I’m one of those unfortunate souls cursed with a bad case of sleep apnea. For several years I’ve been sleeping with a mask over my face to make sure my airways stay open at night. My first CPAP machine was a Resmed S8 Compact. It worked well but I often had bad nights once in a while and last year I was finding that it just wasn’t working well for me. There’s nothing wrong with the hardware and I still keep it as a backup.

My sleep significantly improved when I bought a new Resmed S8 AutoSet II last year. It’s capable of automatically adjusting my pressure within a certain range. I’ve been very happy with that model since I got it.

However, just as glasses help with vision but are a problem when swimming, so is a CPAP a problem when camping or otherwise without power. We’re planning a trip for later this year when I may be away from power for several days at a time so I started looking at a solution.

At first, I looked at various sealed chargers/car starters that are basically car batteries in fancy packaging. Overall, other CPAP users’ comments weren’t promising and the cost seemed high relative to the usefulness.

Finally, I stumbled upon CPAP.com‘s battery backs made specifically for CPAPs. Specifically, I found the Respironics Battery Kit for S8 Machines, which includes the battery pack and the necessary DC adapter for my machine. I checked with a company that manages one of my health benefits and they replied that it was covered as an eligible expense (the check is actually in the mail now).

I ordered this product and it arrived quickly. Just to make sure it worked I charged it up and used it for two nights without a problem. It would have probably lasted longer but I didn’t want to run out of juice in the middle of the night and not realize it when I did have AC power.

It’s not light (17lbs) but it weighs less than most battery packs for this type of use and it’s not a problem to carry around unless one plans to hike into a campsite. Overall, I’m very satisfied with this product.

Note that with this battery pack, and most others, you can’t use the humidifier with the CPAP. It draws too much power. How much use you can get with a battery pack depends on how much pressure you need.

Respironics Battery Kit for S8 Machines (CPAP.com)

Updated 08/13/2011: So far the battery has held up well and worked exactly as expected. It had one good test while on a trip out in the west Texas desert. It provided power for the CPAP for two full nights while camping. I’ve also used it on a few overnight trips when a power receptacle wasn’t in a convenient location.

I keep it near the CPAP at home and about once a month I top off the charge, run it for two nights, and then recharge the battery again. I do this to help maintain the battery life and to keep it ready in case we have an unexpected power outage.

Updated 03/31/2012: While preparing for a long road trip I decided to bring my CPAP battery along but not to power a CPAP. Instead I’m using it to power various small electronic devices (iPhone, Nintendo 3DS, electronic cigarette charger) and it worked just fine using the standard car adapters for those items. This is an added bonus considering the cost of the battery. It also gives me an additional use for the battery. It might also serve as a good backup plan for charging my phone in the event that we lose power at home.