How to run a ResMed AirMini on a USB power bank

phatair4me wrote: ↑

Tue Mar 08, 2022 8:16 am

Did you ever get the Alibaba supply or is it still on the slow boat?

Hi everyone. It finally arrived! I think it got sent in a bottle.

Update: Just woke up - around 7hours at 14cm2 and according to the 4 battery indicators I’ve used around 50% of battery life. I think I’d get 2 days of use.

Update 2: I got 4.5 hours on the second day so altogether I got 11-12 hours of a single charge.

The battery pack supports a few voltages for the DC port, including the required 24V for the AirMini.

I plugged it in and it appears to work I will test it overnight and report my findings. I require 15cm2 so that should be a good test.

1) the Battery:

https://m.alibaba.com/product/160024582 ... 00mah.html

What I like:
- it is sizeable but by no means huge.
- it is travel safe.
- Supports PD 60W. Charges all the things, including my MacBook Pro.
- Good build quality.
- Cheap.

2) the Cable:

The DC port fits the “Medistrom Pilot Output Cable for ResMed AirMini CPAP” cable found below. It simply fits, nothing else to plug or do.

https://m.catch.com.au/product/medistro ... p-6553595/

dsjustice wrote: ↑

Tue Mar 08, 2022 8:14 pm

If you're considering this, be advised that a 20W power bank is insufficient.

Guess I'll be upgrading to a 40W bank.

It supports 60W PD and 24V/2A. Initial tests seems positive but I need to see if it lasts the night @15cm2.

These guys seem to stock the same product from alibaba. For those in Australia you can get it more quickly through these guys, although you will be paying another $80aud for the convenience (or there about). There’s also a review video in their site (not a cpap review).

https://www.auspowerbanks.com.au/produc ... -24000mah/

Hello everyone. First post, but I've been reading the forums a decent amount since being diagnosed with OSA in January. Thanks for the great resource!

Now that I'm comfortable with therapy, I purchased an Airmini as a travel machine and will be building a battery unit to go with it. I have a 3D printer, and while I'm a relative novice with 3D CAD, I have a good friend who is a professional modeler and he has offered to assist in the creation of a custom enclosure to house everything. I will share all the CAD files and STLs here once it is complete in case anyone else is interested in printing.

The plan for the enclosure is as-follows (subject to change!):

• We will be modeling a single enclosure that the battery bank slides into and out of. The male USB-C cable end will be captive in the back of the enclosure, and when fully seated, the battery will plug itself into this cable.

• On top of the battery will be an enclosed space for the boost converter and cabling. This compartment will run the length of the battery

• On top of the electronics compartment will be clips to accept the Airmini. When put together, it will be a single unit with minimal external wiring (only the Airmini power lead will protrude out of the enclosure to allow for plugging the Airmini in to power.

Here's a list of the parts I've purchased for the project:

• Battery Bank: RAVPower 20000mAh 60W PD 3.0 Power Bank (I already own this one, it powers my laptop @ 20V, so it should work well) - https://www.ravpower.com/products/rp-pb ... new-plugin

• USB C PD 20V trigger cable (2-pack): https://www.amazon.com/gp/product/B08NTVBHLP

• DC/DC Boost Converter: https://www.amazon.com/dp/B00LP2LZ4M/

• Airmini DC power cord: https://www.aliexpress.com/item/3256803626131876.html

It's unfortunate that Amazon no longer sells Ravpower battery banks. I purchased the one above for $49.99, and Ravpower lists it for $89.99 currently. That said, once I get my unit built, I don't mind modifying the battery compartment to fit the consensus "best bang-for-the-buck" battery banks (say that 5 times fast).

Looking forward to updating as we make progress, and maybe giving back to the community in a small way.

Cheers!

