fisherman is spot on with his advice and the 6volt thing just seems weird to me just buy a better 12v battery like an agm. cabelas agm grp 27 batteries are on sale right now for $169. i had a 3bank charger on my boat for a 24v trolling motor and my one starter. the new used boat i am upgrading to only has a 2bank on-board charger so for $40-$50 i'm going to buy a single water proof battery tender for the starting battery, rather than spending $300-$400 on a new 3bank unit.
