(07-08-2022, 02:29 PM)BigMikes901Adventures Wrote: "...how to power my Dream Station 1. It draws 80w..."
80 watts seems way over the top for powering a CPAP, assuming you can turn the humidifier heat off (never used this model, but could turn off heat on all my prior CPAPs).
If you're getting the 80 watt figure from the Dream Station's "80 watt power supply", that figure likely means that's the most that power supply can safely deliver.
I can't predict what power draw your CPAP will have, nor whether you can tolerate CPAP without heated humidification, but you can try the latter at home (see above for my sleeping bag trick), and you can measure the former with a power meter. There are inexpensive power meters available on Amazon, starting at around $13. They wouldn't do for NASA, but they're close enough to get a good number on how much your machine is actually using via the power cord to get enough portable power.
I did a detailed overnight measurement* of my Devilbiss Intellipap Auto machine on the 12vdc side (I bought this machine 'cuz it will run on 12vdc - no efficiency loss from converting DC battery>AC>back to DC). My machine uses an average 4.9 watts. No heater, and 10 cm/H2O pressure, with pressure relief turned on.
If I'd measured at the plug on the AC side, using a wall-wart power supply, it probably would've used a little more for AC>DC conversion, and that additional power would all be lost as waste heat. So powering straight 12v DC, if you can do so, makes the best use of your naturally limited battery power.
So, turn off the heat, measure your power draw, or take the advice of someone here with an identical setup and pressure, and base your power delivery system on that. Test it at home before you head out on the road.
Hope this helps.
* Geeky details: I did this detailed DC measurement with a "Pro Micro" Arduino-compatible microcontroller, and current and voltage sensors, which are available on Amazon. I logged to an SD card every minute, and averaged. I did this measurement to size a rechargable Lithium-Polymer battery. A 3S battery has a nominal 11.7 DC voltage, which runs this CPAP just fine. If you were to go this route, you'd quickly realize as I have that there's no FAA approval for a non-medical LiPo battery I wired up myself, so no in-flight on battery if they want to bug me. Also, LiPos of an appropriate size are typically used for R/C, outdoors, and they're used to battery fires and they take precautions (battery safety bags/bunkers for charging, etc.). I have to contend with the inherent fire risks of using Lithium batteries, while charging, discharging, dropping it, can't put in checked bags, can't ship unmarked, etc.