When we had the trailer, my significant other had a Resperonics, so I hooked up a 12v outlet and and plugged in a small inverter and it worked fine for her. 2 12 volt batteries didn't have any problem keeping it going all night.
Then I was diagnosed as needing one. I started with a GoodKnight, but the blasted thing wouldn't work for more than 6 months or so without breaking. And eventually nobody in town carried them and the factory wouldn't accept it from me directly. So I got Resperonics' new model, the one which senses you breathing out and drops the pressure (forget what they call it). Wow, what a differance. Now I almost never wake up with mask leaks. The motor home does not have 12v outlets, but I could easily add them (mine runs off 12v directly). Its just that we never boondock in the motorhome, so I haven't got around to it.
John (40' 2004 Country Coach Inspire DP)