Dual Batteries

[trailshredder]

I have 2 batteries in my boat I bought this spring. They are not identical batteries on one is not connected to the other in any way. Was told that the one battery was just in there as a spare in case the other died. I am considering doing a dual battery hookup in Parallel (12V) but thinking I probably shouldn't with the batteries not being identical in amps. Is my thinking correct or would it be ok to do? Would the higher amp battery discharge the lower amp battery and defeat my goal?

 

[bruceb58]

Re: Dual Batteries

Its fine since you typically don't leave them connected all the time.

 

[Auger01]

Re: Dual Batteries

To expand on what Bruce said, if the batteries are connected in parallel all the time, you might have a problem with them.

 

[Grandad]

Re: Dual Batteries

I have 2 batteries in my boat I bought this spring. They are not identical batteries on one is not connected to the other in any way. Was told that the one battery was just in there as a spare in case the other died. I am considering doing a dual battery hookup in Parallel (12V) but thinking I probably shouldn't with the batteries not being identical in amps. Is my thinking correct or would it be ok to do? Would the higher amp battery discharge the lower amp battery and defeat my goal?

I think that the only reason to parallel batteries is to provide twice the current to temporarily power a very heavy load. If you don't have such a need (I doubt that you do), I'd keep them separated by a battery selector switch. I have 2 identical batteries, but interchangeably select only one at a time, leaving the other in reserve. This way, I have no worries about battery voltage differences or battery failures. Eventually one battery will deteriorate before the other, unless they're both replaced early (my plan), so eventually a parallel arrangement could invite disaster or inconvenience on the water. Peace of mind is worth more than the price of a switch. - Grandad

 

[Roberthill]

Re: Dual Batteries

I use two batteries hooked up together . Sometimes I use trolling motor a lot but I run motor and it keeps batteries charged up .Never had batteries low enough to give me any problem .Put them on charge after a day of fishing (slow charge) and after a couple of hours they are charged complete .