

When I first installed it, the SG behaved similarly to how you describe. It rarely showed above 80% capacity. It dropped pretty fast when away from the dock. Alternator charging was even lower and slower. The SG had the entire season to "learn" but it never really seemed to learn very much. 

The DC wiring on my boat was old and a bit dodgy in places. Everything worked and it wasnt dangerous but it was do for a re-wire. Unrelated to the SG I decided to do this project over this past winter. I didnt expect that the odd SG behavior was related to the wiring.

To my delight, ever since the rewire, the SG has working perfectly. After installing the SG 'learned" pretty quickly (8hrs ... maybe 12). The SG rises to 100% capacity quickly when on the charger. it drops as expected when away from the dock. Its rises to ~93% after motoring a few hrs. Completely different from last year. 

Last year I was skeptical about the SG and really didnt feel that I could rely on it. But now I see it in action working as it should. 

Since it was a full re-wire I can't say exactly which change had the effect. Undersized wires? marginal ground? I can't say since I literally ripped out all of the old and started from scratch. 

additional data points: 
- Last year the ProCharge Ultra, in bulk mode, never ramped up to full amperage output. it was always "holding back" and would rise to only ~80% of max. After the rewire it rises to 100% output immediately (while in bulk mode) as expected.
- Last year the autopilot would reboot when starting the engine (often a sign of marginal ground). After the rewire this issue is gone as well. 

So I'm afraid I can't say what exactly fixed it ... but in my case it was related to the overall health of the wiring.


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## Minnewaska (Feb 21, 2010)

If replacing all the DC appliance wiring made a difference, I can only assume there was a subtle short somewhere prior. As is the case with my SG, I assume you wired it with new cabling to the batts. Interesting thought over whether a subtle leak would affect the SG. Shorts are never good. 

I'm still wondering if being plugged in for a week straight, after the initial installation or factory reset, messes up its analysis. 

When I take off cruising in a couple of weeks, I'm tempted to do another factory reset after unpluggging and sailing for a few hours to let the batts rest. This way, it will begin to see cycling every day for a few weeks. 

I now recall that I messed with the SOC setting immediately after I installed it initially. Since I knew the batts were full at the dock, I bumped the defaulted 75% to 100%. I'm going to leave it alone this time.


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## bristol299bob (Apr 13, 2011)

Minnewaska said:


> If replacing all the DC appliance wiring made a difference, I can only assume there was a subtle short somewhere prior.


perhaps a subtle short, or some combination of subtle anomalies.



> As is the case with my SG, I assume you wired it with new cabling to the batts.


Yes, all new, to spec, direct to the batts.



> I'm still wondering if being plugged in for a week straight, after the initial installation or factory reset, messes up its analysis.


FWIW I dont think so.

pre-re-wire I saw similar behavior and I thought the same as you (that being plugged in immediately after a rest was throwing t off since it could not see normal usage patterns). And I tried many variations on the theme of performing a factory reset. (in particular, reset it prior to leaving the dock for a week or so with the intention that the SG would see and learn the batt characteristics under normal cycling conditions. ). nothing ever worked.

However, post-re-wire the SG adapts quickly and leaving it plugged in for week or two straight does not throw it off (noticeably). It adapts quickly when unplugged.

Post-re-wire the SG is behaving exactly as I'd expect, no fiddling, no resets, no babying it, no trying to second guess it. nothing. it just works ... and this why I bought the damned thing after all!

I have to say the way that it was behaving last year, I would never have recommended it to anyone. But this year its completely different and I'm actually thrilled with it.

In my case the problem was not the unit itself at all. Clearly the problem was in my house wiring, although I didnt know it at the time.


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## aeventyr60 (Jun 29, 2011)

I think the weak link in the BM unit is too many connections to the automotive spade type fuse assembly....FWIW, I'd change to an inline marine fuse holder.


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## john61ct (Jan 23, 2017)

Don0190 said:


> But I can do all that with my battery monitor. And it's you posting about how your SG isn't accurate so don't make the excuse that BMs aren't accurate. If I know how many AH out and voltage of my batteries I know pretty much their state of charge and how much is left.
> 
> Yes I'm content not having a SG. I wanted one once and came close to getting one. But decided I didn't need another magic box to tell me lies.
> 
> A smart gage is over half the price of my house bank that I replaced after 6 years of abuse even though they had at least 80% capacity still. So. Don't see how having one would save money.


Yes obviously the payback of a good BM will be slower with an inexpensive bank. The SG isn't perfect, but it's certainly better than the shunt-based units, especially at rest after a few weeks learning.

Many sailors have both a coulomb-counter to tell them amps in and out, as well as a SG to give generally more-accurate SoC indication.

But they would mostly have bigger, more expensive banks, or simply feel the extra data points is worth the extra money.

Plenty of people burn through their dollars on less noble causes.


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## Minnewaska (Feb 21, 2010)

Good point, John. When I'm done upgrading my house bank alone, it will be about $3,600 to replace it all at the end of its useful life. That excludes equally as many other batts, which separately run powered windlass, thrusters, winches, starts, etc.

Makes great sense to monitor their care.


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> Merely pulling the fuses or negative does not perform a factory reset on the SG. Start with a factory reset...


I did the factory reset, according to the manual, and returned the setting to Gel. She spent a few weeks on shore power, interrupted by weekend overnights and never showed more than 75-80% capacity. I just spent nearly three weeks off the dock, only charging via the genset or alternator. My new Mangum inverter/charger remote would typically get to Float in about 2.0-2.5 hours of running the generator, but I never saw Full off the dock.

I would typically see the lowest voltage either at the end of a day of sailing (no motor) or first thing in the morning, after a night of lights, inverter making coffee, etc.

At 12.3 volts, the smartuage would generally read in the range of 50% capacity. That made sense for a gel. After charging back to Float stage, voltage would settle down to the range of 13.0 volts. By settle, I mean no substantial load other than the fridge for hours. The smartguage capacity never read above the 70s.

I just returned to the slip and plugged back in. After an evening on shore power, the Mangum says Full Charge, voltage is 13.1 and its charging at 0 amps. The smartguage reads 72% capacity.

I give up. Either there is something I'm doing wrong, my unit is defective, or it doesn't work.

Help.


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## john61ct (Jan 23, 2017)

Of course it is possible that unit is broken, or that your particular Gel bank has some characteristics unusual enough the SG algorithms don't work.

You need to have another means measure SoC to compare.

Best would be measuring Amps flow charging off shore power, verify the voltage is kept at mfg spec for Absorb for many hours. 

Understand that alt or generator will never get the bank to full, just not worth burning dino juice for that many hours as the Amps absorbed declines.

The mfg will have a spec for "trailing amps" or endAmps, say it is .01C, or 1A of current per 100A. What model batteries are your gels?

Only end charging when amps is reduced to that point.

That is 100% Full. In fact at this point I'd recommend using **only** this measure as reliable. Even though Magnum makes excellent units, there may be customization settings needed in order to keep it from going to Float too early, in general, charge sources are often innacurate out of the box.

Using a shunt-based SoC BM, you would tell the BM, in effect "reset" it each time it is full; better models automate the process, but still need periodic calibration.

You also need to tell it the actual AH capacity, if say 450AH to start when new, after three years may have declined to 380AH. This number is determined by a 20-hour load test as Maine Saile has detailed.

You would now have two alternatives to the SG for comparison. Many people keep both BMs, since the AH counting gives more detailed information, even if it is (usually) less accurate than the SG.


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## wsmurdoch (Jan 23, 2007)

It would be nice to know how the Smart Gauge works. As best I know, there is no public information. I've looked for a patent without success. If we knew how it worked, it would be easier to know if it is working. Right now it seems to be voodoo.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> ...You need to have another means measure SoC to compare.


Is the magnum charger reading Full an acceptable alternate? I expected the SG to read in the upper 90s at this point, if not 100.



> Understand that alt or generator will never get the bank to full, just not worth burning dino juice for that many hours as the Amps absorbed declines.


I do understand that. I referenced it to suggest the batts went through many varying cycles, including returning to Full at the slip.



> You also need to tell it the actual AH capacity, if say 450AH to start when new, after three years may have declined to 380AH. This number is determined by a 20-hour load test as Maine Saile has detailed.
> 
> You would now have two alternatives to the SG for comparison. Many people keep both BMs, since the AH counting gives more detailed information, even if it is (usually) less accurate than the SG.


I understand how a shunt based Ah meter works and it's shortcomings. I thought the SG was supposed to be "smart" enough to account for reduced capacity over time.

Is it possible that it is telling me that my bank is only at 72% of its original capacity, when Full? I doubt it, as I can't imagine how it would know. While reduced over the few years since I installed new batts, I would still think it would show 100% of its marginally reduced capacity.

I don't recall the manufacturer and I can't see it easily in the battery compartment. I believe it was a quality brand. There are 4 group 31s, iirc. Each was either 105 or 110 Ah rated.


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## john61ct (Jan 23, 2017)

If Gibbo had ever published the details of his proprietary system, it would have shortly been available for a small fraction of the price from China.

From past threads:

​AC impedance spectrography: put AC voltage across the bank, measure the phase angle and amplitude of the current, derive the impedance of the battery. Use a wide variety of frequencies and analyse the results against an internal database of known chemistries using sophisticated proprietary mathematical algorithms.

​Small "load tests", high frequency conductance tests involving, micro-burst current pulses, measuring voltage changes at millisecond intervals, derive internal resistance / that's why you have to use #14 AWG wire.


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## bristol299bob (Apr 13, 2011)

Minnewaska said:


> Is it possible that it is telling me that my bank is only at 72% of its original capacity, when Full? I doubt it, as I can't imagine how it would know. While reduced over the few years since I installed new batts, I would still think it would show 100% of its marginally reduced capacity.


Your suspicion is correct, the SG displays percentage based on the bank's capacity at the time. Based on my observations (not measurements so grain of salt and all that) my SG is doing just that.

I'm happy with my SG now. But at one point I considered this monitor instead, which appears to be "smarter" in the sense that it uses both volts and amps in its algorithm.

Intelligent Battery Monitor BMPro for 12V Systems Boats


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## wsmurdoch (Jan 23, 2007)

john61ct said:


> If Gibbo had ever published the details of his proprietary system, it would have shortly been available for a small fraction of the price from China.
> 
> From past threads:
> 
> ...


If the Smart Gauge was measuring impedance, an oscilloscope would show the AC signal. It has been looked for, but not found.

From Smart Gauge Battery Monitoring Unit Photo Gallery by Compass Marine How To at pbase.com

"But RC how does it work? You've got me..? I have no idea how it works, at least at the programing/algorithm level (proprietary stuff), but it is reportedly designed to track voltage. Many internet posters have assumed, posited and suggested, that it checks internal resistance and pulses across the battery etc.. It may, but I have not seen evidence of this on the power / volt sensing wires, even with an Oscilloscope."


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## john61ct (Jan 23, 2017)

Oh well, I agree would be nice to know, but meantime I'm happy to use it anyway, Gibbo's certainly a clever fellow.


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## colemj (Jul 10, 2003)

This is just anecdotal. I spent 2 months with a trawler which had both a 12V bank and a 24V bank. Each bank had its own alternator and mains charger sources, which were of equivalent ratings. It had a Smart Gauge for each bank.

One of the gauges works perfectly. The other one works just like the OP describes his. No amount of resetting, talking to the factory, changing parameters, etc has been able to get that gauge to ever operate correctly.

I suspect that either bad gauges are more common than expected, or that there are certain very particular, and non-obvious, electrical system parameters that prevent the gauge from operating correctly.

Mark


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## john61ct (Jan 23, 2017)

Or that a particular bank has some characteristics unusual enough the SG algorithms don't work.

Balmar generally does give good support if you call them. Ask for Tom Pusateri


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## colemj (Jul 10, 2003)

john61ct said:


> Or that a particular bank has some characteristics unusual enough the SG algorithms don't work.


I include the bank itself in the "electrical system parameters".

Mark


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## john61ct (Jan 23, 2017)

Sorry missed this before.



Minnewaska said:


> Is the magnum charger reading Full an acceptable alternate? I expected the SG to read in the upper 90s at this point, if not 100.


 Magnum makes great products, but in a case like this, known-good instruments independent of any charge source would be much better, precision real-time amps as well as volts. If you have cheap ones, reference/calibrate them against a pro's.



Minnewaska said:


> I referenced it to suggest the batts went through many varying cycles, including returning to Full at the slip.


Forget WAG expectations, troubleshooting requires observed facts. Just because you think it's full doesn't mean it is.

True 100% can take a very long time, and any problems can have multiple causes.



Minnewaska said:


> Is it possible that it is telling me that my bank is only at 72% of its original capacity, when Full? I doubt it, as I can't imagine how it would know. While reduced over the few years since I installed new batts, I would still think it would show 100% of its marginally reduced capacity.


No, the SG should be reporting SoC as a percentage of the actual capacity, not the original when new.



Minnewaska said:


> I don't recall the manufacturer and I can't see it easily in the battery compartment. I believe it was a quality brand. There are 4 group 31s, iirc. Each was either 105 or 110 Ah rated.


Well we need that to help. Brands mean little, actual model and age please, assuming they are a matched set.

12V automotive sizes are notorious for fraudulent marketing in the US. If their capacity is now lower than 80% of new - quite likely in your situation - they are well on the way to needing replacement.

Only way to really tell is a proper 20-hour load test, but poor charging performance can be a decent symptom.

It might be worth starting your own thread, starting off with all the detailed info you can collect into the initial post.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> .....Magnum makes great products, but in a case like this, known-good instruments independent of any charge source would be much better, precision real-time amps as well as volts. If you have cheap ones, reference/calibrate them against a pro's.


The Magnum volt readout is identical to the SG and I also checked on my Sinometer UT270. I'm not following what amp test to do. When the Magnum says its full, it's not sending any amps. I could confirm there is drain on the bank, from operating systems, but I don't follow what that would tell me.



> Forget WAG expectations, troubleshooting requires observed facts. Just because you think it's full doesn't mean it is.


What do you suggest I test, when the Magnum says it's done? Not for total capacity, but to confirm it's really full? Resting voltage at Full seemed to corroborate it was close. The SG stills says 70 something.



> No, the SG should be reporting SoC as a percentage of the actual capacity, not the original when new.


That makes most sense. Thanks.



> Well we need that to help. Brands mean little, actual model and age please, assuming they are a matched set.


They are Group 31s. Four of them. Installed in 2013. I do not recall the brand, but they were purchased from a local reputable marine battery dealer.



> 12V automotive sizes are notorious for fraudulent marketing in the US. If their capacity is now lower than 80% of new - quite likely in your situation - they are well on the way to needing replacement.
> 
> Only way to really tell is a proper 20-hour load test, but poor charging performance can be a decent symptom.


I agree with the fraudulent issue, however, Gels are not made by many at all anymore. Not very likely to be junky frauds, given the source.

Let's say your supposition that they are at 80% of original capacity is true, what does that mean for the SG? Shouldn't it still read 100% of whatever?



> It might be worth starting your own thread, starting off with all the detailed info you can collect into the initial post.


This is my thread that I started for this specific issue discussion. Thanks for the input.


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## Bleemus (Oct 13, 2015)

How many amps are the batteries getting just before it hits float?


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## SanderO (Jul 12, 2007)

Minnewaska said:


> I give up. Either there is something I'm doing wrong, my unit is defective, or it doesn't work.
> 
> Help.


I have a link 20 and gave up too. One thing is to simply use the voltage as a measure of the batteries' state. Forget % full and all that AH left nonsense. It's really a waste of time, and frustrating.

We don't know the age of the your boat, its wiring and the connections... but you seem to have a lot of "ongoing electric loads".. which I suspect are drawing more that you think.

I am not on shore power and so rely on a few solar panels to keep the 2 AGM 8Ds topped up. I use the boat mostly on weekends and when I arrive the house voltage is 13+ ALWAYS. The Optima start batt is on an echo charge and is likewise fully charged.

BUT I don't use the inverter for anything these days... don't use 12v refer. Why do I need to keep the box cool for 5 days when I am not there???? All lamping is now LEDs except a few nav lights I haven't gotten to yet. Refer is engine drive and I ALWAYS will run the motor a few hrs a day when I am cruising.., and that cools the box down. When I bring food/beverages that needs cold I bring ice or ice encased in sheets of cubes which travels with the cooler for transporting cold things.

Basically rather than add all manner of charging sources... I limit the electrical needs and it works out fine. I find these charge monitors are just a pain in the ass... The voltmeter is accurate and perhaps the amp draw or gain. Forget about the hours to go, % of full charge. and so on. Keep you bat voltage as full... for gels and AGMs something like 13. You'll be fine. Boil water with gas. toss the toaster...

KISS

Good luck.


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## BeachCruiser (Apr 3, 2008)

I had a similar experience as the OP with the SG and a set of 5 year old GEL batteries. I would charge my batteries on shore power until they were 100% (usually 2 or 3 days on shore power). Shortly after removing all charging sources the batteries would drop to somewhere around 70%. I attributed this to old batteries loosing capacity, so I replace my battery bank. I switched to 6V golf cart batteries and the SG has worked well for 2.5 years now.

I also have a Magnum inverter/charger and it would read a very different SOC than the SG. To the OP, you may want to test your batteries for capacity. I don't know if it was the GEL type that had the problem or not, but I had 5 years of full time cruising on the GEL batteries, so it was time to replace them before I left the USA again.

Barry
s/v Beach Cruiser


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## john61ct (Jan 23, 2017)

Yes, sorry forgot they were Gel. Yes true deep cycle, but also more likely to be in need of replacement, very easily murdered if the mfg specs not closely adhered to, chronic under or overcharged, etc.


Bleemus said:


> How many amps are the batteries getting just before it hits float?


Yes, that is the test I meant.

Deplete the bank a bit, charge at Absorb voltage watching Amps accepted by the bank decline.

The charger should not switch to Float until Amps has dropped to .01-.02C, 1-2A per AH of bank capacity, e.g. 6A for a 600AH bank.

That is an objective measure of 100% Full.

The actual number for a given model bank will be spec'd by the mfg, could go right to .005C in some cases.

If necessary do the above with an adjustable power supply, or cheat by setting Float to same as Absorb, but Magnum should be adjustable enough on how long Absorb is held - does it have a trailing amps setting?

Obviously no loads connected while testing this.

Resting voltage, after the bank has been been isolated for say 48 hours should still match the mfg chart, and subsequent charge cycles act normal, going to float pretty quickly if no power draw-down in between.

A proper 20-hour load test will verify state of health for the bank if it looks like the charger has been tuned and working correctly.


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## john61ct (Jan 23, 2017)

Yes really can't beat old-school robust FLA for good value and standing up to sub-optimal conditions.

Or Firefly Oasis for chronic PSOC specifically, but a larger investment up front, precision "restore capacity" charging protocol.


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## Minnewaska (Feb 21, 2010)

Thanks for the input. I am not concerned with the health of our batteries or the sufficiency of capacity, despite the understanding that they couldn't possibly be near original after a few years. I'm not at all worried about the amount of electrical equipment we have or whether the bank is sufficiently sized.

I am only concerned with why the SmartGauge is not working. Unless the Magnum charger is only getting them to 70ish% full, then the gauge is wrong. I can check the amp flow when in float, but the Magnum remote panel tells me what it thinks it's sending. I see that change from bulk, which starts in the 90 amp range and decline, but I don't recall to what. Our rated capacity is in the 400ah range and I will see what it think it's sending in float. I suspect it's higher than 4amps, more like 10. I'm not sure what that means, if it is.

I should probably clarify why I cared to have this gauge at all. I believe I have a pretty good sense of Full, because the charger will tell me when it's in float. That should be in the high 90% range, if I understand float correctly. For our Gels, I try not to go below 12.3v, which I understand to be about 50% capacity remaining. Everything in between is a mystery. There are times when I would like to know I have enough capacity remaining to go to sleep, without running the generator for a couple of hours. If the gauge were working properly, I would be able to identify a reasonable drop in capacity each evening (or other scenarios) and know if I have ample capacity above 50% to work with.

Unfortunately, the SG is not helping..... yet. @Maine Sail, you able to chime in?


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## SanderO (Jul 12, 2007)

Minni,

Color me dumb but I think the think is "confused" as a result of how you use your electrics. You are constantly draining and adding from different sources and so on. Maybe even draining when charging. 

What are these instruments using to determine charge etc? I think voltage and some sort of algorithm or charge over time.

Again...

