Thread: Battery Charger question....

Originally Posted by mrwillis

So, Im hoping I can explain this correctly in order to get a correct answer. My battery set-up is pretty simple, actually. I have 2 batteries linked for a 12/24 selectable MotorGuide Trolling motor (gives me either 12v or 24v, with the flip of a switch). Then, I have another separate battery for everything else. SO, I HAVE THREE BATTERIES.....2 dedicated strictly dedicated for trolling (and run together), and one dedicated for everything else.

Now, I have a 2 bank charger on my boat, and it works great. It is 5 amp each bank. Now, I will buy a new charger if needed, but I don't want to have to drop $200 on anything like that right now. Im would like to dedicate one bank to the "accessories" battery. I would like to be be able to use the other bank for the trolling battery.....being able to charge both trolling batteries with the one bank, IF POSSIBLE. I would think that it could, being they are linked/connected.

Am I right about this, or am I needing to break down and buy a 3 bank charger?

I hope this all makes sense.....looking forward to hearing answers.

Mrwillis

Best way to do that is to charge the trolling batteries in parallel (assuming they're of equal size and age), and use the other bank for the starting battery. Keep in mind that charging current will be cut in half, and it will take twice as long to charge. At 5 amps total you would be getting 2.5 amps per battery, say those are 100 amp hour batteries that you discharge 50%, they would take a full day to recharge (50/2.5=20 hours).

You do not want to charge unequal batteries in parallel.