04-02-2023, 04:36 PM
(This post was last modified: 04-02-2023, 04:41 PM by PedanticDan.
Edit Reason: Word choice
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RE: ResMed Airsense 11 battery backup
(05-14-2022, 08:04 PM)davidgr Wrote: Electrical mystery. First of all, the good news. In my at-home experiment, I have just gotten through 4 nights in a row with my cpap powered by the airmini dc to dc converter and a 100 amp hour deep cycle marine battery. If it lasts another night, the battery will get me through my 5 nights of camping coming up in early June in the Cal Redwoods.
Here's the mystery. If I first attach the clips to the battery and plug the converter into the cpap secondly, the light goes out on the converter and the cpap does not go on. BUT, if I plug the converter into the cpap first, and secondly attach the clips to the battery, the cpap works. Why would that be? (This could be the reason that some folks think the airmini adapter won't work. FYI for you here in this post).
When you connect the converter to the battery first, the output of the converter is at full voltage when you plug it into the CPAP machine, so the CPAP machine gets a nearly instantaneous jolt when you plug it in. That jolt can cause weird situations for digital electronics (and possible shorten their life expectancy).
When you plug the CPAP into the converter first, the instantaneous jolt is absorbed by the converter and the CPAP machine gets a more controlled voltage rise.
In general, it’s better for electronic devices if you connect them to their power adapter before connecting the adapter to the power source.