# Portable Generator question



## SVGratitude (Sep 25, 2007)

It seems a lot of cruisers are using portable generators to help charge their house bank while at anchor. I'm considering the purchase of a Honda 2000 to charge my house bank. 

I have 55 amp alternator, a 30 amp shore power system, a house charger (120v, 25 amp), and a 450 AH battery bank. Can I plug the generator into my shore power input and charge up my house bank in this way? 

The Honda spec's say it puts out a max of about 17 amps. Will my 25 amp house charger run OK with this setup?

We are 1/3 of the way into a 6 month trip to the Bahamas and back ( having a GREAT time BTW).

Thanks,
Mark


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## gc1111 (May 13, 2004)

The power available is the limiting factor. Power is voltage times current. As a first approximation, the 115 volt output from the charger is 10 times the 12 volt output of the charger. So 1 amp at 115 can give (more or less) 10 amps at 12 volts.
When you say the house charger is 120v, 25 amp, I assume that is 25 amp on the 12v side. Is that correct? If so, the Honda should easily power the charger.


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## PBzeer (Nov 11, 2002)

I use a Honda 2000, plugged into my shorepower receptacle to power my TrueCharge 20 amp charger for a 315ah battery bank. If using much power and low to no wind (for wind gen), I generally run it for a couple hours in the am, then a couple more in late afternoon. If I stay off he computer, I need it far less 

Glad to see you're still moving on.


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## sailingdog (Mar 19, 2006)

SVGratitude-

Yes, you can plug your Honda into the shore power system...and your 25 amp house charger will probably be fine. Just remember the 25 amp charger is 25 amps @ approximately 12-15 VDC, which is 2.5-4.x amps or so at 110 VAC, not counting conversion losses.

*Be aware that the generators are rated for resistive loads, and inductive loads should be doubled to get a good estimate of what the generator can handle. *For example-a 100 Watt incandescent light bulb or 1500 Watt heater are going to use about what they say... and the Honda 2000 can handle about 20 of the 100 Watt light bulbs... but if you have a 1200 Watt microwave oven, the Honda 2000 will probably have some trouble feeding it-since it is mainly inductive loads, not resistive.

Highly recommend that you have a CO detector aboard and running, since the exhaust from the generator is a serious hazard.


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## NautiG (Apr 23, 2007)

I have a cheapo 2 cycle generator that I bought from Northern Tools. It only cost me $150. It claims to put out 1200 watts, but I think that is an exaggeration. It will only get my 40 amp battery charger up to the mid 30s. 

So far it works great. But I've only had it a month. It sounds like a moped while running. I anchor from the stern and place in on the foredeck. That way the exhaust blows off the boat, not over it. 

Remember to ground your generator. I can't find a ground on my "fire sale" boat (thanks SD), so I just connected a wire to the generator ground and tossed it overboard. A little "trailer park", but it works. You might not want to be tempted to connect to the AC ground on your boat. On my boat, it appears that the only ground for the AC panel runs to the shore power line. So the only way you are grounded is if you are connected to shore power.

I run my computer all day, but besides that, I just run a few lights, electric start the engine, charge a few AA batteries and a cellphone. I only have to run the generator every other day, for about an hour or so before I run out of juice.

Scott
Gemini Catamaran Split Decision
nautib.blogspot.com


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## sailingdog (Mar 19, 2006)

NautiG said:


> I have a cheapo 2 cycle generator that I bought from Northern Tools. It only cost me $150. It claims to put out 1200 watts, but I think that is an exaggeration. It will only get my 40 amp battery charger up to the mid 30s.


This may well be due to the fact that a battery charger is an inductive, not resistive, load.



> So far it works great. But I've only had it a month. It sounds like a moped while running. I anchor from the stern and place in on the foredeck. That way the exhaust blows off the boat, not over it.


Have you read Don Jordan's article on anchoring from the stern. I do that a fair bit with my trimaran...and she seems happy about it.



> Remember to ground your generator. I can't find a ground on my "fire sale" boat (thanks SD), so I just connected a wire to the generator ground and tossed it overboard. A little "trailer park", but it works. You might not want to be tempted to connect to the AC ground on your boat. On my boat, it appears that the only ground for the AC panel runs to the shore power line. So the only way you are grounded is if you are connected to shore power.


I would be wary of grounding to the water...since that is an excellent way of creating a galvanic corrosion problem, especially on the Sillette sonic drive leg that the Gemini's use. Until you are sure you're not creating a problem, I would highly recommend tilting the sonic drive leg up. Also, grounding the AC genset to the water may also create an electrocution hazard for people in the water... I'd check with the manufacturer about the proper grounding method for using it on a boat.



