# Hello Pearson P 30 with Electric Yacht motor checking in



## escape plan (Dec 7, 2015)

Hello,

The P 30 is my second sail boat. 
It is in fairly good shape needing only minor work and a bottom job 
The power plant is a freshly installed 48 volt system from Electric Yacht. 
The delivery trip was only 18 miles. This was done at night because of tide restrictions, leaving the canal where she was docked. Under a full moon the water was extremely calm and a following wind of 5 kts. 
We ran the motor the entire way at about 800 rpms. With the roller furling up, she maintained a average speed of a 2.75 mph.
The P consumed approximately 30 % of the reserved power.
Plans
Solar panels
Wind generator
Coastal cruising while motor sailing as green as possible.

The best part is my relationship with one of the father's of solar powered boats.
Doug Cobb is the owner of a electric powered boat called SeaLectric 2. It was built 20 years ago. Along with Doug's dream of green powered boats in masses on inland water ways.
SeaLectric is over 20 years old now and cruising the Swanee River
on a regular basis. She was just upgraded to lithium batteries and new solar panels.
Doug is very excited to get his hands on the P.
As I am fairly new to sailing, I will be asking lots of questions.
Tim:svoilier:


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## eherlihy (Jan 2, 2007)

Welcome to Sailnet!

I am familiar with the Pearson 30 (a great boat), and look forward to learning more about your electric install.


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## PaThomas123 (Mar 29, 2011)

Welcome I have always been interested in electric propulsion without trying to be rude what was the cost of the repower?


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## eherlihy (Jan 2, 2007)

If I am reading your post correctly; you traveled 18 miles, with running lights, at 2.5kts and used 30% of your range? I don't understand your comment about having "the roller furling up." Do you mean that you sailed only under the jib or genoa (ie. no main)?


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## Ajax_MD (Nov 24, 2009)

The OP either has four 12v batteries, eight 6v batteries or six 8v batteries.
In any case, that is a pretty small bank, IMO. The higher the voltage, the smaller his capacity. The 6v batteries would offer the most capacity.

The canal may indicate that some current was in play, even if the water was calm, so I'm not sure if he had a foul or fair current, which would affect how much of his reserve he used.


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## escape plan (Dec 7, 2015)

eherlihy said:


> If I am reading your post correctly; you traveled 18 miles, with running lights, at 2.5kts and used 30% of your range? I don't understand your comment about having "the roller furling up." Do you mean that you sailed only under the jib or genoa (ie. no main)?


Sorry for the confusion. 
We only had the jib up while also running the motor at 800 rpm to achieve the 2.75 mph. No main sail
The wind was a very light following breeze at 5 kts.
The lights and navigation system use a different power source.

The P came with the Electric Yachts system already installed, I do have all the receipts.

The parts cost
Brush less 10 kw motor and drive system $4500
Controller $350
8 each 6 volt 220 ah batteries $1800 dollars
Battery charger $350 dollars.
(those numbers are rounded up)

We did run higher rpm/voltage during egress from the canal. Approximately 30 minutes.
And that's not the first time I have been accused of having something small lol


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## krisscross (Feb 22, 2013)

Sounds interesting. Welcome to Sailnet.
One thing that appeals to me in electric propulsion is eliminating the through hulls for water intake, discharge, and exhaust. That, and minimal noise.


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## Ajax_MD (Nov 24, 2009)

Let's see...when I had my electric VW Beetle, a 6v battery typically weighed 64lbs. At eight batteries, that's 512 pounds.
The motor, controller and charger won't weigh very much. The motor would be the heaviest...probably not even 100lbs.

The Atomic-4 that was replaced, weighed 310lbs dry, a 22 gallon tank probably weighed oh...40lbs, empty? Gasoline weighs 6.3 lbs. per gallon, so 139 lbs.
So I figure a "wet" engine plus support systems weighs about 500lbs. fully fueled.

The current electric system is a nearly equal swap that didn't upset the trim of the boat if they were carefully placed. I think I'd like more capacity. I wonder if you could safely squeeze 2 more batteries in there...

