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As the title suggests, this post describes using the HDM Z1 on battery at high altitude. I am writing this to give back to this community as I was able to learn useful information from posts in this forum. Hopefully, some of this info and data will be useful to others. Now for disclosure: None of what I am writing on this forum should be considered advice. I am simply reporting what I did and what worked for me. What I will describe is not within manufacturer recommendations and to be safe everyone should follow their own device manufacturer and physician recommendations.

So I am a new PAP user with a new sleep apnea diagnosis. I had plans for an 8 day trek up Mount Kilimanjaro and in the process got a checkup and a new diagnosis of sleep apnea a couple of months prior to the climb. I was prescribed an APAP unit and got a Resmed AirSense 10 and finally settled on a Dreamwear full face mask. I started looking at portable units and battery supplies for the seven nights, not planning on recharging during the trek.

I selected the Z1 for a number of reasons (cost, controls on the device, and 12v supply.) The HDM battery solution was not as appealing due to high cost and I needed 7 nights on battery and was not sure how many nights I was going to get from a battery. I wound up getting a Talentcell 12v lithium battery from Amazon (really 11.1v nominal, 3s3p.) https://www.amazon.com/gp/product/B016BJCRUO The battery ranges from 12.6v with a cutoff at 9v. The plug on the HDM Z1 is a 5.5x2.1mm power connector but it will also work with the 5.5x2.5mm plug that came with the battery so it will connect directly. The battery will power the Z1 but it does not work reliably even at full charge. During use it will shut down. (I think due to voltage dropping below the specs for the HDM batttery which is 14.4v nominal.) The power supply that came with the Z1 APAP is 15v, 30 watts. Still interested in using the battery, I bought a boost module for 12v to 15v (9v to 14v input rated at 75 watts) https://www.amazon.com/gp/product/B01116VJP6 In order to get a better idea about remaining battery life I used a watt meter on the battery output so that I could record the watt hours used each night. https://www.amazon.com/gp/product/B001B6N2WK I mounted the boost module and watt meter onto a lipo safe bag (for a phantom battery) with a 90 deg power connector for the battery and 6 foot lead for the Z1. https://www.amazon.com/gp/product/B0714FJ45Y/ The boost module puts out 15v (I do not have a scope but just measured with a voltmeter) and the Z1 runs fine with the wall plug indicator on the screen and likely cannot tell it is on battery. The battery has an advertised output of 12v at 6amps and the boost module 75 watts (I did not test either but both are well above the 30 watt rating of the Z1 supply).

I found the Z1 noisy with the Dreamwear mask and tried the HDM Q1 muffler which helped some. I changed to an Amara view mask which worked better for me with the Z1 as I think the tube noise is the problem and on the Dreamwear it has tubes next to both ears. I also added a tube cover as I was planning on using it in cold temps. https://www.amazon.com/gp/product/B00AJW7S40?th=1 For me, the cover helped further with the noise and I removed the Q1 muffler which I personally felt restricted the flow rate.

The following was testing the Z1 at sea level on APAP 5-20, Z-breathe 2, bluetooth off, 4' slim hose, amara view mask, with the time and pressure listed below from the nitelog app, battery consumption from the watt meter:

6.7 hours, 8.1 cm H2O, 21.1 Wh
7.5 hours, 8.2 cm H2O, 25.6 Wh
7.6 hours, 8.3 cm H2O, 25.8 Wh
7.6 hours, 6.8 cm H2O, 21.1 Wh

The battery gave up after an hour into the 5th night and I switched back to the AC adapter. So I got around 100 Wh out of the battery which is what I was expecting (it is over specd at 132Wh.) The above draws are measured from the battery. The boost module has a claimed 93% efficiency so the actual draws from the unit should be a little less than those listed above. The average draw over those four nights would be 3.18 Watts (total Wh/total hours.)

I was also concerned about low temps (below freezing) and lack of humidification while climbing. So I experimented with placing the Z1 unit in the bed with me to draw warmer more humid air. In order to avoid restricting the airflow into the device I placed it inside an expandable mesh (pop-up butterfly tent.) https://www.amazon.com/gp/product/B006V7NCMY It seemed to work OK and was less noisy under the covers.

I would have liked to have more time for testing but I was quite happy with the battery supply getting 4 nights at home. I bought two more batteries and set off for Tanzania. I used the Z1 on battery for 7 nights all at altitudes above the recommended operational limit of the device. The temp inside my tent dropped to at least 36 deg F on summit night. I did increase the min pressure to 8 and then 11 cm after a couple of nights. The following is my data for the 7 nights including the altitude:

#1 - 8694 feet, 6.7 hours, 8.4 cm H2O, 27.2 Wh
#2 - 11,844 feet, 7.2 hours, 7.9 cm H2O, 29.4 Wh
#3 - 13,780 feet, 7.4 hours, 9.0 cm H2O, 33.9 Wh
#4 - 13,189 feet, 7.4 hours, 8.4 cm H2O, 32.6 Wh
#5 - 12,467 feet, 7.3 hours, 12.3 cm H2O, 46.7 Wh
#6 - 15,748 feet, 4.0 hours, 12.2 cm H2O, 24.6 Wh (from memory, I unplugged it accidentally while trying to take a pic of the meter)
#7 - 12,959 feet, 9.4 hours, 9.1 cm H2O, 42.1 Wh

