Originally Posted by
Hatchet_1697
I use the Z1, and being an engineer-hiker I contacted the manufacture for info and ran my own tests to find the lightest possible solution. The manufacturer will say the only solution is to use their medical grade batter pack; I never saw the need for a battery with the medical certifications (e.g. won’t spark in a high oxygen environment) on any trail. It’s also not weight efficient. So any decent lithium ion battery pack (lightest battery technology available) that will not automatically shut off will work.
From a very helpful HDM technician, I was told the Z1 is designed as a 15VDC device with a minimum voltage of 11.8VDC (before it shuts down) and a maximum voltage of 16.5VDC. So a 12-16VDC battery capable of supplying up to 2 amperes and has a 2.1mm x 5.5mm plug will work.
I use a 15VDC battery from bixpower.com (MP100-15V) and it is 98Wh. The Watt-hour (Wh) number will determine how many days you can go between charges. In my testing the Z1 uses an average of 19.6Wh per night (avg. 7.5h of sleep), so I get ~5 nights of sleep between charges if I don’t also use it to top off my phone.
Your usage will differ depending on the settings. Automatic (APAP) uses more power than Continuous (CPAP) due to the need for pressure changes. Higher pressure uses more power than lower pressure, so finding the lowest setting that works for you will extend battery life. The all-knowing Google can tell you how to hack into your device and change the settings.
Z1 CPAP (10.8oz) Z2 should be similar but quieter
4’ Hose (2.2oz)
Mask (1.15oz)
MP100-15V Battery (30oz)
Battery Charge (7oz)
A few other tips: Don’t bother with the HDM moisturizer adapters, they add weight, don’t work that well, and saline spray is lighter. Use the shortest hose possible and SleepWeaver cloth masks are the lightest. Keep the battery and Z1 in their own waterproof bag; water and 98Wh of power do not mix well. At shelters/campsites I tell folks near my hammock I’m using one in case they hear it, and point out the slight electric-fan / breathing sound is much better than the alternative noise they would be hearing.
Hope that helps, good luck!
H