My $270 100 Watt returnable Solar
My Working 100W Solar Panel System: Made It Myself For $270 - General After-Market Accessories Forum - The Casita Club Forums
I suggest you don't adhere the panel (s) to your camper because it's better to be able to move the panels into direct sunlight, and leave the camper set up.
I find I'll move my panels 3-4 times a day if there's a tree near me, in order to capture the most sunlight.
Get long (30 ft) cables from the controller out to the panel (s) so you can chase the sun, around trees and your camper.
My Patriot uses some electricity for the water pump and the propane
alarm. With LED's, I have plenty of light
inside for a few hours in the evening, and I never go below 12.5 volts. That's good. Even on intermittent sun days, it stays above 12.5 until morning when I can start charging, again.
Best of all, it requires no babysitting. I can leave it all day and it's charging without me. No fuel to carry, no moving parts, nothing to fix or rust. I drive with it on my bed, and have a thick chain on it when charging so no one can walk away with it without some rather large bolt snippers.
As the long post states, there's one technical issue, but it's easily dealt with.