50% DoD (depth of discharge) is the max that lead acid batteries will tolerate before shortening their total lifespan. You're saying that you discharged 30% at 2.5 knots with a following breeze and it only took you 18 miles? Somehow I expected better performance than that.

An electric motor has a completely different torque curve than an internal combustion engine. I wonder if a different prop is in order, that might be more efficient?
Also, in order to maximize your range and performance, the hull and running gear should be kept perfectly clean to minimize unwanted drag. How clean was the hull for this trip?

Please don't take my comments as criticism. I actually support the concept of electric auxiliaries. I'm just trying to understand your system and what's going on.


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## mbianka (Sep 19, 2014)

Welcome Tim:

Always glad to see another boat in the electric fleet. Converted my 1986 Nonsuch 30 back in 2008. Also have solar and wind for charging and a Honda 2000 for hybrid extended cruises when the wind fails. Never once wished I had the old diesel still on board. Especially don't miss the maintenance.  Batteries (AGM) still holding up well after eight years too. Enjoy the quiet and clean.


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## escape plan (Dec 7, 2015)

Doug and I are creating a log book for the P. 
Each trip will be data logged for future reference.
I did do a short trip today. At 69.8 amps straight in to a 7 mph wind turning 1580 rpm she did 3.8 mph for about 1 hour. 
I also did a very short burst of WOT top speed motor only is 5.3 mph
We consumed 17 % of reserves.
Then sailed and motor sailed back, and motored to the dock.
Total consumption 19%
These readings are based on the Electric Yachts controller.
Doug will be installing 2 new meters that will track precisely how many amps go out and how many go in.
He thinks the display may be giving false readings.
Stay tuned.
ps
The hull is not perfectly clean. Condition of prop unknown.


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## escape plan (Dec 7, 2015)

mbianka said:


> Welcome Tim:
> 
> Always glad to see another boat in the electric fleet. Converted my 1986 Nonsuch 30 back in 2008. Also have solar and wind for charging and a Honda 2000 for hybrid extended cruises when the wind fails. Never once wished I had the old diesel still on board. Especially don't miss the maintenance.  Batteries (AGM) still holding up well after eight years too. Enjoy the quiet and clean.


You have the setup I want wind/solar and Honda.
I am thinking about flexible panels on all parts of the hull that does not normally get walked on.
Lucky for me I have one of the best, solar boat consultants, in the family.
Please share more details about your wind and solar setup.
Also does your electric propulsion motor have the ability to do regenerating while you sail?
Thanks for the welcome.


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## Ajax_MD (Nov 24, 2009)

Hull speed for the Pearson 30 is 7.1 knots. I think your motor is a bit undersized.
I realize that pushing to hull speed would deplete the batteries rapidly, I would at least want the capability to do it for short periods, if necessary.


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## Maine Sail (Jan 6, 2003)

escape plan said:


> I did do a short trip today. At *69.8 amps* straight in to a 7 mph wind turning 1580 rpm she did 3.8 mph *for about 1 hour*.
> I also did a very short burst of WOT top speed motor only is 5.3 mph
> *We consumed 17 % of reserves.*
> Then sailed and motor sailed back, and motored to the dock.
> ...


You state you have a bank of eight 6V batteries for a 48V 220Ah bank..

You applied a load of 69.8A for 1 hour or 69.8Ah's consummed (not accounting for or correcting for Peukert)

This is 32% of the total "as new" 220Ah capacity (your capacity is not likely to still be 220Ah) and you only want to discharge to 50% SOC.

Your total consumption from just that 1 hour run would be 63.5% of your _total usable capacity_ (not accounting for Peukert)

Now if we take a 220Ah bank and apply a Peukert of 1.25 we now have a total usable capacity, when loaded at 69.8A, of 139Ah's. In just one hour at 69.8A you were already beyond 50% DOD.



escape plan said:


> *He thinks the display may be giving false readings.*


Yes your method of determining capacity is definitely based on false readings. First your total usable capacity is only 50% of the banks actual physical capacity. Second the rate at which you discharge the bank changes how much capacity you can pull from it.

You simply can NOT forget about Peukert when dealing with _high rate discharge_ use.

You bank is only 220Ah when discharged at 11A, at 77-80F, which is the 20 hour _discharge rate_.

