I use the Marine batteries they sell at WalMart..Everstart Maxx I think is the brand name. I'm not saying these are the best batteries on the market, but they are the only batteries that I use. The one I have in my boat now are going on 4 years old and I have not had any problems with them. About 4-5 years ago, I had some battery problems and WalMart exchanged them with no questions asked. The reason I use these batteries is because there is always a WalMart close by no matter where you may be fishing. I used to use Interstate batteries, but I ran into a problem with a new battery one time and there was not an Interstate dealer in that area.