This battery box sits on my enclosed trailer and feeds my truck camper and trailer use. Charging comes from the camper convertor and truck alternators while the little 10w solar panel keeps it up when being stored. There are provisions for a second mounted panel, but I use the trailer enough that the single panel keeps the batteries from running down since there are no parasitic loads when sitting.
My enclosed trailer does carry an additional 100 lbs of LPG inside, but these bottles are not connected to anything when stored or transported. It also carries 15+ gallons of gasoline and 80+ gallons of fresh water for those longer boondocking trips.

