ResMed CPAP machines can run directly off of a 12 volt battery, without the heated humidifier, using a set of connector wires with alligator clips on one end and a cylinrical plug to fit the CPAP machine's receptacle. You must connect the connector wires with the proper polarity to avoid damaging the machine. A $40 18 amp-hour gel cell battery will run a CPAP without humidifier for two to three 8-hour sleeps. You can recharge gel cell battery with a battery minder or other smart charger. Some CPAP machines like Respironics do not run on 12 vdc and must be powered by a 110vac inverter connected to your house battery, a seperate battery, or plugged into your RV's 12 vdc TV receptacle. My next CPAP machine will be a ResMed that runs directly off a 12 volt battery using a simple $40 battery connector harness.Check the specs for other brands/models of CPAP machines concerning whether they will work off 12 volt DC batteries or must use inverters providing 110vac.