So I got quick fix for the USB power bank issue without spending 499.99 here are the parts
XTPower XT-20000QC3 PowerBank=89.99
https://www.amazon.com/gp/product/B07K4 ... UTF8&psc=1
idunmed DC 24V Power Cord, 5.5 x 2.1mm Male to ResMed AirMini Plug Power Supply Cable=48.90
https://www.amazon.com/gp/product/B09P3 ... UTF8&psc=1
total cost=138.80 not bad and works all night

I don't have much background in electrical engineering - so kindly educate me

1. Would this work?

Amazon 88.8Wh|65Watts Portable Laptop Charger with AC Outlet, A Super Travel Portable Battery Pack & Power Bank for HP, Notebooks, MacBook, Laptops

It has AC output and it would allow one to use their ResMed device using its original accessories and without needing a "Pilot Output Cable".

2. If yes, how many hours can one expect from this power bank?

Here is my very uneducated guestimation - kindly correct me
- Looks like the linked battery is rated at 88.8Wh with its AC outlet rated at 110V 65W AC and the ResMed device's default power brick is rated 20W AC Adapter with input range of 110-240 V and 05 - 0.3 A, so the power bank should be able to support it.
- As per the description on Amazon page, the expectation of inverter efficiency seems to be 85% => so the Working time = 88.8Wh* 0.85 / 20 W (operating power of your device) = 3.774 hours. If this is right - then this battery plan wont really work

Can anyone confirm if my calculations are right?

Hi,

Has anyone tried a USB to Car Power Socket Adapter connected into Resmed's 12-24V DC/DC converter? This should allow any power bank to be used.

Some examples of the adapter here:
https://www.ebay.co.uk/itm/164315553713

https://www.amazon.co.uk/VBESTLIFE-Ciga ... 104&sr=8-4

Chimaera724 wrote: ↑

Thu Jul 21, 2022 2:26 am

Hi,

Has anyone tried a USB to Car Power Socket Adapter connected into Resmed's 12-24V DC/DC converter? This should allow any power bank to be used.

Some examples of the adapter here:
https://www.ebay.co.uk/itm/164315553713

https://www.amazon.co.uk/VBESTLIFE-Ciga ... 104&sr=8-4

1 amp at 12 volts equals 12 watts. I believe the Resmed DC to DC convertor is 90 watts.

stevenal wrote: ↑

Thu Jul 21, 2022 8:59 pm

1 amp at 12 volts equals 12 watts. I believe the Resmed DC to DC convertor is 90 watts.

According to this document, with the DC converter, the Air Mini draws a max of 0.76A:

https://document.resmed.com/documents/a ... lo_eng.pdf

Apologies I posted the low power versions. This USB C to female car 12V socket is rated for 65W which I think is well within the power consumption of the AIrMini?

https://www.amazon.co.uk/gp/product/B08 ... AN8FW&th=1

Hello all. I want to say just how much I appreciate this forum. I have recently gotten the Resmed Air Mini and I am looking for a way to run it via a battery. I spent quite a bit of time trying to finding a Medistrom Pilot Output Cable for ResMed AirMini CPAP adaptor.

I did however find a resmed air mini cable kit that has the air mini propriatary cable going to a usb C plug. I am wondering if anyone has an idea of a power back with a usb c port that would be able to power the air mini via this cable damaging it? https://batterypowersolutions.net/produ ... cable-kit/

This cable kit was designed for freedom v2 batteries that cost over $330. Which https://www.amazon.com/Battery-Power-Co ... B08FBH34BR

I am open to a power "station" if it provided several nights worth of a charge. It seems like there sould be something like this with a USB C output larger than 5.5.
https://www.amazon.com/Portable-Flashfi ... r=8-3&th=1

It has also occured to me I might be able to use an adapter like this is it can pull 24v. However, I would need a good
https://www.amazon.com/Charger-Waterpro ... =8-14&th=1

Any thoughts?