What matters is the voltage of your batts with no load on them. If you have sealed batts you want them to be 12.8 or more... and don't let them go lower. You'll be OK.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Thanks for the input. I am not concerned with the health of our batteries or the sufficiency of capacity, despite the understanding that they couldn't possibly be near original after a few years. I'm not at all worried about the amount of electrical equipment we have or whether the bank is sufficiently sized.
> 
> I am only concerned with why the SmartGauge is not working. Unless the Magnum charger is only getting them to 70ish% full, then the gauge is wrong. I can check the amp flow when in float, but the Magnum remote panel tells me what it thinks it's sending. I see that change from bulk, which starts in the 90 amp range and decline, but I don't recall to what. Our rated capacity is in the 400ah range and I will see what it think it's sending in float. I suspect it's higher than 4amps, more like 10. I'm not sure what that means, if it is.


My strategy is to check whether or not the fault is actually with the SmartGauge, by **objectively** verifying that the other components are working as they should.

That verification requires a certain amount of precision, and ignoring your (quite possibly correct) assumptions and expectations, at least for now. The possibility does exist that the SG symptoms are caused by **something** other than a flawed SG unit, right?

So to start, disconnect all loads, get Bulk/Absorb voltage into the bank, make sure to keep pumping charge in at that voltage until your verified known-good ammeter shows current has declined to say 2A. Disconnect the charger.

Set the SmartGauge manually to 100% full.

Ideally let the bank rest 24-48 hours, record bank voltage.

Reconnect a moderate load, draw off say 100AH, let the bank rest, then record bank voltage again.

What does the SG SoC display?

Recharge, same routine as before, try to set Hold Absorption so that the Magnum's endAmps is the same every time without your having to babysit it. Don't manually set the Full point again, unless e.g. your algorithm changes, you find out your bank mfg recommends ending sooner, say at trailing amps of 4A rather than 2A.

Hopefully after a few such cycles, either the SG is working properly, or you have discovered needed settings changes, or perhaps a fault elsewhere in your gear.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> Minni,
> 
> Color me dumb but I think the think is "confused" as a result of how you use your electrics. You are constantly draining and adding from different sources and so on. Maybe even draining when charging......


Perhaps, but I don't think this would be all that unusual. Essentially, we only have two charge sources: the magnum and the engine alternator. The magnum can be run by either the shore or the generator, but I would not think it would know the difference. I dare say that nearly everyone will be drawing on something, like their fridge, even when they are charging. The SG would be worthless if it couldn't deal with it. Perhaps the extent to which we have systems running (2 fridges, water pumps, electric heads, etc) is more than it can handle.

However, then I have claim to return the thing, I guess.


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## john61ct (Jan 23, 2017)

It is most accurate with a bank at rest.

Active loads may throw it off, higher currents more than low, I've read as much as 4%.

Charging throws it off as much as 10%.

Still more accurate overall than coulomb-counting BMs.


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## SanderO (Jul 12, 2007)

Minnewaska said:


> Perhaps, but I don't think this would be all that unusual. Essentially, we only have two charge sources: the magnum and the engine alternator. The magnum can be run by either the shore or the generator, but I would not think it would know the difference. I dare say that nearly everyone will be drawing on something, like their fridge, even when they are charging. The SG would be worthless if it couldn't deal with it. Perhaps the extent to which we have systems running (2 fridges, water pumps, electric heads, etc) is more than it can handle.
> 
> However, then I have claim to return the thing, I guess.


Minni,

As I wrote earlier... I just gave up on all the rubbish... and watch the voltage. But I don't run loads during the time I am not on board... none... just the occasional and rare automatic no float switch bilge pump. No gen sets, no shore power... just engine alt and some solar... frig is engine drive Complexity confuses even smart instruments.

Mine link went bonkers a month ago and I had to reset and it was fine.


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## colemj (Jul 10, 2003)

john61ct said:


> It is most accurate with a bank at rest.
> 
> Active loads may throw it off, higher currents more than low, I've read as much as 4%.
> 
> ...


If it gets thrown off 14% from just running the microwave and charging hard, then that definitely isn't more accurate than our CCBM.

Our BM counts perfectly steady, with a slowly, and linearly, accumulating error. Every couple of months, it will read -50Ah (out of 675) when the batteries are completely full. A simple reset and it is good to go for another couple of months.

IMO, if one is continually worried about having enough battery capacity to last overnight, then one either needs more battery capacity or better power consumption management (LED's, reefer insulation, etc).

Mark


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## Minnewaska (Feb 21, 2010)

colemj said:


> .....IMO, if one is continually worried about having enough battery capacity to last overnight, then one either needs more battery capacity or better power consumption management (LED's, reefer insulation, etc)....


This is a good point, if it were continual.

The issue is the occasion where there has been a great day of sailing (i.e. limited engine running, but all the electronics on), a trip straight to shore the moment the anchor sets, etc. Maybe just a lot going on, or having started the day less than full, with limited recharging time.

Hypothetically, the batteries read 12.6 volts, just before knocking off for the night, which means nothing. Not full, not at 50%. Do I annoy my anchorage neighbors with my genset running for an hour or just chill. It's not everyday. Thought the SG would help manage the bank, without always going the conservative route and recharging.

So far, my experience and intuition are still better than the SG.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> Minni,
> 
> As I wrote earlier... I just gave up on all the rubbish... and watch the voltage. But I don't run loads during the time I am not on board... none... just the occasional and rare automatic no float switch bilge pump. No gen sets, no shore power... just engine alt and some solar... frig is engine drive Complexity confuses even smart instruments.
> 
> Mine link went bonkers a month ago and I had to reset and it was fine.


I hear you, but our use is different. Our fridge remains stocked like it was our second home, because it is. In fact, we have two fridges. If I'm away for days and plugged into shore power, all DC loads are shut down, with the exception of the fridges and bilge pump. Lots of 110v AC loads stay on (ice maker, air conditioners set to dehumidify, battery chargers, etc).


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## john61ct (Jan 23, 2017)

colemj said:


> If it gets thrown off 14%


No, those are maximum total discrepencies, not accumulative


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## mitiempo (Sep 19, 2008)

Minnewaska said:


> I can check the amp flow when in float, but the Magnum remote panel tells me what it thinks it's sending. I see that change from bulk, which starts in the 90 amp range and decline, but I don't recall to what. Our rated capacity is in the 400ah range and I will see what it think it's sending in float. I suspect it's higher than 4amps, more like 10. I'm not sure what that means, if it is.
> 
> I should probably clarify why I cared to have this gauge at all. I believe I have a pretty good sense of Full, because the charger will tell me when it's in float. That should be in the high 90% range, if I understand float correctly.


Charging is really done in bulk and absorption. When the batteries hit the set absorption voltage the charge source (Magnum for example) should stay at the absorption voltage for hours. The batteries should be within couple percent of full when switching to float. Float is more of a maintain stage than a charging stage. Virtually all chargers, whether they cost $200 or $2000 switch into float way too soon. The battery bank is full when it is accepting about .5% of bank size in AH - for a 400 AH bank that is 2 amps - at absorption voltage, not at float voltage. After float kicks in not much happens really.


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## Bleemus (Oct 13, 2015)

I will ask again. Using an ammeter how many amps is your charge source putting out just before going to float? Float amps is meaningless to solving this mystery.


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## Minnewaska (Feb 21, 2010)

Bleemus said:


> I will ask again. Using an ammeter how many amps is your charge source putting out just before going to float? Float amps is meaningless to solving this mystery.


That's going to be hard to identify, without staring at it for untold hours in absorb. My recollection is seeing the Magnum gauge read 15-20amps after some time, but that's not very scientific. I do know that it would read 90-95 amps in bulk, when I would fire it up, after a good drain on the batts. Even starting at 12.3v resting, it would fairly quickly go from bulk to absorb, say never more than 20 mins, then sit in absorb for a long, long time. Hours.

I have no idea what it read immediately before going to float. Any convenient way to identity this without staring for hours?


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## Minnewaska (Feb 21, 2010)

mitiempo said:


> .....The batteries should be within couple percent of full when switching to float. Float is more of a maintain stage than a charging stage.....


Exactly my understanding, although, the SG does not indicate anything near it.



> Virtually all chargers, whether they cost $200 or $2000 switch into float way too soon. The battery bank is full when it is accepting about .5% of bank size in AH - for a 400 AH bank that is 2 amps - at absorption voltage, not at float voltage. After float kicks in not much happens really.


It is my understanding that the Magnum would do this correctly. My old Xantrex I/C did not, which may or may not have limited the lifespan of the batts, but I don't think it matters to the issue of whether the SG is reading correctly.


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## john61ct (Jan 23, 2017)

The batts nearing end of life are one possible cause of what you're seeing.

Only a 20-hour load test will really tell.

But closely monitoring a few full charge cycles will be informative.

A good coulomb-counting BM will allow exporting data logs to say Excel for graphing.

But without that, rather than sitting staring waiting for transition to float, really the question is how long does it take to get from say 40-50% down to full (current dropping to at .005C)?

Set Vfloat same as Absorb and check amps every 15 min.

There are photo-timing apps let your smartphone do it for you, say every 3 min.

The key is precise measuring instruments.

Check yourself as you get close, not going to hurt FLA overcharging but Gel is more sensitive.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> The batts nearing end of life are one possible cause of what you're seeing.


Could you help me understand why? To my understanding, while capacity would be greatly reduced, the SG should still register them at 100% of whatever they are.



> ......really the question is how long does it take to get from say 40-50% down to full (current dropping to at .005C)?


Can't answer exactly, but does this help? When I drove the bank down to 12.3v (which should be around 50% capacity on a gel), it would take 3 or more hours to get back to float. Overnight to get to Full. We have a 400ah bank that starts charging at around 90amps on Bulk and trickles down over the next few hours. Seems normal to me.

Here's another scenario. I motored for about 4 hours the other day and then plugged into the slip. The charger immediately said float. I got to thinking that the voltage was probably artificially high, from the alternator charging, so I shut the charger off and ran systems aboard for three hours, with no shore power. 2 fridges, lights, fans, etc. When turned the charger back on, it still went directly to float. Would I be right to think that junk batteries would have dropped further than that?


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## Bleemus (Oct 13, 2015)

Wait. You ran two fridges, lights and fans for two hours and your charger still thought they should be in float? Something is definitely not set right. I am guessing you are suffering from a severe case of premature flotulation (sic). The SG saying 70% is probably the most accurate piece of equipment you have right now.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Could you help me understand why? To my understanding, while capacity would be greatly reduced, the SG should still register them at 100% of whatever they are.


If it is the batts being so shot they aren't even charging properly, I can see the SG's algorithms just getting confused.

Not everything that goes wrong internally is just a normal capacity walkdown. After 75-80% all best are off they should be scrapped.

Or it IS accurate, put a new bank in and everything is fine.

Not saying that is the case but foe me, **knowing** not guessing at this sort of info would be a top priority. Well, second, after being **able** to do so.



Minnewaska said:


> Can't answer exactly, but does this help? When I drove the bank down to 12.3v (which should be around 50% capacity on a gel), it would take 3 or more hours to get back to float. Overnight to get to Full.


Well there's a huge red, flag to me right there! Hasn't it been made clear yet? No quality charge source properly configured should go to Float until the bank is 100% full. A decent sized bank at 50% will take 8-10 hours at Absorb voltage to get there.

Float means "compensating for self-discharge, no further charging, ready to feed any loads".



Minnewaska said:


> We have a 400ah bank that starts charging at around 90amps on Bulk and trickles down over the next few hours. Seems normal to me.


If you mean the current quickly drops to a small fraction of maximum, yes that's normal. But that happens in the first hour of an 8+ hour cycle.

If you mean voltage, then something is wrong with the charge source or your settings.



Minnewaska said:


> Here's another scenario. I motored for about 4 hours the other day and then plugged into the slip. The charger immediately said float. I got to thinking that the voltage was probably artificially high, from the alternator charging


If your alt was properly charging the House bank (that's the only bank we're talking here right?) and SoC was already high, no big loads, then nothing "artificial", maybe the bank was just actually full.



Minnewaska said:


> so I shut the charger off and ran systems aboard for three hours, with no shore power. 2 fridges, lights, fans, etc. When turned the charger back on, it still went directly to float. Would I be right to think that junk batteries would have dropped further than that?


The healthiest bank in the world should have triggered Absorb. Would be a weird fault to present too high a voltage.

Have your charger checked out.

And I'd say wiring infrastructure, busses, switches, circuit protection, terminations etc.

You still haven't told us the make/model of your bank right?


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## Minnewaska (Feb 21, 2010)

john61ct said:


> If it is the batts being so shot they aren't even charging properly, I can see the SG's algorithms just getting confused.


I see your point. They are 4 years old and spend most of their time plugged in to a charger. It would seem unlikely that they are that shot.



> Well there's a huge red, flag to me right there! Hasn't it been made clear yet? No quality charge source properly configured should go to Float until the bank is 100% full. A decent sized bank at 50% will take 8-10 hours at Absorb voltage to get there.


Really, 8-10 hours? Are you taking into consideration that folks have different charging capabilities? I have a 400 ah bank and discharged it to 12.3v, which would approximate half it's capacity. I have a 125amp charger, which is not fully utilized, but starts around 90amp in bulk. I have to replace no more than 200ah and probably less, given they aren't at full original capacity. So, taking several hours (say 4), with declining amp acceptance to get to the high 90s seems too quick? Getting that last bit from float to full takes forever.



> Float means "compensating for self-discharge, no further charging, ready to feed any loads".


Agreed to the definition, but doesn't a charger switch to the Float charge profile at high 90% of capacity, not 100%? It does take 8-10 hours to get to Full.



> The healthiest bank in the world should have triggered Absorb. Would be a weird fault to present too high a voltage.


So, let me be sure I didn't overstate the situation. It's not like the fridge ran for hours non-stop, nor the lights or fans. In fact, in three hours, the combination probably used 5 or 10 amp hrs of the bank, probably less. That's a few percentage points of bank capacity. My real point for not turning the charger on, right at arrival at the slip, was to see if the artificially high voltage, from motoring for four hours was throwing it off. Further, since some things were drawing on the bank, if it were as bad as some suspect, I would have thought a more substantial drop would have been noticed. A full bank staying in float, after a few percentage points of capacity have been used, only suggested to me that the bank's health was not a disaster.



> Have your charger checked out.


Magnum, brand new out of the box, three months ago. Further, I bought this smartgauge last year, when a different charger was installed and had the exact same symptoms.



> And I'd say wiring infrastructure, busses, switches, circuit protection, terminations etc.


I would not rule that out on any boat, but ours is fairly tidy.



> You still haven't told us the make/model of your bank right?


I haven't identified the brand, which you said you didn't need anyway. I've repeatedly indicated they are Gel batteries, Group 31, four of them in parallel, approx 105-110ah out of the box each. What more are you looking for and how would it help? If your suspicion is they are cheap, improperly suited batteries, that's all but certainly not it. They were purchased from a very reputable batter supplier and were not cheap. Not many even make Gels anymore, let alone cheap discount versions.


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## Minnewaska (Feb 21, 2010)

Bleemus said:


> ........I am guessing you are suffering from a severe case of premature flotulation (sic). The SG saying 70% is probably the most accurate piece of equipment you have right now.


I appreciate the thoughts, but would need to better understand how you got to them for it to be helpful. First, I bought a Magnum charger, which does not suffer from the condition you mention. Many other chargers do.

Secondly, let's say it did. Eventually, the bank is going to be charged above 70% of capacity, just sitting at the dock, plugged in with virtually no 12v appliances running. It's been months at the slip. The gauge defaults to 75%, when first booted up and has never shown anything above it.

I am beginning to wonder, since Gel batts are becoming fairly uncommon, whether the algorithm really isn't all that good on Gels. Both charging and discharging profiles for Gels are very different.


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## SanderO (Jul 12, 2007)

I am curious.... with all that stuff using current... why is your house bank not larger capacity? 

It seems that your approach is to be constantly pumping a lot of amps in as you draw it out with shore power and "chargers". This may be why your monitoring is getting "confused" which was my original thought.

My bank is 20% larger and my loads are WAY less then yours and I don't use shore power or a lot of charging sources, my pair of 8D AGMs are over 5 yrs old. Things did get out of sync and I had to reboot the link20. But the house bank is mostly quite full.

Minni, I am thinking you need a larger house bank. You're drawing down and filling up and the monitor seems to be confused about the battery state. Or maybe the battery is not liking this sort of continual draining - charging thing.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> I am curious.... with all that stuff using current... why is your house bank not larger capacity?
> 
> snip.....
> 
> You're drawing down and filling up and the monitor seems to be confused about the battery state. Or maybe the battery is not liking this sort of continual draining - charging thing.


I do plan to upgrade, it's the standard config for this boat, which is often undersized on production boats. However, for our current use, it's really fine. If we're on anchor and not running plotters and auto-pilots, we'll get nearly two days from a near full bank. If we sail, with no motor, all day long, it will indeed need some topping before bed.

As we run the generator for hot water and the ice maker at least once per day anyway, it's not an inconvenience. On our summer cruises, we do burn a lot of diesel, relatively speaking. But it's vacation and an extra $50 in fuel over weeks isn't a big deal.

I am suspicious that the gauge just can't keep up with a lot of charging and draining. She sits at the dock for days at a time, even a couple of weeks on rare occasion, fully charged and the gauge doesn't seem to understand that.


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## SanderO (Jul 12, 2007)

I am curious.... with all that stuff using current... why is your house bank not larger capacity? 

It seems that your approach is to be constantly pumping a lot of amps in as you draw it out with shore power and "chargers". This may be why your monitoring is getting "confused" which was my original thought.

My bank is 20% larger and my loads are WAY less then yours and I don't use shore power or a lot of charging sources, my pair of 8D AGMs are over 5 yrs old. Things did get out of sync and I had to reboot the link20. But 

Minni, I am thinking you need a larger house bank. You're drawing down and filling up and the monitor seems to be confused about the battery state. Or maybe the battery is not liking this sort of continual draining - charging thing.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I see your point. They are 4 years old and spend most of their time plugged in to a charger. It would seem unlikely that they are that shot.


Unless they've only rarely been fully charged. As in right up at Absorb Voltage to 100%, not 99%.



Minnewaska said:


> Getting that last bit from float to full takes forever.


Aaargh! There is **zero** gap in a proper setup between those two last, how many times?

Going to Float before 100% Full is premature, and murders banks early.

Even the best charging hardware needs careful setting, verification calibration, its OOB settings are never perfect.



Minnewaska said:


> Really, 8-10 hours? Are you taking into consideration that folks have different charging capabilities?
> ...
> So, taking several hours (say 4), with declining amp acceptance to get to the high 90s seems too quick?
> ...
> Agreed to the definition, but doesn't a charger switch to the Float charge profile at high 90% of capacity, not 100%? It does take 8-10 hours to get to Full.


Depending on voltage, there is usually little to no real charging going on in Float, never getting to Full that low. AGAIN do not pay attention to the charge source definition of Full, outside tools, known to be accurate, watching declining Amps at Absorb, please go back reread the details.

Higher amp charger reduces total by say 30 minutes. First 2 hours may get you to 90%, still need 5+ at **Absorb**, until current flow is 1-2A (or)



Minnewaska said:


> So, let me be sure I didn't overstate the situation. It's not like the fridge ran for hours non-stop, nor the lights or fans. In fact, in three hours, the combination probably used 5 or 10 amp hrs of the bank, probably less. That's a few percentage points of bank capacity. My real point for not turning the charger on, right at arrival at the slip, was to see if the artificially high voltage, from motoring for four hours was throwing it off. Further, since some things were drawing on the bank, if it were as bad as some suspect, I would have thought a more substantial drop would have been noticed. A full bank staying in float, after a few percentage points of capacity have been used, only suggested to me that the bank's health was not a disaster.
> 
> Magnum, brand new out of the box, three months ago. Further, I bought this smartgauge last year, when a different charger was installed and had the exact same symptoms.
> 
> ...


You keep assuming you **know** things that AFAIC need verifying.

If looking at the bank is too hard, then it feels like the much more challenging tasks required for proper diagnosis won't get done, which means you're wasting a lot of time endless wording here, not to mention not absorbing, forcing repitition but no action steps taken.

Something is really wrong with your setup. It may not be a hardware problem, and yes, maybe the bank has survived the resulting four years of abuse.

At this point I say get a known-good professional on board to check **everything**, including a proper 20-hour load test.

If not, and you really think the SG is the problem, get a Victron BMV-702 to manage your tracking, but IMO your charge cycle is definitely whacked.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I would not rule that out on any boat, but ours is fairly tidy.


Tidy has nothing to do with it.

Amps, volts, resistance, heat, functionality!


