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Can I Power a CPAP With a Car Battery?

Although Continuous Positive Airway Pressure (CPAP) treatment brings many benefits to sleep apnea sufferers, it does impose one obligation -- you have to sleep near a power source. When you're camping, on the road or suffering a power shortage, powering your CPAP can be a challenge. Fortunately, there are three ways you can power your CPAP through a car battery.

  1. With an Inverter

    • An inverter converts DC power from a battery to the kind of AC power that comes out of a wall outlet. You can connect an inverter directly to a battery with clamps, or through the vehicle's cigarette lighter, and then plug the CPAP into the inverter. Just make sure the inverter is rated for the amperage draw of the CPAP machine (usually around 2 amps at 120 volts AC). Note that while this approach requires no special equipment, inverters aren't 100 percent efficient, so you'll use up battery power faster.

    Direct to Battery

    • Most newer CPAP machines have a DC power jack, so they can be directly powered from batteries. One DC adapter design has a plug for the CPAP machine on one end and battery clamps on the other. To use it, plug the cable into the CPAP machine, place the red clamp on the positive battery terminal and the black clamp on the negative terminal or the vehicle ground. Note that the vehicle can not be running when the battery is used in this way.

    Through the Cigarette Lighter

    • Another common design for DC power cables has a plug for the CPAP machine on one side and a large DC plug for a cigarette lighter on the other. This eliminates the need to open the hood, and this type of DC cord can also be used when the engine is running. You do need to make sure the DC lighter jack is also powered when the vehicle is not running --- some aren't.

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