> I run my computer all day, but besides that, I just run a few lights and electric start the engine. I only have to run the generator every other day, for about an hour or so before I run out of juice.
> 
> Scott
> Gemini Catamaran Split Decision
> nautib.blogspot.com


This of course is partially dependent on how large your house bank is, what kind of computer you have and whether the lights are incandescent, cold cathode fluorescent, halogen or LED.


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## NautiG (Apr 23, 2007)

Hey SD,

I prefer to anchor from the bow, especially in cold weather. Less wind in the cabin. I have an outboard on my old Gem, not a stillete. I don't think corrosion will be a problem seeing as how the generator is on the bow and the outboard is 30 feet away on the stern. I am careful that there are no swimmers, but I think it's better to ground to the water, than not at all. I don't want to electrocute myself by touching a charged generator. I don't know where else you would ground to while at anchor.

Scott
Gemini Catamaran Split Decision
nautib.blogspot.com


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## erps (Aug 2, 2006)

> Can I plug the generator into my shore power input and charge up my house bank in this way?


That's what I do and I get between 60/70 amps from the battery charger.


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## RandyonR3 (Oct 2, 2005)

When searching for a generator, a good point is how much noise it makes.. Kinda strange subject to bring up but I have been in anchorages
that were peasefull, quiet, and our early morning coffee was shared with the birds and the noises of nature...
And then some idot comes in drops anchor and fires up his generator..
and the reason we were there has just disappeared.. The EU model of the honda is a pretty quite unit..dont opt for an off brand without noise reduction.. You'll make enimies in an anchroage really fast.........


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## Idiens (Jan 9, 2007)

If you are feeling green and have a ready supply of methanol, how about one of these...

www.efoy.com


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## sailingdog (Mar 19, 2006)

That's right...the very early Geminis were outboard powered... 

Yes, anchoring from the stern is only good in light winds and warmer weather... makes no sense in the rain or strong winds...

Probably still worth checking in with the manufacturer about their recommendations as well as lifting the outboard as much as possible.


NautiG said:


> Hey SD,
> 
> I prefer to anchor from the bow, especially in cold weather. Less wind in the cabin. I have an outboard on my old Gem, not a stillete. I don't think corrosion will be a problem seeing as how the generator is on the bow and the outboard is 30 feet away on the stern. I am careful that there are no swimmers, but I think it's better to ground to the water, than not at all. I don't want to electrocute myself by touching a charged generator. I don't know where else you would ground to while at anchor.
> 
> ...


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## Valiente (Jun 16, 2006)

sailingdog said:


> Have you read Don Jordan's article on anchoring from the stern. I do that a fair bit with my trimaran...and she seems happy about it.


I'm going to have to think about that one. I have aft bollards welded to the deck that are strong enough to handle a stern anchor bridle or a Jordan Series Drogue, and so this is a possibility for me. But I will also have a windvane back there and I have a transom-hung rudder, so it's already going to be a busy location.

I am about halfway through Earl Hinz's Big Book of Anchoring, and will figure it out after I've absorbed that fairly significant amount of technical information.

As for the AC ground on a Honda generator, I have to figure this out as well, because that "steel boat thing" is a special case. I have a book to read on that, as well, called "Metal Corrosion in Boats". The whole topic's a real pain in the anode.


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## sailingdog (Mar 19, 2006)

Valiente—

A corrosion problem on my boat does little...on your boat it may leave you swimming, so it is a different order of problem. 

You'd need a pretty hefty JSD...given the size and mass of your steel beastie.  One of my projects this winter is to fabricate new chainplates for the JSD I have. I want to move the hardpoints for it outboard more and give it a longer bridle to use. Right now, I'm thinking the in-board side of the amas for the bridle, rather than outer sides of the main hull, which is what I'm currently using.


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## Valiente (Jun 16, 2006)

I've heard that the JSD works well, but that it is a real trial getting it back aboard in any kind of a sea. The Pardeys favour a Para-Anchor style of sea anchor...further research is required/


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## sailingdog (Mar 19, 2006)

I've test deployed mine... and pulling it back aboard is a bear. One thing I found works fairly well is to walk the JSD around to the bow, and then drift down on it...hauling it up on to the ama decks as we drift down on it... but that's not a good option for you... since you ain't got no amas to do this with.


