Thanks for the comments and suggestions.
CPAP's are one of the joys of getting older.
My model is a Respironics PR System One REMstar 60 Series Plus with humidifier (
http://www.thecpapshop.com/respironics-pr-system-one-60-series-plus-with-humidifier-tube). I use 11cm (it goes up to 20), so it'd probably be less than the 5A listed on the device, and even less without the humidifier.
I'm an occasional hunter & camper, but use an old trailer or tent without internal batteries, so would be able to carry the weight of batteries. For short term home use, I could use a generator, but that would quickly use up fuel supplies, at night, and possibly attract unwanted attention, if the wrong scenario played out.
I am looking into this device as a non-CPAP option
http://www.glidewelldental.com/dentist/services/removables-silent-nite.aspx. With the cost of going to batteries, that device may be a better option.
Thanks.