This CPAP battery is great, works perfectly with my AirSense 11.
I got it because I really need my CPAP machine to have good quality sleep, and if power goes out in the middle of the night, it really messes up my sleep. This peoduct has pass-through mode, which means it can power your CPAP machine at the same time as it is connected to its power source, so if power goes out then the battery kicks in (sort of like a UPS).
I took a nap and tested this battery to see how long it would power my AirSense 11 with humidifier and tube heating, i started with 100% battery, my nap lasted for 1 hour and 15 minutes and the battery was left with 76% of juice, which is not bad, that means if I ran it all the way down to 0 maybe it would have lasted almost 5 hours. This was a bit surprising because I tested how many watts my AirSense 11 pulls and I saw it oscilates between 25 and 30 watts, so I was expecting less than 4 hours total (but maybe the tube heating goes on and off during sleep and it actually consumes less than 25 watts?)
But this battery is very versatile, it could also be used to power your internet router (configuring the right voltage) so you don't lose internet during a power outage, or it can also charge your laptop or cellphone.
The size is pretty compact for its capacity, the build quality is great and it actually looks nice. The charge percentage display and voltage indicator are really useful.
I definitely recommend this product.