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## Vasco (Sep 24, 2006)

The Honda EU2000i is the most popular portable generator with cruisers. Just plug it into your shore power with a 15/30 amp cheater and a short extension cord. It works best with a large smart charger. I have a 100 amp charger and when my wind generator doesn't keep up due to no wind I fire up the Honda. A friend of mine had the same generator but with a 20 amp charger and no panels or wind generator he had a hard time keeping his 450 amp house bank up. He thought his fridge had crapped out but it was his batteries. If you run the house bank down 50% it'll take you more than 15 hours to bring the bank up with a 20 amp charger and the Honda. If you rely only on the Honda and a 20 amp charger you'd better run it at least four hours a day to try and keep up with using about 100 amps a day. You'll still be losing. Just do the math.


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## sailingdog (Mar 19, 2006)

Vasco-

Of course, you do realize that you're mainly charging the batteries from 50% up to about 80%... since you're not going into the absorbtion or float stages of charging with such a short run.


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## camaraderie (May 22, 2002)

Dawg...I don't get how you arrive at that. 
If he has 100amp 3 stage charge and needs to replace 225 amps (from 50% of 450ah capacity), then he will be at 80% once he gets to 360amps total or 135amps delivered. 
With a 100amp charger this will take place in about 1 hour and 15 minutes after which he will probably get to about 90% charged as the charger ramps down to absorption levels in just 2 hours. More if you use the whole tank of gas...but not much efficiency in doing that. 
Am I missing something? 

Val's larger point is correct about needed a good sized charger to take advantage of the Honda.


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## Vasco (Sep 24, 2006)

sailingdog,

When I use the Honda I'm usually going from 50% to 85% because you have to run it too long to get the last 15% in. So in effect I'm only using 35% of my bank. When it blows again the batteries get back up to 100% thanks to my KISS. A couple of years ago I used the Honda to equalize a bank of flooded batteries. Had to run it all day, hardest part was refilling the gas without causing a fire! I changed to AGM's last year.


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## sailingdog (Mar 19, 2006)

Cam-

It's just that the absorption stage drastically drops the current acceptance rate... and it usually switches from bulk to absorption at about 80% or so. Unless you're running the charger for more than a couple of hours, you're probably only getting from 50% up to about 80-85%... since you're now on the part of the curve where running the gen just doesn't really make that much sense in terms of what it returns. 

Yes, you do need a fairly high amperage charger to get the greatest efficiency out of using a Honda genset, and AGM batteries are needed too. Unless you have a pretty massive battery bank, it won't accept 100 amps for very long if it is made up of wet cells.


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## camaraderie (May 22, 2002)

OK...I guess we agree then...I am just saying that getting from 80-90% in 45 minutes at absorption ramp-down is quite reasonable. We both agree that getting from 90 to 100% is not possible. Split the difference and call it 85% like Vasco says! (g)


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## Valiente (Jun 16, 2006)

Vasco said:


> sailingdog,
> 
> When I use the Honda I'm usually going from 50% to 85% because you have to run it too long to get the last 15% in. So in effect I'm only using 35% of my bank. When it blows again the batteries get back up to 100% thanks to my KISS. A couple of years ago I used the Honda to equalize a bank of flooded batteries. Had to run it all day, hardest part was refilling the gas without causing a fire! I changed to AGM's last year.


You've illustrated a good point for me here. With wind and plenty of solar available, plus a 100 amp charger, for me the charging aspect of the Honda 2000 will be primarily as a "stop gap" to charge a large bank to the "functional" 80% point, after which either the sun will be out, the wind will be blowing, or I'll start the damn engine!

The primary purpose of the Honda for me will be to power standard 115 AC hand tools on deck (grinding metal parts or cutting wood) when I want to avoid a big draw on the inverter and/or have a reason to get the work out of the forepeak workshop.

I can also see bagging it and taking it onto a beach to do work in a portable fashion. Certain places in the Pacific I can see a good way to make pals locally would be to bring your own dozen amps or so.


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## sailingdog (Mar 19, 2006)

LOL... works for me Cam... hard to say exactly how fast it drops off without knowing what the batteries are and what charger is being used. 

Valiente-

Again, just remember that the Honda is rated for 2000 Watts of resistive loads...which is only about 1000 Watts of inductive loads... most tools are inductive loads.


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## heslopg (Feb 14, 2005)

I use a Honda IU2000. I know it's limited in it's DC output, but I plug it directly into my shorepower inlet & power the battery charger, along with the AC water heater, computer, lights & everything else I can plug in. Works fine for me. Noise is the issue. It's pretty quiet in itself, it's the vibration it makes while sitting on deck.

Glenn.
s/v Seawing.


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## Vasco (Sep 24, 2006)

I place mine on a closed cell foam pad and this absorbs much of the vibration.


