Educate me on battery systems and set ups?

[ShoestringMariner]

As I mentioned in another post, I’ve been considering adding to 12 V batteries upfront in parallel to run a 12 V trolling motor. Then when I upgrade, I’ll be going with the 24 V troller. So two 12 V batteries in series. I hope I got that right.

but last night I read about two batteries in a system hooked up to the outboard. These batteries serve as the starting power, and the trolling power. Not sure how I feel about that. Also not sure if my alternator on my outboard is enough to charge them. It’s a 1975 Merc 650. I am assuming it has an alternator, because the starter battery never seems to drop in voltage every time I check it.

in any case, I’m not too savvy with electrical/electronic stuff. But I do like the idea of having only two batteries as opposed to two dedicated for trolling and one dedicated for starting.

but that’s also a lot of weight

what do you guys think? I’m going to be completely going through this boat this winter or next and doing it up to a T. What would your choice of systems be

I also assume that onboard charging system capable of charging two or three batteries is required. If anybody has thoughts on those systems, I’d like to hear it. I know nothing about this stuff

 

[Silvertip]

It doesn't matter if you have a brand new outboard with a high output charging system or your current motor. Neither will charge a deeply discharged battery bank in a short run back to the dock. You still need an on-board charger of 6 - 10A per bank that can be plugged into shore power for overnight charging. The answer to this issue is also covered in your other post.