Update,
I installed the 6 volt energizer batteries from Sams Club, and the solar kit. I glued the flat panels directly to the roof membrane, and wired up the simple controller that came with the panels. I used the 10 gauge wires that were factory installed, plus a few extra as needed. It worked out good. I spent a month in the camper, and never had an issue with low batteries. I did drive around quite a bit, but I had a few instances where I spent 3 days in one spot, running the furnace and the cpap machine all night, charging the phone and the laptop, and the batteries stayed up with no generator or no truck running.
Also, I ended up driving into a 30 mph head wind, doing up to 65 mph, and the panels didn't blow off.
So I consider the installation a success!
