charging 3 batteries, 3 bank

sstauss

Recruit
Joined
Jul 31, 2010
Messages
1
I have 3 batteries, 1 for starting and 2 for trolling/acc. I have a 3 bank maintenace charger. the 2 trolling batteries are hooked in parallel for 12 volt. the starating battery is seperate. I have leads running directly to each battery.
All batteries brand new and identical. The starting battery shows complete charge but the other 2 never say charged. Do I need to isolate the 2 trolling batteries so they are not parallel for charging. I'm thinking there is enough backfeed from each other to "fool" the charger.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: charging 3 batteries, 3 bank

Very possible. It is a good idea to separate the batteries anyway. No two batteries are identical so the weaker will suck the life out of the stronger until they equalize. So when running the troller, running off one battery at a time may provide a very slightly longer run time than both together because of this parasitic draw. It will also ensure both batteries get an optimum charge.
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: charging 3 batteries, 3 bank

I'm with ST on running the 12V TM batteries separate. I have a battery switch between mine and they last longer then when I had them paralleled.

I would check the charger's manual and see if the outputs can be combined as that is what you are doing by hooking 2 outputs to a paralleled battery bank
 
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