CPAP on battery power

Using a battery to run your CPAP machine is something that everyone eventually wonders about, whether you're planning a camping trip or just worried about an outage due to a storm. Your CPAP machine can be run on a battery, but the details of how to do so depend on the brand of CPAP machine. And the type of battery you'll want depends on the conditions under which you plan to use it. Any battery that you use will eventually need to be recharged or it'll stop working. And regardless of your situation turning off the humidifier on your machine will help save battery life as the heater used to warm the water in the humidifier is by far the biggest energy draw.

The amount of charge stored in a battery is measured in amp-hours. If you have, for example, a 20 amp-hour battery that means that you can supply 20 amps of electric current for one hour, or 10 amps for two hours, 5 amps for four hours, and so on. The number of amps times the number of hours gives you the electric charge measured in amp-hours. The greater the number of amp-hours the longer your battery can run without needing to be recharged.

The rechargeable battery with the largest number of amp-hours is the lead-acid deep cycle marine battery. These batteries are heavy and bulky, so if you desire something more compact or light weight you will have to sacrifice amp-hours to get it. One good alternative to lead-acid batteries are lithium-ion batteries.

Another factor to consider is the type of electricity needed for your CPAP machine. Is it ac or dc? And how many volts does it need? Batteries supply dc electricity, the electricity in your home is ac. Most CPAP machines require 12 volts or 24 volts. The electricity in your home is either 120 volts or 230 volts. When you have your CPAP machine connected to the electricity in your home the machine has takes care of converting the electricity for you, so you don't have worry about it.

In the case of Respironics machines the 120 volt or 230 volt ac electricity in your home is converted to 12 volt dc electricity. You can therefore connect a Respironics CPAP machine directly to a 12 volt battery.

Many manufacturers will sell you a battery pack that will change the dc electricity of its battery to the ac electricity normally provided in your home. This is referred to as an inverter.

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