Knowing nothing, I was curious (there's also an apnea comment). It seems travel CPAP and APAP (auto pressure) is a thing, but travel BiPAP (inhale/exhale pressures; required by some conditions) not so much. A recent reddit comments suggest non-existent (exhalation relief only). Most all need Heat Moisture Exchange plugs. Yet I noticed eg the Philips BiPAP Pro Bi-Flex, bit of a brick (1.5 kg; 2500 linear cm - but qualifies as a medical device), but its spec says ok for airlines w/o humidifier attachment. So I'm puzzled.

So airlines allow 2 batteries of up to 160Wh (with airline approval) and as many 100Wh batteries as you can carry [note: I have not actually tried to show up to the TSA security line with a suitcase full of 100Wh batteries, so your mileage may vary].

A BiPAP machine uses 50-150 Watts, according to a random Google query, so you're looking at somewhere between 500 and 1400 Wh of total storage to get your 9 hours of sleep on a plane.

So what you're looking for is (a) a way to daisychain these batteries together so that you don't need to wake up ever 40 minutes to 2 hours to swap batteries and (b) a way to plug in your BiPAP machine, if your battery packs are all USB-C and your BiPAP isn't.

Ehm this is not really accurate. Not many people use a BiPAP machine. They're only for very old people who have serious difficulties breathing. A BiPAP machine can serve a largely different pressure for exhaling and inhaling, a normal CPAP machine can only do that with about 2cmH2O difference which isn't a lot. But normal people have no issue exhaling against the output of a CPAP anyway so it's not a problem.

For this reason BiPAPs have much more beefy motors so they can ramp up and down quickly. Or perhaps two separate motors, I have never taken one apart (I have normal CPAPs which is basically just a pressure fan in a box with some regulation electronics)

But anyway my point is, a normal CPAP doesn't use that much power. It may use more than that if a humidifier is used (which is probably not a bad idea on a plane, but it requires distilled water which is an issue to bring on the plane in sufficient quantity). Because the humidifier is just a heater and heaters use lots of power.

I don't use a humidifier, my CPAP has a PSU of about 60W but I doubt it uses more than 20. The problem is more that they are not USB-C powered, nor are there official USB-C converters for it. I could probably construct one but bringing home-built electronics on a plane is probably not a great idea either.

So yeah I don't think this will be a great option tbh. If power is provided on the plane it would work but I've never seen this on my flights except in business/first.

Sorry, my bad - regional availability and cost were the challenge, not BiPAP-ness. A Luna TravelPAP looks 20 W max and there's a USB-C cord. Heat and humidity is separate - a disposable sponge.

Given 100Wh batteries, I've wondered if one could kludge a TSA-compatible carry-on electric mobility device, like skateboard wheels plus selfie sticks, as a one-bag travel scooter. My hungry laptop already needs several. Or carry a conversion kit for an "amazon, use, then give away" inexpensive manual kick scooter.

BiPAP is very very rare. It's only for very frail people that probably don't fly anyway. A BiPAP can lower the pressure considerably when the user exhales, that's why. They need power to ramp up/down quickly. Most people have a normal CPAP or an Auto CPAP. The auto mode is often used to determine the optimal pressure and then that is set to be fixed (because the ramping up/down of the auto mode can be annoying).

Travel CPAPs are a thing but you can't just buy one where I live. They're only supplied by the medical service here, and they don't do travel versions. It's not allowed to buy one yourself (and they're very expensive, around 700 bucks).

> you can't just buy one where I live [...] very expensive

Ah, ok. Tnx. I assumed availability(eg [1]), so with a $1k-ish cost similar-order to travel, I wandered off looking for other obstacles.

The HME plugs used with travel CPAPs instead of a humidifier, with calcium chloride foam to transfer heat and moisture from exhalation to inhalation, looked interesting tech with winter coming. But for day-ish replacement.

[1] https://www.youtube.com/watch?v=hHSc1N0ervY

Oh yeah I can't stand humid air anyway, it makes me feel like choking. So I do without a humidifier even though I get nosebleeds in winter. I tend to rub some lip balm inside my nose and it alleviates it somewhat :P

And yeah the Resmed Airmini and Breez Z2 are the only ones I've seen for sale in my previous country (where it was legal to buy them personally if you have a prescription) but they added up to well over 1000 euros with the battery kit which for some weird reason is not included. For my country (medium-wage) that's pretty steep.