There is a kit that will work to charge a pair of batteries with solar panels on the roof of your truck camper, and it also includes the controller you'll need:
- Go Power Solar Flex Eclipse Charging System # GP67MR
The # GP67MR comes with a 190 watt solar panel, works with lithium, sealed, gel, and flooded lead acid batteries, the controller has a 30 amp input, and it includes the cables needed to go from the panel to the controller. It also has available expansion kits should you choose... view full answer...
I have a solution for you:
**Stromberg Carlson Folding Handrail for RVs - Stainless Steel - 24" Tall - 200 lbs # AC-300.
*Grip Tape with Adhesive Backing - Black - 16' x 2" # PT57ZR.
With your steps I recommend the SC folding handrail, you can mount it near the door in any location to help you traverse up and down.
I also suggest putting down some grip tape on the steps to help out too. view full answer...