At discharge rates above the 20 hour rate (11A) your bank gets CONSIDERABLY SMALLER..... You will need to know the Peukerts constant for your batteries in order to determine how much capacity you have at varying rates of discharge.

Here is an example of a 6V 375Ah battery at varying discharge rates:


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## miatapaul (Dec 15, 2006)

escape plan said:


> Doug and I are creating a log book for the P.
> Each trip will be data logged for future reference.
> I did do a short trip today. At 69.8 amps straight in to a 7 mph wind turning 1580 rpm she did 3.8 mph for about 1 hour.
> I also did a very short burst of WOT top speed motor only is 5.3 mph
> ...


Do yourself a favor, as most things you read is going to be in knots, and nautical miles such as charts and what not, just start thinking in Knots not MPH. It is a small thing, but makes comparisons easier.

Also listen to Maine Sail, he may not tell you what you want to hear, but will tell you what you need to hear. Don't go past 50% of your batteries capacity except in an emergency. Electric propulsion is really hard to get real figures on. Most manufacturers will use 70-80% of battery capacity in there ads as it makes them sound better, but your batteries will not last long doing that. Do you have flooded, Gel, AGM or Lithium Ion batteries? Do you know how old the batteries are?

Good luck with the boat, it is a great sailing boat, I might have bought one if I had found the right one.



Maine Sail said:


> You state you have a bank of eight 6V batteries for a 48V 220Ah bank..
> 
> You applied a load of 69.8A for 1 hour or 69.8Ah's consummed (not accounting for or correcting for Peukert)
> 
> ...


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## misfits (Dec 9, 2011)

escape plan said:


> The hull is not perfectly clean. Condition of prop unknown.


Congratulations, on the new boat. 
You should check with electric yachts & see what size wheel/prop they recommend. 
This way when you pull the boat you'll be able to see what's actually on her. 
You'll want a three bladed wheel. With EP the bigger the prop means more bite & you'll use less energy.


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## escape plan (Dec 7, 2015)

Thanks for all the input.
All suggestions are noted and appreciated.
The beautiful thing about a sail boat is sailing.
Something I am still learning the finer points of.
With the motor that came on the boat while sailing I can regenerate power to the battery bank.
There is also the ability to change pullies to increase speed.
Motoring speed is not something that I worry about much.
To be quite honest the destination is arrived at when I step on board.
Thanks for the warm welcome.

Ps
AGM mat batteries


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## Ajax_MD (Nov 24, 2009)

I agree that aux. propulsion is of secondary concern but when you need it, you *need* it. 
Misfits had a great point about checking with the system vendor for the correct prop. It could make a huge difference in speed and power consumption *and* power regeneration when you're sailing!

It sounds like a cool system. I'd love some photos of how it all fits in the old engine bay.


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## Maine Sail (Jan 6, 2003)

escape plan said:


> Ps
> *AGM mat batteries*


You mentioned 220Ah and the Lifeline 4CT is 220Ah. It has a fairly low Peukert but is still affected by high rate discharge.

When Lifeline batteries are new this is what the discharge curve should look like. This means that at approximately a 3 hour discharge rate (in between the 2 hour and 4 hour discharge curves) 220/3=73.3A (but you are actually closer to a 3.15hour rate at 70A) you need to stop discharging, when under load at approx 11.85V (chart) or 47.4V. Drawing the batteries any lower than 5.925V (at 6V) 11.85V (per chart) or 47.4V per your pack at 70A, is taking you below 50% SOC....










So charge your batteries to 100% SOC then go run the boat at 70A, with a known accurate digital voltmeter connected directly to the battery terminals, and when the voltage gets to the equivalent of 11.85V, which will be 47.4V, that is how long you can run before hitting 50% SOC.

In other words at 70A DO NOT let the batteries go below 47.4V! Course this all changes with the discharge rate so use the chart if you have Lifelines........


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## escape plan (Dec 7, 2015)

Thank you that is awesome info.
I motored out this morning to do so testing.

