I am in the market for a new charger. I do not leave my batteries in my boat i put them in my shed to charge them. Have been through a few chargers throughout the years with not much longevity from any of them. Looking to be able to charge more than one battery at a time if possible. Minn kota offers one (portable type) that will charge two at a time. Is it possible to use a on board type charger in my shed to charge batteries. Any help would be appreciated.