How to Buy the Best CPAP Battery for Your Machine

Summer is a time to explore scenic routes, sip margaritas by the beach and set up camp under star-studded skies. The days grow longer and we have more time to just think. As you sit there, listening to the chirping of crickets and basking in the slowly fading warmth of the day, your mind wanders to your neighbor, Steve.

Steve, who won’t stop talking about how he sleeps like a baby while camping, thanks to his new CPAP battery. You know you should really get a CPAP battery too, well aware that your sleep apnea symptoms return when you miss out on therapy. Despite all this, you still leave your CPAP at home because you’re not sure how to buy the best CPAP battery for your machine.

To help CPAP users make sense of the battery buying process, we’ve created this guide which lists important questions to ask before you buy a CPAP battery for camping or travel. This guide also provides useful tips for informed buying decisions.

In This CPAP Battery Guide:

Let’s start with an introduction to what CPAP batteries are and why you should use one.

What Are CPAP Batteries?

CPAP batteries are portable lithium-ion batteries that provide backup power to your machine. They come in various sizes, with most of them around the size of a tablet. Depending on the brand and model of CPAP machine they are designed to work with, they can be either 12V or 24V. These batteries can be used as a stand-alone power source and/or as an uninterruptible power supply (UPS), depending on the battery.

A fully charged battery can typically run a CPAP machine (with heated humidifier and heated tubing disabled/removed) for up to 2 nights on an average pressure of 10 cm H₂O. However, when you add a heated humidifier and heated tubing to the machine, your battery runtime will decrease by at least half.

Why Should I Use a CPAP Battery?

CPAP batteries are great for frequent travelers and camping enthusiasts. They can power your machine when you’re camping off-grid or on a long-haul flight so you don’t need to suffer any interruptions to your sleep therapy. UPS CPAP batteries are a good investment if you live in an area with frequent power outages, as they ensure your CPAP continues to operate when the power goes out.

Can I Use a CPAP Battery With a BiPAP Machine?

BiPAP machines use more power than CPAPs because they deliver higher pressures and come with more advanced features. BiPAP machines with more advanced therapy modes, such as a BiPAP ST (Spontaneous Timed), even provide backup breaths to the user. You can imagine then, that these machines use a lot more power in comparison to a CPAP and won’t run very long on a CPAP battery.

If you use a BiPAP machine, make sure you look for a battery that is compatible with your specific BiPAP brand and model. There are many different types of BiPAP machines, (auto BiPAP, ASV, BiPAP ST, BiPAP ST-A) so knowing your specific BiPAP brand and model ensures you purchase the right battery.

The Philips PAP Battery Kit, shown on the left, is one of the few batteries that are compatible with both CPAP and BiPAP machines. This particular battery supports nearly all Philips Respironics CPAP and BiPAP models from the System One 60 Series to the latest DreamStation 2 Auto Advanced CPAP. It is both a stand-alone power source and an uninterruptible power supply.

What to Know Before You Buy a CPAP Battery

In this section, we’ll look at important questions you should ask before you buy.

What is My CPAP or BiPAP Machine Brand and Model?

It’s important to understand that most batteries are machine-specific. Take for instance, the Medistrom Pilot-24-Lite Battery which is only compatible with specific 24V CPAP machines. If you have a 12V CPAP machine such as the DreamStation 2 Auto CPAP Advanced, you’ll need the Medistrom Pilot-12-Lite Battery instead.

Another example is the Transcend P8 Travel Multi-Night CPAP Battery which is designed exclusively for the Transcend Micro and Transcend 3 Travel CPAPs. Compared to the Pilot-24-Lite, this battery is even more exclusive as it only supports select Transcend devices.

There are also universal CPAP batteries that work with all brands and models. A major advantage of these batteries is that they won’t become obsolete if you replace your machine.

For example, if you were using the Medistrom Pilot-12-Lite Battery with your Philips Respironics DreamStation Auto CPAP and then decided to replace the DreamStation with the ResMed AirSense 10 AutoSet, you’ll have to purchase a new battery because the AirSense 10 is a 24V machine. However, if you have a universal CPAP battery, your battery will still be compatible with the new CPAP machine.

Does Insurance Cover CPAP Batteries?

Most insurance providers do not cover CPAP batteries because they do not consider batteries a medical necessity. Since CPAP machines can be powered by an AC power source, a battery is considered an optional accessory.

We provide a detailed list of items covered by insurance in our article “Do You Bill My Insurance Company?”

What is the Maximum Battery Runtime?

Battery runtime depends on various factors such as pressure setting, therapy mode, altitude, temperature and humidifier and/or heated tubing use. Most battery manufacturers state their product provides 1 to 2 nights of continuous use at average pressures.

