Battery backup - Emergency power

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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Battery backup - Emergency power

Post by SmallCityDave » Sat Mar 27, 2021 10:50 am

With the power issues in Texas I wanted to have a power backup for my CPAP I explored a couple options and ran some tests, my understanding of batteries/electricity is rather remedial knowing what I now know I would have done a few things differently but there is some good information that can be taken away.

First and foremost you will likely want an adapter so you can run your CPAP from DC power since it's more efficient this adapter is for my Airsense 10 Autoset ... UTF8&psc=1

I bought this "Power Station" ... UTF8&psc=1 because it was cheap and versatile it can be recharged in your home or car and it gives you a lot of information it can tell you how much power you are using and when you are recharging it tells you how much power it's consuming. Despite it's small size it powered my CPAP for 3 nights (23 hours).

Some numbers for reference about power consumption of my CPAP (not using the humidifier):
About 45 watts running on AC power
About 25 watts running on DC power
About 6 watts using the cpap with the mask on dc power

My initial tests were done by just turning the CPAP on and measuring the power usage I didn't know/remember that the CPAP uses a lot less power when you are actually using it. My 1st day I ran the CPAP on the Power Station for 8.5 hours the battery was down to 1 bar (about 20%) I was a little disappointed. I actually used the CPAP for 8 hours it only used "about" 1 bar (obviously these numbers aren't exact.

My initial thought was to use a deep cycle battery with the hopes of being able to use it for 7-10 days without needing to recharge the battery. The battery I bought before I had the Power Station was: ... /164242687 I ran the CPAP for 12 hours the power drop was relatively minimal it went from 12.6v to 12.49 if I was actually using the CPAP the power drop would have been much less. I feel confident that I could have ran the CPAP for 24hours without the battery voltage dropping to a level that would have damaged the battery. Simply "running" the CPAP was using 25 watts and "using" the CPAP was closer to 6 watts. I feel confident that the battery would have lasted the 7-10 days I was looking for unfortunately I couldn't measure the DC power consumption until until I had the Power Station and at that point I had returned the battery.

I hope this helps someone.