[atreis]

You can convert 12V DC (from your batteries) to 117V AC using an inverter. There are two basic types - modified sign wave (MSW) and pure sine wave (PSW). The former are cheap, but the power is noisy (stepped square wave instead of a sine wave) and won't work with everything. The latter are more expensive, but the power is clean.

HOWEVER - you'll find that cpap machines take a lot of juice and will drain your batteries quickly. This will lead you down the path of also needing a fair amount of solar panels or a generator.

Storms came through here Saturday... Lots of damage. I feel for the people at the campground near my house (which was without power for two days - along with my house, but we have a backup generator).