2 bank charger and 3 batteries

[Ice Cold Peanuts]

I just moved from a 12v trolling motor to a 24v set up. I've been using a 2 bank onboard charger on the 2 batteries but now that I have 3, will one bank handle the cranking while the other bank handles both trolling motor batteries? They're wired in series. If so, how is bank 2 wired to the trolling motor batteries?

I don't know that my outboard charges the cranking battery. I've got a 1987 Mercury 115. Is it standard that outboards have alternators?

 

[Silvertip]

Re: 2 bank charger and 3 batteries

In 1987 your Merc definitely has an alternator and it does charge the battery. You can use your two bank charger to charge both trolling motor batteries IF (note the IF) the charger is relatively new and has isolated ground leads. Chances are it does but you can check with the manufacturer to make sure it can be used on a 24 volt system. You simple connect one set of outputs to each battery. Just make sure you don't mix up the grounds. OUTPUT + and - must go to the same battery.

 

[Ice Cold Peanuts]

Re: 2 bank charger and 3 batteries

In 1987 your Merc definitely has an alternator and it does charge the battery. You can use your two bank charger to charge both trolling motor batteries IF (note the IF) the charger is relatively new and has isolated ground leads. Chances are it does but you can check with the manufacturer to make sure it can be used on a 24 volt system. You simple connect one set of outputs to each battery. Just make sure you don't mix up the grounds. OUTPUT + and - must go to the same battery.

Wonderful. The boat is a 1987 Kingfisher and was completely rewired by the previous owner so I'm thinking I have an adventure on my hands. This website is going to be a blessing. Thank you so much.