to follow Dans recommendation and and get something like the Black and Decker charger. Not a thing in the world wrong with that if you plan on installing something larger and more permanent later. The second way, the way I did it, is to buy a marine charger that is just large enough to handle the loads you expect to have someday and install it hard wired in with a disconnect switch. Then, down the road, install a larger charger or maybe a charger/inverter to run normally. That way if your charger tanks some rainy night you just have to turn it off and turn on the other one with the flip of two switches. It's a good thing to have redundant systems especially if you are away from home/ the dock much of the time. If you're going to spend the money anyway, why not do it right?