Now this is by far an electrical schematic, but it gets the idea across. I am working on a concept for wiring up my tool trailer and am wondering if this concept will work. After I drew this up, I realize, the battery maintainer should be connected on the other side of the switch. So the 110V should be direct to the switch, eliminating the junction. One thing I'm confused on is, how would I connect a solar panel to charge the battery? Would I need a second switch that connects the solar panel and the 110v line power to the battery maintainer?