On Board Charger assembly

[RO'Donovan]

I just bought a wheelhouse. There is a battery in front and two batteries in back. They are all connected. I am going to buy an on board charger to plug into 110 so when I have the generator going it will charge all batteries.

Question...can I buy a single bank charger and have it charge all three? Or will it overload the first battery while trying to charge battery 2 and 3? Thanks for the help.

[Whoaru99]

Are all three batteries connected together?

Also, if you have a gennie, why are you messing with batteries - if you don't mind me asking?

Unless you are going to buy a huge charger, you're going to have to run the generator for several hours anyway to charge the batts.

[RO'Donovan]

All three batts are connected. I would like to fish using the batteries and only start the generator to charge the batts. My generator is too loud to run all of the time. As I understand it, a single bank would charge all three. However, as you said, it would take a long time to charge all three that way. (?) Also I would be concerned that battery one would be "overcharged" while battery 2 and 3 are being charged. (?) Or..should I just buy a 2 or 3 bank charger?

[Whoaru99]

When all the batteries are connected together, they will (theoretically) all charge and discharge equally. However, if the batteries are of different ages and capacities, it may not work like the theory says.

Assuming all the batteries are connected in parallel, a single bank or multi-bank charger will both work the same way - all the charging amps will be divided equally between all the batteries.

A multi-bank charger provides a clear advantage (besides possibly more amps of charge) only if you remove the jumpers between the batteries when you charge them. Removing the jumpers allows the multi-bank charger to see and charge each battery individually according to it's needs rather than as one big battery when they're connected together.

How long you must run the generator depends on how many amp-hours you have discharged from the batteries and how much charging amps you have available.

If you have taken 50 amp-hours from the batteries and have a 5 amp charger, the generator is going to have to run 10 hours or so to put back the 50 amp-hours. If the charger is 10 amps, then it will take about 5 hours, if the charger is 20 amps, then about 2.5 hours of charging/generator run time.

Clear as mud?

[RO'Donovan]

Thanks for the good information.

[Whoaru99]

You're welcome.

Just keep in mind the 50 amp-hours in my example was just that, an example.

If the batteries are discharged more or less than that, the charge time/generator run time will increase or decrease proportionally.