Wander the West: CPAP and electrical requirements for camper - Wander the West

I am in the planning stages for my Four Wheel camper and am trying to determine my electrical needs to run my CPAP w/humidifier while sleeping, as well as the other misc. “stuff”. Does anyone else have experience using a CPAP in their camper?


How much “juice” will I need to run everything without draining the battery? According to the manual, my Respironics CPAP/humidifier consumes 6.67 amps in 12VDC, while 2.0 - 2.1 amps in 100-240 VAC.

So, if I go with the standard Auxillary battery setup provided by Four Wheel Camper, will that battery setup be adequate to meet my needs?
Or, do I need to get a second house battery for the camper to meet these needs?
If I drive a few hours, to the next campsite, will that be enough to recharge the battery (batteries)?
Do I need or should I get a solar panel (which I am thinking about anyway)?
Will the standard 80W solar panel setup from Four Wheel Camper be adequate?
Am I forgetting anything?
Sorry for so many questions, but I want to get it right the first time out, and not run out of power in the middle of the night with this setup.

In addition to my CPAP, I will most likely have a 12V fridge (most likely an Engel 45 refrigerator mounted in cab), LED lights (inside and out), FWC furnace, Fantastic vent fan (1 or 2), as well as a couple of 12V outlets to run a laptop, maybe run a small 12V fan on really hot nights, etc. Might even check out a small “Swamp” cooler (http://swampy.net/camper.html), as I like camping in the desert. My wife and I like background noise when sleeping, so would most likely have a small fan or the Fantastic vent fan running all night as well. Not sure if I am going with electric or manual water pump (leaning to manual), and not if I will have onboard hot water (might go the ZODI route of similar). So at the minimum I would have the CPAP, fan(s), and fridge running all night long.

Most of the time I don’t usually spend more than one or two nights in one spot when I camp and have not been camping since I started using a CPAP machine, but am itching to get back out there.
Sorry for the long winded topic.
Thanks for any and all input. This is my first topic posting. I have been reading this website and Expedition Portal for the last 6+ months, and have been laying awake at night dreaming and thinking about one day owning a Four Wheel Camper for my Tacoma.
Jay

Do you NEED the humidifier portion going regularly? If not that should save you some amps big time I believe. Otherwise you're pulling 60ah over a 9hr period which means you'd want at least a 100ah battery to cover just one night. Add in a compressor fridge which on average pulls about 24amps in a 24hr period and you need 84amps per day. This would take a single 100ah battery into the zone most manufacturers state you'll be doing damage (usually about 80% discharge but anything over 50% starts shortening the life cycle curve noticeably).

Driving for a couple hours will not reliably fully recharge things, you'll get some and the larger gauge wiring you use the more you'll get but I can't speculate what. If you were relying on solar make up assuming 8hrs of GOOD sun and 70% efficiency you'd need about 180watts worth of panel to recharge.

Start tacking on the fans, lights, swamp cooler, etc. and you're gonna need a big battery bank and/or a daily reliable recharge method.

As I mentioned above see about doing away with the humidifier, otherwise a 6.67amp load all night long is a killer for a basic battery setup. If it's a must then plan to size for it.

I agree that your "needs" are overwhelming. You will need a huge battery bank and likely a genny given all your appliances and draws.

I'd go with 2 batteries, plus 150-200 watts of solar, add in some driving around each day and you should be good for 1 or 2 day at a time. But you aren't going to make it much longer than 2 days before you deplete your batteries to the point where solar won't keep up.

I'd cross out the swamp cooler and the running the furnace much as well and focus on keeping the cpap and fridge going.

pods8, on 01 June 2012 - 02:35 PM, said:

Yes, from what I have read, the heated humidifier can often have a greater electrical demand than the CPAP itself as it is an electrical resistance type device. It looks like I will have to use the CPAP without the humidifier. Thanks for your input.

MakersTeleMark, on 01 June 2012 - 04:13 PM, said:

I guess I am going to have to rethink my "needs". Was just trying to keep the wife a happy camper. I was trying to avoid it, but might have to eventually go with a small generator. If I do, I have read quite a few good things about the Honda EU2000i generators, or the smaller 1000. Thanks.

What is your CPAP's Duty Cycle, i.e. does it run and stop, run and stop or does run constantly?

Could remove the fridge from the overnight electrical demands by going to one that can run on propane. I'm amazed at how little propane is used to run ours. A std bbq tank would easily last us a week of constant use.

I read and heard good things about those little Honda gensets, but I've heard even better about the little Yamaha gensets. Supposedly they are better than the Honda's in every aspect except price. Only what I've heard, haven't had need or cause to investigate further.

Doc Foster, on 01 June 2012 - 03:57 PM, said:

Have you tried the CPAP without the humidifier?

My father in-law has one and will not use it without the humidifier, it just isn't worth it to him to wake up feeling dry and worse off than when he went to bed.

I think you can pull it all off with 2 batteries and very conservative use of other 12v stuff.

I use a CPAP in my 4Wheel Camper. I have a portable CPAP machine, which has it's own Li-ion battery, and is designed to run on DC power. So at home, it runs on the battery with the battery plugged in to constantly recharge. In the camper, I do not plug it in to DC at night, and it is good for about 1 1/2 nights of use on its own Li ion battery. So I use it during the night without plugging it in. Then in the day, I plug it in to recharge. I have 120 watt solar, which is good to recharge it. Or if I am driving, this also helps to recharge, but it is not really necessary as long as the sun is shining. I do not use a humidifier. But at home I have a passive hudimifier, which simply passes the air over water, using 0 electrical power (for the humidifier.) I could use that on the road as well, and might start doing so. My CPAP machine is a AeioMed Everest 3. The included Li-ion battery says it is 6,000 mAH. I suspect this set up, which is designed from the beginning for DC use, is the best way to go.

UglyScout, on 02 June 2012 - 09:59 PM, said:

I've got one (haven't used it much in the last year though) and I never bothered using the humidifier. Kinda like chapstick, if you get used to using it you need it otherwise you likely don't most of the time.