View Full Version : CPAP's and Quiet Hours

01-11-2016, 10:40 AM
My wife and I both use CPAP's to sleep and this creates a problem if we are someplace that requires Quiet Hours. Our generator, although extremely quiet, still is a generator and during quiet hours needs to be shut down. Considering this, I came up with the solution that seems to work well for us. The generator supplies power to the entire AC distribution panel by going through an automatic transfer switch with one side fed by the generator and the other from shore power. When power is available on the generator side, it automatically transfers to that power. Using that as the model, I purchased and installed another automatic transfer switch. I took the power from the feed from the AC panel that goes to the outlets in the bedroom, used that as one of the two available supplies and took power from a 2000 watt inverter for the other side. The output from the switch goes to the outlets. I put the control for the inverter in the control panel which allows me to turn it off to prevent power drain from the batteries when not in use. This arrangement allows us to use battery power for the times the generator cannot be run, and as soon as those hours are over, start the generator and recharge the batteries.

01-11-2016, 01:22 PM
Did you look at your CPAP most of them run on 12 volts all you need to do is put a plug in for the CPAP off your 12 volt battery

01-11-2016, 03:41 PM
Yes, I looked, and unfortunately, both of ours are pretty new and neither are set up for a DC source. For that matter, there are NO DC outlets anywhere in our trailer, so this was the best alternative. I realize that a pure sine wave inverter is the best, but I have run CPAP's on regular inverters with no problems.

01-11-2016, 04:02 PM
What if you switch the CPAP to airplane mode and see if the batteries in the coach can support them?

01-11-2016, 06:31 PM
We bought the 12V adapter for my wife's machine and I installed a 12V plug near the head of the bed, tapping into the 12V power supply for the TV booster in the bedroom closet. As a plan B, in cases where we're drying camping and want to preserve the trailer's batteries, I also have a spare deep cycle battery and can connect her machine to that with a female 12V socket with alligator clips.

It works really well.

01-11-2016, 06:37 PM
Using a 12V device directly from the 12V battery will be much more efficient than inverting to 120V and then converting back to 12V. The batteries will be less discharged.

01-12-2016, 01:14 AM
Agreed, it would be more efficient (line losses, conversion efficiency, etc.) but the CPAP's we have just do not have a DC adapter. We were stuck with AC or none.