Wow is hard to register, but i just did to share my battery setup.
Hi All CPAP people.
(disclaimer1- im not native English speaker so some mistakes can occur, and i can't writte Dutch)
(disclaimer2 - i'm not sponsored by anybody, I wish i would... Yes is to You XTPower)
(disclaimer3- if you folow my post and do same i don't take any responsibility for your equipment and any loses you may experience, do on your own risk)
I just realised that i can't sleep without my machine anymore, but also I can’t afford another travel cpap.
Probably with 12V or 24v you can stay alive with just DC-DC converter and extra battery.
I decided to go battery operated travel solution and perhaps off-grid...
I’m a DIY-er so having some electronic background, but I’m scared to play with my CPAP, it is my life saver so this time I decided to use components from shelf.
First I did some research on what battery I need.
I use Resmed A-10
I need minimum of 7-8h of sleep
my working pressure is 7-13 cmH2O
On travel I don’t really need humidifier (if needed I can put a wet towel near my machine )
So according to resmed “BATTERY GUIDE” document for my power usage will be between 0,79 – 1.06A, so to make it safe constant 1.1A for 7hours, that makes8Ah power I need. To make it safe knowing that all power banks have some efficiency lose and DC-to DC converting also causes some losses I said I need 16AH power bank capable of ~30W of constant power.
I found one power bank that works for me.
XTPower XT-27000DC-AO-PA (google it You will love it)
Why it is special? It can spit out 24V (DC out) with 80W output with battery capacity of 26,8Ah=99Wh. Yes you can take it on plane(!)
So NO(!) DC-DC converter needed...
But that is not all. As it is a buffer battery you can charge it and discharge it in same time. So connect it to 5v (in train, plane, etc)input and cpap on output and your battery will stay longer alive.
Great charging capabilities. With given 230V(EU) I charge it in 2,5h. With USB-C(15W) phone charger it takes 6h. But there is also possibility to connect it to Solar panel DC plug 14-20V (45W) max so probably. Of course it has small display to show not only % left but also how many Wats are drawn.
Bonus feature it is a power bank also capable of charging my phone and laptop (5,6,9,12,14,15,16,19,20,24V setings) (boom), endpieces included, and if you need extra one that fits you just order from producer.
OK. So, I think battery is in theory arranged. Now we all can be happy… not so easy...
I needed still needed a proper cable to connect it to my CPAP. I took my original power supply and started to check what plug I need and what is on that plug.
I found on forum info that this plug is 7.4mm x 5mm 3 pin plug, and that it needs 24v +, ground and 3.3V on middle pin. I confirmed that by measuring my own power supply.
There are some end pieces for that power bank included, but after connecting and checking 3 of them (ordered extra 2 for testing from power bank producer) i measured 0V on first and 6,8V on second 13V on third. So, none of those were usable for me…
So 24v we have but where to take 3.3v? Of, course You can make small voltage divider, add step down voltage regulator, or like said by forum add 2.7Kohm resistor in series and done, but as I said NO DIY.
So I ordered P24R10DC online so called ”SHORT DC OUTPUT CABLE TO USE WITH RESMED AIRSENSE10 SERIES POWER ADAPTER”
It is hard to come by as company is not willing to sell it directly, but I found one shop in Australia that has it on stock, or if you know someone with this producer battery just ask them for serial number of battery and you can order one directly.
It just came and after measuring it on power bank YES i have 24+, ground and 3.3V
So that’s it my out of box CPAP ResMed A10 power bank. Total cost 150Euro
After tests i get 10h of cpap use (no humidifier, no heating hose, airplane mode on) and full phone battery charge and still 15% left in battery.
Of course it will work with other cpap devices as long you get diferent and proper cable.
Want to know more look on my topic in this forum:
http://www.apneaboard.com/forums/Thread ... heap-setup