The following readings are from the controller provided with the Electric Yacht motor.
The speed readings come from GPS

173 apps at 5 knt

2 amps at 1 knt*

6 amps at 1.7 knts*

16 amps at 2.2 knts

32 amps at 2.9 knts

80 amps at 4 knts

122 amps at 4.6 knts

161 amps at 5 knts

169 amps at 5 knts


Yes all readings are in Knots as provided by GPS

So top speed is currently 5.5739 mph. Give or take a little lol

Thought you all might enjoy some data


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## misfits (Dec 9, 2011)

escape plan said:


> Thank you that is awesome info.
> I motored out this morning to do so testing.
> 
> The following readings are from the controller provided with the Electric Yacht motor.
> The speed readings come from GPS


Below is the projection for my 28 & granted projections are like EPA estimates for fuel economy but at 4.2 knots your amp draw is 2X's what's been projected for my boat. EY has over 300 installs out there so I have to assume their projections aren't based upon junk science. You know what they say about assumptions..... My boat is 28' & displaces 7900 lbs, the projection was based upon a 10 KW drive. It would be interesting to see if the PO still has the projection for your boat & if not I'll bet EY does. At least you'd have a baseline to work from, FWIW.

Speed & Power 
Kts Amps Watts 
2.6 10 480 
3.3 20 960 
4.2 40 1920 
5.3 80 3840 
6.0 120 5760 
6.7 160 7680 
7.2 190 9120


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## finnarne (Aug 26, 2014)

The data from misfits is the twice of what I've calculated for my boat. And I think what I've calculated is closer to what I've read that mBianka has experienced with his setup. 
I myself still have some work to do on the boat before I can properly test my setup. 
For now I'm focusing on fixing leaks that causes my boat to be a bit to damp for my likings, and a bit to damp to do the necessary reinforcements to the engine mounts.


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## misfits (Dec 9, 2011)

finnarne said:


> The data from misfits is the twice of what I've calculated for my boat. And I think what I've calculated is closer to what I've read that mBianka has experienced with his setup.


The data came from the EY vendor, maybe it's not realistic. 
I seem to remember a very knowledgeable & respected forum member mentioning that in a previous EP thread.


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## Maine Sail (Jan 6, 2003)

misfits said:


> Below is the projection for my 28 & granted projections are like EPA estimates for fuel economy but at 4.2 knots your amp draw is 2X's what's been projected for my boat. EY has over 300 installs out there so I have to assume their projections aren't based upon junk science. You know what they say about assumptions..... My boat is 28' & displaces 7900 lbs, the projection was based upon a 10 KW drive. It would be interesting to see if the PO still has the projection for your boat & if not I'll bet EY does. At least you'd have a baseline to work from, FWIW.
> 
> Speed & Power
> Kts Amps Watts
> ...


I will be curious to see where you land on this. In my experience the estimates from EB conversion companies are rather often overly optimistic and very often use "fuzzy math" or incomplete math..

I think they are starting to get better, I know some of us in the industry have been holding their feet to the fire on this, but I shared a booth with one of them at a boat show that did not even fully understand Peukert.

I think what is interesting is a P-30 with 10kW plant and _actual amperage data_ right above yours and the two are broadly different. He is double your projections at 4 knots and I can't imagine that other 40A is all current or wind. It brings up the point that prop selection, proper sizing and an accurate meter all matter. I think the P-30 numbers are higher than they should be but do build in some fudge factors. I was out on a 48V 10kW boat two years ago (27 footer) and IIRC he was about 55A at about 4 knots. I think 40A would be on the low side of the range but still in the potential range.

One thing I see very often is numbers based on _ideal conditions_. Usually no current, no wind and ideal prop. At your desired SOG changes in these can all conspire to make a 4 knot 40A assumption vastly different under differing conditions. Helm mounted current and pack voltage meters (that are accurate) can't be discounted. I believe MBianka has done this and it is a very good idea. It is also a good idea to get a discharge graph vs. voltage vs. SOC like the Lifeline chart I posted above. Create a cheat sheet and when you hit XX.XX volts at XX current then it is time to charge...


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## mbianka (Sep 19, 2014)

escape plan said:


> You have the setup I want wind/solar and Honda.
> I am thinking about flexible panels on all parts of the hull that does not normally get walked on.
> Lucky for me I have one of the best, solar boat consultants, in the family.
> Please share more details about your wind and solar setup.
> ...