What they mean is that you can expect 1 to 2 nights of runtime at a fixed pressure of 10 cm H₂O without a humidifier and when using a non-heated CPAP hose. Heated humidifiers and heated CPAP hoses use a lot of power so we recommend leaving those at home or turning off the humidifier.

Auto CPAP mode also drains the battery, so if you’re using auto CPAP mode instead of fixed pressure CPAP, expect your CPAP battery to last for one night of continuous use. Similarly, if your CPAP pressure setting exceeds 10 cm H2O, the battery runtime will be reduced as well.

How Do I Connect the CPAP Battery to My Machine?

Many batteries connect to machines via adapter cables. These adapter cables are machine specific and may be included with the battery or they may have to be purchased separately. Once you know the brand and model of your device, you can easily confirm whether you need to purchase any additional cables.

If this sounds like a hassle, you can opt for a battery that doesn’t require any cable connections. Such batteries eliminate the need for specific adapter cables since they come with an AC outlet that you can directly plug your machine into. Think of these batteries act as portable wall sockets.

An example of a battery that does not require any adapters is the Zopec EXPLORE Oxygen CPAP Backup Battery. This battery features two 110V AC outlets and is compatible with all brands and models of CPAPs and BiPAPs.

Learn more about this universal CPAP battery in our 2023 Best CPAP Battery Review.

How Do I Charge the Battery?

It may surprise you to learn that many CPAP batteries don’t come with an AC power supply. Instead, they are charged using the CPAP’s power supply. Of course, since CPAP batteries are designed to be used when there aren’t any AC power sources around, most of them can also be charged using your car, boat or RV with a DC converter. These battery specific DC converters are sold separately.

In addition to DC power, many batteries can also be charged using solar energy. Battery manufacturers make foldable solar panels that are portable and lightweight, making them perfect for backcountry camping trips. Bear in mind though, that charging times will vary greatly depending on weather conditions.

Is the CPAP Battery FAA-Approved?

Only FAA-approved CPAP batteries can be used in-flight. This is important because while airlines allow passengers to use CPAP machines on the plane, in-seat power may not be available on all aircrafts. Additionally, some airlines do not allow passengers to use in-seat power for their machines.

For more information on flying with a CPAP including packing tips and using a CPAP overseas, check out “How to Travel with a CPAP Machine.” We recommend becoming familiar with your airline’s in-flight CPAP use policy well in advance of your flight to avoid potential interruptions to your trip.

If you don’t plan on using your CPAP on the plane but wish to bring your CPAP battery to your destination, keep in mind that uninstalled lithium-ion batteries are not permitted in checked baggage. They must be packed in your carry-on luggage. Additionally, each passenger is limited to two lithium-ion batteries, each with a capacity of 101-160 watt hours.

Preparing Your CPAP Battery Before a Trip

Before disappearing off into the great outdoors or hopping on your red-eye flight, it’s important to have a sense of how long your battery will last. Fully charge your battery according to the user manual and use it at home with your CPAP machine. Make sure to use your CPAP in the exact same manner you plan on using it during your trip.

If you plan on using your CPAP without a humidifier, test out your battery with your CPAP humidifier removed or turned off. If the lack of CPAP humidification causes unpleasant CPAP side effects such as dry mouth, sore throat and nasal congestion, we suggest adding a heat moisture exchanger (HME) to your setup.

A HME is a small filter that provides heated humidification in place of a humidifier. It’s a convenient way to enjoy the benefits of a humidifier without the added bulk and the need to pack distilled water. Simply place the HME between your mask and non-heated hose, and it will recycle the heat and moisture from your breath to prevent CPAP dry mouth and nose.

See how HMEs work and learn about the various HMEs for different CPAP machines:

CPAP Battery Guide: The Takeaway

A CPAP battery is likely the most expensive CPAP accessory you’ll buy for your machine, so it’s a good idea to do your research. Make sure you know the brand and model of your machine to avoid battery-machine incompatibility and always check whether you need any special adapters to connect the battery to your CPAP. You’ll also want to ensure you know how to charge your CPAP battery pack.

Equally important is understanding the specifications and features of the battery—what is the battery runtime when fully charged? Is it FAA-approved? Does it kick in to provide power to my CPAP during a power outage? All of these are questions to ask when comparing batteries so you can find the right one for your needs.

We hope this CPAP battery guide provided you with a better understanding of CPAP batteries and a clearer idea of how to shop for one. If you have additional battery questions, feel free to contact us using one of the methods below.

The RespShop medical team is happy to help you find the best CPAP battery for your machine or answer your sleep apnea related questions.