I have been using a C-pap since I was 32 years old, I'm 56 now. My insurance Co. Buy's me a new machine every 3 years. So I've had multiple brands and have always used on camping and hunting trips ever since. I ordered a 12 volt ciggarete lighter end and tried to run from my truck to a tent. Not enough powewr, so I removed Cig Male end and put battery clamps and hooked directly to my truck battery and it worked problem free for years,(I still have that cord in case of an emergency) My current machine runs of my inverter tied to 4 6v 120ah battery bank. I remove the Humidifier and it draws 2a, problem free.
Mel