Having solar, wind and Honda battery charging abilities covers all charging bases for me. Only time I need to go to a dock is for water these days. I'm using a 48 volt Marine Air X wind turbine for charging. I have two separate solar panel systems on board. They help charge the original 12 volt house bank and 48 volt Kanaka panels are used for charging the EP bank. I've incorporated the panels to make a solar dodger and bimini. Works very well and keeps the cockpit/helm area much dryer in nasty weather. It's a win win situation. 
The solar panels are hard ones. 
Though if I were building it today I might go with all flexible panels as they are lighter and can be moved/removed when needed much easier. I am planning on buying some flexible panels for my plans to be used elsewhere on the boat. I had one that got blown off last season because I got lazy on securing it.  I should be able to use them to power along at around 2.3 knots quite easily under solar alone. Nice thing about EP is you don't have to do everything at once or can modify things. I started out with the Honda and added the wind generator followed by the solar bimini. Now several years later I'm planning on adding some additional solar. Just love the flexibility of being able to improve things.
My system does regen once I start hitting around 6 knots under sail. I love to watch the amp meter and see smooth energy transfer from battery to the sails as the wind picks up. Harvesting energy from the wind is a great thing.


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## mbianka (Sep 19, 2014)

misfits said:


> The data came from the EY vendor, maybe it's not realistic.
> I seem to remember a very knowledgeable & respected forum member mentioning that in a previous EP thread.


I've posted some data for my boat taken a few years ago during one of my annual harbor tests. 
THE BIANKA LOG BLOG: HARBOR TEST 2013 Part Two: Watts Up With The Data!
It shows the raw data and the average results to compensate for the harbor currents during the test. 
Here are the results from my latest test which used the same methodology:
THE BIANKA LOG BLOG: HARBOR TEST 2015

As Maine Sail said there are variables on each boat including prop which do affect the results. I'm using the same three bladed prop that I used with my Westerbeke Diesel. My boat is 16,000 pounds and has an 11 foot beam.


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## ebourg (Dec 3, 2015)

Is there anyone looking into alternative battery technology with regard to this application? Specifically I'm thinking of something like the 600V units used in the Prius cars? A higher voltage battery/motor combination would reduce the needed current (and corresponding heat losses). There also much better energy densities available than you can get from a lead/acid battery. I realize that there may be issues with higher voltage in a salt water environment , it would be counter productive to burn down the boat in the interests of efficiency!


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## Ajax_MD (Nov 24, 2009)

There are several unknown variables here. We don't even know the condition of the OP's hull and prop. Simple fouling with a hull beard and prop barnacles would skew the data quite a bit, to say nothing of having a sub-optimal prop for this application.

The Pearson 30 usually came with an Atomic-4 with no reduction gear, spinning a teeny, 2-blade prop at high speeds to achieve 6.8 knots with a clean hull at around 2100 RPM's.
A diesel has more torque and would use a different prop.
An electric motor has all torque at zero RPM's and would use a different prop.

We don't have enough data here.


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## misfits (Dec 9, 2011)

mbianka said:


> I've posted some data for my boat taken a few years ago during one of my annual harbor tests.


Mike, I remember seeing this when you posted it over at E.S. Quickly comparing your "Harbor" data with the projection given to me, I'm good with it.

Hopefully Escape Plan can figure out why his amperage draw is twice that.


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## RobGallagher (Aug 22, 2001)

ebourg said:


> Is there anyone looking into alternative battery technology with regard to this application? Specifically I'm thinking of something like the 600V units used in the Prius cars? A higher voltage battery/motor combination would reduce the needed current (and corresponding heat losses). There also much better energy densities available than you can get from a lead/acid battery. I realize that there may be issues with higher voltage in a salt water environment , it would be counter productive to burn down the boat in the interests of efficiency!


Size and shape will be an issue. If I had the room and the resources for an experiment, I'd be looking at a Nissan Leaf battery...but then again, I'm afraid of working on things that might electrocute me. 






This guy purchases salvaged batteries from EVs and reuses them.

A salvage Leaf with useable motor, batteries, charger and controller would probably make for an interesting and affordable project. But again, I'm just guessing. I just happen to drive a Leaf and love it.


