Generator battery - no charger???

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jann

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I have a Mainship 34T

I was under the assumption that Mainship would have wired the separate battery for the generator to the main AC battery charger. To keep the generator battery charged at all times.

My friend says no. He put in a separate trickle charger for that battery. He found this out only when his generator would not start because of the battery not charged.

Has anyone else experienced this problem. Please advise.
 
We have no external charger for the engine and generator start batteries. They only get charged when the they are running by their own alternators. A battery in good condition should only loose about ~3 or 4%/month of it's charge at rest. In 7 years on Hobo and 10 years on the last boat, we never needed to jump start.
 
Our vessel has a separate Newmar charger for the engine and generator starting batteries. It is on a switch/breaker and part of the main E panel. If for some reason the inverter charger isn't operable the Newmar will charge the house banks too through the parallel switch, albeit slowly as compared to the inverter.

Lots of ways to skin a cat in the charger arena.
 
Our genset battery was not tied to the charger either. I needed space for additional house batteries so I eliminated the genset battery and tied the genset to the port engine battery that doesnt have the ability to tie to boat loads.
 
I too set up mine with gennie sharing engine batt. I find no downside to that arrangement. I also disabled the gennie charging circuit, as its regulator is very crude and tended to overcharge. With gennie running, batt gets charge from boat charger or the more precise main engine alt.

In the OP's case, I don't see any big need to add a charge link to gennie batt. Many boats run same configuration with no issue. As others have posted, without any drain the batt will maintain charge for a long time. Maybe a trickle charger (maintainer) for winter layup.
 
Is your genset battery the same technology as your engine start battery? If so, no problem combining the two as one 'start bank' and charging both as you do now for engine start. If your genset start battery is just a small-ish/basic thin-plate flooded auto battery, then check if your genset has a small alternator already fitted: they often/usually do for charging such a battery.
 
My philosophy...if your genset isn't keeping it's own battery charged.....you aren't running your genset enough and it's dying a slow death like most.

If for any reason you can't or won't run your genset...and you pickle it for 6 or more months....then I just throw a good electronic portable charger (25 amp max) on it till it says fully charged which is between 1/2 to an hour tops.

More wiring and charging circuits is just "extra stuff" in my mind for a genset...I prefer to run mine every month to make sure it's there when I need it.
 
psneeld said:
My philosophy...if your genset isn't keeping it's own battery charged.....you aren't running your genset enough and it's dying a slow death like most.
Click to expand...

Running often it is good. But to keep a genset alive the longest, running it under the proper load is the best thing you can do for it. Most gensets die an early death not so much from non-use as from running hours and hours on end under a light load.

As to the genset battery charging issue, as others have pointed out it's not mandatory to have one but as you found out it can be nice to have. And these days a low amp output smart charger is not to expensive to get and install. And a lot of boat come with one. So if you feel more comfortable having one as a back up, go for it.
 
Our genny battery is a 4D and is also shared with the wing and the engine has a dedicated 8D, the engine and gen/wing batteries are charged by a separate charles charger although if it broke I could parallel them with the house and charge them like that or if they went dead.
 
I have had the same problem. I picked up a trickle charger for the genset battery only. No problems since. It is plugged into an AC outlet. It was about $25 bucks at Wally's back by the tires and batteries: )
 
I have a dedicated 25w solar panel via a basic regulator to maintain the 150ah genset battery. Full batteries are happy batteries and live longer. My Onan genset has a 35A alternator.
 
Capt.Bill11 said:
Running often it is good. But to keep a genset alive the longest, running it under the proper load is the best thing you can do for it. Most gensets die an early death not so much from non-use as from running hours and hours on end under a light load.

As to the genset battery charging issue, as others have pointed out it's not mandatory to have one but as you found out it can be nice to have. And these days a low amp output smart charger is not to expensive to get and install. And a lot of boat come with one. So if you feel more comfortable having one as a back up, go for it.
Click to expand...

This is a highly debated topic and I doubt there's definitive proof either way.

Yes ....too light of a load isn't good...never said run it unloaded.

Also..a large chunk of the cost of gensets isn't just the engine the electrical side loves to work rather than sit and rust too.
 
sunchaser said:
Our vessel has a separate Newmar charger for the engine and generator starting batteries. It is on a switch/breaker and part of the main E panel. If for some reason the inverter charger isn't operable the Newmar will charge the house banks too through the parallel switch, albeit slowly as compared to the inverter.

Lots of ways to skin a cat in the charger arena.
Click to expand...

We have the same kind of setup.

The inverter/charger charges the house bank

We have a Charles industries 40 amp charger that charges the two start batteries, and the genset battery. With the closing of a breaker we can use it to charge the house batteries as well, but as you indicated much slower.

Redundancy is a good thing.
 
psneeld said:
This is a highly debated topic and I doubt there's definitive proof either way.

Yes ....too light of a load isn't good...never said run it unloaded.

Also..a large chunk of the cost of gensets isn't just the engine the electrical side loves to work rather than sit and rust too.
Click to expand...

I don't think there is much debate about it. At least not among all the diesel techs, engineers and service shops I've spoken with over the years. Wet stacking, carbon build up, etc. are common results of under loading a genset. Hence the use of "night" gensets and load banks in some cases.

The kw capacity of gensets in most boats has been picked based on the potential max amp load for that vessel. And since those gensets may rarely see even 50% of that for long stretches, they end up wearing out prematurely not from lack of use, but from continual light load use.

But of course the reality is they can still run for thousands even under light load use. Just smoke a bit more while doing so. :)
 
Capt.Bill11 said:
I don't think there is much debate about it. At least not among all the diesel techs, engineers and service shops I've spoken with over the years. Wet stacking, carbon build up, etc. are common results of under loading a genset. Hence the use of "night" gensets and load banks in some cases.

The kw capacity of gensets in most boats has been picked based on the potential max amp load for that vessel. And since those gensets may rarely see even 50% of that for long stretches, they end up wearing out prematurely not from lack of use, but from continual light load use.

But of course the reality is they can still run for thousands even under light load use. Just smoke a bit more while doing so. :)
Click to expand...

I think what he means is that it's highly debated by him...as are many things. You'll get used to it. :D
 
Psneeld
I like your Idea best
When I don't use my genset I will exercise once a month, under load ( with both AC's on), for 30 min.

Prior to turning on the generator, I will charge the battery until full with my garage charger.

Don't need any more "stuff" on board

Thanks again
 
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