I am trying to figure out a good way to have my interior lighting work on mine without having to have the truck running, which is how it works now. I wouldn't mind having battery power in the trailer and keep it charged when the truck is running and towing but it's not quite as easy as it sounds. I do have a battery on the trailer for emergency break away braking and it charges while the truck is running but it's just a little battery really only good for emergency braking use. Don't really want to tie the lighting into that. Thinking about a battery with a solar charger.