Operating your device with a Battery
Many people choose to use CPAP devices running on battery power in situations where mains power is not available, such as on camping holidays, or in boats and motorhomes. Some people use battery power in remote areas where mains power may not be supplied, or as a backup in areas prone to power failure. This Tech Note will help you understand the requirements for running a flow generator or humidifier from battery power.
Most common set of equipment

Does the following describe your situation?
- You wish to run a ResMed CPAP unit from a battery, and
the CPAP was manufactured in the year 2000 or later (it has a serial number beginning with 2000 or higher) - you do NOT intend to use a humidifier while running on battery power, and you intend to use the battery for a single night before recharging it
Then the following set of equipment will be suitable:
- ResMed flow generator such as S6™, S7™, S8™, AutoSet™ T or AutoSet Spirit™ (but no humidifier)
- A modified sine wave inverter with continuous power rating of 150 watts or high (available at electronics stores)
- A marine battery or deep-cycle battery rated at 50 amp-hours or higher (ask a battery supplier for help choosing
one)
Other situations:
If you have different requirements (such as needing to run a HumidAire 2i™ or HumidAire 3i™ humidifier, using a converter, running a VPAP, or needing to use battery power for longer than one night before recharging), then please read this whole document to ensure that you choose the best set of equipment for your needs.
Download the instructions on how to Connect a converter/inverter to a battery (PDF 125kb).