Over the 7 nights I averaged 4.79 Watts with the higher pressures and altitude. The Z1 seemed to work at all of the altitudes. Sleep is a little harder to report on as I was up at altitude sleeping on the ground in a sleeping bag for 7 nights, neither do I do often and 6 of the seven nights were higher than I had ever slept. I did place the unit in my sleeping bag inside the butterfly net and it worked OK for heating the air and for humidity. I had a problem one night and overheated the Z1 getting a Fault 27. I awoke with the unit shut down and the fault code. After letting it cool for a few minutes and repowering the unit it restarted fine. I cannot remember if it was night 5 or 6. I was more careful after that to ensure better airflow to the Z1. I had changed the batteries after the 3rd and 5th nights and used some of the remaining charge in the used batteries to charge other gear with the USB ports.

Cost:
HDM Z1 $510
Amara view mask $64
Talentcell batteries $65 x3 - $195
Boost module $26
Watt meter $30
Lipo safe bags $15
Cables with 5.5x2.1mm connectors (one straight, one 90 deg) $7
Pop up butterfly tent $8
Snuggle hose cover $15
velcro, heat shrink $5

total: $875
total measured weight (Z1 APAP, 3 batteries, boost supply/meter, battery bags, hose, mask, cover, pop-up tent, Z1 bag): 2652 grams, 5.85 pounds

I was overall very satisfied with this set-up, especially given that just an HDM powershell with 3 batteries would cost $1127 alone. I used the set-up after climbing Kilmanjaro in Moshi and on safari. The power in Moshi, TZ was not reliable and went out one night in the hotel. I was glad to have the battery to just plug in and power the unit. The tented lodges I stayed on safari in ran off solar power so I just used the batteries for the most part there as well. Additionally the Talentcell batteries have a usb connector as well and happily charged my phone over night at the same time while powering the Z1 (I only did that later and it was not included in the numbers I showed above.) I did read the reviews (some negative) about the Talentcell batteries and I don't know if I just got lucky but the three I have worked fine. I do charge and store them in lipo safe bags, however. I think my gear does weigh a little more than the HDM powershell and 3 batteries, but I gained nearly $1000 savings, an actual power meter and USB charging ports.

Also, I am not affiliated in any way with Talentcell, HDM or any of the things I have mentioned. Remember, I am just reporting what I did in case anyone else might find it useful.

Last three photos.

This is extremely helpful. I have moderate sleep apnea and use a Z1 when I travel. I just plug it in.

I am traveling to Machu Picchu on January, flying into Cusco, spending a few days there to acclimate and then doing the 4 day Inca trail hike. I will use an outlet at the hotel in Cucso (11,000 feet) and then need a battery for the 4 day hike, where elevation will be between 8,000 and 14,000 feet. Sound like the battery you described provided plenty of power for 4 nights?

Any other advice for a trip of this length and altitude?

Thanks again!

Very cool. Seriously, and very competently geeky and informative.

NOLAfriend wrote: ↑

Sun Aug 19, 2018 6:56 pm

This is extremely helpful. I have moderate sleep apnea and use a Z1 when I travel. I just plug it in.

I am traveling to Machu Picchu on January, flying into Cusco, spending a few days there to acclimate and then doing the 4 day Inca trail hike. I will use an outlet at the hotel in Cucso (11,000 feet) and then need a battery for the 4 day hike, where elevation will be between 8,000 and 14,000 feet. Sound like the battery you described provided plenty of power for 4 nights?

Any other advice for a trip of this length and altitude?

Thanks again!

NOLAfriend,

The altitudes you describe are similar to what I trekked . The battery I described did work well for me but it was not plug and play. The Z1 would cut out after a while directly on the battery. The voltage boost module I used made it very stable and then it worked fine. The watt-meter was optional but helpful. If you look at my data I posted from use at altitude there were a couple of days where I could only have made two nights on the battery even though I made four days at home. If you want to use it you will need a voltage booster, try it out at home and plan on bringing more battery power for use at altitude.

BTW this setup continues to work well for me and I don't even bother trying to plug it in sometimes for use at a camp, etc. I just use the battery with my phone and the Z1 plugged in and don't have to worry.

Stom wrote: ↑

Sun Aug 19, 2018 7:32 pm

Very cool. Seriously, and very competently geeky and informative.

Thanks

mech18 wrote: ↑

Mon Sep 24, 2018 8:09 pm

NOLAfriend wrote: ↑

Sun Aug 19, 2018 6:56 pm

This is extremely helpful. I have moderate sleep apnea and use a Z1 when I travel. I just plug it in.

I am traveling to Machu Picchu on January, flying into Cusco, spending a few days there to acclimate and then doing the 4 day Inca trail hike. I will use an outlet at the hotel in Cucso (11,000 feet) and then need a battery for the 4 day hike, where elevation will be between 8,000 and 14,000 feet. Sound like the battery you described provided plenty of power for 4 nights?

