Battery Charger Circuit Breaker

[seasick]

The choice depends on how long you are willing to wait for enough batter charge to go out after finding out that you left something turned on after the last visit. In simple terms, the 36 amp is going to charge up the depleted batteries in half the time that it would take the 20 amp Are the four batteries set up with two banks of 2 batteries in parallel or are the batteries set up with ACRs or some other 'smart charge controller connected to the motors charge circuits

 

[Harrysea]

The choice depends on how long you are willing to wait for enough batter charge to go out after finding out that you left something turned on after the last visit. In simple terms, the 36 amp is going to charge up the depleted batteries in half the time that it would take the 20 amp Are the four batteries set up with two banks of 2 batteries in parallel or are the batteries set up with ACRs or some other 'smart charge controller connected to the motors charge circuits

I have 2 banks of 2 batteries in parallel. I rarely go out two days in a row, but I think my batteries are pretty much fully charged when I come home anyway. I don’t run anything but the charger when I hook up to shore power at the dock.

 

[Gulffisher]

For shore power charging and battery maintenance between boating trips you should be OK with 20 amp, but remember that is only 5 amps per battery (or more likely with silly GW battery configuration, 10 amps per two battery bank regardless of two or four charger leads). If you intend to charge batteries off generator while on board and while running two MFD's, radar, VHF sound system, spreader lights, bait well pump, fridge, etc. then 20 amps may not be enough.

Update after reading you subsequent posts, I think you should stick with 40+/- amp 2-bank charger unless you soon plan to isolate the batteries.

 

[Harrysea]

Any recommendations for charger brand/model? I have a ProMariner unit now. I think original equipment was Guest.

 

[Gulffisher]

My 2005/06 OEM Guest still works. And I think the ancient jon boat has Guest. I assume their newer models are likely similarly good.

Wanting a bit more charge capacity, I recently replaced the Guest on my GW 330 with a 60 amp Minn Kota (it is a heavy beast) but havent use it long enough to know how durable it might be. There are several newer options, none of which you might need and some may be gimmicks, like flooded, AGM, and Li charging capabilities.

 

[Fishtales]

You want to see how the (4) batteries are connected. Usually GW wires (2) batteries together for each bank. Put a 4 bank charger on that and you'll have issues. If the batteries are not connected, then you will be fine with a 4 bank charger.

 

[Coastboater]

Any recommendations for charger brand/model? I have a ProMariner unit now. I think original equipment was Guest.

I’ve had NOCO Genius in my last 3 boats. No issues.