My existing unit is a Philips Respironics System One (model#460P — RemStar Pro C-Flex+ with humidifier and heated hose). The power going into the unit (after the external power supply) is 12V, max 6.5A and averages 2.2A.
There are battery-powered CPAP machines on the market:
General bits of advice:
- "Most batteries with enough 'oomph' for a CPAP are about the size of a car battery."
- Is a normal car battery capable of running a CPAP machine all night, and still have enough charge to start the car?
- Even if you could carry the weight, it's still impossible to hike with a normal (lead-acid) car battery, because they're vented / unsealed.
- A number of people used a deep-cycle marine battery
- There are several ways to reduce the power that your CPAP draws:
- Disable the heated hose.
- Disable the humidifier.
- Reduce the pressure setting. (obviously not a great option, but if you can get by with a little less pressure, it may be enough to make a marginal battery work fine)