Paul_P

I've been researching battery power for my cpap machine and came across this product :

The Future Starship Power Bank

40,000 mAh, Power Delivery 3.1, 140w usb-c, usb-a output ports -- 900g

The interesting part is the accompanying 140w GaN charger can recharge the battery in 1.5 hours. This makes it possible to recharge during a meal or coffee break somewhere with an outlet.

159 $US, 209 $US with the charger. Due to be available in december.

While this is an inherently risky kickstarter project, the AOHi company does have existing products including a less powerful powerbank (30,000 mAh).

A USB-C PD trigger module or cable is probably also necessary to invoke the voltage required by the CPAP machine.

Tourist in MSN

Just an FYI, I am clueless on this topic, but I recall a thread on this topic recently, at:
Touring with a CPAP

Yan 

Just be aware that the largest battery allowed by airlines is 27k mAH.

Paul_P

Yes, thanks, I read that and this thread is sort of a continuation of that one with new info.

What I have yet to establish is how many mAh I need per night, taking into account that the powerbank's rating is way above it's effective capacity.
In my favour is that my machine is a Philips which requires 12v which is easy enough to set up (all voltages are a conversion from lithium batteries' 3.something voltage).

I read a post where someone claimed to have gone five nights on a 40k mAh powerbank, though this seems pretty optimistic.

I won't be flying anywhere, not that I wouldn't want to...

Tourist in MSN

Just a reminder, you saw in that other thread that I commented that Li Ion batteries lose capacity in cold weather. I have found that turning on my phone and getting a weather forecast could cost me 10 percent of my battery when it was in the 40s (F), where if it was in the 70s (F) it might have only cost me 2 percent of the battery capacity.

So, at night you might need a plan to keep your battery warm if it is a chilly night. I have no idea if keeping it in your sleeping bag is practical or not, I warm up my blood sugar meter in my sleeping bag while I am still in it in the morning before I take a reading. And if I want a weather forecast, same with the phone.

Paul_P

I've slept with water bottles before, when camping at -20c/-4f.
Battery + cable shouldn't be a problem, especially if it lets me sleep.
Nor sure about pumping cold air directly into my nose, though. Never tried it.
I think I'll stick to warmish weather anyway, for weight-related reasons.

JohnJ80

I'm an electrical engineer and I had a friend with whom I travel ask me for help with this. You don't have to get all whacky with batteries to run most CPAP machines. Look at the AC Adaptor and get the wattage and voltage on the output side. Many of them have pretty standard voltages. And they almost all have a cigarette plug adaptor that expects 12V input. So, it then becomes a case of getting an appropriate standard USB-C PD battery, a trigger cable for the right voltage and then matching the plugs. What I did for him was find a 20,000mAH battery that was around 74WH capacity. His CPAP was a Z2 travel CPAP and we were able to find a 15V USB-C trigger cable on Amazon that plugged directly into the CPAP. That battery will give him around 2 nights of CPAP usage with probably about 30% of the battery left over. I imagine that's going to very by machine and by the user's demand and habits. I'd guess that a 100WH battery should be fine for most everyone for at least one night. As well, that's the max size you can take on an aircraft without any special permission or anything.

Then, get a compact GaN USB-C charger that puts out 60-100W and with that, you should be able to charge that 75WH battery in 45-90m depending on the adaptor. I prefer the ANKER adaptors on Amazon that folding plugs and one or two USB-C ports. They are tiny, they weigh nothing and they will charge the battery very fast.

The medical guys make this super complicated but it really isn't and it's more a matter of getting or making the right cable to attach the right connector to your USB trigger cable. If that's intimidating, then you can always get the 12V cigarette plug adaptor for a car for the CPAP and then make a converter cable that goes from a 12V trigger cable to a female cigarette plug and you're good to go.

We set this up several years ago for a sailing trip our families took. It's worked fine and we've just refined it from there.

Here are the parts we came up with: UZE Bold 265W,100WH power banks.

Trigger cable, in our case 15V although you can get them in 5V (i.e. straight USB), 9V, 12V, 15V, and 20V.

Anker Power adaptors (these are really cool) and come in 67W and 100W versions.

You'll also need a straight up USB-C PD cable that can charge at 100W. There are a multitude available. Important to get a 100W version.

We were able to make this work with two different travel CPAP machines he had. One was a Z2 (don't know the company), and the other was some Transcend machine. The Z2 took a 15V trigger cable and the other one took a 20V cable (its power adaptor said 18-20V).

The whole thing is quite compact and works very well. As well, most of the components have multiple uses while traveling. For example, since the battery has plenty of capacity for a night, you would have the ability to use it to charge other devices. When that particular battery is charging, you can also use it as a charging hub to charge phones, bike computers and other stuff at the same time. There is also a charging puck for an Apple Watch built in. The power adaptors are straight up USB-C with at least one USB-C and one USB-A port. So you get extra charging ports there too. If you got the 100W version, you should be able to charge everything up pretty quickly in maybe an 45 minutes or so for the battery and maybe a little longer if you add more stuff.

J

Paul_P

John, the reason I started this thread is because things have evolved a bit since the previous thread on cpap batteries. Bigger batteries are available, but the big thing is the time to recharge them. This is especially important for camping, making multiple nights possible and recharging at a rest stop when necessary. A lot of existing big batteries/chargers can take 6-8 hours to recharge which is difficult to achieve while camping.

The new thing seems to be Lithium Graphene batteries and chargers like this GaN 270 watt one.

The Z2 is by Breas and is very attractive given its size/weight at 10.5 oz / 300g.

DCwom

I'm a "medical guy" and an electrical engineer. Its the FDA (in USA) and risk mitigations that makes things complicated, its about safety. Any deviation from a medical device manufacturer's Instructions For Use can lead to unknown consequences and therefore unknown risks. With that said you can do what you want, people usually do. Personally I'd be more concerned about the safety of what battery you use more than the CPAP connections.