http://www.thepowerapp.com/ The "humless" generator. Supposed to be quiet and can be charged with AC power and then stored. I don't know much about supplemental power, but if I was dry camping and I wanted to keep my computer or electronics charged or the fridge if I ran out of propane. IDK, i am just looking at lots of different things. I looked at genneys, but the one I looked at was way too heavy to pick up and if you want to keep things running while you're gone leaving it in the truck wouldn't make much sense. I was also thinking about it as a backup at home in case of power failures