Any other advice for a trip of this length and altitude?

Thanks again!

NOLAfriend,

The altitudes you describe are similar to what I trekked . The battery I described did work well for me but it was not plug and play. The Z1 would cut out after a while directly on the battery. The voltage boost module I used made it very stable and then it worked fine. The watt-meter was optional but helpful. If you look at my data I posted from use at altitude there were a couple of days where I could only have made two nights on the battery even though I made four days at home. If you want to use it you will need a voltage booster, try it out at home and plan on bringing more battery power for use at altitude.

BTW this setup continues to work well for me and I don't even bother trying to plug it in sometimes for use at a camp, etc. I just use the battery with my phone and the Z1 plugged in and don't have to worry.

Thanks for the advice! Just put in orders for all of this and will test at home as you suggested. I went with 3 batteries since it is really only 4 nights. For anyone interested I'll try to remember to post a follow up in January to report on how it went.

So I have everything and am trying to give this set up a test run. I know this sounds like a dumb question, but I am having trouble figuring out how you connected the converter to the battery. Can you provide a little more explanation or a photo of that?

NOLAfriend wrote: ↑

Sat Dec 15, 2018 4:54 pm

So I have everything and am trying to give this set up a test run. I know this sounds like a dumb question, but I am having trouble figuring out how you connected the converter to the battery. Can you provide a little more explanation or a photo of that?

Sorry I have not seen this post until now to reply. The two pictures in my first post show all of the connections before I mounted the converter onto the lipo safe bag. I soldered on a connector with a right angle plug to the watt meter input (source.)

https://www.arrow.com/en/products/10-01 ... ernational

That 90 degree connector is then plugged into the battery (in the 12v socket.) See my photo from the second post showing the end of the battery with the 90 plug inserted into the battery 12v port. There is a piece of electrical tape and a "B" label covering up the 9v port on the battery.

The watt meter output (load) is then connected to the boost converter input. The converter output is soldered to a straight connector to plug into the Z1 cpap.

https://www.arrow.com/en/products/10-01 ... ernational

You have probably already finished this but hope it helps. If you want to eliminate the watt meter you could put the plugs directly onto the converter. One for the input to connect the battery and one on the output for the Z1.

I'm wanting to build a trekking/travel kit like you did. I'm curious--how do you like the Z1 as an APAP machine? I also have the ResMed S10 Autoset, so that would be my frame of reference. At home, I use 5-10, EPR 2 on the ResMed.

Specifically, how do you find the noise levels and the adaptive pressure performance? Is it good enough that you'd use it in any scenario besides a full-on trek?

@mech18 Thanks, I'm going to try to reproduce this setup.

milehigh wrote: ↑

Wed Feb 13, 2019 11:53 am

how do you like the Z1 as an APAP machine?

- If you get a travel machine, make sure to try it out for a few nights at home before heading out.

- The current model is Z2 - https://www.cpap.com/productpage/z2-aut ... ap-machine

- Note in the link: "With a new motor 29% quieter than the Z1, the Z2 is designed to minimize the pitch of the motor for optimal comfort. At 26 decibels, the sound the Z2 makes is almost like a whisper, quietly working in the background while you sleep. With the included Q-Tube Muffler, the sound will dampen even further, creating a sleep environment with possibly fewer interruptions."

- And, "30-Day Money Back Guarantee"

I have a Z2 Auto. I purchased it for business travel, and I don't use any DC powered setup.
I had a trip to Las Vegas for a few days, and it did a good job. My Resmed unit failed in June. They sent it back not repaired properly, so I've been using the Z2 except for a couple of nights since the beginning of June. (They are allegedly getting me a new Resmed Airsense 10 Autoset.)

A few observations:

I originally had the Z1 Auto. My wife complained about the noise, so I swapped it out for a Z2 due to the noise improvement, and also the Auto start/stop feature, which is a big deal for me.

The Z2 is a bit quieter than the Z1, but still has a bit of the whirring noise on transition from inhale to exhale.
I've got a portable A/C unit running in our bedroom. That coupled with setting the unit down inside my night stand drawer has made the noise issue pretty much moot.

I used the unit on my trip to Vegas, and while it's definitely not as quiet as my Resmed unit, I was able to sleep well.
They have an EPR feature on the unit that they call Z-Breathe. It has 3 settings, but you cannot turn EPR off. I think the noise would be much less if you could turn that off.
All in all I'm satisfied with the unit. It seems that the therapy is about as effective as my Resmed unit. The main attraction is the small size and potability.
IMHO it's a good unit for travel, but be aware that all of the travel units have a bit more noise than your Resmed or Philps full size units.
It definitely is a unit to consider if portability and size is a consideration.

jsmit86 wrote: ↑

Sat Jul 27, 2019 7:02 pm

has made the noise issue pretty much moot.

In other words, your machine is mute.

ChicagoGranny wrote: ↑

Sun Jul 28, 2019 5:30 am

jsmit86 wrote: ↑

Sat Jul 27, 2019 7:02 pm

has made the noise issue pretty much moot.

In other words, your machine is mute.