Powering a CPAP while camping without electrical hookups

[Blue Bertha]

Hi all,

I have a Resmed CPAP that I have to use due to sleep apnea. We recently purchased a Boler in the fall and have only been out in it a couple of times since we got it, both times to sites with power hookups.

We have a few trips planned this summer to campgrounds without hookups and I need to figure out the best way to keep my CPAP going while we're out. I do have a new 12V system off of a deep cycle battery but I don't want to drain it with my CPAP and a) not be able to run anything else and b) not be able to use my CPAP once it's drained.

I know some people use solar to ensure constant top up of the 12V system but I don't have the time or money to install that right now. I asked my sleep clinic about it and they said some people use a car battery. I do have the 12V adaptor kit from Resmed for my unit but I was told that the battery they sell is only good for one night, and it's quite pricey, so I don't think that's the right solution.

Does anyone here use a car battery for their CPAP? How does it work? How many nights does it give you? How do you re-charge it once you get home? I know NOTHING about electrical so please answer as though I'm six years old.

Thank you!
Amber

[Alex Adams]

Amber, there are some basic questions that need to be answered. What is the capacity of your deep cycle battery in Amp-hours? How many amps at 12 volts does your CPAP machine draw? What else are you attempting to run from the battery (lights, pump, etc.)? The battery capacity in Amp-hours should be on the label. The company that makes your CPAP machine should be able to tell you the Amp draw at 12 volts.

I can tell you that you will definitely need a way to charge your battery. Two basic non-expensive methods would be to run jumper cables from your tow vehicle to the battery and run the car for a while. Alternately, if your battery charges while towing, you could plug into the tow vehicle and run it to change the battery. I have used both methods when camping in the woods ( I have solar but it doesn't work well shaded).

[Glenn Baglo]

If you continue to use your tow vehicle as a battery charger, you will eventually be camping in a desert; no trees to block the sun.

[Steve Carlson]

I specifically bought a CPAP that runs on 12V as well as 120V AC household current. That way I can run it off of anything from a cigarette lighter 12V outlet in a car, to a set of jumper cables off of a car battery. https://www.amazon.com/gp/product/B0...7-47e776481440

You can also buy lithium ion "generators" (they are marketed as generators but are basically fancy battery units with 12V outlets, 120V inverter outlets and such) like this example https://www.amazon.com/NinjaBatt-Por...xpY2s9dHJ1ZQ==
to run your CPAP, and you can charge from your car or solar or other source during the day.

You will get a LOT more life out of your battery if you can get by without a humidifier. You will also get a lot more life out of the battery if you can run direct current from the battery without converting to AC with an inverter (the standard household-looking outlet on the above "power station".

[EricAllyn]

I use a CPAP and find that it will go 2 nights, but we don't use anything else. We at that time had only a deep cycle. Now with solar I don't worry as much, and we tend to drive every other day to recharge, with solar on the other days it works. This summer I will have a 200 Lith Ion battery, and 200 watts of solar, microwave, and lights, so will see how that works. I carry a 100' extension cord, and have sometimes plugged into a bathroom for a couple hours to boost a battery if needed.

[thrifty bill]

You will save enough by dry camping versus full hookup to pay for a solar system.

[ZachO]

You could do like the local guy I sometimes run into camping around here and just run a generator 24/7. He literally (in the correct usage of the word) never shuts it off. It sits on the picnic table with two gas cans next to it for constant refills.

All I can figure is he runs a cpap. I don't know for sure.

Hopefully you don't do that...

Only you can say what you have time and money for, but I think you'd be surprised how cheap and easy solar can be. I installed a 100w panel, with charge controller and wiring myself for well under $300. I'm being liberal because I don't feel like going back to actually look at receipts. But it may have actually been under $200.

[Iowa Dave]

While my son in law does not use a cpap, he does like to use 12 volt devices while camping without regular household (110volt) power. I gave him a 105 amp hour ( I think group 27 trolling motor battery I had. Then he bought the little 100 watt solar panel, the extension wire and a controller. He can use all the devices he likes to use and not run the battery below 50%. Not even close. He has a 12volt fan, lights, and other devices. Nothing scientific about my post just the encouragement to give it a try. I’m not a car battery use promoter because I hate dead batteries.
Iowa Dave

[Blue Bertha]

Thanks for the great responses! As far as solar goes, I would rather do that than have to constantly be trying to find an outlet to charge a power source. I'm just intimidated by it and unclear what size panel I would need and where best to buy it.

I've looked at Canadian Tire (I'm in Canada :-) ) but they carry pretty low-end to mid-range products like Coleman and Noma that don't have great reviews on their site. And the 100 watt panels I've looked at there are quite large. I'm hoping to find something smaller than that as space in the tow vehicle is at a premium already with an 8 year old, a large dog, and all the stuff that comes along with both of them!