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## colemj (Jul 10, 2003)

Minnewaska said:


> Here's another scenario. I motored for about 4 hours the other day and then plugged into the slip. The charger immediately said float. I got to thinking that the voltage was probably artificially high, from the alternator charging, so I shut the charger off and ran systems aboard for three hours, with no shore power. 2 fridges, lights, fans, etc. When turned the charger back on, it still went directly to float. Would I be right to think that junk batteries would have dropped further than that?


That doesn't sound unreasonable. I can't speak for the Magnum, but our Victron would probably do the same. Running a few lights and probably a 30% duty cycle fridge for a couple of hours wouldn't use much of the battery capacity. Probably only the surface charge left on them. Our Victron calculates when to go into float based on some internal experimenting - it outputs a large current, and if the voltage immediately rises high enough, it goes straight into float. Yours may be doing the same, and you just didn't catch that very short period of time it tested a high current.

Mark


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## john61ct (Jan 23, 2017)

Yes for charge cycle testing purposes, you needs to get the bank down below 70% to start with. 

And you can't rely on the bank voltage to give accurate SoC, use lights or water heater, e.g. known .1C load for three hours.


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## Bleemus (Oct 13, 2015)

I have to agree with John here. You have good equipment in the Magnum but I believe you are relying on it to tell you your batteries are full yet all signs point to that not being the case. Buy or borrow a recording multimeter to find out what is really going on. My guess is your never getting to 1% amp draw before float and your batteries are compromised. It seems like your reluctant to conduct the tests and are relying on what you see. If that is the case you have two options of either hiring a pro or living with it.


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## john61ct (Jan 23, 2017)

And unlikely but even a brand new Magnum could be faulty even if the settings were tweaked correctly.


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## Minnewaska (Feb 21, 2010)

Folks, I will test it this weekend. I haven't been aboard to do so, since I reopened this thread. No need to get testy. But some of the input here is not correct and I'm not going to challenge you and get into a pissing match. I do appreciate the thought process and it is helping me get to the bottom of it. Not interested in a match of wits. 

If you really think that 4 year old gels batts that have been plugged into shore power for most of their lives could really be at 70% of capacity, when a brand new charger is done charging them, we have very different intuition on this. I unnderstand, you haven't tested them either. 

Would you acknowledge that a bank that could only be charged to 70% of it's capacity, would have a serious performance problem? That's just not the case. They aren't performing notably worse than when they were new and shouldn't be. They take about the same amount of time to charge (on two different chargers), they have the same amount of endurance, etc. It's only the SG that says otherwise.

I do think the algorithm could be messed up by some other wiring issue or it just doesn't work well with Gels. I also wonder if the algorithm works, if you start with aged batteries. We'll see what the final amps are in float and I will report back.


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## john61ct (Jan 23, 2017)

No one is saying they are actually at 70%.

But if they are rarely actually getting charged to full, maybe other abuse happened unawares, yes the bank could easily be shot.

Your usage patterns may not be stressing the bank at all.

Point is nobody knows for sure without hard data from testing.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> .....yes the bank could easily be shot.....


But, it doesn't behave "shot". I will get the final float amps and report back. It will declare Full, which is zero, that I know. But, if it's not behaving shot in use, I'm just not following why the suspicion is the charger/batteries and not the SG.


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## mitiempo (Sep 19, 2008)

Minnewaska said:


> I will get the final float amps and report back.


Absorption, not float. At float voltage batteries accept very little current and that would not tell you anything.

Do you know what voltages the Magnum is set at? Are they adjustable in .1 volt increments? Do you know how long absorption is set for on the Magnum? Is it adjustable to 4, 5, or 6 hours?


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## john61ct (Jan 23, 2017)

We don't know the nominal AH capacity of the bank right? So let's assume C=400AH for sale of the discussion, adjust accordingly.

Do not trust the Magnum's amps readout for now, use a verified known-good ammeter. Obviously no loads connected while testing this.

Test 1:
Deplete the bank with a 100A load for an hour, or 50A for two, goal is to get down to 60-75% of actual C.

Then set the Magnum to continually charge at Absorb voltage, and as it does so, record Amps and Volts every 15 minutes, how long it takes to hit Absorb and then just Amps accepted by the bank as they decline.

When current **at Absorb** drops to below 2-3A, record the time, then isolate the bank from everything but the SmartGauge, and let things rest overnight.

This is an objective measure of 100% Full, so if SG is off, set it so. If you want to recalibrate the SG in future, above is the protocol to follow.

Now next is getting the Magnum configured properly. You want to try to get it to do the above protocol, every time without you babysitting.

It should **not** switch to Float until Amps has dropped to below .01C. .005C is also OK, but not much lower, if there is a lot of variability .02C sometimes is OK but tweak it so usually gets below .01C.

Ideally you would get the precise actual numbers for your given model bank as spec'd by the mfg.

Resting voltage, after the bank has been been isolated for say 48 hours should still match the mfg chart, and subsequent charge cycles act normal, going to float pretty quickly if no power draw-down in between.

A proper 20-hour load test will verify state of health for the bank if it looks like the charger has been tuned and working correctly.


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## Maine Sail (Jan 6, 2003)

From all the way back in post #2 we still don't have an answer for what the batteries actually are, brand and model#? Pretty important stuff....

Where is the SmartGauge physically connected? (exact spots for pos & neg connections please)

What Gauge wire was used for the SmartGauge to house bank?

How is the multi-battery bank wired? Are pos & neg take offs from one battery?

What is the absorption voltage setting in the Magnum ME-ARC?

What is the float voltage setting in the Magnum ME-ARC?

What is the absorption duration set to in the ME-ARC?

Did you use the custom profile in the ME-ARC to set up your charger?

What are you using to determine the end of absorption? Time, SOC (only with the optional ME-BMK) or end amps?

What is the voltage drop between the inverter and battery bank at full charger output?

What amperage is the charger section?

What gauge wire between battery bank and inverter/charger

How long is the inverters DC circuit in feet (both pos & neg)


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> From all the way back in post #2 we still don't have an answer for what the batteries actually are, brand and model#? Pretty important stuff....


I will find them. Group 31 Gel is all I know for sure. Been through that question before (for Xantrex question) and recall even you saying they were quality.



> Where is the SmartGauge physically connected? (exact spots for pos & neg connections please)


Opposite ends of a 4 battery parallel bank. Just like the charger is connected, but on opposing terminals. ie. if the charger is on the north pos and south neg, the SG is on the north neg and south pos. Pole analogy just to demonstrate opposite ends of the parallel bank, perhaps there is a better word for it.



> What Gauge wire was used for the SmartGauge to house bank?


I will have to dig in. I'm sure it is what was spec'd. I have tons of different gauge marine wire.



> How is the multi-battery bank wired? Are pos & neg take offs from one battery?


I get your concern, but no. All take off connections are at opposite ends of the bank.



> What is the absorption voltage setting in the Magnum ME-ARC?
> 
> What is the float voltage setting in the Magnum ME-ARC?
> 
> ...


Clearly you're beyond my grade level. I don't recognize what ME-ARC means. I may have set something I don't recall, but to my recollection, there was a menu item for battery type, which I set to Gel. I do not recall customizing any voltages or durations.

I looked up the terminology. ME-ARC = remote panel. My answer stands nevertheless.



> What are you using to determine the end of absorption? Time, SOC (only with the optional ME-BMK) or end amps?


I has to be Magnum's default. I would not have guessed at that. It's an MS2812.

I do not have the ME-BMK = optional battery monitor.



> What is the voltage drop between the inverter and battery bank at full charger output?


Easy to check, will get back. I will have to run the bank down to get it to full output first.

From recollection, the Magnum says 90-95amps at first. I recall this because I would always wait for the charger to kick in, when starting the generator, before I turn other systems on.



> What amperage is the charger section?


You mean the chargers rated amperage? 125amps



> What gauge wire between battery bank and inverter/charger


4/0



> How long is the inverters DC circuit in feet (both pos & neg)


While the devices are about 2 feet from each other, there is about 4-5 feet of cable to get through cabinetry and to the opposite end of the bank.

Thanks for the feedback. You're the SG supplier here. :wink:


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> Opposite ends of a 4 battery parallel bank. Just like the charger is connected, but on opposing terminals. ie. *if the charger is on the north pos and south neg, the SG is on the north neg and south pos.*


For starters the SG should be on the same terminals as charge and loads take off from, there is no need to flip flop it and you can actually create negative consequences by doing so. In other words don't vary from the installation manual or trouble shooting will be impossible. We need to start with a _legit installation_ first...

We need to remember that the SG is making on the order of 20,000 calculations per second and is MUCH, MUCH more sensitive than the _dampened_ voltmeter section would have you believe....


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> For starters the SG should be on the same terminals as charge and loads take off from, there is no need to flip flop it and you can actually create negative consequences by doing so. In other words don't vary from the installation manual or trouble shooting will be impossible. We need to start with a _legit installation_ first........


Thanks. That's an easy switch. I do not recall the _legit installation instructions_ making this point.

If I missed it, I guess I deserve the criticism. I will look.

Actually, the charge and load cables are also at opposing opposite ends of the bank. That's not unusual, is it? Which of the two should the SG be sitting on top of? I believe they are currently on top of the load side.


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## SanderO (Jul 12, 2007)

Aside from programming a "charge profile algorithm" how can any meter know what type of batters are being measured?

Aren't there simple means to evaluate the condition of a battery? Wouldn't this be a good place to start?

Are you certain each of your batteries is in the same condition? Are in parallel?

Many electrical issues present from corroded connectors... you need to consider this as well.

Is it possible for the SG to be confused by multiple charging sources and types and same for loads?

Batteries lose capacity with increasing charge cycles. Does deep discharge hasten aging faster than shallower discharge cycles?


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## Bleemus (Oct 13, 2015)

I didn't see any one getting testy and if my post came across as such I apologize. I am very curious about this mystery as those that I know with a a SG claim it is their favorite piece of electrical gear. Looking forward to the final analysis.


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> Thanks. That's an easy switch. I do not recall the _legit installation instructions_ making this point.
> 
> If I missed it, I guess I deserve the criticism. I will look.


The hook up schematic for the SG shows it:












Minnewaska said:


> Actually, the charge and load cables are also at opposing opposite ends of the bank. That's not unusual, is it? Which of the two should the SG be sitting on top of? I believe they are currently on top of the load side.


The bank take off points (opposite ends) should be the same for charge and load...


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## john61ct (Jan 23, 2017)

SanderO said:


> Aside from programming a "charge profile algorithm" how can any meter know what type of batters are being measured?


This thread is about diagnosing a specific member's problems, so basic general questions will likely just be distracting, especially as they generate their own side discussions.

See this new thread I started for that purpose
http://www.sailnet.com/forums/showthread.php?t=294538


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> The hook up schematic for the SG shows it:


With all due respect, I do not see either the charge or house load takeoffs on that diagram to know the SG should be installed on top of them. Only the SG hooked up at opposite ends, like I did.



> The bank take off points (opposite ends) should be the same for charge and load...


Well, that is going to take more than a little surgery. I'm sure the 4/0 cabling will be too short, in some cases, to move.

Is this not common to have them at opposite corners? If so and the gauge is sold to consumers, that should probably be identified, if it has anything to do with the operation of the SG.

Maybe expanding the house bank capacity and rewiring is due for a winter project. This SG issue will remain open until it works properly. Thanks.


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## john61ct (Jan 23, 2017)

The miswiring issues may or may not be the primary causes of what the SG is reporting.

They may also be causing the other more fundamental symptoms that also may have nothing to do with the SG.

I would advise getting to the bottom of the latter issues sooner rather, than later.

Best to know what is going on, to inform your planning, know exactly what you want to accomplish before the professionals come on board.

At this point an AH counting monitor seems IMO like a minor investment to help with diagnostics at key circuit locations, even if the SG does end up being more accurate for general SoC once you get things fixed up.


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## Minnewaska (Feb 21, 2010)

Okay, new season. I found some terminal corrosion, so I replaced the batteries with new. (I think my old inverter/charger may have killed them). I have a new Magnum inverter charger and all charge, take off and sensor cables are together, at opposite ends of the bank. That required making a few 2/0 cables. I also did a factory reset to the SG and reset it for Gel. Stay tuned. Hope this works.


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> default to what amounts to "_kitchen timers_".........
> 
> Ignore the _idiot_ lights on the charger! All they are telling you is what the charger "_thinks_" it should be doing and this may be grossly incorrect and usually is especially with "_egg-timer_" chargers........





mitiempo said:


> ...... the charge source (Magnum for example) should stay at the absorption voltage for hours......


I went through all the setting on the Magnum again. Definitely set for Gel and I've confirmed charge voltages are correct. It's Absorb that has me puzzled. I understand the Magnum to have a real "smart" charger. However, in the setup is has a timer for Absorb. For my 400aH bank, it seems to recommend 90 minutes on Absorb. Seems light. 
@Maine Sail or @mitiempo what are your thoughts. Batteries are UltraPower Group 31 Gel. 98aH x 4.

From the Magnum manual.


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## john61ct (Jan 23, 2017)

Your actual goal is 100% Full as per trailing amps. Calibrating an egg-timer approach requires a bit of trial & error.

If your load usage patterns are consistent then just keep bumping up the Hold time, until you observe the source hitting that goal, say at least half the time.

If inconsistency makes this difficult, you may need to Finish charge manually once in a while.


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## Minnewaska (Feb 21, 2010)

After the new batteries charged for about 12 hours, the reset SG now says 89%. It reportedly takes 48 hrs to figure things out, but it’s progress from the default of 75%. I shut the charger off to put some load on the batts. A dozen or so lights, the nav equip, etc. 

Voltage dropped to 12.5-12.6 volts under load. Seems normal. After an hour or so, I turned the Magnum charger back on and it immediately went to float. I think it will do that at voltage above 12.4. I was hoping it would default to the 90 min Absorb and I could set a timer to 85 mins and watch final amps. Not sure how to do this now.


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## Don L (Aug 8, 2008)

The only way I can get my charger to get out of float once it goes into it (too early and 1 of the reasons I'm researching replacements) is to put it into equalize. It of course doesn't go into equalize voltage as the batteries aren't really fully charged, but it will drive toward full charge and the voltage will climb as it does. So I just keep an eye on the voltage and acceptance amps till it get to where I want.


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> The only way I can get my charger to get out of float once it goes into it (too early and 1 of the reasons I'm researching replacements) is to put it into equalize. It of course doesn't go into equalize voltage as the batteries aren't really fully charged, but it will drive toward full charge and the voltage will climb as it does. So I just keep an eye on the voltage and acceptance amps till it get to where I want.


Interesting thought. Thanks. I wasn't sure how to manually charge with this unit.

You can't equalize Gel batteries, as the high voltages will boil the electrolyte in the Gel and ruin them. However, on the Magnum, equalize voltage is set the same as Absorb, to prevent this. I think I have a contact with Magnum in my future.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Interesting thought. Thanks. I wasn't sure how to manually charge with this unit.
> 
> You can't equalize Gel batteries, as the high voltages will boil the electrolyte in the Gel and ruin them. However, on the Magnum, equalize voltage is set the same as Absorb, to prevent this. I think I have a contact with Magnum in my future.


it may not allow you to go into equalize then as on a lot of chargers that is only available in the Open Cell program mode

this whole go into float too early is one of those things where the makers of battery charger manufacturers show they don't really understand even though they try to tell you how "advanced" their units are


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## Minnewaska (Feb 21, 2010)

I figured out it won’t start over in bulk, unless the charger loses shore power for a bit. Batteries were at 12.4 volts. They were 5 minutes in bulk, then to Absorb. It’s been 1 hr on Absorb at 14.3 volts (temp adjusted from 14.1v, as the batteries are 62 degrees) and they are taking 28amps. We’ll see.


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## john61ct (Jan 23, 2017)

Most chargers will reset back to CC/CV once disconnected at both ends for a while, maybe put in strategic switches if you regularly need to do this to combat premature infloatulation manually

With the SmartGauge my understanding is it can take a half-dozen cycles before its learning curve for your bank dials in, obviously will vary depending how closely your batt's behaviour matches one of the patterns in its database, as opposed.

The "reset to 100%" feature should not need to be used regularly, but as long as you are being consistently precise in your measurement and actually stopping at endAmps, it may help early in that learning phase.

In looking over my notes from various old threads' speculation on the exact mechanisms used internally, "impedance spectroscopy, micro-burst currents, frequency response analysis conductance tests, deriving internal resistance" I came across 

"that's why you have to use #14 AWG wire"

I can't see that in the instructions, ring a bell with anyone here?


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## Minnewaska (Feb 21, 2010)

It jumped to float, while I was distracted. It was drawing about 15amps in Absorb last I looked. Now 12 amps in Float. I’m going to up the Absorb time to 2 hrs and run her down again tomorrow, to see if she charges better.

The SG now says 74%, while the charger is in Float. Starting to feel like the same pattern as last time.


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## john61ct (Jan 23, 2017)

I would set Float=Absorb and just watch, will be a while before you hit endAmps even then. What's your target, 1 or 2A?

Then tell SG it's at 100%.

Getting your HAT calibrated, I'd probably set very high and watch trailing amps against overcharging, then adjust downward as needed.

Going a bit too long sometimes is less harmful than only rarely getting all the way.


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## mitiempo (Sep 19, 2008)

john61ct said:


> I would set Float=Absorb and just watch, will be a while before you hit endAmps even then. What's your target, 1 or 2A?
> 
> Then tell SG it's at 100%.
> 
> ...


Keeping the batteries at absorption voltage for too long isn't much of an issue - as their internal resistance rises they will accept less and less current.

On the other hand too short of an absorption time will leave the batteries less than fully charged and that is damaging.


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## Minnewaska (Feb 21, 2010)

mitiempo said:


> Keeping the batteries at absorption voltage for too long isn't much of an issue - as their internal resistance rises they will accept less and less current.
> 
> On the other hand too short of an absorption time will leave the batteries less than fully charged and that is damaging.


After I got back from dinner last night, the Magnum remote said the batteries were Full. I don't really understand how it determines that, but it doesn't appear to be time based. Can batterries get to Full on unlimited float voltage?

She's been charging all night and now says Float charging again, at 10amps. I'm guessing that's due to fridge drain.

While Magnum recommends 90 mins in Absorb, what's the downside to cranking it up to hours?

p.s. the SG now reads 85%, when I'm sure 99% is more accurate. Still needs a couple more cycles.


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## john61ct (Jan 23, 2017)

Don't (ever) believe **anything** telling you "full" except **amps acceptance measured at the bank** dropping below the bank mfg endAmps spec.

Then the first time, you reset the SG and cover it up, don't even look at it for a week of daily cycling getting back to that definition of Full each time.

Meanwhile working to make sure your adjustments to your charge sources are getting them to hold Absorb until endAmps without your watching, at least most of the time.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Can batterries get to Full on unlimited float voltage? sure
> 
> While Magnum recommends 90 mins in Absorb, what's the downside to cranking it up to hours?I have my alternator regulator set to stay in absorption for 4 hours when motoring. I'm it had this way over a year and have paid attention to the battery acceptance amps and sometimes when it goes into float I reset it to put it back into absorption again because the amps say it isn't really 100% charged. The only down side for me it that I have to remember to turn the start battery off because it's a sealed battery and the voltage is too high for it.
> 
> p.s. the SG now reads 85%, when I'm sure 99% is more accurate. Still needs a couple more cycles I don't see the value of the SG.


Have you acturally watched your battery ampere acceptance while in absorption? I would be interested in knowing what % of 20 hour AH capacity it is when the SG is still saying the batteries are at 85%. If my battery monitor was telling me the batteries were 15% lower than they really were it would me crazy with the unneeded extra charging I would end up doing.


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> Have you acturally watched your battery ampere acceptance while in absorption? I would be interested in knowing what % of 20 hour AH capacity it is when the SG is still saying the batteries are at 85%. .


I have a roughly 400aH bank. The last I saw, maybe 5-10 minutes prior to it flipping over to Float, she was still taking 15ish amps in Absorb. Would 4-8 amps have been expected for this bank?


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Don't (ever) believe **anything** telling you "full" except **amps acceptance measured at the bank** dropping below the bank mfg endAmps spec...ll.


For the life of me, I can't find "mfg endAmps specs" anywhere. Where do I find them for UltraPower Group 31 Gels?


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## mitiempo (Sep 19, 2008)

Minnewaska said:


> I have a roughly 400aH bank. The last I saw, maybe 5-10 minutes prior to it flipping over to Float, she was still taking 15ish amps in Absorb. Would 4-8 amps have been expected for this bank?


