
We have yet to take our first trip, but I couldn't wait. Actually I found used panels and a charge controller on Craigslist and picked them up the same day we got the trailer! Someone was selling a pair of 50 watt panels and a 15 Amp charge controller.
As it turned out, the hard part of this installation was not electrical but rather mechanical - finding beams to screw into, without perforating the rubber roof unnecessarily or causing leaks.
Some details on both electrical and mechanical install: