1982 Holiday Rambler Solar panel install questions

I previously had an 1989 HR Imperial and had to purchase a hitch mounted metal storage box for added storage. It worked quite well as long as I didn't put real heavy stuff in it. I don't know if it would be feasible for yhou to store two or more batteries in a hitch mounted box. The box could also serve as a storage place for the panels when they were not in use.