I specifically bought a 12 vdc machine so I could take it on a boat or RV with the least hassle even though I would have preferred the ResMed LCD display.
Next month I think I will get a 100AH or better deep cycle bat and an appropriately sized charger an build a DIY uninterruptible power supply. My wife IMO will be getting a cpap machine soon so a battery box with 2 12vdc sockets, charger, and LCD state of charge voltmeter sounds like a good idea.
If experience is any guide once I am prepared for a power outage it will never happen again LOL
Updated: Philips Respironics System One (60 Series)
RemStar BiPAP Auto with Bi-FlexModel 760P -
Rise Time x3 Fixed Bi-Level EPAP 9.0 IPAP 11.5 (cmH2O)