Forum Discussion

jaycocreek's avatar
jaycocreek
Explorer II
Sep 15, 2020

Using a c-pap in a TC Inverter numbers W/Humidifier.

Again,in the TC forum because a TC is one of the only RV's that came and come with just one battery.My C-Pap is a Phillips System One

I have looked and never seen the numbers of a C-Pap on 12V then on an Inverter with the humidifier on..Everyone says never run the C-Pap with the humidifier while boondocking without any numbers to back it up..So I did the test on 12V and with the Inverter!

C-Pap on 12 volts without humidifier..



C-Pap on 12 volts with humidifier on set at 2..I didn't make much of a difference between 1-2 and 3 with the humidifier on.



C-Pap off the 1000 Watt pure sine wave inverter without the humidifier..



C-Pap off the inverter with the humidifier on attwo.



As you can see the C-Pap uses less power on 12V both with the humidifier and without..Off the inverter without the humidifier on,the inverter uses twice the power as just on 12 volts..With the humidifier on,12 volts uses 20 watts less..

Hope this helps with the numbers to back up why 12 volts is the way to go with a C-Pap even with the humidifier on...81 Watts(Inverter) with the inverter equals 6.75 amps and 64 watts(12V)equals 5.3 amps.
Truck Campers
  • Geewizard's avatar
    Geewizard
    Explorer
    Sep 16, 2020
    I use a Philips Respironics Respironics DreamStation CPAP machine which has a heated humidifier and tube that I can shut off. My CPAP can run off of 12VDC and that's what I use in the TC or RPod.

    When I'm traveling in my TC or in my small RPod trailer, I shut off the heated humidifier and tube and use it in "cold passover humidification" mode. That saves a lot of power. And doing so works ok for me.

    There are cold passover humidifier devices available as well.

    https://www.cpapwholesale.com/info/passover-or-heated-humidifier

    https://www.cpap.com/cpap-faq/Passover-CPAP-Humidifier
  • JimK-NY's avatar
    JimK-NY
    Explorer II
    Sep 16, 2020
    The Phillips System One operates on 12 volts. That is absolutely the way to go. Never get a CPAP for RV use that requires AC power unless you never plan on camping without a hook up. As the data shows and as is also shown my the CPAP manual, 110v operation will use much more power than 12v operation. In addition an inverter would be needed to supply 110 from batteries. Inverters waste power in the form of heat. Many even waste more heat operating a fan to cool the inverter. Avoid the use of an inverter whenever possible.

    Humidifiers relay on a heater next to the water tank. Depending on the device and setting they can use much more power than the CPAP itself. There is another potential drain that is even bigger. Many CPAPs now have a heated tube from the unit to the mask. Those are huge, huge power hogs.
  • jaycocreek's avatar
    jaycocreek
    Explorer II
    Sep 16, 2020
    ICamel wrote:
    Thank you @jaycocreek for that detailed information. It confirms what I have known for almost twelve years using my CPAP w/Humidifer powered by a pure sine wave inverter in either 5th Wheels or our current truck camper. I can go for at least four days without a recharge on my dedicated CPAP batteries and almost unlimited time with a daily two hour recharge from the Honda EU2000i.


    I also had a dedicated Cpap battery as well as a dedicated TV/DVD battery..lol..Having only one 12V battery for the coach in an odd spot that won't let me add another battery,I have to stick my extra batteries in the wheel wells with heavy duty 12V cables with a cigarette lighter plug..Kinda redneck but it works and that's all that counts in my book.

    Funny how we tend to take things for granted,yesterday some poor soul cut the fiber optic cord that brings internet and phones into two small communities here..Our Banks had to close/the courthouse closed and the hospital had to re-route emergency patients to hospitals miles away..All cell towers were down also!..Kinda scary something so minor shuts everything down..
  • Bumpyroad's avatar
    Bumpyroad
    Explorer
    Sep 15, 2020
    jaycocreek wrote:
    ..Everyone says never run the C-Pap with the humidifier while boondocking without any numbers to back it up. .


    I don't think anybody said to NEVER run the humidifier when boondocking, just that it will use up some of your battery power. also a recent post reminded me that my heated hose also will draw something.
    whether this is a problem would be on a case by case basis.
    bumpy
  • ICamel's avatar
    ICamel
    Explorer
    Sep 15, 2020
    Thank you @jaycocreek for that detailed information. It confirms what I have known for almost twelve years using my CPAP w/Humidifer powered by a pure sine wave inverter in either 5th Wheels or our current truck camper. I can go for at least four days without a recharge on my dedicated CPAP batteries and almost unlimited time with a daily two hour recharge from the Honda EU2000i.
  • jaycocreek's avatar
    jaycocreek
    Explorer II
    Sep 15, 2020
    I should have added how many watt hours they would use in a nights sleep off your battery but I wasn't sure how to do it..

    Assuming you have a 100ah battery which is 1200 watt hours,this is what you would use running the C-Pap with the humidifier..(If I did it right LOL)

    81 watts off the inverter for 8 hrs = 648 watt hours.
    81 watts off the Inverter for 6 hrs = 486 watt hours.

    64 watts off 12 volts for 8 hours = 512 watt hours
    64 watts off 12 volts for 6 hours = 384 watt hours

    So if these numbers are correct,you could run your C-Pap with the humidifier, off an inverter for atleast one night for 6 hours and be above the 50% of the lead/acid battery.Using 12 volts easily for one night off of a lead/acid and more if you have a lithium battery for both ways.

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