Help with Battery Charging?

[PaulAlford]

I have a new/used boat that has 2 12v batteries in the back just for the trolling motor. There is a control panel in the bow with a toggle switch for trolling and charging. The batteries each have separate pos/neg cables for each battery. When I connect the charger to ONE battery, will it charge them both ? I assume I need to have the toggle switch in the "charge" position.

 

[Silvertip]

Re: Help with Battery Charging?

That switch controls whether the batteries are in series (Trolling) and as such provides 24 volts to the trolling motor. In the Charge position, the batteries are placed in parallel and yes, if you connect the charger to one battery, the other will charge as well. Keep in mind you MUST have a 24 volt trolling motor if you use the Troll switch position. Connecting a 12 volt motor would likely fry the electrics. When the boat is NOT in use AND the charger is NOT connected, DON'T leave the switch in the CHARGE position. Having the batteries in parallel for an extended period will cause them to equalize meaning the weaker one will draw on the stronger one until the two are equal. If both batteries are in good shape, the same size, and same age this won't be a serious issue. If one battery is weaker than the other then it is an issue.