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## mbianka (Sep 19, 2014)

RobGallagher said:


> Size and shape will be an issue. If I had the room and the resources for an experiment, I'd be looking at a Nissan Leaf battery...but then again, I'm afraid of working on things that might electrocute me.
> 
> 
> 
> ...


IMO the LEAF battery looks to big and heavy for on board use on most boats. I'm still very happy with my AGM 8A4D bank. I'm still not convinced I should convert to Lithium Ion with it's complexity in charging and $$$. The older I get the less sense it makes to switch.  Especially if the AGM's keep holding up the way they are. Think I still have a few years before I will need to reconsider replacing them.


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## misfits (Dec 9, 2011)

mbianka said:


> I'm still very happy with my AGM 8A4D bank. I'm still not convinced I should convert to Lithium Ion with it's complexity in charging and $$$. The older I get the less sense it makes to switch.


You've got my vote on that. I just can't wrap my head around why anyone would spend that much $$ for batteries. I understand the "benefits" but I'm not drinking the cool aid.

The other thing using AGM's or flooded, weight wise it helps to keep the boat in "trim" when compared to the weight of a ICM & a tank full of fuel.


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## ebourg (Dec 3, 2015)

Watching the recent news with the "hover boards" bursting into flames kind of makes one wonder about installing a bank of these batteries in the boat that might be the only thing standing between me and a whole lot of water. I'm sure they could be made safe and reliable but it's not something to be taken lightly, IMHO.


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## miatapaul (Dec 15, 2006)

ebourg said:


> Watching the recent news with the "hover boards" bursting into flames kind of makes one wonder about installing a bank of these batteries in the boat that might be the only thing standing between me and a whole lot of water. I'm sure they could be made safe and reliable but it's not something to be taken lightly, IMHO.


This is something I have brought up in the past, but people seem to think somehow Lithium Ion can be made safe. I am sure the better batteries are safer than the cheap Chinese batteries that have been catching on fire. But it has happened to Dell and other computer makers as well. Issue is that once it starts to burn it is very hard to put out. They need very careful management including temperature sensors and sophisticated electronics. Not very DIY friendly.


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## mbianka (Sep 19, 2014)

misfits said:


> You've got my vote on that. I just can't wrap my head around why anyone would spend that much $$ for batteries. I understand the "benefits" but I'm not drinking the cool aid.
> 
> The other thing using AGM's or flooded, weight wise it helps to keep the boat in "trim" when compared to the weight of a ICM & a tank full of fuel.


Indeed when I installed my EP system the total weight of it including the AGM batteries was about 100 pounds lighter than having the Westerbeke diesel. That's not including all the diesel fuel I removed. Since I built my battery platform over the engine stringers the boat was still trimmed nicely. I also was able to remove a whole bunch of hoses, wiring, hydro hush muffler and engine control cables. Also spare quarts of oil and antifreeze, associated containers, engine and parts manuals. Which lightened it even more.


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## escape plan (Dec 7, 2015)

Finally an update on the P.
Currently the mast is off the boat as I repair the compression post.

The prop is 3 blades and covered with growth.
It will be cleaned this week and new profomance data compiled.

Will update again soon


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## RobGallagher (Aug 22, 2001)

miatapaul said:


> This is something I have brought up in the past, but people seem to think somehow Lithium Ion can be made safe. I am sure the better batteries are safer than the cheap Chinese batteries that have been catching on fire. But it has happened to Dell and other computer makers as well. Issue is that once it starts to burn it is very hard to put out. They need very careful management including temperature sensors and sophisticated electronics. Not very DIY friendly.


So far, anything that stores energy in density is pretty volatile if used incorreclty. Be it plutonium, gasoline, diesel or lithium ion batteries.

21 months of DAILY charging and discharging.... My Nissan leaf has failed to burst into flames or explode... so far...I'll keep ya'll posted.


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## mbianka (Sep 19, 2014)

escape plan said:


> Finally an update on the P.
> Currently the mast is off the boat as I repair the compression post.
> 
> The prop is 3 blades and covered with growth.
> ...


