How are you guys wiring the panel in? Do you still a hole or keep the wires outside direct to the battery or where does all the rest of the stuff go? Need to figure out the solar stuff as I would like to install a single panel on mine. I have one of those little ones that Is 5w and it keeps one of the batteries topped off if not in use but won't charge, just kind of my tender while it sits and even then the little bit of draw from the camper still pulls it down a little bit.