Check out US battery based out of Memphis Tn.... They have tons of great batteries. I Chose to go with 2 golf cart batteries which gave me more power then the group 31 I had previously,,,,I believe you Could use a group 31 or maybe go with the cart batteries as well,,,, they even have blem batteries in either one for cheap,,,, Like 100 bucks ech,,,great buy for getting the best IMHO,,,,happy fishin!