End amps @ full is between .5 and 1% for any lead acid battery. For your 400 AH bank that is between 2 and 4 amps.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> For the life of me, I can't find "mfg endAmps specs" anywhere. Where do I find them for UltraPower Group 31 Gels?


I don't know, but being able to get that sort of detailed tech info easily, as well as being able to pick up the phone and reach a tech support engineer, is to me important criteria for choosing what batteries to buy.

I am only familiar with Sonnenschein as being quality makers of GEL, maybe Deka in a pinch.

For now, I'd just go with .01C, pushing to .005C, so 4, down to 2A.

How old is the bank?

It is possible their internal electric behaviour just isn't matching up with any of the entries in SG's database, but as I said don't judge anything until you've done a 100% reset and allowed a half dozen 50-100% cycles to pass.


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## Don L (Aug 8, 2008)

Minnewaska said:


> I have a roughly 400aH bank. The last I saw, maybe 5-10 minutes prior to it flipping over to Float, she was still taking 15ish amps in Absorb. Would 4-8 amps have been expected for this bank?


As already said you aren't really fully charged till your batteries only accept about 2 amps, and it would stay there a long time if you kept charging. Like most battery chargers yours is more worried about overcharging than getting fully charged! It sound that you are able to adjust the time in absorption, so turn it up while you can be around to watch the amps (bet it takes 4+ hours) till you get to 2 amps or less for an hour or so.

If they were still accepting 15 amps they probably are only in the lower 90% charged.

I have no plans to get a SG, but I'm interested in whether it can be closer than my battery monitor that I've tweeted the settings to match the way I normally operate my system.


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## john61ct (Jan 23, 2017)

Don0190 said:


> It sound that you are able to adjust the time in absorption, so turn it up while you can be around to watch the amps (bet it takes 4+ hours) till you get to 2 amps or less for an hour or so.


Yes, since absorption voltage of GEL batteries is so low, they charge much slower than AGM, at least 7 hours total to get from 50% to 100% Full.

And if they've not been treated as the should, even Sonnensheins would be suffering poor State of Health after a hundred cycles or two.

GELs really need coddling, way too easily murdered otherwise.


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## Minnewaska (Feb 21, 2010)

Batterries are new, on Tues of this week. 

I shut the charger off this morning and turned on all sort of unnecessary things to drain them during the day. Nav equip is on, as if we were sailing (I’m commissioning at the slip this week). Later today, I think I will crank the Absorb time up to 10 hours and set an alarm to check every hour to determine where Float should really start.


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> Batterries are new, on Tues of this week.
> 
> I shut the charger off this morning and turned on all sort of unnecessary things to drain them during the day. Nav equip is on, as if we were sailing (I'm commissioning at the slip this week). Later today, I think I will crank the Absorb time up to 10 hours and set an alarm to check every hour to determine where Float should really start.


As has been stated the low absorption voltages of GEL batteries leads to longer absorption times. Generally speaking you're looking at a minimum of about 4 hours for absorption but it can be more or less depending upon the charge rate.

When you see less than 1% of Ah capacity flowing in, @ absorption voltage, but preferably lower, like 0.5%, the batteries are pretty much full. Seeing over 12A _at a float voltage_ is quite a ways from full. The last 5% of charging is painstakingly slow due to the horrible Coulombic efficiency when you near 100% SOC.

Your Ultrapower batteries are just Deka/East Penn GEL's. When we were conducting the AGM Battery PSOC testing for Practical Sailor, East Penn insisted that return amps needed to fall to 0.3% for their AGM's. Keep in mind this was with absorption voltages of 14.6V. I would aim for at least 0.5% of Ah capacity at 14.1V.

For what it's worth this is a 400Ah bank, @ 12V, of Trojan L-16's. When full, all the way full not "premature floatulation full" this bank needs only 0.1A or 0.025% of Ah capacity in charge current to maintain 14.4V.


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## Minnewaska (Feb 21, 2010)

Here’s another indication of being no where near full. I just disconnected the charger and turned more load on about 3 hours ago.

Chart plotter, autopilot (not doing anything) vhf radio, stereo, 12 cabin lights, 2 fridges (already cold, not running continuously),bilge and freshwater (also not running continuously). This is a reasonable facsimile of being underway. Bank is already down to 12.3v, under load. 

Charger is coming back on after a few minutes of rest. I am putting the Absorb time out to 10 hours and will monitor. I don’t think the Magnum remote shows anything under 1amp.


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## Minnewaska (Feb 21, 2010)

Ironically, my old Xantrex charger was set up by inputting total bank capacity, although, may have converted this to Absorb time. I certainly recall that Aborb took longer than Magnum’s 90 min recommendation. This Magnum setup sets time in Absorb. Why wouldn’t the a multi-stage charger just have a setting for charge amps to switch over? Seems simpler.


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## john61ct (Jan 23, 2017)

Because without a shunt/BM at the bank, charge sources only know what they are outputting.

Not what the bank is accepting, when loads are also running.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Here's another indication of being no where near full. I just disconnected the charger and turned more load on about 3 hours ago.
> 
> Chart plotter, autopilot (not doing anything) vhf radio, stereo, 12 cabin lights, 2 fridges (already cold, not running continuously),bilge and freshwater (also not running continuously). This is a reasonable facsimile of being underway. Bank is already down to 12.3v, under load.
> 
> Charger is coming back on after a few minutes of rest. I am putting the Absorb time out to 10 hours and will monitor. I don't think the Magnum remote shows anything under 1amp.


That voltage is pretty meaningless as an indication of state of charge. If you want to see what the load really did you would have to turn off all the DC loads and wait hours for the batteries to rest and remeasure the voltage. Based on my experience with my 440ah bank your 12.3v with that loading suggests the batteries were pretty well charged.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Ironically, my old Xantrex charger was set up by inputting total bank capacity, although, may have converted this to Absorb time. I certainly recall that Aborb took longer than Magnum's 90 min recommendation. This Magnum setup sets time in Absorb. Why wouldn't the a multi-stage charger just have a setting for charge amps to switch over? Seems simpler.


My charger uses amps. But all it knows is that it supplying 10amps. But that might be still putting 8 into the batteries and that's only 95-98% charged


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## john61ct (Jan 23, 2017)

Which might still be 2 hours from 100%


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## Minnewaska (Feb 21, 2010)

I think we’re on to something here. I ran my batteries down to 12.3 volts, under load. The Smartguage said 50% of capacity. 

I set the charger to Absorb for 10 hours and turned it on. It went into Bulk at 82 amps for 5-10 mins, then dropped to Absorb. Here’s the Absorb progression.

Hours - Amps from charger - Smartguage reading

0 - 63a 
1 - 36a - 64%
2 - 24a - 74%
3 - 21a - 81%
4 - 21a - 86%
5 - 18a - 91%
6 - 18a - 95%
7 - 18a - 99%

If I assume some minor loads on the system (fridges and lights) this amount of output would seem about right to put ~200 Ahrs back into the bank. 

Unfortunately, I can’t get it to stop Aborb and force to Float. It wants to finish. I hope the 10 hrs doesn’t hurt anything. 

I’m hittitng the sack. We’ll see what it says in the morning.


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## Minnewaska (Feb 21, 2010)

I got up randomly in the middle of the night, at hour 11 of charging. The charger was on Float, but it said 0 amps. I interpret that to suggest it was less than 1amp, since the Magnum charger reads in whole digits and, if it were truly zero, it would have read full. When I woke up at hour 16 of charging, the charger was on Full and 0 amps with 13.1 volts. The Smartguage now reads 100%!!

I can't tell exactly when it dropped from the 18 amps of charge in Absorb to just a few amps. Somewhere between hours 7 and 10. I was asleep.

Any reason not to just leave Absorb time at 10 hours? Would it hurt anything?

Looks like I might not need to return the Smartguage to @Maine Sail after all, but was a victim of premature floatulation.


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## Minnewaska (Feb 21, 2010)

p.s. I’ve ordered the Magnum battery monitor, with a shunt. It plugs directly into the charger and will read on the remote. Perhaps it monitors charge state better and this Absorb time thing isn’t relevant. I can’t find where it says that’s the case, but it’s boating. If something is a problem, throw money at it.


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## Don L (Aug 8, 2008)

I've never seen 0 amps on my battery monitor with the battery on float. Isn't your charger reading in total amps supplied? If so wasn't the refrigerator or something running?

Regardless glad you got charged. There probably isn't anything wrong with leaving your charger in absorption for 10 hours, but I don't think I would do so if my system. I would be more inclined to put it in 4 hours and let the batteries be at 99% and then every once in a while, say every couple weeks, run it longer. I have no experience with gel batteries, but think there's a bigger concern with over charging them than open cell FLA. Either way I would made changes slowly so I knew the amps and knew when the change over should be.


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## john61ct (Jan 23, 2017)

Good stuff.

I generally don't trust charge source readouts, but Magnum's got a great rep. Fact they only do whole numbers is odd but perhaps just honest.

I have to believe that BM is a good one, and will at least integrate with the Magnum mains charger to control Absorb-Float transition based on some endAmps, hopefully you can custom set it to 2A.

You should definitely be mindful with GEL to not be overcharging i.e. too long HAT, more than a few hours a few times per week.

The BM will have you covered for shore charging.

If there is an extra relay on the BM, perhaps it can also be triggered by the same setpoint? Then the Victron SC can be left at a **very** long Absorb time setting, but the BM opens the connection between the panels and the SC.

Otherwise once the BM is in place, just keep tweaking the Victron max HAT setting until you see it's hitting 2A endAmps before dropping to Float at least a couple / few cycles per week.

When cycling solar only as above there really isn't that much danger of too much overcharging given that sunset comes daily. But still keep an eye on things, and if the Victron's dynamic algorithm seems too strong when the boat's not in use, definitely dial the HAT back until you getback in cycling mode. 

If you care for maximum accuracy put an accurate ammeter on the bank next cycle and give SmartGauge that 100% Full reset right at the point when trailing amps hits 2A.

If you don't have a decent ammeter I guess tgat can wait for the BM, but then SG may need to start its learning curve all over again. NBD really lon as you're aware.

Great progress, congrats!


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## john61ct (Jan 23, 2017)

Don0190 said:


> There probably isn't anything wrong with leaving your charger in absorption for 10 hours


There isn't, even with GEL, when it's just a few testing or maintenance cycles under manual observation.

Wouldn't leave an automated setup there unless endAmps shows it's needed, big enough bank low enough charge source like solar-only, it could be required, maybe still not Full by sunset is pretty common.

And a sign to start Bulk charging from dino juice in the mornings.

> I would be more inclined to put it in 4 hours and let the batteries be at 99% and then every once in a while, say every couple weeks, run it longer

No, for longevity getting to Full 100% should be at least twice a week, more frequently is better.

For that purpose there is a big difference chemically between 100% as per endAmps, and even 98-99% SoC.

Going a bit too long on hold time is not really risky with GEL, it's too high a Voltage where you get into actual damage.


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## john61ct (Jan 23, 2017)

OP, are you planning on charging your GELs from Alt?

Since we now know your bank is Deka, I'd try to get their detailed spec sheets for their GEL lines even if they don't publish for the Ultrapowers specifically.

Pretty sure 14.2V is at the **high** end of where you want to go.

Deka/East Penn (888) 844-7704


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## Minnewaska (Feb 21, 2010)

Thanks for all the input!!

This last cycle was likely from as low as could be anticipated. I changed Absorb time to 7 hours and will see what the next cycle looks like. If I was certain that a longer Absorb time won’t hurt the batteries, I would leave it at 10 hours. From my amateur understanding, the Banta will just take lower and lower amps, so I’m not sure the downside. 

The Magnum said 14.3 volts in Absorb, but it adjusts for cold temps and has a temp sensor on the bank. It shows the bank at 62 degrees, which pushes the voltage up from the standard 14.1 volts in Absorb.


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## Don L (Aug 8, 2008)

FWIW - I'm ain't no expert and never claimed to be. I'm a practical cruiser engineer type and am not interested in little petty corrections to practical useful answers/info into being the correct "technical" answer. In my years of naval ship operations, application engineering, and sailboat ownership I've yet to discover the correct technical answer to be of more use than the practical application use. I definitely have not found a boat that seems able to read and okey manuals, including nuclear subs! As such it is a waste of time to quote me and make minor petty useless "someone is wrong on the internet " corrections!

Don "ain't no expert" :kiss


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## Minnewaska (Feb 21, 2010)

I went through the day yesterday, in normal fashion. I left her plugged in, charger on and used 12v appliance as usual: lights, stereo, etc. As stated, I woke up, with the charger on Full, zero amp output, batteries at 13.1v and the SG said 100%! Overnight, the only thing that would have drawn 12v would be the fridges, but it was cold and doubt they cycled much. 

As the morning wore on, the charger remained on Full, while voltage began to drop slowly to 12.9, then 12.8. At some point, not long after 12.8v, the charger comes back on in Float mode? It stays on for a couple of hours and returns to Full. The Smartguage now reads 91%.

My head is spinning.


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## Don L (Aug 8, 2008)

Glad I don't have one of those "Smart" Gages. I can't help you with it other than to suggest to maybe disconnect it so it stops making you crazy. I run my system based on amp-hrs out, voltage, and battery acceptance. But it sound that my $120 battery monitor State of Charge reading is at least as accurate as your "SG".

You battery charger turns itself off and on when on float????


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## Minnewaska (Feb 21, 2010)

It isn’t the Smartgauge as much as the charger that is driving me nuts. Yes, the charger shuts itself off, when Full. There is a settting that I believe keeps it on Float permanently, but it’s not the default.


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## john61ct (Jan 23, 2017)

I also don't see the problem so much with the SG, and I don't pay attention to charge sources' attempts to guess SoC.

But the behaviour of the charger definitely seems bizarre.

I'd start a new thread and see if those familiar with the Magnums can help.


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## Don L (Aug 8, 2008)

One of those extra special smart chargers that it trying to save power &#55358;&#56618; I think it’s a California requirement thing. Turn it’s power saver function off!


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## Minnewaska (Feb 21, 2010)

I’ve been reading up on the separate shunt based battery monitor that Magnum makes, which integrates with the remote. Seems this is not so optional to get charging correct. It is on its way. Next weekend is sails and dinghy, if the weather cooperates. If not, back in the bilges for more wiring!


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## john61ct (Jan 23, 2017)

Yes if you're fitting the shunt based controls, I guess don't bother troubleshooting the base charger in the meantime.

If you still haven't given the SG its initial 100% reset based on stopping at endAmps manually measured at the battery, I'd say get that done sooner rather than later.


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## Minnewaska (Feb 21, 2010)

Do I need to reset the SG? After it sat on Absorb for 10hrs, it got to 100% on its own.


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## john61ct (Jan 23, 2017)

Not "have to". I doubt if it makes any difference a dozen cycles later in either case, but in the interest of letting you evaluate its accuracy fairly, sooner rather than later, I reckon a good idea.

Else why would Gibbo have put it there?

My assumption is it gives greater accuracy to its learning curve if done early on.

If done later, maybe it starts learning again from scratch?


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## Minnewaska (Feb 21, 2010)

Just posted an update on the Magnum thread as well. I think I finally have this one in the bag.

First, I replaced the house batteries. They were 6 years old, not as young as I thought.

Second, I rewired the house bank, so all take offs are together on opposite ends of the parallel bank. (The Smartguage instructions do not say this is a necessary). Previously, the inverter/charger and distribution takeoffs were on Bats 1 and 4, but on opposite terminals. Ie previously, the charger was on Bat 1 pos and Bat 4 neg. the distribution take off was on Bat 1 neg and Bat 4 pos. Now, everything is together. 

I then installed the Magnum shunt based battery monitor, which is necessary for identifying a proper charge profile.

Next was an upgrade to the Magnum advanced remote. I had originally installed the basic remote, not knowing they made two. The advanced remote allows the charge profile to watch acceptance amps during Absorb and only switch to Float when they get down to whatever acceptance amps you choose. I set mine to 0.5% of bank capacity. 

Viola! After a couple of cycles, the Smartguage now reads 100%! This was a long road. Having a relatively small bank for a power hungry boat, it was important to maximize its usefulness, but also important for batt life and the accuracy of all these instruments. Not only did the charge profile need to be adjusted to truly get to 100%, but I also needed to forestall the Float stage, while out cruising, to get usefulness out of the Absorb stage. Previously, it would go to Float too soon and burning diesel in Float is a waste. Premature floatulation, as our friend MS says. It’s been a massive education and I would like to thank everyone for their contribution!

If anything changes mid-season, I will report back.


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## john61ct (Jan 23, 2017)

Great result, congrats!

The batt's age and improper bank wiring may very well have been the biggest factors in your setup not working optimally.

Not to mention your reported SG inaccuracy. 

Not that my faith in Gibbo's invention was ever really shaken , 

but always nice to get a fly in the ointment cleared out.


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## Bleemus (Oct 13, 2015)

Minnewaska said:


> Second, I rewired the house bank, so all take offs are together on opposite ends of the parallel bank. (The Smartguage instructions do not say this is a necessary).


Every reliable source on parallel battery wiring states this so Balmar would assume it.

Glad to hear you got it sorted out. My faith in the SG was never shaken and knew you would eventually get to the solution! Well done!


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## Minnewaska (Feb 21, 2010)

Bleemus said:


> Every reliable source on parallel battery wiring states this so Balmar would assume it.
> 
> Glad to hear you got it sorted out. My faith in the SG was never shaken and knew you would eventually get to the solution! Well done!


Thanks!

Just in the event you misunderstood the parallel wiring point, I'm not simply saying opposite ends of the bank. That is the more obvious point and, in fact, the installation diagram does say to install the sense wires on opposite ends. I'm saying the guage apparently needs everything on the same opposite ends. My OEM wiring had some things on Pos on the front end, Neg on the back end, with other devices Neg on the front end, Pos on the back end. Both on opposite ends of the parallel bank. I've seen many installations like this, although, I know there are a ton of mistakes out there. I just think it warrants a clearer explanation in the SG installation manual, if users could find their current installation incorrect for the SG to work.


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## john61ct (Jan 23, 2017)

Just so it's clear for newbies googling later, there are lots of mistaken diagrams on the web.

All charge sources, all loads and all bank-level monitoring gear must ultimately be connected to the same pair (+/-) of termination posts.

It is very rare (e.g. LFP cell-level monitoring) to connect anything to any other posts, other than the intra-bank wiring.

I consider this page canonical: http://smartgauge.co.uk/batt_con.html

And highly recommend taking anything Maine Sail writes as gospel

https://marinehowto.com/category/electrical/batteries/

https://www.google.com/search?q=wiring+batteries+OR+bank+maine-sail


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## Minnewaska (Feb 21, 2010)

New development. 

I left last Mon, with the Smartguage reading in the upper 90s. I returned Fri and it read 86%. It’s been plugged in the entire time.

Here’s what I think is going on. Once my Magnum inverter/charger goes through a full cycle of charging, at the slip, from Bulk to Absorb to Float, the SG reads 100%. The charger will stay in Float until is senses no load for 4 hours, then shut off and monitor voltage. Naturally, some 12v appliances use power in the meantime. It will come back on in Float mode, when voltage drops below 12.7v and stay in until no load for four hours. 

Is it possible these loads, when the charger is off, are draining more than the charger is able to put back at Float voltage?


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## john61ct (Jan 23, 2017)

Yes.

Float mode is only for carrying loads and counteracting the bank's self-discharge rate.

In effect, while loads are present, the definition of Float may as well be "no real deep-cycle charging is going on".

You should be able to increase the frequency of your charger restarting a full from-Absorb charge cycle.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I left last Mon, with the Smartguage reading in the upper 90s. I returned Fri and it read 86%.


And here is where an AH counting view of your SoC% is useful as a sanity check on the SmartGauge.

It may be overestimating DoD at the moment, but then get more accurate over time.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Naturally, some 12v appliances use power in the meantime.


And of course, these should be limited to only those that are strictly necessary while you're away from the boat for any length of time.

Another approach with a very expensive bank but lots of necessary ongoing draws while docked, would be to

isolate the loads from the main bank and

use an intelligent but (inexpensive) low-amp charger to Float maintain the main bank and

use the main shore charger as a "converter" to just carry the loads while on shore power. A Starter batt can act as buffer if necessary.

Note a good solar controller can also handle the Float storage role since it is redundant while shore power is available.

With your very intelligent and adjustable charger I'm sure **you** don't need such a kludge, better to KISS.

But there it is as an alternative for others.


