Adding Trolling Motor Battery

[amateurfishing]

thinkin bout adding 2nd trolling motor battery for emergency backup, what is best thing to do and does it need to be same brand?

...keep batteries separate and just change power to trolling motor as necessary or....

...hook both batteries up together (parallel or whatever) so both are always connected to trolling motor together.

...and would it matter that 1 battery is 2 years older than other or is it best to get 2 new ones at same time that work together?

thx

[CAMAN]

If you're going to have two different ages and/or brands/sizes then definitely add a selector switch. If the batteries are identical in every way age/size/brand then you may hook them up in parallel. But be sure the trolling motor leads are hooked to opposite batteries by wiring the batteries in parallel (+ to +, - to -) but have the red motor lead attached to battery 1's +, and the motors black lead attached to battery 2's -. This will be sure the batteries drain evenly. But be aware hooking them up in parallel, if one battery goes bad for any reason, it will quickly kill the other if not caught fast enough.

[BobT]

If you're going to have two different ages and/or brands/sizes then definitely add a selector switch. If the batteries are identical in every way age/size/brand then you may hook them up in parallel. But be sure the trolling motor leads are hooked to opposite batteries by wiring the batteries in parallel (+ to +, - to -) but have the red motor lead attached to battery 1's +, and the motors black lead attached to battery 2's -. This will be sure the batteries drain evenly. But be aware hooking them up in parallel, if one battery goes bad for any reason, it will quickly kill the other if not caught fast enough.

I agree with this but just for my own piece of mind, I would personally keep them separate (either physically or with a switch) and just connect to one battery at a time for the reason CAMAN speaks of when one goes bad. But that's just my preference. Either way will work fine.

One other thing. If you're not comfortable knowing the difference between connecting in parallel vs series, don't guess! Get help from someone who knows. If you accidentally connect in series on a 12v motor, you will inject it with 24v and could very likely damage the motor.

[marine_man]

Assuming you have a 12V motor... which it sounds like it is... this is how you would connect in parallel:

marine_man

[amateurfishing]

that's what I figured, i'll just keep em apart& dummy proof

[amateurfishing]

that's what I figured, i'll just keep em apart& dummy proof