Corrected Post: I had "ResMed" and "Respironics" info reversed.
I was thinking of the lesser weight (15 pounds)and portability of an 18amp/hour gel cell battery as used in my mobiility scooter. I opted for an automatic model ResMed S8 Autoset II machine last time and it accepted 12vdc power without an battery/inverter pack. The current ResMed S8 models do not allow direct 12vdc power but Respironics still does. You can use a cheap Radio Shack battery cable. There are cheaper non-auto brands and models, some of which accept 12vdc, some requiring a battery/inverter pack or equivalent probably to accomodate a heated humidifier attachment which I don't need/use. I have plugged my CPAP into my emergency car starter thing. I haven't checked amp draw of current CPAP but recall that most draw about 1/2 to one amp (like one 12 volt light bulb). Almost anything considered "medical" costs like crazy. Don't leave home without your CPAP and periferals for camping off grid.