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## Minnewaska (Feb 21, 2010)

I finally got connected to East Penn-Deka and they confirmed the 0.5% of 20hr capacity as the acceptance amp trigger for my gels to go into Float. I then explained that my charger will run on float for four hours and shut off. It will come back on float after the bank declines to 12.7 volts. They said this was a perfect profile. There is more current flowing than the 0.5% amp acceptance, when re-topping at Float voltage, but they say that is correct too. 

However, after a few cycles of this, the SmartGauge progressively shows lower % charge as time passes. It gets to 100% after a full charge cycle, then after several Float-Off-Float cycles, it gets down in the mid-80% range. 

The remote on the Magnum says its 100% charged. Not sure what to think.


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## RegisteredUser (Aug 16, 2010)

Im guessing that it senses 100% and its program backs off the charging.....doesnt hold there...again programing.
I dont think the chargers etc are quite there yet....being so smart.


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## Minnewaska (Feb 21, 2010)

State of Charge profiling is an option, but I don’t have it turned on. Instead, I chose the End Acceptance Amps profile.


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## john61ct (Jan 23, 2017)

Is SG set to #2 for GEL?

The **actual** 100% Full is endAmps at Absorb V. Seems that's what SG is looking for. 

GEL may be better off with the gentler Float cycling.

To test just let it do its thing for a couple weeks, remove loads, until Magnum says Float-Full, 

note SG's %

then see how many more AH get accepted between that point and FULL-Full at Absorb.

Compare to what SG says.


As long as the FULL-Full Absorb V profile does run at least once or twice a week I'd think NP, leave it at that.

Did you try tweaking to accomplish that automatically with the advanced remote, rather than having to work out a manual spoof / kludge?

You could also tell / reset SG the bank's "Full" based on Float-Full, sees if that sticks.


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## john61ct (Jan 23, 2017)

RegisteredUser said:


> Im guessing that it senses 100% and its program backs off the charging.....doesnt hold there...again programing.
> I dont think the chargers etc are quite there yet....being so smart.


The Advanced remote controlling tgat Magnum is fully tied into a shunt BM, seems they're at least trying to be as smart as those top-notch solar controllers that do the same.


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## john61ct (Jan 23, 2017)

But **no** SoC guesstimator should be used to actually control end charge.

EndAmps at Absorb is always the best way to do that.

If trying to use a well-calibrated SoC estimate to end **discharge**, that's certainly better than Voltage (LVDs), but I would be upwardly conservative, and manually verify that calibration very regularly.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Is SG set to #2 for GEL?


Yes.



> The **actual** 100% Full is endAmps at Absorb V. Seems that's what SG is looking for.


Interestingly, it's hard to imagine how the SG can sense end amps, as it simply has a lead to the pos and neg terminal only.



> GEL may be better off with the gentler Float cycling.
> 
> To test just let it do its thing for a couple weeks, remove loads, until Magnum says Float-Full,
> 
> note SG's %


Unfortunately, I'm not going to be able to do this test, now that our season is underway. We keep the fridge stocked and it's beer season. There must be another perishable in there too. 



> then see how many more AH get accepted between that point and FULL-Full at Absorb.
> 
> Compare to what SG says.


I've recorded the acceptance amps and SG reading for 9 straight hours, as an alternative. When the acceptance gets down below 2 amps (ie 0.5% of 20hr capacity) and flips to Float, the SG reads 99%. It gets to 100% in a few more hours. That part seems pretty close to correct.



> As long as the FULL-Full Absorb V profile does run at least once or twice a week I'd think NP, leave it at that.


I think you're probably right and I'll leave it alone for a bit. We get back to the slip for a 100% recharge almost every week. There will only be 4 or 5 all season this doesn't happen. Even then, we sometimes land a transient slip. The folks at Penn-Deka said the charge profile I'm using is ideal, therefore, I suppose it really shouldn't matter what the SG says.

By the way, Penn-Deka believes the Gel batteries are ideal for boating. Much better than AGM. Other than the higher charge acceptance from AGM, they felt the Gel was much better suited to the harsh cycle conditions of a boat. Interesting.



> Did you try tweaking to accomplish that automatically with the advanced remote, rather than having to work out a manual spoof / kludge?
> 
> You could also tell / reset SG the bank's "Full" based on Float-Full, sees if that sticks.


I have not tried to fake it out yet, nor reset by hand to 100%. I think I'll give it a month or two of use and see what happens.


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## Maine Sail (Jan 6, 2003)

A healthy GEL battery will rest at 100% SOC slightly above 13.0V. Deka states 12.85V or above as 100% SOC resting voltage. 

This means that if you have loads connected, and the charger pauses and drops to 12.7V (below 100% SOC), and then only recharges to a "float" voltage you're not getting back to a true 100% SOC before discharging slightly again.. Remember the last few % of SOC are horribly inefficient and require a lot of time at absorption voltage.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Interestingly, it's hard to imagine how the SG can sense end amps, as it simply has a lead to the pos and neg terminal only.


Sorry of course I didn't mean SG is directly measuring that. Just that its determination of Full is coming at around this point

> When the acceptance gets down below 2 amps (ie 0.5% of 20hr capacity) and flips to Float, the SG reads 99%. It gets to 100% in a few more hours. That part seems pretty close to correct.

> The folks at Penn-Deka said the charge profile I'm using is ideal, therefore, I suppose it really shouldn't matter what the SG says.

Well I'd prefer either of the two alternatives I gave to get the two "sync'd", but you're right, from a purely practical POV.

> By the way, Penn-Deka believes the Gel batteries are ideal for boating. Much better than AGM. Other than the higher charge acceptance from AGM, they felt the Gel was much better suited to the harsh cycle conditions of a boat. Interesting.

Well their AGM are not great, and the market likes sealed.

But yes, they last a long time, and their "fragility" is just a susceptibility to overcharging, IOW a greater need for precisely regulated charging.


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## Minnewaska (Feb 21, 2010)

Maine Sail said:


> A healthy GEL battery will rest at 100% SOC slightly above 13.0V. Deka states 12.85V or above as 100% SOC resting voltage.
> 
> This means that if you have loads connected, and the charger pauses and drops to 12.7V (below 100% SOC), and then only recharges to a "float" voltage you're not getting back to a true 100% SOC before discharging slightly again.. Remember the last few % of SOC are horribly inefficient and require a lot of time at absorption voltage.


If I follow your point, you're saying the SG is actually correct, as the Float charging isn't putttng back what was used, by the time it trips back on.

If it is a user adjustable setting, would you increase the voltage to come back out of standby to Float to 12.85v?


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> If I follow your point, you're saying the SG is actually correct, as the Float charging isn't putttng back what was used, by the time it trips back on.
> 
> If it is a user adjustable setting, would you increase the voltage to come back out of standby to Float to 12.85v?


Increase stand-by voltage to above the natural resting voltage of the battery eg; 13.1V to 13.2V... 12.7V is okay for most flooded batteries but not for many GEL or AGM's as 12.7V is slightly below 100% SOC.....


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## Minnewaska (Feb 21, 2010)

If I were to set standby voltage to be 13.1 or 13.2, would you expect Float to ever shut off, given we maintain some load nearly 24/7?

I have to look more carefully at the Magnum advance remote options to see if this is even a possibility, but I do know that keeping float on perpetually is an option. I didn't select it, as I was concerned to overcharge.


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## john61ct (Jan 23, 2017)

Maine Sail said:


> Increase stand-by voltage to above the natural resting voltage of the battery eg; 13.1V to 13.2V


So "stand-by" is the threshold *below* Float? In other words, where the charger stays dormant?

Looks like even higher for Float itself would be fine, as long as the temp compensation's working properly.

At 77° looks like Absorb 14.0V, Float 13.7V

And floating continuously is not meant to be bad for any lead, the standby functionality is just designed for energy saving afaik.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> .....And floating continuously is not meant to be bad for any lead, the standby functionality is just designed for energy saving afaik.


If this is substantiated (you did qualify with afaik), I would leave it on float then. The shore power is a flat fee.


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## john61ct (Jan 23, 2017)

Actually I just recalled my past emails with a Firefly engineer, their carbon foam chemistry can be Floated all the time @ 13.2, but they believed long term longevity is best served by a "just stop" charge profile, as with LFP.

But since their Indian take-over, they've been more marketing oriented, raised max Float to 13.4V, so now the company would likely also say full-time Float is just fine.

____
Of course, contacting Deka again to verify a new & improved regime would help ease your mind.


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## Minnewaska (Feb 21, 2010)

By now, I’ve overnighted at anchor or mooring for a dozen nights. I’ve drawn down the batts, while sailing, partially recharged from the generator and fully recharged at the slip. Presumably, The SmartGuage has finished its learning. Every time I leave the boat plugged in for a few days, I return to find the SG in the mid 80% range, although, was well in the 90s, when I left. I realize this is because the boat is using more amps than the Float is putting back, when it automatically waits to come back on at 12.7v. I can’t find a setting to trip it on at a higher voltage, as MS recommended. 

I found a feature in the Magnum remote that allows one to restart the charge cycle, from Bulk, at any time. I started doing this once per week, when I returned, to top up the batteries for capacity, as well as their health. As the batteries were already around 12.7-12.8v, it would drive voltage to Absorb in seconds. Although, Absorb was pushing more amps than one would expect in a full battery, so they were clearly below full. This method was working and the SG would show 100% after several hours and off I would go sailing. 

For the last couple of weeks, the method is not getting the SG to 100%. It’s a rainy morning here, so I decided today was good day to log the charge cycle. Here’s what I found........

The batteries started at 12.8v and the Magnum charger said they were full and the charger was off. The SG says the batteries are at 84%.

I manually tell it to start Bulk, which flips to Absorb in seconds and begins to push 42amps into the bank (as measured on the battery monitors shunt)

1 hour in, the batteries are down to accepting 2amps, in Absorb, and the SG reads 87%.

1.5 hrs in and they are accepting 1.8-2.0amps and the SG reads 89%.

2 hrs in and the charger has moved to Float, they are accepting 1.2amps and the SG reads 90%.

3hrs in, they are accepting 1.2 amps and the SG reads 90%.

I’m sure this will end around 92-93%, as it has recently been doing. 

I have approx 400ahrs in gel batteries and have set my charger to move from Absorb to Float at 2 amps acceptance. I would consider lowering that value, however, it’s what Deka recommended and the SG was showing 100% for a while. 

I’m hesitant to push it, not knowing if it’s just the SG that’s wrong. If the shunt says the 400ahr batteries are only accepting 1.2amp, I would think they must be over 90%. Is this right thinking?


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## Minnewaska (Feb 21, 2010)

The rest of the charge cycle......

4 hrs in, batteries are accepting 0.8amps and the SG still reads 90%.

5 hrs in, the charger switches to Full and shuts off. The SG still reads 90%. I didn’t notice exactly when this happened in the last hour. When I checked, the bank was drawing 1.5 amps out and the voltage gauge read 13.1 volts. I would not exactly call it resting. 

The SG seems wrong to me.


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## john61ct (Jan 23, 2017)

Yes, the trailing amps is canonical for 100%, **stop pushing** those GEL higher than mfg spec, easy to reduce lifetime that way, top priority is do not overcharge!

Also be careful about voltage, are you high or low in their Absorb range?


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## john61ct (Jan 23, 2017)

So the SG is not tracking the high end for that specific bank chemistry.

Maybe the problem is something wrong with the bank?

You did fix that wiring misconfig right?

You could reset the 100% marker as per endAmps, maybe a few resets at the top end will help it get better at the top end?

then see how useful it is on the way down to 50% while cycling, help you not draw too deep.

You also have a full fledged AH counting BM with that Magnum setup right?


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## john61ct (Jan 23, 2017)

Finally, I would really try to engage with Magnum TS to prevent the Float transition until endAmps is reached.

Isn't that a feature of their pricey remote reading off **a batt shunt**?

Grounds for returning the whole shebang IMO.

Not saying do that, but that's the stance I'd take if their engineers aren't proactively forthcoming on the issue.

They obviously want to compete with Victron and MasterVolt in this segment, and they should have a USP with this feature, at least for a while. . .


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Also be careful about voltage, are you high or low in their Absorb range?


No idea what you are asking. Absorb voltage is temp adjusted for Gels. Spot on.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> So the SG is not tracking the high end for that specific bank chemistry.


Seems so.



> Maybe the problem is something wrong with the bank?
> 
> You did fix that wiring misconfig right?


I'm 99.999999% certain I have the wiring right and doubt it's the brand new bank.



> You could reset the 100% marker as per endAmps, maybe a few resets at the top end will help it get better at the top end?
> 
> then see how useful it is on the way down to 50% while cycling, help you not draw too deep.


I'm tempted to reset to 100%, when the charger trips to Full, but it was reading 100% a few weeks ago, so I'm reluctant.



> You also have a full fledged AH counting BM with that Magnum setup right?


Yes


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Finally, I would really try to engage with Magnum TS to prevent the Float transition until endAmps is reached.
> 
> Isn't that a feature of their pricey remote reading off **a batt shunt**?
> 
> ...


I think you misunderstand. The charger does just fine waiting until and end amp (acceptance) level is reached, before switching to Float. I have that set to 2amps on a 400Ahr bank.

The issue is it eventually shuts off and won't come back on, until the bank declines to 12.v, which is too low. Therefore, returning to Float is not sufficient to fully recharge.

Although, even when I restarted from Bulk to Absorb, the SG never reads above the low 90s now. I really don't think it's the charger.


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## john61ct (Jan 23, 2017)

My notes on Deka GEL is that 14.2V is very maximum. Therefore charge slow, 7+ hours from 50% SoC to Full, endAmps .005C.

Resting Full should be 12.85V, little more if shorter rest.

Float 13.2V

Does that jibe?


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I'm tempted to reset to 100%, when the charger trips to Full, but it was reading 100% a few weeks ago, so I'm reluctant.


I would do it, based on .005C or maybe a little earlier, as I said maybe will help its "learning".

Or even if not, maybe needs to be done every X cycles with those particular GELs.

Over time as long as the top mark is calibrated, see how the discharge metering matches up with your coulomb counting BM.


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## john61ct (Jan 23, 2017)

And yes the most important issue is getting Bulk Return started at a much higher setpoint.

I would prefer to see it based on AH drawn since Full rather than Voltage.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> The batteries started at 12.8v and the Magnum charger said they were full and the charger was off. The SG says the batteries are at 84%.
> 
> I manually tell it to start Bulk, which flips to Absorb in seconds and begins to push 42amps into the bank (as measured on the battery monitors shunt)


Might be worth checking how accurate the shunt is.

So with 400AH, that is a .1C rate, so yes not close to Full.

> 1 hour in, the batteries are down to accepting 2amps, in Absorb, and the SG reads 87%.

That should have been your endAmps Full, go to Float time at .005C

Do not push past that anymore, harmful to the bank.

Make the SG reflect 100% there, or just ignore it at the top end.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> My notes on Deka GEL is that 14.2V is very maximum. Therefore charge slow, 7+ hours from 50% SoC to Full, endAmps .005C.
> 
> Resting Full should be 12.85V, little more if shorter rest.
> 
> ...


From 50% to Full takes the charger over 9 hrs. I think that's right for Gels. The correct Float voltage is 13.6, so I'm sure the 13.2 was on the way to settling down to resting voltage.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Might be worth checking how accurate the shunt is.


How would I do that?



> > 1 hour in, the batteries are down to accepting 2amps, in Absorb, and the SG reads 87%.
> 
> That should have been your endAmps Full, go to Float time at .005C
> 
> ...


I agree, I'm not going to push it.

To be fair, I have rounded my bank capacity. As published it's 392ahrs. While they are new this spring, at most I could convince myself they have decline to 380, which would call for end amps at 1.9. In terms of the SG reading wrong, however, I think this is splitting hairs. Even at 2.0 end amps, a 380ahr bank should read over 90%. Make sense?

Ignoring it at the top end would be easy. I'm really only interested in how far I am from 50%, to determine when to recharge. It's just hard for me to believe it knows 50% any better, if it can't identify 100%.


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## Don L (Aug 8, 2008)

So do you believe the SG is correct?


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> Glad I don't have one of those "Smart" Gages. I can't help you with it other than to suggest to maybe disconnect it so it stops making you crazy. I run my system based on amp-hrs out, voltage, and battery acceptance. But it sound that my $120 battery monitor State of Charge reading is at least as accurate as your "SG".
> 
> You battery charger turns itself off and on when on float????





Don0190 said:


> So do you believe the SG is correct?


I heard your position that you think this gauge is a waste of time. However, it's forced me to educate myself and troubleshoot this system, so I've found it very worthwhile. For that matter, I have to assume Gels are the least common marine battery type. If I can help troubleshoot this thing to work better, someone else may benefit.


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## john61ct (Jan 23, 2017)

I think the SG will be more correct in the middle ranges if it is set to 100% at **your** definition of 100%.

If it turns out to need that done (is off by 8+% at the top) more frequently than once a month, then it is not working for that setup, reason TBD.

Of course **only** the top end has a truly accurate known-good / canonical measurement to compare to.

In the middle we hope for consistency between the SG, AH counter (Magnum's being relatively new to the groupmind) and voltage correlation, known to be pretty inaccurate.

If not, then which is "closer to right" is a judgment call, unless say a 712-BMV can be borrowed as a third opinion.


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## john61ct (Jan 23, 2017)

wrt shunt accuracy, additional ammeters can be used to compare / calibrate

Same uncertainty as above, but a major obvious problem should show without spending too much.

It is the low current high-resolution accuracy that is more important.

Clamp ammeters is one choice, costs vary but decent ones start at $50

Inline units are available on eBay for a bit less

And of course any full AH counting BM also can display live Amps.


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## john61ct (Jan 23, 2017)

Finally if a pro is aboard at any time, their presumably more expensive calibrated gear should be used to benchmark all the boat's meters in regular use.

Charge sources' built-in readouts are notoriously often way off the mark.


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## Don L (Aug 8, 2008)

Don0190 said:


> So do you believe the SG is correct?


Asked a simple question, why is it hard to answer without being defensive? Do you believe the SG is reading correct or not?


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## john61ct (Jan 23, 2017)

Obviously it is not at this time, unless the meter used for endAmps is very inaccurate.

But there is a reset-at-100% switch as is common with all BM types, and that has not been used for a long time.

Even the best AH-counting meters require that for accuracy, ideally every cycle.

SG is unique in that with some banks it may remain more accurate without having to do that, or at least much less frequently.


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> Asked a simple question, why is it hard to answer without being defensive? Do you believe the SG is reading correct or not?


Not sure.


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## Minnewaska (Feb 21, 2010)

Interesting update. I was off the dock for a short while this morning. It’s a cleaning and chores weekend, getting ready for a Jul 4th cruise. 

When I unplugged, the SG read 89%. When I got back, before plugging back in, the SG read 88% and the bank was at 12.7v. The alternator probably did replace whatever was used, just exiting and returning to the harbor. When I plugged back in, the Magnum charger automatically restarts from Bulk, which switches to Absorb in seconds and is taking roughly 70amps, but declining acceptance quickly. 

After plugged in for 90 mins, the charger is in Float, the bank is accepting 1.0 amps and the SG reads 91%.

After plugged in for 4hrs, she’s still in Float, accepting 0.6amps and the SG reads 96%.

After 5hrs, the charger shut off and the SG reads 96%.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Not sure.


What not? What does the SG reading have to do with the others questions regarding your batteries and charging system?

You spent the money and time to get the SG that is independent of all the other items. Wasn't that the point?


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## Minnewaska (Feb 21, 2010)

Don0190 said:


> What not? What does the SG reading have to do with the others questions regarding your batteries and charging system?
> 
> You spent the money and time to get the SG that is independent of all the other items. Wasn't that the point?


Because they don't agree and I've found one or the other was the problem previously.


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## Don L (Aug 8, 2008)

Minnewaska said:


> Because they don't agree and I've found one or the other was the problem previously.


I get that. But wasn't the reason for the SG is that battery monitors are considered to not be accurate for state of charge?

I don't really understand why the SG would read "wrong" as my understanding of it is that it is directly reading and measuring the battery. If it reads different than say a battery monitor wouldn't you believe it is the BM being wrong?

And while I'm trying to understand, not judge, if the SG isn't going to correctly measure the battery SOC what good is it?


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## Minnewaska (Feb 21, 2010)

Reportedly, the SG, once it “learns” the chemistry, can tell the state of charge, even when the capacity naturally deminishes over time. Amp hour counters need to be told what Full capacity is and they count down from there. The user, however, can’t know what naturally declining capacity is over time. Therefore, since it assumes the original capacity, one is very likely to be below 50%, even though the amp hour counter doesn’t think so.

