I bought a dokio 100 watt suitcase and clinko adapter plug off amazon. i used it on a 1 week trip over the 4th, worked fine, easy to move around as the sun moves, mostly propped it up between the propane tanks and front of the trailer. hard to say how much it charged the batteries, but combined with some occasional generator use, never ran out of battery power, including watching movies and kids on the ps4 pretty much every day.seems like a nice way to top off the batts for a minimal investment.