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## Valiente (Jun 16, 2006)

sailingdog said:


> Again, just remember that the Honda is rated for 2000 Watts of resistive loads...which is only about 1000 Watts of inductive loads... most tools are inductive loads.


Most of my tools are 6 amp draws or less, so it's not a problem. I think even my "cabin" ShopVac (much more effective than those gutless hand vacuums everyone has!) draws only 6 amps.

Another use for the Honda is in the case of catastrophic failure of the boat's electrical system, but no actual hull damage: You can use (with filtering, I suppose) the Honda to power radios, lights and even radar for a time. It's more a form of "life support", but as long as the gas holds out and you can keep it dry on deck, it's possible within limits to keep your boat electrically "alive" until you can reach shore.

I also carry a 700 watt "power pack" with jumper cables. I've used it to run a hand sander for half an hour working on smoothing down glass work on a RIB before it got to 50%. Because it's just a 25 pound AGM battery in essence, I would choose this over the Honda if I needed to illuminate a sail with a hand spotlight or needed to charge hand held radios, etc.


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## SVGratitude (Sep 25, 2007)

Thanks everyone for your input. It seems that it should work pretty well for its intended use (supplemental charging).

I'm off to pick up my Honda 2000 tomorrow. I'll post a follow up after I've used it and formed an opinion.

Thanks again,


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## Valiente (Jun 16, 2006)

Let us know if you get a good price and what connectors/plugs/grounding procedures are necessary on board, please.


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## paulfitch (Nov 1, 2000)

I've used my Honda 2000 for 4 years now without any electrical problems. I plug it into the shore power input. I have a Freedom/Heart 1500 inverter/charger and the Honda regularly puts 60+ amps into the house bank when the batteries are down 100 amp hours or more. I'm also on a Gemini and always pump up the Silette leg when at anchor. Gen. sits on back transom so wind carries away exhaust. I haven't grounded the gen. and have found no electrical problems in the past 4 years. Just had it in the shop about a month ago. Not bad service for a boat that's gone from Florida to Panama mostly in a salt air environment.


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## NautiG (Apr 23, 2007)

Hey Paul, Gemini owners unite! We'll take over the world.

My concern about placing the generator on the stern is that there is a wind eddy created by the bimini (hard top on newer gems). The first time I ran my generator I had it on the stern, and I felt a little dizzy. But mine is a crappy two cycle, and probably puts off a lot more pollution than yours. I'm also particularly sensitive to chemical fumes. If you have a carbon monoxide detector you should be fine.

I'd recommend locating the DC ground on your boat, just for informational purposes. My boat does not seem to have one, but then again, it's a grandaddy gem, and has some other design flaws.

Scott
Gemini Catamaran Split Decision
http://nautib.blogspot.com


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## dvdcnl (Apr 9, 2000)

*another gen*

I've heard about using a car alternator with a small lawnmower type engine. That way you don't have to use a battery charger to get dc.


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## sailingdog (Mar 19, 2006)

The portable Generators, like the Honda 1000 are inexpensive enough that you really shouldn't bother futzing with a kludge like that.


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## warmbeer (Jan 4, 2008)

I have a Honda 2000 that I was thinking about plugging shorepower into to keep batteries up since I run the engine a little as possible. I keep the boat on a mooring and mostly anchor when travelling and have 2 house X110ah ea with Freedom charger/inverter and Link remote panel that can limit draw in the Honda.
The Honda 2000 has a floating neutral and I read somewhere that this situation is a problem on boats if you plug in shorepower. I can't remember if it was 110v danger or corrosion risks.
Need to do some research I guess unless anyone here knows what that's all about???

Thanks


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## sailingdog (Mar 19, 2006)

Warmbeer-

Should work just fine, since many people do just that with the little Honda generators.


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## speciald (Mar 27, 2007)

The guy anchored next to me had his Mastervolt genset pulled for repair. He bought a Honda to keep his fridge, chargers.etc runningtwo weeks ago - it was alot cheaper than putting in to a marina while his Mastervolt is repaired. It is a little noisy, however.


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## greg.hadaller (Jul 5, 2000)

We use a Honda 1000 generator plugged into our shorepower outlet feeding our ProSine inverter/charger. Works great. The Honda pumps in 32 amps, continuously for at least three hours (the longest we've tried). Our 120 amp charger lets me limit the amps it pulls from the generator by configuring a 'breaker size' on the setup panel -- not sure how effective this setup would be without that ability, as if the 'breaker size' is set too high, the Honda pops its circuit breaker. 

Note that our Honda has DC output at 8 amps, which works fine, but why settle for 8 when you can get 32 via AC output and a charger? Not sure why Honda restricts it to 8 amps, when clearly more power is available.


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