The truth is, my house bank is too small at 400 amp hrs, so I’m trying to manage it better. The next reincarnation will be a larger bank, possibly changing out to AGM. That will require an alternator upgrade and various other changes. 

Since my bank is now new, I was hoping they would be more similar. She sits at 96% charged, according to the SG, right now. Given a constant draw from two fridges, it seems reasonable. Just not sure why it didn’t say so yesterday, but does today.


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## Don L (Aug 8, 2008)

Isn't %SOC still %SOC regardless if the bank bank is 40AH or 100AH?

Is knowing a battery is at 80% SOC useful if you don't really know the capacity? As example if a 480AH bank is now only 400AH and is at 80% SOC on the SG does than mean you have 320AH of charge in the battery still. 

I'm just asking as I considered getting a SG at one time and would still consider one. But it has to work and pay for itself in battery costs. I have a 460AH house bank and try to not baby it too much. Near as I can tell I feel my battery monitor is within 5% of being correct on the bank SOC, but .I don't really pay much attention to SOC and pay more to -AH.


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## john61ct (Jan 23, 2017)

Nothing reads SoC directly.

Nothing affordable (under $1000) is very accurate.

A quality AH counting BM can be pretty good at guesstimating as long as you get the programming inputs right, calibrate to changing SoH capacity as that declines, and reset 100% often.

SG in practice ends up being more accurate in most setups than the AH counting units, with much less fuss and no need to calibrate to changing SoH capacity as that declines.

A knowledgeable person willing to go to the trouble certainly can coddle their big expensive bank without any SoC meter.

The question as to whether it is worth paying for one is of course up to each of us to decide.

Just owning one certainly is no magic bullet.

And most boaters, who only spend a few hundred on their bank, and don't mind replacing it every few years would certainly not see a quick ROI from a strictly economic POV.

While others are willing to spend their money on electrickery gadgets just for the fun of it.


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## Bleemus (Oct 13, 2015)

While I will refrain from jumping in on the debate going on here there is something fishy about Minnewaskas setup that hasn't been figured out yet. If he has 18 gauge wire as instructed by SG then something else doesn't make sense. Never seen the kind of discrepancies that he is seeing with my SG. Something just ain't right. Not pointing fingers but this whole thread just doesn't match my, and my best friends, experience with the SG on our respective boats. It is one of the most trusted pieces of gear we both own. Hope we can find a solution for Minnewaska.


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## Minnewaska (Feb 21, 2010)

Thanks for the encouragement, Bleemus. 

As to the wiring assumption, I’m sure I used at least the size they specified, but may have used larger. I have everything from 12g to 18g in both black and red in stock. Too early in the morning to crawl under there. 

My best guess is the Gel battery chemistry either doesn’t work as well or is taking much longer to learn. Are yours Gel?


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## Bleemus (Oct 13, 2015)

Minnewaska said:


> Thanks for the encouragement, Bleemus.
> 
> As to the wiring assumption, I'm sure I used at least the size they specified, but may have used larger. I have everything from 12g to 18g in both black and red in stock. Too early in the morning to crawl under there.
> 
> My best guess is the Gel battery chemistry either doesn't work as well or is taking much longer to learn. Are yours Gel?


I am FLA. Never have tried gel.

I remember reading somewhere that Balmar says to use only 18 gauge wire for some reason. Might be worth checking.


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## Maine Sail (Jan 6, 2003)

Bleemus said:


> I am FLA. Never have tried gel.
> 
> I remember reading somewhere that Balmar says to use only 18 gauge wire for some reason. Might be worth checking.


18GA is the _bare minimum_ size you can use. Balmar manuals are not always well done in fact I have three versions of the Balmar Smartgauge manual one stating 14AWG, one stating 16AWG and one stating 18AWG. Every single Smartgauge install we've done has used 14AWG.


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## Minnewaska (Feb 21, 2010)

All indications are, I finally nailed this one. Smartguage reads 99%, when I get back to the boat this morning. I was away 3 days. I ran it down to 12.3 volts last weekend, before recharging, with the SG on. Here are the things I needed to do......

1. I identified that the take offs from the parallel bank were not at the opposite ends, rather one last battery was skipped on one end. Rewired. 

2. I had to relocate the SmartGuage sensor wires to the same lugs as the take offs to the bus bar, which is not identified in the instructions.

3. I changed my invertor charger and added a shunt so it would know when to switch from Absorb to Float, based on acceptance amps. I then changed my charger settings to stay in Float permanently, rather than cut off after 4 hrs at full. The problem here was that it would not come back on Float, until a factory preset voltage, which was too low for Float stage to recover. 

I would come back to the boat, after this Full to Float to Off to Float cycling and the SG would say the house bank was 85-90%. Turns out, it probably was, as the fridge and bilge pump were draining the bank below the point that float could recover. Now that Float never goes off, it’s just replacing usage real time.

Much happier. I now head off the dock with 20% more usable capacity. While a serious pita, the SG forced me to troubleshoot a bunch of OEM errors.


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## john61ct (Jan 23, 2017)

Excellent account of the process and great result


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## Minnewaska (Feb 21, 2010)

Ok, we’re back. This gizmo is simply frustrating. 

I left the slip last week, with the SG reading 99% and spent several days on the hook. Some recharging was done while motoring, but mostly by running the generator several hours per day. When retiring for the evening, the SG would typically read in the mid 80s. Some mornings I would awake and it would read only 5 points or so below where it was the night before. Other nights, it would drop to the 60s or by 20+ points. No discernible difference in usage those evenings. Voltage was always fine, never below 12.5v. 

I get back to the slip last night and plug in. The SG says 72% at that point. The charger starts in Bulk and gets to Absorb fairly quickly. This morning, it’s now in Float (which it now remains in permanently) and the acceptance amps across the shunt are 0.2amps or (0.0005C). That’s full. The SmartGuage reads 88%. 

WTF.


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## bristol299bob (Apr 13, 2011)

I've got an SG and I'll admit I'm not sure I trust it after reading your experience.

After installing my SG a few years ago I had a similar "flaky experience". The numbers it reported just didnt match up with my observation. After a bit of a battle with it, and after a lot of upgrades to the electrical system (which were due anyway) it seems to be working "fine". But I'm losing faith.

This one intrigues me: https://store.marinebeam.com/bm-pro-intelligent-battery-system-monitor/. It seems to be a legit "intelligent" monitor that bases it's computation on voltage and amperage.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I get back to the slip last night and plug in. The SG says 72% at that point. The charger starts in Bulk and gets to Absorb fairly quickly. This morning, it's now in Float (which it now remains in permanently) and the acceptance amps across the shunt are 0.2amps or (0.0005C). That's full. The SmartGuage reads 88%.


Did it get powered down / disconnected so that it started its learning all over?

If you reset it at 100% Full, see how it goes.

If not, maybe it's broken, that can happen of course. Call Balmar CS they may be able to help.

Maybe sell you the SG-200 at a deep discount?

Sorry for your troubles


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Did it get powered down / disconnected so that it started its learning all over?
> 
> If you reset it at 100% Full, see how it goes.
> 
> ...


It's not been powered down, since I started it back up two months ago. I left the boat this morning for three days. I'm going to see what it says when I return, before trying the manual reset. That will be my next move. I should be off the grid again for a few days over next weekend, so we'll see.

I suppose it could be defective. While it caused me to debug a bunch of house bank issues, I'm plumb out of believing there is anything left on my end. The bank is accepting virtually no amperage in Float and I can't think of any other condition, other than Full, that would represent. The SG reads in the 80s. Geesh.

I bought it from @Maine Sail and would be interested if he's ever come across a defective unit.

Another curiosity is whether this unit works as well, if plugged into shore for lengthy periods of time. The first month it was reinstalled, was at the dock commissioning. I wonder if that perpetually topped up condition screws up it's brains.


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## john61ct (Jan 23, 2017)

Can't imagine how, it's just not learning anything useful while the bank's not being cycled.


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## Minnewaska (Feb 21, 2010)

I was away from the boat for a few days and when I return, the SG still reads mid 80s and the shunt is showing 0.0-0.2 amps accepting in Float. That should be a sign of Full. We head off the slip and run the batteries up and down at anchor for a couple of days. The day we left the slip, we had to motor quite a bit. When we arrived at anchor a few hours later, the SG now read low 90s. That made no sense. 

Back to the slip last night and plugged in. This morning, she’s in Float, accepting 0.2 amps and the SG reads 83%. 

Next move is to manually reset the SG to 100% and see what happens, next we leave the slip. Not impressed. I still wonder if it’s just not as good at Gel profiles.


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## SanderO (Jul 12, 2007)

How did I avoid all the concern about state of charge and fretting about it? I suppose it's because of both the banks capacity relative to use... constant small regulated solar, high output alternator w/ smart regulation and an accurate volt meter - link20. I simply ignore all the other readings which never make sense. Boat is on a mooring and voltage reads over 13v when the sun in shining. When a few small loads are on voltage is usually 12.80 +/-. Refer is engine drive.. so when I do cool the box I am ADDING amps to the bank. Since I am not using a lot of amps typically I don't see that bank voltage drop very much and it's of no concern. Windlass is a high draw but that only used with engine. No need for a generator. No microwave or electric coffee maker. All lamping/lights changed to LEDs. Don't leave plotters on when we are not sailings. AP is very low draw. I suspect if bank is rarely deeply discharged... the state of charge is not a worry.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Next move is to manually reset the SG to 100% and see what happens, next we leave the slip.


I suggest you do so just after verifying that charging

at Absorb voltage

with high amps available

has tapered down to the endAmps value that actually defines Full for your bank.

Following that, make sure the next dozen or two cycles go between

that point and below 30-40% DoD.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> How did I avoid all the concern about state of charge and fretting about it? I suppose it's because of both the banks capacity relative to use.........


No doubt, that's it. If you overbuild the bank, relative to your use, you get away with all sort of inefficiency.

Our bank is probably undersized for the amount of electronic devices (3 electric heads, for example) at only 400 Ahrs. The battery compartment will not fit more, so cabling to a nearby place would be the next step. I'd rather make the best of what I have, for now, and upgrade to Lithium next time. That should allow me the capacity in the same space I have available now.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> I suggest you do so just after verifying that charging
> 
> at Absorb voltage
> 
> ...


I've already set and confirmed voltage for Absorb and Float and the switch to Float happens at acceptance amps of 0.5%C (ie 2 amps on a 400 amp bank). Then Float remains on permanently and the acceptance declines to near zero. At this point, this morning, I manually adjusted the SG to 100%.

I also wonder if the SG get confused by a boat that is plugged in for several days per week and remains on Float voltage permanently. ????

While a typical sail would get me to that level of DoD, over the day, it's a bit hard to manage, if the engine is running alot to make a long passage. This happened this weekend, as one leg required 3 hours of motoring in zero wind.


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## john61ct (Jan 23, 2017)

I think the goal now is enough deep cycles in a row for learning.

Let them carry the loads without charge input until well depleted, then reconnect manually.

Not saying any of this is needed in practice for your apparent use case.

But to get the SG tuned in, trying to get meaningful SoC numbers must require some "exercising"


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## SanderO (Jul 12, 2007)

Minnewaska said:


> No doubt, that's it. If you overbuild the bank, relative to your use, you get away with all sort of inefficiency.
> 
> Our bank is probably undersized for the amount of electronic devices (3 electric heads, for example) at only 400 Ahrs. The battery compartment will not fit more, so cabling to a nearby place would be the next step. I'd rather make the best of what I have, for now, and upgrade to Lithium next time. That should allow me the capacity in the same space I have available now.


Minni you clearly have a lot of electric devices so you are placing a lot of demands on your bank. While your box may be too small... AGMs for example can be placed in any orientation and it seems that in a boat of your volume you can find a location for more and larger batteries. That you can't seems odd.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> ....But to get the SG tuned in, trying to get meaningful SoC numbers must require some "exercising"


Understood. I've cycled down to 12.4 volts or what it thinks has been in the 50-60 SOC range at least a half dozen times already. Maybe a dozen or so more times to various other SOC, before plugging back in. Has me wondering if I have a slow learner. 

While an amp hour counter does nothing for me, my charger remote has one. Counting amps has never seen below 70% SOC. Although, I often make a pot of coffee in the morning, which draws roughly 100 amps DC, so the peukert impact on the counter has it wrong, for sure. Not to mention, it's fairly common for us to draw more than the 20 hr rate. It stands to reason the bank would really be in the 50s, withe counter thinking the 70s.


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## Minnewaska (Feb 21, 2010)

SanderO said:


> Minni you clearly have a lot of electric devices so you are placing a lot of demands on your bank. While your box may be too small... AGMs for example can be placed in any orientation and it seems that in a boat of your volume you can find a location for more and larger batteries. That you can't seems odd.


I can find room, for sure. However, the battery compartment is fully contained in cabinetry under the nav station and can't be made bigger. It would require surgery through some cabinetry and a bunch of cabling to get to nearby space. It could be done, but I'd sooner spend the money on upgrading to lithium. I'd rather not do the modifications and spend the money on expanding the bank, when it isn't the long term goal.

Nevertheless, the SG simply doesn't read correctly and that's the purpose of this thread.


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## SanderO (Jul 12, 2007)

Minnewaska said:


> I can find room, for sure. However, the battery compartment is fully contained in cabinetry under the nav station and can't be made bigger. It would require surgery through some cabinetry and a bunch of cabling to get to nearby space. It could be done, but I'd sooner spend the money on upgrading to lithium. I'd rather not do the modifications and spend the money on expanding the bank, when it isn't the long term goal.
> 
> Nevertheless, the SG simply doesn't read correctly and that's the purpose of this thread.


Minni.. regardless.. maybe you should consider a new location... larger size.. not so accessible required for maintenance free batteries. for your new battery bank. Use the old location for.. regulators, or storage of tools or similar.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Has me wondering if I have a slow learner.


Certainly possible it's faulty, but I'd put the odds on another cause and would just plod on with the process myself.

Excuse my faulty memory, but is it you that found a cause before and thought everything was OK, at least for a time?

If you did ever want to give up, it would be interesting to run it in parallel with the new SG-200


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## Minnewaska (Feb 21, 2010)

john61ct said:


> ....Excuse my faulty memory, but is it you that found a cause before and thought everything was OK, at least for a time?....


I thought I had (for one cycle). The latest was that I found the Magnum charger would automatically shut off, after 4 hours in Float, and not come back on to Float, until voltage declined to 12.6v. It's a factory set voltage trigger that can't be changed. When I'd return, after a few days away, to find the SG showed SOC in the 80s, it may have been correct. Float alone would not recover from the drain down to 12.6v.

I was able to turn that feature off altogether, so it remains in Float permanently, while at the slip. I checked with East Penn, who said this was fine, as long as I was going off the shore power periodically, which I obviously do. On my first full cycle, off shore power, drawn down to 12.3v, and then fully recharged, it read 99%. Thought we had it. Then, after a couple of more cycles of "learning", it now only reads in the mid 80s SOC, immediately after clearly reaching a Full charge.

I say clearly Full, as acceptance amps are flipping between 0.0 and 0.2 amps at Float voltage, on a 400 ahr bank. Is there any way they could not be Full, with this charge condition?

I'm off the boat for a couple of days. It will be interesting to see if the 100% SOC I set manually is still the case, when I get back. Then I'll unplug and run another cycle or two. We'll see.

I still question whether it can handle being plugged in several days per week and if it does well will Gel technology.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Float alone would not recover from the drain down to 12.6v.
> ...
> I say clearly Full, as acceptance amps are flipping between 0.0 and 0.2 amps at Float voltage, on a 400 ahr bank. Is there any way they could not be Full, with this charge condition?
> &#8230;
> I still question whether it can handle being plugged in several days per week and if it does well will Gel technology.


Yes, 100% Full is benchmark ed by holding **Absorb** until endAmps.

That Magnum "feature" I think for current purposes, you need to override by rebooting, force a return to the Absorb V Deka gave you, maybe also kludge a long enough AHT if needed.

With Gel being more sensitive to overcharge do ensure you are there - ideally with a known good separate ammeter - to terminate at endAmps and reset the SG to 100%.

Those Magnum "features" are bizarre!

Manually cycle I think, as I said deep enough for a good dozen for purpose of testing SG.

Returning at 12.6V should be with full Absorb voltage.

BTW what specs did Deka give you for Gel, Absorb and endAmps?

Since Magnum is in effect not supporting Floating - which is supposed to only be used to maintain 100% Full

maybe California compliance?

I would try setting Float V to =Absorb

make sure the automated termination whatever you use

maybe reset back to endAmps based?

does not allow overcharging the Gel, use an additional ammeter to verify stopping on time, default to a little earlier (higher endAmps) rather than allowing occasional too-long (lower endAmps) as is fine for FLA.

If they give a range for Absorb V, maybe also use the low end.

But the ideal for all lead is staying Full, letting Float carry loads, even if it means isolating the Gel bank, one way or another I'd try to get back to that no matter what CA or Magnum say.

But all that is not relevant to the testing SG phase.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> When I'd return, after a few days away, to find the SG showed SOC in the 80s, it may have been correct. Float alone would not recover from the drain down to 12.6v.


That is possible

> Then, after a couple of more cycles of "learning", it now only reads in the mid 80s SOC, immediately after clearly reaching a Full charge.

Since we now see that is actually not Full, if only at Float V, the SG may indeed be correct.

I'm thinking different ways of compensating for the non-optimal Magnum behaviour, but will stop for now let you come up with what you think best for your setup, I think you have all the info you need just a question of priorities, simplicity vs automation.

But keeping the Gel online while at the dock is certainly not necessary, since they're not getting Floated properly by Magnum anyway.


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## Minnewaska (Feb 21, 2010)

John, I think you missed that Magnum does have a setting to allow for permanent Float, which I've now selected. The default it comes with has Float shut off, after 4 hours. I'm told it is an environmental setting that I've now overrode. 

I really don't think it's a good idea to set Float Voltage = Absorb voltage. I assume you were trying to think of a way to get to proper end amps, but Magnum has a setting for it and I've already done that. I have endAmps set to 0.005C (2 amps on a 400 amp bank) and have witnessed it holding Absorb until then and then dropping to Float for the remainder. It then takes hours for acceptance amps to drop from 2 to 0, in Float voltage, but the bank should be damn near Full at 2 amps anyway. 

It's at this stage of charging (Float voltage, accepting <0.0005c) that I believe I "know" the bank is Full, but the SG still says mid 80s. SOC.

My question..... is there any way a bank could be less than Full, if it's accepting <0.005c in Float voltage. The SG thinks so. I don't.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> John, I think you missed that Magnum does have a setting to allow for permanent Float, which I've now selected.


No, I did note that, and that is great for **after** your bank is Full.

> The default it comes with has Float shut off, after 4 hours. I'm told it is an environmental setting that I've now overrode.

Yes, that's the California Energy Compliance reg, see MS' video on how Sterling handled it, falsely named "power supply mode".

> I really don't think it's a good idea to set Float Voltage = Absorb voltage. I assume you were trying to think of a way to get to proper end amps, but Magnum has a setting for it and I've already done that. I have endAmps set to 0.005C (2 amps on a 400 amp bank) and have witnessed it holding Absorb until then and then dropping to Float for the remainder. It then takes hours for acceptance amps to drop from 2 to 0, in Float voltage, but the bank should be damn near Full at 2 amps anyway.

I was only talking about for the SG calibration, where precision is needed.

The whole point of a source using endAmps is to hold **Absorb** voltage until that point. Going to Float means (should mean) charging is finished.

> My question..... is there any way a bank could be less than Full, if it's accepting <0.005c in Float voltage. The SG thinks so. I don't.

The purpose of Float is **only** to counter self-discharge in storage, and to carry loads so as to keep the bank from unnecessarily using up limited cycling.

So there is no point to measuring amps acceptance while at Float voltage, charging at Absorb should have already got to endAmps, whatever current happens to be at Float is meaningless wrt measuring SoC.


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## john61ct (Jan 23, 2017)

Sterling Power ProCharge Ultra - BC & PS Modes






http://www.cruisersforum.com/forums...rged-at-float-voltage-215346.html#post2847732


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## Minnewaska (Feb 21, 2010)

john61ct said:


> .....So there is no point to measuring amps acceptance while at Float voltage, charging at Absorb should have already got to endAmps, whatever current happens to be at Float is meaningless wrt measuring SoC.


Gotcha. Absorb is held until 0.005C, so that should mean Full. Nevertheless, it does decline to even less, over time, when in Float voltage

Stating my question differently, is there any condition in which a Bank is not Full, when accepting 0.005C at Absorb voltage? I think not. The SG thinks so.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> Gotcha. Absorb is held until 0.005C, so that should mean Full. Nevertheless, it does decline to even less, over time, when in Float voltage
> 
> Stating my question differently, is there any condition in which a Bank is not Full, when accepting 0.005C at Absorb voltage? I think not. The SG thinks so.


No, in fact different makers spec higher/earlier Full endAmps. Did you get .005C from EPM?

And this is why we're using the SG reset, once you get to Full (at Absorb)


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## Minnewaska (Feb 21, 2010)

john61ct said:


> No, in fact different makers spec higher/earlier Full endAmps. Did you get .005C from EPM?
> 
> And this is why we're using the SG reset, once you get to Full (at Absorb)


Yes, I got the half percent of total bank capacity, to end absorb, from East Penn directly.


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## john61ct (Jan 23, 2017)

Tx. I believe 14.2V is max Absorb, at least from Sonnenschein? 

What is the minimum?


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Tx. I believe 14.2V is max Absorb, at least from Sonnenschein?
> 
> What is the minimum?


That's what it uses, adjusted for temperature. Bulk gets it to that level and Absorb holds it.


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## Minnewaska (Feb 21, 2010)

I didn’t get back to the boat until today. The SG still read 100%, which it should. That was encouraging. We were delayed by some family obligations, so we’re not leaving the slip today. It’s rest day. 

I decided to just shut the charger off, at the remote, and see what happens to the batteries/SmartGauge. According to the battery monitor, we’re drawing anywhere from 1.5 to 8.0 amps, when I glance over. This would be from the fridge compressors cycling on and off. Maybe more for a few seconds, when the bilge pump evacuates air conditioning condensation or the fresh water pump runs.

The battery monitor says we’ve used 13 amps since we arrived and shut off the charger, earlier this afternoon, which gut checks as about right. On a 400 aHr bank, one would expect to have something in the mid 90s SOC, or higher, given the low draw rates. The SG now reads 89% SOC with 12.8v. This test is only several hours old so far. 

One could theorize that the bank has lost a bunch of capacity and that’s to be seen. However, the gel batteries are only one year old and maintained well charged, so I would not logically expect significant reduction yet. 

My theory still has me wondering if sitting at float voltage all week, causes the SG to learn an artificially high voltage rate as full. I’m leaving the charger off all night. We’ll see what it says tomorrow morning, then I’ll recharge and see if the SG follows it back to 100% SOC, which it hasn’t been.

I guess I’m chronicling this for myself, as much as anything.


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## RegisteredUser (Aug 16, 2010)

This sounds...
Overly stressful
Overly techie
Overly never sure
Overly....unecessary


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## john61ct (Jan 23, 2017)

So just ignore it dood.

The case of sitting at a dock on Float is so bog-standard normal for 99.9% of boats, there's no way that alone would cause Gibbo's design to get out of whack.

Sorry not to go searching, but what is the Ah counter? Great you have a point of comparison. . .


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## Minnewaska (Feb 21, 2010)

john61ct said:


> ....Sorry not to go searching, but what is the Ah counter? Great you have a point of comparison. . .


It's the Magnum inverter/charger Advanced Remote, which adds a shunt to the package. This morning, the shunt monitor now says we've used 55 amps and should be at 86%. The SmartGauge says 77%. Battery voltage is 12.65, while only drawing 2 amps. As a capacity rule of thumb, the SG would be nearly correct (12.65=75% for gel), if that voltage was resting, but it's not, suggesting resting voltage and capacity are higher.

For those 55 amps to truly represent a decline of 23% of capacity, the bank's total capacity would have to decline from 400 amps to 239 amps, ignoring pheukert, which at these draw rates would not have accelerated the decline anyway. That would be destroyed and impossible to believe, after one year of use and well charged. I'm not even sure they'd take a charge, if that hurt.

As I've said, my real issue now is whether the SG will recognize the recovery to 100%, when I recharge.


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## Minnewaska (Feb 21, 2010)

For those who find this unnecessary, imagine the comical irony that you took the time to write that. 

Several have been very helpful in this odyssey, for which I’m appreciative. 

The recap allows me to document the analysis for myself. It’s necessary, because I’d like to be sure I’m maximizing capacity on a power hungry boat. The two that I most hope will read it are Balmar and the guy on this forum, who sold it to me. 

I’m very open to have made a mistake, but this $300 gauge is marketed as “screw it on and let it learn for a few cycles”. That’s been far from my experience, other than a few moments of encouragement. 

The current experiment is having manually reset the SG to 100%, after acceptance amps in Absorb voltage dropped below 0.005c and then below 0.0005c in Float voltage. I’ve shut the charger off to record drain over time. Next I’ll recharge to see if the SG re-recognizes 100%. 

No need to follow along, if not interested. I don’t read 75% or more of the threads here. For some posters, who have even claimed to call the USCG about me, that’s 100%. :wink


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## MarkofSeaLife (Nov 7, 2010)

OK, so I only read 75% of your post.

Who are you? 

:laugh


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## Minnewaska (Feb 21, 2010)

Weird twist from folks who don’t want to discuss the subject of the OP, huh. 

Waited for the SG to read 69%, and voltage now reads 12.5v under load. The battery monitor says we’ve used 71 amps and the bank should be at 82%. It took almost 24 hours of normal non-sailing usage (with just two of us aboard) to discharge to this point.

I turned the charger back on in Bulk and it began accepting 80 charging amps, into the batteries. It only took 5 minutes to get to Absorb voltage and switch over. Still accepting 80 amps. The fast Bulk stage suggests to me that it was not down to 69%, as the SG thought. Note: this SG was booted up at the beginning of the season and has made at least a dozen cycles off the dock by now. 

We’ll see what happens when charging flips to float, which I expect to take many hours.


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## eherlihy (Jan 2, 2007)

I just came across this device in another forum; https://www.amazon.com/LPHUS-Blueto...e-Diagnostic/dp/B07LBDZ5SG/ref=cm_wl_huc_item










For ~$31 it is about 1/10th the cost of a Smartgauge and it gives you much more information via BlueTooth.

From what I can read it reports SOC, Real-Time Battery Voltage and graph of BV over time, Real-Time Charging Status... The only drawbacks that I can see are that it reads 0.03V low in several YouTube reviews, and does not understand batteries other than FLA.

Heck, I just ordered one.


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## john61ct (Jan 23, 2017)

eherlihy said:


> I just came across this device in another forum
> &#8230;
> From what I can read it reports SOC


I do not see how it can do that last, just reading voltage,

but it does look interesting and thanks for the link.


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## john61ct (Jan 23, 2017)

Why did you start the recharge at such a shallow DoD?

I thought the current hypothesis we're testing is, the SG is not learning well enough from your usual dockside usage pattern.

Making the goal now to manually control cycling to ensure the next 12-20 cycles go down to 50% or so, for enough deep cycles in a row for learning.

Just for testing the hypothesis, to get the SG tuned in, trying to get meaningful SoC numbers must require some "exercising".

Let the bank carry the loads without charge input until that point, then reconnect manually.

If you just keep doing what you've been doing, likely you'll just get the same results?


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## eherlihy (Jan 2, 2007)

john61ct said:


> eherlihy said:
> 
> 
> > I just came across this device in another forum
> ...


The SmartGauge also reports SOC based on voltage input and some internal black magic.


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## john61ct (Jan 23, 2017)

Van Gogh and my kid's artwork are both paintings, it's those "extra little magic details" that make the results so very different.

If a voltmeter's all you want, can get a collection of dozens for that price, why waste your $30 on all that unit's bells and whistles?


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## Minnewaska (Feb 21, 2010)

John, I've already cycled the batteries down to near 50% more than once this season, which has me at this stage.

I decided I would recharge, when the SG said 70% (although the amp counter said 82% SOC). 24 hours with out recharging is a pretty normal cycle for us, so it's real life.

The verdict........ crap again.

Took the charger somewhere between 2 and 3 hours to get the bank back to accepting <2amp, ie 0.005c and switch to float. What's the SG say? 85%. Same as it was before I manually reset it to 100. It simply thinks Full is 85%.

I recall @Maine Sail talking about incredibly accurate bench testing. I wonder if it's ever really been tested well IRL, plugged into shore power most of the time in Float and cycles that rarely get all the way down to 50%. That's is, until now.


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## eherlihy (Jan 2, 2007)

john61ct said:


> Van Gogh and my kid's artwork are both paintings, it's those "extra little magic details" that make the results so very different.
> 
> If a voltmeter's all you want, can get a collection of dozens for that price, why waste your $30 on all that unit's bells and whistles?


Both the device that I posted about above, and the SmartGauge use voltage as the only inputs to determine State Of Charge. SmartGauge has some special-proprietary-seceret sauce that makes it, and it alone, better?










Minne's and my experience with the SmartGauge show that we are not true connoisseurs of SOC gauges. In my case, I have become skeptical of the device. Several other posters here that have experience with the device seem to be of like mindset.










I will conceed that the SmartGauge has provisions for alternate battery chemistries, but the question raised by Minne in this thread is how accurate the magic inside the SmartGauge is at translating from the voltage input into SOC. After having a SmartGauge on my boat for the past five years I now have my doubts as well. In my experience the SOC seems to drop precipitously from the mid-90s to the mid-70s when I have applied little to no load (keeping my cellphone above 80% charge and powering an LED pilot light for about 2 hours) on my 220AH House bank.

For reference- my SmartGauge was installed with AWG 14 wire, and uses an ATC 3A fuse on each lead to the battery bank's positive lead. There are no shunts or inverters in my electrical system, and my boat spends most of the time in the summer on a mooring.

The BlueTooth device above graphs voltage over time which is something that the SmartGauge does not do. If I am understanding the directions, this doo-hickey also records up to 35 DAYS of information at 10mS intervals AND it makes this information available via BlueTooth, which means that I don't have to stop whatever it is that I am doing at any given time to push a button on the SmartGauge or mess with the probes on any of the several DVMs that I keep aboard.

The ability to graph battery voltage over time at the sampling interval will allow me to analyze; how powering my cellphone and the pilot light are really affecting the battery voltage over time, how running my 12VDC refrigeration impacts my battery bank voltage - that is when I choose to run it, how *exactly* my alternator's output (Leece-Neville 90A) affects my battery, and what happens to my battery when I am at anchor.

Your comment about my "wasting $30 on this unit's bells and whistles" makes me suspicious. What is YOUR connection in Balmar or SmartGauge? My relation to SG is that I am a customer, and I have helped sell a couple of them to my clients. Before I decided to purchase my SmartGauge I spent several hours reading everything at their UK website: SmartGauge Electronics - SmartGauge battery monitor

My experience is this: after I spent/invested/wasted $331 for a SmartGauge in April of 2014, I have never feelt "warm and fuzzy" about the SOC that the SG tells me that I have in my battery bank. I believe that the <$32 spend/investment/waste to record and analyze battery voltage history with this device is worth it to me. YMMV.


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## john61ct (Jan 23, 2017)

Minnewaska said:


> I've already cycled the batteries down to near 50% more than once this season


I believe the SG may need in this case a dozen true deep cycles to complete its learning after your 100% calibration.

Ideally in a row, but at least within a few weeks if interspersed with your usual pattern barely-cycles.

Maybe more, possibly less, varies by all the factors unique to your setup. But "more than once" in a season, or anything like your usual automated patterns, IMO just won't cut it for learning purposes.

Once dialed in, then hopefully no need to worry about it.

Meantime ignore its readings, go off the Ah counter, voltage and your gut, but lower SoC the better each cycle.

48hrs, five days without charging whatever, or if you want put an intentional high load on to speed things up.

This is IRL testing, not of its usual accuracy, but for the purposes of facilitating its **learning** process.


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## john61ct (Jan 23, 2017)

eherlihy said:


> Both the device that I posted about above, and the SmartGauge use voltage as the only inputs to determine State Of Charge. SmartGauge has some special-proprietary-seceret sauce that makes it, and it alone, better?


No Merlin's SG does not just use voltage.

As you say, secret and magic proprietary algorithms involving measuring changing impedance behaviour compared to SoC/voltage changes, comparing against an internal database of known behaviours, takes time to learn, maybe some bayesian neural net / fuzzy logic stuff.

"AC impedance spectrography" is in the ballpark maybe?

Anyway, no not just voltage. Just because we don't know or understand its algorithms, "secret and magic" to me is accurate, does not mean they don't work.

And no not unique, Balmar calls it "Active Impedance Compensation" and in their SG-200 combines that data with old-school Ah counting, but as other quality BMs like Victron, Mastervolt and Xantrex do, not like the $30 varieties (another option unrelated to your voltage logger)

> Your comment about my "wasting $30 on this unit's bells and whistles" makes me suspicious.

That was tongue in cheek, obviously $30 is pocket change. That voltage logging is indeed useful, but has nothing to do with getting an accurate objective SoC reading, more like additional data for using your intuition to do so. Not disparaging that approach either, but also not related to the goals of a proper BM.

Are you sure your SG is actually installed properly? Strictly complying with every detail of the manual's instructions is critical.

I would also parse this carefully https://marinehowto.com/smartgauge-battery-monitoring-unit/


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## eherlihy (Jan 2, 2007)

john61ct said:


> Are you sure your SG is actually installed properly? Strictly complying with every detail of the manual's instructions is critical.
> 
> I would also parse this carefully https://marinehowto.com/smartgauge-battery-monitoring-unit/


I am sure that it is installed, *not* as the SG manual instructs (which is incorrect), but as RC has posted on the Compass Marine website using AWG 14 wire;


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## Minnewaska (Feb 21, 2010)

The SG installation manual is bad. That should have been a sign. I originally attached it to opposite ends of my bank, but not the same ends as the takeoffs for the load. I only did this to reduce connections, but MS later posted they needed to be on the same side. Not that anything changed, when I moved them. 

The SG manual is also written badly. There are some setup instructions, prior to it telling you how to get into the setup menu. It’s illogical.

I’m going to try another experiment. What the heck, I own the ballast now. I’m not too interested in trying to manage a dozen cycles down to 50 SOC. They just don’t time well with my usage and forcing heavy loads to get there quicker is undesirable. I get there in daylight hours, if I have multiple people aboard, we sail all day, with all the nav/comm on and lots of lights, fans, heads flushing, etc. 

When I disconnected the charger this past experiment, the SG dropped from the manual 100% SOC I set (where it was still in Float and accepting between 0.0 and 0.2amps) to 95% almost immediately. Then it dropped to 90% very shortly afterward, while I was only drawing a few amps on a 400 Ahr bank. IOW, as the batteries voltage declined from Float voltage to a stable 12.9v, it decided the SOC declined too. This initial delta between its calculated SOC and the SOC suggested by the amp counter then held fairly constant the rest of the way. I’m going to turn off the charger, wait a half hour for voltage to stabilize, then reset to 100% again. 

None of this is as advertised. On Amazon, I’d give it 1 star, maybe 2, since the voltage meter works, but not the SOC.


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## Don L (Aug 8, 2008)

Well I find it telling when people who have paid to drink the koolaid say they don't like it. Normally people always defend a tech purchase because they "spent money on it".

SG doesn't sound very smart.


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## eherlihy (Jan 2, 2007)

I'm not saying that the SmartGauge is worthless, but I do think it is worth less than the ~$300 that they charge for it. For the past five years it has HELPED me to better maintain my batteries than I could have with the old analog gauge that was included with the boat.

The problem, for me at least, comes down to this; NO ONE *KNOWS *how the SOC calculation in the damn thing works. Therefore, no one *KNOWS *how to use the SOC function.

Stevie Wonder sang; "When you believe in things that you don't understand then you suffer. Superstition ain't the way. No, no, no."

Our friend, Maine Sail, ran multiple bench tests with calibrated multimeters, power supplies, data logging, known loads, etc., for a couple of months and walked away impressed with the results. However, after all his tests he posted that he didn't understand how it worked [in my technical training days we used to call this "F.M."]. I didn't understand the SmartGauge either but I bought it anyway. I placed my faith in RC's testing (and my wallet suffered to the tune of ~$300).

RC states the following on his web page (where he is selling the thing);


> But RC how does it work?"
> 
> You've got me..? *I have no idea how it works*, at least at the programing/algorithm level (proprietary stuff), but it is reportedly designed to track voltage. Many internet posters have assumed, posited and suggested, that it checks internal resistance and pulses across the battery etc.. It may, but I have not seen evidence of this on the power / volt sensing wires, even with an Oscilloscope. If I had a tracking o-scope I may have seen something but I don't.
> 
> ...


Albert Einstein is credited with saying; "If you can't explain it simply, then you don't understand it well enough."

I have now been using a SmartGauge on my boat with a VERY simple electrical system for the past five years. The bottom line is that I don't trust it when it tells me 98% SOC vs 72% SOC. After seeing the SOC, I ALWAYS push the voltage button because I don't understand or trust, and no longer believe the stated SOC.

I can't explain the SOC, but I grok the SmartGauge's voltage reading. Therefore, the $30 bluetooth voltage tracker seems like a better solution for me. I'll have to see how it works on my boat before I reccommend it to anyone.


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## eherlihy (Jan 2, 2007)

Here is a link to one of the initial threads on the SmartGauge: https://www.sailnet.com/forums/electrical-systems/136673-smartguage-review.html


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## john61ct (Jan 23, 2017)

Minnewaska said:


> as the batteries voltage declined from Float voltage to a stable 12.9v, it decided the capacity declined too.


Not a substantive point, I'm sure you know this, just clarifying semantics for others:

SoC is what the SG measures, how "full" the battery is, a fraction expressed as a %.

Capacity is something else, the maximum Ah the bank will hold, the denominator of that fraction.

So drawn down 100Ah out of 400Ah is 75% SoC, the capacity remains at 400Ah.

As the bank ages, to the extent capacity is reduced is its SoH, as a % of what it was at install time.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Not a substantive point, I'm sure you know this, just clarifying semantics for others:
> 
> SoC is what the SG measures, how "full" the battery is, a fraction expressed as a %.
> 
> ...


Good typo catch. I edited capacity to SOC. I guess I was thinking remaining capacity.


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## Don L (Aug 8, 2008)

eherlihy said:


> [in my technical training days we used to call this "F.M."].


sound like amateur hour

the correct term is pfm

But I'm not convinced either apply to a SG as in order to do so the thing has to acturally work.


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## eherlihy (Jan 2, 2007)

eherlihy said:


> Both the device that I posted about above, and the SmartGauge use voltage as the only inputs to determine State Of Charge. SmartGauge has some special-proprietary-seceret sauce that makes it, and it alone, better?
> 
> 
> 
> ...


So it has been a little under a week since I received and installed the above device. So far, I am happy with the purchase. Install on my two 12V battery house bank was simple, and the device was able to span the two batteries in the bank. I like that I can read the voltage of the battery real time when I am ANYWHERE withing bluetooth range - recently I was on my mooring naighbor's boat and was able to look at the voltage and (reported) SOC of my boat. The BlueTooth Battery Monitor seems to report the battery's SOC lower than the SmartGauge. I was pleased after leaving the boat at 93% SOC per the SmartGauge, that even with the BlueTooth voltage monitor broadcasting my Voltage and SOC to everyone in teh marina that my battery's SOC was 92% SOC per the SmartGauge 2 days later.

Frankly I really like having BOTH the SmartGauge and the BlueTooth battery monitor, and have no intention to remove either. But for the money, I believe that the BlueTooth Battery Monitor is a better value.


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## Minnewaska (Feb 21, 2010)

Glad to hear that new device seems to be working. I’d consider it, but we’ll see. Does it have a setting for Gel?

Before leaving the slip yesterday (awesome wind and sailing), I turned off the shore charger and waited several minutes for the battery voltage to decline from float. The SG was reading 85%, when acceptance amps prove it was just Full. I enter the setup menu. Battery type comes up first and is correct. Then comes SOC, which I manually adjust to 98%, then press set. Next are some settings for alarms, which I don’t use and are already indicating Off. 

At this point, I try to Exit the setup menu, but it won’t. I wait for the two minute timeout, but it’s still on the alarm setting. I wait 10 more minutes. IT’S FROZEN! What a total POS. 

The only way to correct was to pull the fuse, which loses all its learning memory, not that any of it was correct anyway. I boot it back up and manually set 95% as the SOC (it defaults to 75% at startup), then go out sailing. 

Naturally, it doesn’t match the amp hr counter this morning, after a night off the dock. Of slight interest is that it still reads about 10 percentage points below the amp hour counter, like it did after its previous couple of months of “learning”. I’ll be curious to see what happens, when I plug it back in later today. Albeit, the same curiosity one would have watching a squirrel trying to cross a busy four lane highway. 