After many years of scrapping finally found an easy way of cleaning the prop before launching you may find helpful:
THE BIANKA LOG BLOG: SPRING CLEANING: PROP


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## finnarne (Aug 26, 2014)

RobGallagher said:


> 21 months of DAILY charging and discharging.... My Nissan leaf has failed to burst into flames or explode... so far...I'll keep ya'll posted.


There is a big difference. When in a car, you can let gases out under the car. That's hard to do on a boat. And you have better cooling under a car, then inside a hull.

And if a car starts burning while driving, you can stop, and get out. Well, you could do that on a boat as well, but...

And there is these articles (sorry about the norwegian): TESLA-FIRE - Carwreck and charger station to be examined


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## Maine Sail (Jan 6, 2003)

RobGallagher said:


> So far, anything that stores energy in density is pretty volatile if used incorreclty. Be it plutonium, gasoline, diesel or lithium ion batteries.
> 
> 21 months of DAILY charging and discharging.... My Nissan leaf has failed to burst into flames or explode... so far...I'll keep ya'll posted.


How about the BILLIONS of Li batteries in tablets, laptops, smart phones, cordless tools etc. etc. etc.. The failure rate, vs. the sheer number of Li batteries in use today is pretty infinitesimal. Between our house & barn/shop we have well over 40 Li batteries....

16+ Li Cordless Tool Batteries (Porter Cable, Ryobi & Milwaukee)
4 Li Tablets
3 Li Smart Phones
7 Li Laptop Batteries
6 Home Phone Li Batteries
4 Li batteries for boats in my shop
5 Li Remote Control "RC" Hobby Batteries

and I know I have left a bunch out....

ZERO ISSUES

Heck Tesla sold 17,000 cars last quarter alone, the Chevy volt is now over 100,000 and the Leaf I believe is now over 200,000. Dangerous failure rates based on those numbers have a *.* then a lot of zeros in front of it. More people die in bathtubs than have died from Li batteries. Should we curtail the use of bath tubs....?:laugh

I have had LiFePO4 on board for 4.5 years now (approaching 750 cycles most to 80% DOD) and I consider my LFP system far safer than any lead acid battery system I have ever used or installed on a boat because of all the redundant protection systems that prevent the battery from getting over charged or over discharged.......

The vast number of deaths attributed to Li batteries are kids swallowing Li "button batteries", about the same size as a nickle. Clearly we need to stop using nickles...:wink

It seems everyone wants to compare LiFePo4 (what is being used on boats) to the Boeing incident, which occurred with a very high strung Li chemistry (LiCoO2), and that is like comparing the properties of cow dung to gasoline.

Imagine if _glass_ or _electricity_ were invented today. Neither would ever be allowed with today's level of thinking... Think about it, really...:wink

We need to remember that ALL batteries can be dangerous!


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## escape plan (Dec 7, 2015)

New profomance data on 30 foot Pearson with electric yacht 10 kw system. 


Speed. Knots * * * * * RPM. * * * * *Amps. * * L mrtTemp

2.5. * * * * * * * * * * * * * * *774. * * * * * *7. * * * * * * * * 78

3. * * * * * * * * * * * * * * * * *1079. * * * *17. * * * * * * * 80

3.8. * * * * * * * * * * * * * * * 1305. * * * *28. * * * * * * *80

4..3. * * * * * * * * * * * * * * * 1505. * * * 42. * * * * * * *84

4.9. * * * * * * * * * * * * * * * *1754. * * * 64. * * * * * * *86

5.4. * * * * * * * * * * * * * * * 1926. * * * *90. * * * * * * 93

5.8. * * * * * * * * * * * * * * *2115. * * * * 122. * * * * *100

5.9. * * * * * * * * * * * * * * *2193. * * * * * 141. * * * * 107


Conditions light wind little tidal movement.
Clean prop and clean hull.
Quite an improvement.


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## misfits (Dec 9, 2011)

escape plan said:


> New performance data on 30 foot Pearson with electric yacht 10 kw system. Quite an improvement.


Those are very good numbers! Surprising the difference a clean bottom & prop makes. The good thing about this exercise is you now have a before & after picture. So when the amps start going up, it's time to unload the extra baggage..


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