Okay all you electrical/battery gurus, I have a couple of questions. I have a 67 lb thrust trolling motor on a standard 12/24 volt set up. I am starting to have some trouble. Probably a bad cell, but I want some input before buying new batteries again. Lately fishing in windy conditions where I have been using the tm alot, I am running down one of the batteries totally. The last time was this past Sunday in only a few hours. When I switch over to 24 volt I have power again. Shouldn't both batteries run down somewhat equally during use since they are wired together? When I switch to 24 volt am I simply switching over to the other battery since I again have power? I do notice when I do so that the tm isn't as strong on 24 v as normal. Is this problem as simple as a bad battery or should I be checking other things as well? I put the batteries on charge as soon as I return and they stay charged via my on-board charger. If it is time for new batteries I will probably go with Optima this time. Who/where has the best deal on the blue tops as well as one for cranking (yellow top?)?

Thanks.