My two big questions about solar are:
- Would I just somehow tie it in to the existing 12V house battery and have it constantly giving a small charge to that and run everything, including the CPAP, off of that or would I have a separate battery that I would use just for the CPAP? Or could I use the solar panel to top up both batteries?
- How large a panel would I need to get? I know it depends on what I'm using it for but if it was just for the CPAP, could I get away with a 40 watt panel that I just keep plugged into the battery to top it up for the day?

The specs on the CPAP from its manual are:
- 90W power supply unit
- AC input range 100-240V, 50-60Hz 1.0-1.5A, Class II
115V, 400 Hz 1.5A, Class II
- DC output 24V (solid line over dotted line) 3.75A
- Typical power consumption 53W (57VA)
- Peak power consumption 104W (108VA)

I have a manufacturer DC/DC Converter (90W) with little jumper cables on it and a 12V cigarette lighter outlet.

I appreciate any additional guidance anyone cares to share.

Thank you!
Amber

[Glenn Baglo]

I find two 40 watt Coleman panels from Canadian Tire are sufficient for my needs. We like to camp in the spring and fall so the furnace is our biggest draw. Lights are LED, fridge is on propane. Need to charge phones, laptop and tablet, but that's about it.
I have a single group 27 battery. I believe there are solar calculator apps to help you determine what you need.
The Honda generator now stays home.

[DaveMinBako]

Amber, those specs you quoted will be for the unit using the humidifier heater. Just turn off the humidifier, & power consumption will go down. If you suspect a cold night coming on, warm up the humidifier water before filling the chamber - doesn't need to be more than 'warm'.

[Alex Adams]

You might want to post the make and model number. I know there are a few members using CPAP machines and they may have the same one.

[Radar1]

I use a 12 volt powered CPAP, but never use the humidifier part because that takes a lot of power. Mine (without humidifier) uses about 8 amp hours per night, and with our 12 volt 155 amp hour golf cart battery backed up by a 90 watt solar panel on the roof we never have any power issues when boondocking.
As long as you don't use or need the humidifier part, even a small 40 watt solar panel would extend your battery life to last several days.

[ThomasBalmer]

I have a Resmed CPAP, and I chose not to use it in my camper. It runs on 24 volts, and the 12v adapter that plugs into the 12v outlet in the camper draws a lot of current (converting to 24v), and is almost as heavy as the CPAP machine. I replaced it with a Respironics that is smaller and lighter, and only uses 12v. The 12v adapter is about $36 as compared to $85 for the Resmed. The Respironics draws 3 amps without the humidifier. Before I installed a solar panel on the roof of my Scamp, I either recharged with the tow veh, of ran a small generator in the daytime to recharge.

[saabbob]

For years I have dry camped doing paleontology field work. The cpap I use is a 12 volt without the humidifier. I use a Goal Zero Yeti 400 power supply and a 30 watt folding solar panel. Fully recharged, the power supply will run my cpap for about 4 or 5 days. If I use the solar panel, I can completely recharge the power unit and any other rechargeable devices in about 10 hours.

Most of the new cpaps are 24 volt. This created a problem for me, so I use my old one in the field.

[Steve Carlson]

Originally Posted by Steve Carlson

I specifically bought a CPAP that runs on 12V as well as 120V AC household current. That way I can run it off of anything from a cigarette lighter 12V outlet in a car, to a set of jumper cables off of a car battery. https://www.amazon.com/gp/product/B0...7-47e776481440

You can also buy lithium ion "generators" (they are marketed as generators but are basically fancy battery units with 12V outlets, 120V inverter outlets and such) like this example https://www.amazon.com/NinjaBatt-Por...xpY2s9dHJ1ZQ==
to run your CPAP, and you can charge from your car or solar or other source during the day.

You will get a LOT more life out of your battery if you can get by without a humidifier. You will also get a lot more life out of the battery if you can run direct current from the battery without converting to AC with an inverter (the standard household-looking outlet on the above "power station".

FYI my CPAP that runs on 12V is a DeVilbiss IntelliPAP.

[Kevin Probst]

Get this. Fully charged my wife gets 5-7 nights without using the humidifier.
MAXOAK CPAP Battery Backup CPAP Power Bank for Airsense 10 Resmed S9 Philip REMstar System one 60 50 Dreamstation Z1 Aircurve Transcend Mini Travel Camping Emergency Power DC12/15/24V&USB5V https://www.amazon.com/dp/B074N8G8C7..._0v-3EbK0R46RA

[Alan Ursacki]

My wife has a CPAP and we ran the lights, water pump and the CPAP for 10 days on our deep cycle battery without charging with the solar panel. Wanted to see how long we could run on just the battery. So if you use your solar panel every day you should not have a problem.

[herons]

Following.

[Tony D]

This won’t go over well, but should be considered. Buy a generator. Get a small 1000 watt unit with a whisper mode. My Yamaha is quite at full power but is even more quite when it senses a low draw and throttles back. Honda has a great small generator as well.

Anyway, use one of the battery solutions discussed, and run the generator during the day to recharge the battery. Simple solution.

One other note, solar is great. Make it happen for yourself eventually. But for a medical device having a small generator as a back up seems wise.