Bad Battery?

Got a question I’m hoping somebody knows the answer to. I’ve got 2 Optima batteries for my 24v Minnkota Genesis. I bought these batteries at the same time about 3 years ago and have always used them together. Have a 2 bank on-board battery charger on them. Have never had any problem with either of them. This year, the batter life indicator on the trolling motor doesn’t register the “time left” all the time. Wasn’t sure why so I thought I would test the batteries. My boat was wired with a “Battery 1/Battery 2” test indicator switch/gauge. Battery 1 shows good/full charge (12 volts) and battery 2 shows low/charge (3-5 volts).

My question is, is battery 2 just going bad or is it possible there is something else wrong with the electrical system that is draining battery 2? I kind of figured it was about time to be getting new batteries, but don’t want to stick em in if there’s a problem that needs to be fixed first.

Thanks.

JD

It could be either. Do you have a good battery shop that carries Optima around. We have a Batteries Plus here and if I had that trouble I think I’d take them the batteries and ask for an opinion or call Optima maybe they can help.

One thing you didn’t mention. It could be charger? Maybe try swaping the banks and see if the same battery shows bad. This would eliminate the charger as a possibility. Might swap battery 1 completely into battery 2 position and vice versa on the other one, this would also eliminate the wiring.

I haven’t used Optima but I have Dual-Pro and it is same technology so I’d think you expect longer service. I’m going on 4 years now.

Only one suggestions. Make sure the inline fuse isn’t coroded.

I had a similar problem, ended up 1 bank on my charger burned up. The other side followed shortly.

Thanks for the response everyone. I will try those suggestions and see what happens.

JD