I don't really understand as much as I need to about this, but I think chimaera's idea of an adaptor to take Usb c (at 12 v) to a cigarette female connector (to the resmed dc to dc adaptor brick and then to the machine) seems a good idea especially for someone not well versed in electrical stuff. Will it work?

can someone fill me in on how the high speed protocols like power delivery work I can see that the power bank has to have power delivery but does the adaptor need to support power delivery? what about the resmed brick and the machine? or what about other high speed protocols, could they be helpful?

tyrinryan wrote: ↑

Sun Jul 24, 2022 12:56 am

I don't really understand as much as I need to about this, but I think chimaera's idea of an adaptor to take Usb c (at 12 v) to a cigarette female connector (to the resmed dc to dc adaptor brick and then to the machine) seems a good idea especially for someone not well versed in electrical stuff. Will it work?

thanks. I agree. I have a hard time understanding how to determine what USB battery is best to start with and how to calculate how long things will be able to run.

FWIW: I purchased this cable to use with the Renogy 72000mA battery pack on Amazon although didn't get a chance to try it, since my AirMini which I hadn't used in a while (I use an AirSense 10 at night at home) was not working (I sent it in for an In-Warranty Repair):

https://www.amazon.com/dp/B0B3F7ZY65?ps ... ct_details

I believe that cable to be less expensive and a compatible cable with the AirMini. Why? Because a poster on another site tried the ResMed DC-DC converter for the AirMini on their AS11 and it worked without a problem.

Anyway, this Renogy power supply will allow you to set the DC output voltage at 24V, and it has it's own built-in DC-DC converter because it can generate different output voltages, but note that it's capacity is such, it cannot be brought onto an airplane (keep this in mind if you need something for travel by plane):
https://www.amazon.com/dp/B0791WDZTW?re ... tails&th=1

If someone tries this combination and verifies it works well, please let everyone know. I would have liked to have tried it already to report as much on this forum. I think it should be capable of easily supplying 2 nights of therapy and possibly more. I was planning to set up a test jig with a multimeter across a resistor that would result in an approximate 1A draw and see how many hours it produced 24V output from the battery pack... Still thinking about it.

Reader beware. YMMV.

vadersleeper wrote: ↑

Mon Jul 25, 2022 4:50 pm

tyrinryan wrote: ↑

Sun Jul 24, 2022 12:56 am

I don't really understand as much as I need to about this, but I think chimaera's idea of an adaptor to take Usb c (at 12 v) to a cigarette female connector (to the resmed dc to dc adaptor brick and then to the machine) seems a good idea especially for someone not well versed in electrical stuff. Will it work?

thanks. I agree. I have a hard time understanding how to determine what USB battery is best to start with and how to calculate how long things will be able to run.

Power banks typically quote a power output in watt hours (Wh). This is how many watts it could supply for one hour.

https://ap.resmed.com/knowledge/how-muc ... chine-draw
The Resmed site quotes that 'The average current draw for the AirMini does not exceed 0.83A'. As the supply is 24V and P=VI then power consumption is 19.92W.
If you wanted an 8 hour battery then you would need at least 19.92 x 8 = 159.36 Wh.
However:
- The system will have efficiency issues and the battery will not have full capacity for life so you might want a 10-20% larger battery
- Depending on your power settings you may use less power. This website quotes an average consumption of 6.3W which would let you get away with a battery as small as 50 Wh.

https://sleepright.com.au/resmed-airmin ... 20at%2027W.

If you already have a small powerbank at home you might want to try it and see how long it runs for then you will be able to work out how much bigger it needs to be to give you the duration that you require.

I have also since found this which connects to a standard 24V DC port found on many larger powerbanks.
https://www.amazon.co.uk/EASYLONGER-Sup ... ems&sr=1-1

Just found this item, a cable that runs from a USB-C port to the AirMini:

https://914gadgets.com/products/usb-c-c ... irsense-11

This seems to be functionally like the system I rigged up, a USB C power delivery cable connected to
a voltage booster, followed by the cable to the AirMini.

Has anyone tried this cable?

If it's any good, this cable would be preferable to my home-brew setup, since it's one item,
instead of the two cables + bulky adapter box I'm using now.