Re: one bank charging
That will work just fine BUT -- the only problem with that setup is if one of those batteries is the starting battery and you forget to turn that switch off as well as either or both of the other two batteries. That places two or three batteries in parallel and when you hit the key to start the motor, the wiring for the non-start batteries will get very hot and possibly even melt the insulation. Remember, the starter doesn't care where the current is coming from so if the switch for that battery is closed, it will suck juice from it. As far as the starter is concerned, it looks at two or three batteries as one great big one. While YOU may never forget, if you have little curtain climbers with inquisitive fingers in the boat, you will never know those switches are flipped until you smell smoke.
