Need battery backup for trip to Costa Rica - Resmed AirSense

[Extradish]

I am flying to Costa Rica for ten days and the tour company said that people who use a cpap should bring a battery backup, because the power in Costa Rica sometimes goes off for a few hours at a time. I see there is quite a bit about batteries on this forum, but I know technology changes rapidly, and am wondering if anyone can suggest a specific model. If I have to pay $300 I will do it, because I want my cpap to work during this trip I have been looking forward to. I have been using a cpap for a little over a year now, and I use a ResMed AirSense 10 with a Dreamwear nasal mask.

Honestly, I don't even understand how the battery would work. Do you have to choose between running the cpap normally or powering it by a battery, or do you hook up the battery and it kicks in IF the power goes out?

Any help apprecaited.

[klv329]

https://www.cpap.com/productpage/resmed ... hines.html

The color coded alligator clips for the cigarette socket attach to the battery terminals.

Then plug the resmed 12/24 DC converter into the cigarette socket.

Then plug the other end of the resmed 12/24 DC converter into the airsense.

If you will be in a hotel maybe getting a 12 volt battery in Costa Rica might be an option. I think the small portable batteries are expensive, but someone may be able to post a link to one that is more convenient for travel.

When the power goes out I: (1) unplug the AC power brick from the resmed, (2) disconnect the battery tender from the battery, and (3) connect the 12/24 resmed convertrt to the battery and reamed machine. Of course, this involves an interruption in sleep, as it did last Thursday at 1.30 am.

Of course, the set up I am describing also requires a battery tender available at walmart to charge and maintain the battery during the day.

Someone with more experience in batteries might be able to describe how to run the airsense off of the DC battery all night long while the battery is attached to an AC powered battery charger/tender so that when the AC power goes out there is no interruption in therapy and the airsense continues to operate on DC power throughout the night.

[CapnLoki]

Normally I advise on home backup and car camping systems based on lead acid batteries, but since you're flying you probably want a light weight lithium based system. The airlines & the FAA impose a size limit of 100 Watt-hours, which is equivalent to 8 Amp-hours from a 12V battery. This is enough to run one and maybe two nights as long is you turn off the humidifier and heated hose, which shouldn't be a problem in Costa Rica. You may end up charging every day to keep it ready.

There are a variety of packs of this size, but they are mostly targeting cell phone and tablet charging, and you'll have to make sure you can connect to your ResMed pump - you'll need a 12/24 volt ResMed converter, about $85.

Our site sponsor offers a pack that provides the 100 Watt-hours in a form designed for cpaps:
https://www.cpap.com/productpage/bps-fr ... y-kit.html
For a reasonable fee they provide a 12/24 adapter for use with ResMed. Still, the total cost will be a bit higher than your $300 target.

There are cheaper systems but they have been a bit quirky, so you should make sure they're well tested before your trip.

The solution offered by klv329 is a possibility, but implies buying a 12V battery locally and charging it there. A variant would be to bring a small charger and even a small AGM lead-acid battery. This would be much cheaper but is more of a hassle.

[Extradish]

Thanks for the great info. My husband is wondering why I couldn't just wire in series two 8 amp hour 12v lithium batteries to avoid having to buy a converter. Any thoughts about this?

[CapnLoki]

Thanks for the great info. My husband is wondering why I couldn't just wire in series two 8 amp hour 12v lithium batteries to avoid having to buy a converter. Any thoughts about this?

Not only does ResMed use 24 volts, but it has a proprietary plug and signal. If you like hacking electronics, you can find instructions on how to emulate it. I never thought it was worth it.