From CpapWiki
CPAP Power Options
LINKS to Battery operation, camping, power outage
Black and Decker 400
Around $100 at any Walmart, Home Depot and other major distributors. Comes with jumper cables. autobarn link:
Xantrex
Xantrex battery with built in trickle charger, is self contained, tidy and has a carrying handle. Available online and off-brand at CostCo. Amazon links:
Car Charger
Car Charger/DC Plug/DC Cable Purchase a power inverter for your car. It can be purchased from radio shack, walmart, or just about any store with an automotive section. It just plugs into the lighter outlet. If power is out for a few days, it can be charged from the inverter, assuming you can run your car for a few hours to do the charging.
CPAP.com link: DC Cable