H the K wrote:
Lu Powell wrote:
I recently bought a used Champion brand bass boat. It has a battery
dedicated to the trolling motor that is not wired in to the charging
circuit for the cranking battery. The trolling motor battery gets
charged at home prior to a fishing trip.

Is there a simple fix that would let me charge both batteries at the
same time while on the water, and use the trolling motor battery
without draining the cranking battery?


If your outboard's alternator has the "juice" and proper circuitry to
charge two batteries, yes. You could accomplish this with a good
multi-position battery switch. That way, when the outboard is running,
you could set the switch to "BOTH" and both batteries would charge, and
when you wanted the trolling motor only, you could flip the switch to
"2" or whatever the trolling motor is connected to on that switch.

Assuming your trolling motor battery is in the bow, you'd have to run
heavy, heavy battery cables to the switch in the stern. You'd also have
to remember to flip the switch.

This is not a great solution for you, though. In an emergency, if you
needed the outboard in a hurry, you'd have to remember to flip the
switch in order for the outboard to start.

You'd be better off adding another 12-volt battery at the bow for the
trolling motor so it would have two 12-volt batteries wired in parallel.
That would give you more trolling motor time. But you'd still have to
charge 'em up separately.

SW Tom probably could give you more specific and perhaps better
directions on this. But what you want to do is do-able.

WAFA is clueless. Don't try to charge both at the same time. They are
very different batteries.