Battery life and CPAP machine

RJ1958

I have severe sleep apnea that requires me to use a CPAP machine in order to get a good night’s rest. What kind of drain will that kind of machine put on the battery?  I do have a battery attachment I can use in a pinch (in case the power goes out) but then I just have to recharge it the next day. Thanks!

rcuomo

We have run a Resmed for two days using an inverter and it barely impacted the battery. I have since purchased the 12v adapter power supply and it should use considerable less power since you aren’t wasting power converting DC to AC. 

Oneota

Thanks for the question.  My spouse uses a CPAP with heating element.  We did a 5,000 mile trip with our TAB 320.boondocking 2 or 3 nights in a row, then at a campground with electric hookup.  I used the 7AH batteries and inverter, out of the EGO line (batteries for my chainsaw, lawnmower, etc.)  One battery lasted the night, with extra batteries for extra nights, then recharged them when shore power was available at a campsite.

I have not tried an inverter out of the TAB battery, so I'm interested in other responses.  (Once our TAB battery ran low enough the Alde heater controller shut down the heat, even on LP.)

pthomas745

Resmed has a nice .pdf that runs down the power usage in amps for many machines, and pictures and descriptions of how to devise an inexpensive "extra" battery to run your CPAP and save your trailer battery.  I carry a small battery (35AH) for my laptop, etc. that is easy to move around and work with.  I can charge it with my solar panel and I've even charged it with my NOCO battery charger while driving. 

https://www.resmed.com/us/dam/documents/articles/198103_battery-guide_glo_eng.pdf

Once you know the amp hour use of your CPAP, you should be able to predict how many amps it will pull out of any battery you might want to use.

RJ1958

Very helpful. I have a Respironics DreamStation with the optional Rechargeable Li-Ion battery pack with DC output of 21.6V, 2662mAh. I will search to see if Respironics has a similar guide to the Resmed. 

ColleenD2

We bought the 12v cord for Den’s dream at CpapSupply.com. I think it was 25 bucks. He does fine without the humidifier. We make enough humidity in such a small space.

Cbusguy

The key is do not use the humidifier as your power consumption goes from about 1 amp to 8-10 amps with humidifier use.    The higher your pressure needs the more power it requires.    

As others have noted try not to use the inverter,  buy the correct 12 volt power cord as it wastes less power.  There really is no need for expensive single use or device specific battery packs. 

RJ1958

I have a DreamStation Go, which only has a 110V AC connector  I need to contact CPAP.com, where I bought it, to see if I can directly hook it up to 12 volt power. 

pthomas745

Any small inverter that will plug into the 12V (either in the Tab or a separate battery) will work for your "regular plug" CPAP.  You will lose a bit of efficiency, but it will work.  Something like this:

https://www.amazon.com/dp/B07VQ8CGVT/ref=dp_prsubs_2

Cbusguy

@pthomas745  just be aware some cpap machines will not work on a cheap square wave inverter.   

Michigan_Mike

I have used both a Resmed CPAP unit and now have a Dream Station CPAP and in both instances I also purchased the 12V DC plug adapter for these units.  As noted above, the humidifier will easily drain a battery and therefore should not be used.  I have used a CPAP for about 15 years and when traveling with the trailer only use the air component.  I have used inverters too, but they do put added load on the battery and your best bet is to buy a compatible 12V DC cord and plug into a cigarette style receptacle.  

If you do use an inverter I would recommend a portable 600 watt inverter as although a 300 watt inverter will work, I have encountered sporadic problems with these units and have learned that in remote areas you are better off with the larger inverter.  Nothing worse than a CPAP problem late at night and losing sleep as a result of a drained battery or sensitive inverter that does not want to cooperate.