I’ll be out cruising for a few weeks starting next Fri. I’m betting the squirrel doesn’t make it.


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## eherlihy (Jan 2, 2007)

The device is only configured for wet-cell batteries, but I don't place a lot of faith in the claimed SOC. I believe that the SOC as reported by the device is from this table;








However, the ability to see a voltage over time plot is VERY useful to me, and that would work regardless of battery chemistry. I can see how engaging the starter affects the voltage, and what the alternator does for the batteries. I believe that you could come up with a similar table to the one above for your gell cell batteries

Hey, for <$30 it seems like a winner.


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## Minnewaska (Feb 21, 2010)

The problem I find with tracking voltage is that it will differ, based upon the load at the moment. 

When I plugged back in this afternoon, the SG went right back to 85% SOC, even though the charger is now in Float, accepting 0.6amps.


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## john61ct (Jan 23, 2017)

Remember, amps acceptance rate at Absorb V is relevant to establishing 100% Full point not Float.

I think if you aren't able to give it a dozen true deep cycles to learn, in order to determine whether you just have a faulty unit,

you should probably just make do with a $40 coulomb counter.

Or maybe try a Xantrex Link Pro or 712-BMV if you're inclined to throw more money at it.

The SG-200 has a learning curve as well, and maybe too new to know its accuracy for your bank type.


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## Minnewaska (Feb 21, 2010)

Yes, Absorb V was below 0.005c before Float. I find, if that’s not the case, by the time it switches over to Float, then float says it’s accepting higher amps and never catches up. For float to be accepting minuscule amps , Absorb has to have done its job. My experience anyway. 

I leave to go cruising on Fri. That will give it some learning time. I’ll be off the grid for the first ten days. Uncharacteristically, I have two transient slips booked along the way, after that, to meet family. That will get me intermittently back to 100% too. If that doesn’t “teach” it, then it’s junk. By now, I hold no hope, but I’d be happy to report back otherwise.


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## Minnewaska (Feb 21, 2010)

Smartgauge Battery Monitor | Balmar

According to Balmar's website, the SG is "Accurate within 5% after just a Few Cycles". That's not a dozen. Marketing?

Goes on to say "proven in independent testing by Enersys® to be accurate within 3% after 6 months of use". How did time become a factor and not cycles?

And for folks like me  ......... "even the most technically challenged crew member can understand just how much power is left in the battery."

The installation diagram, on this web page, also shows the pick ups for the parallel bank, both on one end of the bank. I have the pos on one end and neg on the other, just like the power pickups.

Truth is, I think I understand this stuff better than the average bear, which wasn't always the case, but I'm no pro.


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## colemj (Jul 10, 2003)

john61ct said:


> I think if you aren't able to give it a dozen true deep cycles to learn


If I had to take my bank through a dozen deep discharges just to get a battery monitor "learned", I'd throw the monitor away. Balmar's information on this does not match your advice. There are many examples on the internet of people having this same issue with their smart gauges, even after many deep cycles. Also examples of it working well - so who knows? I have a friend with two of them. He has identical in all ways split banks that get regularly cycled, and each bank has a smartgauge. One SG works perfectly, while the other gives him all sorts of random information and is never correct.

This is off-topic, but we just installed the new Balmar SG200 on a lithium bank. So far, it is a random number generator, and I have been deep cycling the bank every day for 3 weeks now. Throughout the day, I will see SOH jump to 97% to 25% to 50% - at any time it will be at any random number. Often, it just presents --- instead of a number. The SOC value sometimes reaches 100% right when the batteries reach 100%, but other times reaches 100% hours before the battery, or never reaches 100% at all. Sometimes after reaching 100%, and charging is turned off so that loads draw, it immediately drops to 90% SOC. Perversely, the SOH often jumps up dramatically at the same time. How/when it reaches 100% SOC, and the specific SOH it gives at any time seems to be dependent on how I charge the batteries. The numbers it presents when 150A of mains charging is used are different than the numbers it gives when 20-40A of solar is doing the charging. The voltage seems to be always correct, so at least I have a $250 voltmeter.

To answer the expected questions calling out the installation or operator knowledge, the shunt is the only thing connected to the negative terminal, and it is located 4" from that terminal connected with 4/0 wire. All charging and load sources are connected to a bus bar located 10" from the shunt and connected to it with 4/0 wire. The terminal connections were done professionally with the correct crimper and dies, and I watched them being made (one advantage of living 2 miles from GeniuneDealz). All wires, connectors, bus bars, etc are brand new. I recently did a capacity test on the bank, so know its SOH, and since this is LFP, it is very easy to determine when 100% SOC is reached. Independent voltmeters and current meters were used to make measurements right at the batteries, and they match what is being presented by the SG200 in both charge and discharge modes. Like mentioned, I have the time and ability right now to daily discharge these batteries below 50% SOC and then immediately recharge them to 100% - and they have been cycling like this for 3 weeks.

My initial inclination was to buy the Victron BM, but decided to be a pioneer with the SG200 given the good press about it as well as the promised SOH monitoring. What I really want in a monitor is coulomb counting, which this doesn't do at all. I'm very close to throwing in the towel and buying the Victron. Sometimes the pioneers do get the arrows (and the expensive lessons).

I am working with Balmar, changing some parameters, and hope that this begins to work better. But now I'm left with lingering doubt about the numbers it presents to me, and how accurate they really are or will be. There are no doubts with good coulomb counters, particularly with LFP. I thought SOH would be the killer reason for this over a coulomb counter, but now I know that if in the future it presents me with a worrisome number, I'm going to have to do a capacity test to check against it anyhow. So it isn't very useful for that. SOC is a pretty useless parameter to LFP, because I don't really care what SOC it is in, and would know that anyway with a coulomb counter.

Mark


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## john61ct (Jan 23, 2017)

There may well be circumstances where more learning cycles are needed, others where fewer are enough.

I am not saying 12 is some magic number, just like ensuring each cycle hits both 100% and 50% SoC, may or may not be needed or helpful with a given bank.

Nor do I think that Enersys sentence was meant to imply anything about the required learning period, just saying that they put it through a very long and thorough proving trial.

Finally, I think it's clear that having very high expectations of any BM is a mistake.

Even if another make & model are proven to be "the most accurate" on the market for a wide range of batteries, that is a very low bar to clear.

Just because you decide to spend an extra few hundred, does not guarantee any such device will deliver **you** tremendous utility, end up being greatly valued in **your** use case.

And if not, does not mean others won't find it the best thing since sliced bread, vive la différence, what makes the world go 'round.


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## colemj (Jul 10, 2003)

I don't think you are understanding the problem being presented here. It is not one of "high expectations", nor is it one of "most accurate", nor is it one of relative utility, nor of expense, nor of value.

It is a case of giving random, completely incorrect, totally unusable in any way results.

This is very different from "vive la difference".

If your refrigerator thermostat caused the interior temperatures to range around randomly during operation, and what you set it at in any given time causes it to perform differently than it did the last time you set it there, and it was so untrustworthy that you needed to bring in a second thermostat to monitor and correct the first one, would that just be a case of relative value and vive la difference?

Mark


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## john61ct (Jan 23, 2017)

I was not speaking to any one instance, nor any specific model BM.

And for this case, I did state the unit may be faulty, and hence my suggestion, also several times, to ensure as thorough a test as possible.

A given owner would be advised to make that sort of determination while with their refund period, so if the testing effort is taking "too much" time and effort for their taste they can choose to take another path at just the shipping cost of returning their unit.


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## Don L (Aug 8, 2008)

colemj said:


> If your refrigerator thermostat caused the interior temperatures to range around randomly during operation, and what you set it at in any given time causes it to perform differently than it did the last time you set it there, and it was so untrustworthy that you needed to bring in a second thermostat to monitor and correct the first one, would that just be a case of relative value and vive la difference?
> 
> Mark


If your beer kept randomly changing temperature it would be a more serious problem that expecting this SG thing to work. If you needed a SG to determine if the beer was 34 degrees or only 36 degrees would you really have any use for it?


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## colemj (Jul 10, 2003)

I'm an IPA guy, so anywhere between 45-50F is good.

Mark


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## Don L (Aug 8, 2008)

colemj said:


> I'm an IPA guy, so anywhere between 45-50F is good.
> 
> Mark


Well a smart gage can maybe do that


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## Minnewaska (Feb 21, 2010)

I’ve been off the grid for over a week. The banks would generally run down to what the SG thought was low 60s, but the amp hr counter thought was low 70s. Recharging took various forms, from running the generator to intermittent engine use. Twice I ran the generator until Absorb acceptance amps got as low as 0.5%C. I let the bank rest, for about 30 mins, after the generator was shut down, and manually reset the SG to 95%. Despite this forced learning, it would only read 85% on subsequent charges back to Absorb=0.5%C. It just seems to like that level, as noted above. 

Odd thing happened yesterday. I had to run the engine for 4 hours, underway. I noted that acceptance amps declined to well under the 0.5%C level, more in the range of 0.1%. I do not have a smart alternator, so it essentially maintains a permanent Absorb level charge. The SG, after those 4 hours, now indicated 93%. Still, it was clearly 100%, but I found it interesting that the SG would only recognize charge over 85%, if Absorb went far past where it should.


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## john61ct (Jan 23, 2017)

I reckon three possibilities, in order of likelihood

a bad unit
incompatibility with the bank type
something wrong with the bank or the install

Since you already apparently have a coulomb counter BM you trust more,

I'd probably put the SG up on eBay as "parts only".


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## eherlihy (Jan 2, 2007)

Minnewaska said:


> I've been off the grid for over a week. The banks would generally run down to what the SG thought was low 60s, but the amp hr counter thought was low 70s. Recharging took various forms, from running the generator to intermittent engine use. Twice I ran the generator until Absorb acceptance amps got as low as 0.5%C. I let the bank rest, for about 30 mins, after the generator was shut down, and manually reset the SG to 95%. Despite this forced learning, it would only read 85% on subsequent charges back to Absorb=0.5%C. It just seems to like that level, as noted above.
> 
> Odd thing happened yesterday. I had to run the engine for 4 hours, underway. I noted that acceptance amps declined to well under the 0.5%C level, more in the range of 0.1%. I do not have a smart alternator, so it essentially maintains a permanent Absorb level charge. The SG, after those 4 hours, now indicated 93%. Still, it was clearly 100%, but I found it interesting that the SG would only recognize charge over 85%, if Absorb went far past where it should.


Like you, I do not have a "smart" regulator on my alternator (Leece-Neville 8MR series). I have 2 x 110 AH FLA wet cells connected in parralel as my house bank. I have been playing with a 60 Watt solar panel (actually 4 x 15 Watt panels), and the MPPT controler that was included with the panel to "charge" my house bank. My observation is that the solar panel does not bring the house bank voltage up to 14.x VDC when I connect it. Instead, the voltage starts at 12.xVDC, and as the battery slowly charges from the solar panels, the voltage displayed on the SG slowly raises. As a result the SG does not seem to recognize this as charging the battery at all! The SOC stays right where it was when I connected the solar panel to the batteries. However, if I start my motor, the 90A alternator quickly jumps the voltage over 14 VDC, and the SG SOC starts to rise.

Interestingly, the SOC reported by the $30 BlueTooth battery monitor (BTBM) _does_ recognize the increase in SOC when the solar panel is charging the batteries. Frequently the SG will report 78% SOC and the BTBM will report 80%. While they don't always match the reported SOC, they never seem to be off (in my limited experience) by more than 10%, and are usually within 5%.

Another observation is that the BTBM seems to recognize anything above 13.2-ish (I am not really sure of this number) VDC as charging. Therefore if my batteries are fully charged, such as when I first shut my engine off, this el-cheapo battery monitor will identify the surface charge as charging until the surface charge drops. The BTBM does NOT report SOC while the batteries are charging - this is something that the SG does.

My working hypothesis is that the SG looks at the battery bank voltage only. If the battery bank voltage is over some seceret threshold the SG believes that the battery bank is being charged. The SG then quantifies the TIME above that threshold, and begins to increase the reported SOC as time elapses. If the voltage falls below another threshold then the SG starts to decrease the reported SOC. The further below that threshold the faster the SOC decreases.

Unlike you I am not trying to figure exactly how the SG will report with some exoctic battery chemistry. My goal is simply to keep my house bank viable for as long as possible. For $30 the BlueTooth device seems to meet that need.


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## Minnewaska (Feb 21, 2010)

Another week of cruising. This past week was on an off the dock, as we took some transient slips. 

With the curse of little to no wind, we did quite a bit of motoring, often 4-6 hours at a time. As mentioned above, this motoring would hold Absorb voltage indefinitely, so acceptance amps would decline to a very, very low point. Well lower than the typical switch point to Float voltage. This, however, would cause the SG to read up into the 90s. 

I then spent a couple of days off the grid, with SG reading as low as 60, although, the amp counter would imply something in the range of 70 was more accurate. I then had a 30 minute motor to the slip, so the engine did very little to recover charge. I plugged her in and the charger started in Bulk, then switch to Absorb and then to Float, when 0.5%c was reached. The SG, when in Float was reading 76%.

I give up.

I think John is right. It's either a bad unit, or it just can't learn the Gel chemistry correctly or isn't suited to being on and off the dock. 

I'm clearly open to an install error, but don't see what that could be either.


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## SanderO (Jul 12, 2007)

What you can do is actually get the batts completely topped up. Re set the monitor and then keep an accurate log of amps in and amps out. The log should tell you what the SOC is or how many amps you have used... assuming all used amps have not been replaced by charging sources.

This may reveal the accuracy of the monitor... and the SOC you are after.... and perhaps a error correction value????


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## Minnewaska (Feb 21, 2010)

Good thought, SO. I did exactly that with resetting the monitor to Full. Several times. I thought it was 10-15 points off, but this last effort is showing 25 now. It's actually gotten worse.


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## RegisteredUser (Aug 16, 2010)

Probably proven to be not worthy of such a high level of consternation.
And prob ...not needed.


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## SanderO (Jul 12, 2007)

I f your calculations are complete and accurate... and the meter is not showing this.... it seems that there is a problem in its software.


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## Minnewaska (Feb 21, 2010)

RegisteredUser said:


> Probably proven to be not worthy of such a high level of consternation.
> And prob ...not needed.


Proven not to be worth $300 anyway.

With only 200 ahrs of usable capacity (400 total) on a power hungry boat, I was hoping for a more accurate way to monitor SOC, to get the most out of the top 50%. Amp hour counting ignores what degradation occurs in the batteries over time, unless you guess or factor in an inefficient safety margin. Voltage, under load, might be a conservative measure, if one uses resting voltage estimates. However, still inaccurate and I'm looking for accurate over conservative.


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## john61ct (Jan 23, 2017)

This thread is **not** about Balmar's new SG200, but the old-school original SmartGauge by Gibbo / Merlin, 

for which Balmar is licensed torelabel sell and support in the Americas.

Maybe OP / mods could rewrite the title? or such confusion will continue


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## Sefuller (Jan 7, 2018)

john61ct said:


> This thread is **not** about Balmar's new SG200, but the old-school original SmartGauge by Gibbo / Merlin,
> 
> for which Balmar is licensed torelabel sell and support in the Americas.
> 
> Maybe OP / mods could rewrite the title? or such confusion will continue


Thanks for the heads up - deleted my comments.


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## Minnewaska (Feb 21, 2010)

It was relatively new back when the thread was started in ‘16. 

I wouldn’t change the thread title after the fact, although, I never saw the deleted comments that provoked the suggestion.

The “original new” SmartGuage is still a total POS. Useless. It reads 87 SOG right now, after being plugged in all week and accepting virtually zero amps.


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## eherlihy (Jan 2, 2007)

The Bluetooth Battery Monitor's URL was _swapped_ for some other device at Amazon. The new URL is; https://www.amazon.com/BUNKER-INDUST-Bluetooth-Wireless-Automotive/dp/B07GP1RXYZ/


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## john61ct (Jan 23, 2017)

Most other owners have a very different experience.

https://marinehowto.com/smartgauge-battery-monitoring-unit/



Minnewaska said:


> It was relatively new back when the thread was started in '16.


Lots of forum discussions go back to 2010, around when Gibbo sold it to Merlin. Balmar started selling it within a couple years.

http://www.cruisersforum.com/forums/f14/balmar-smartguage-116995.html

Another more recent thread, also inaccurately titled, afaik Balmar continues to sell and support SG - for very good reasons

http://www.cruisersforum.com/forums/f14/old-merlin-smartgauge-that-balmar-used-to-sell-221286.html


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## john61ct (Jan 23, 2017)

eherlihy said:


> The Bluetooth Battery Monitor's URL was _swapped_ for some other device at Amazon. The new URL is; https://www.amazon.com/BUNKER-INDUST-Bluetooth-Wireless-Automotive/dp/B07GP1RXYZ/


Completely off-topic as well, nothing to do with any "Battery Monitor" functionality as used here, and certainly irrelevant to the Merlin SmartGauge.


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## eherlihy (Jan 2, 2007)

john61ct said:


> Completely off-topic as well, nothing to do with any "Battery Monitor" functionality as used here, and certainly irrelevant to the Merlin SmartGauge.


No, this is related to Minnie's and my experience with the Balmar SG. I have both the $300+ Balmar SG, and this $30 deviice properly installed and working on my vessel. My post that you have quoted above is a follow up to correct the URL for the alternative battery monitor to the one that you seem intent on hawking here. For some reason, if you follow the Amazon link that I initially posted it brings you to a different product. If you have a problem with my post, flag it for an admin to police.

Again, I don't know what your connection to the Balmar SG is, but whatever it is, it should be disclosed. I have little patience with people who are shilling a product.


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## Minnewaska (Feb 21, 2010)

Perhaps it’s the Gel battery chemistry that the SG doesn’t know well, but it’s a POS for me.


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## Minnewaska (Feb 21, 2010)

john61ct said:


> Most other owners have a very different experience.
> 
> https://marinehowto.com/smartgauge-battery-monitoring-unit/
> 
> .....


I'm not seeing how the link to MaineSail's website (a moderator here now) supports the fact that most other owners have a very different experience. That is indeed where I bought mine. If anything, he makes it pretty clear that the installation instructions are wrong. I don't think it's the only thing that's wrong.


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## RegisteredUser (Aug 16, 2010)

Would it be more helpful if they displayed emojis rather than numerals....


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## Minnewaska (Feb 21, 2010)

The promised value of this gauge was to have a better sense of intermediate charging levels. Full and near 50 SOC are not all that tough to know otherwise. Although 50 SOC, based solely on voltage, can be conservative, if one is measuring it under load. 

When away from shore power for any length of time, especially without any passive charging capability, one never sees 100 SOC. The query is whether the generator needs to be run. A standard regimen of every morning and every evening is relatively foolproof. If one is active ashore, that regimen can be difficult to maintain. 

For example, we often spend the entire afternoon and evening, playing ashore or on another’s boat. When we get back late, I’d like to know there are sufficient amps to expect the bank to make it through the night, remaining comfortably above 50 SOC. I have a general sense of my amp draw overnight. Just voltage doesn’t tell me that. Voltage may tell me if I was right or wrong in the morning. 

Old amp hour counters are so-so. Their weakness is not really knowing what Full amp capacity is on a less than new bank and the Peukert ratio. 

The SG promised to deal with this, but it’s witchcraft. Worthless, mythical, witchcraft. At least on my gel bank.


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## Don L (Aug 8, 2008)

Minnewaska said:


> The SG promised to deal with this, but it's witchcraft. Worthless, mythical, witchcraft. At least on my gel bank.


near as I can tell you are under its' spell


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## colemj (Jul 10, 2003)

RegisteredUser said:


> Would it be more helpful if they displayed emojis rather than numerals....


HeHe - that's funny! It would have to display random emojis, though...

Good thing they invented 💩

Mark


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## Bleemus (Oct 13, 2015)

Going on our first year of using Smart Gauge. Works flawlessly on our bank of FLAs.


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## colemj (Jul 10, 2003)

Bleemus said:


> Going on our first year of using Smart Gauge. Works flawlessly on our bank of FLAs.


Just so nobody gets their panties in a bind, are you talking about the original Smart Gauge, or the newer SG200 gauge?

Mark


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## Bleemus (Oct 13, 2015)

colemj said:


> Just so nobody gets their panties in a bind, are you talking about the original Smart Gauge, or the newer SG200 gauge?
> 
> Mark


The original.

I ordered a SG200 from Mainesail but a porch pirate stole it.

Sent from my moto x4 using Tapatalk


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