View Full Version : How to wire Two batteries for a 12v System
jdegn
06-25-2001, 06:01 AM
Hi Group,
This is probably a dumb question but I have always only ran one battery for my trolling motor and now I want to add a second. How do you wire together two batteries so they stay a 12 volt system. Also, because they are linked, can you charge both batteries together. Any other tips would be great.
Thanks for the help.
Jerry
Wire them in parallel. + to +, - to - with jumpers.
T-Mac
06-25-2001, 01:38 PM
Wire like TJ said...and yes you can charge them easily, as they are linked. I like to hook to the + 0n one batt. and the - on the other, when charging them at 12V.
Lucky2
06-26-2001, 05:10 PM
I have two batteries in my boat wired the same way as was earlier stated and it works great. I got an extra plug just like the one on the trolling motor and put two metal ends on it and when I am done fishing and want to charge the trolling motor batteries I just plug in the addapter plug and connect the battery charger and I am done. If you want to spend the money on a on board charger you can just hook it up to one battery and they both will be charged when you are ready to go in the AM. Have a great summer fishing and remember to always keep your line in the water.
Lucky2
JohnH
06-27-2001, 04:46 AM
Yes, running in parallel will let you run longer. Hook up the batteries as the other posts say. But there can be a problem of charging the two batteries with one 12v charger. THe problem is that if one battery is weaker than the other, and your automatic charger will shut off when one gets full and the other does not, or it could cause the charger to over charge the better battery because the weak one can't get charged. I installed an on-board charger, and wired in battery disconnect switches between the pos and neg leads between the batteries. I just turn the switch to connect the batts when going fishing, and have the batts in parallel, and then disconnect when finished to charge.
John