Best off grid Cpap set up???

I need a Cpap that can run on battery and re charge with solar power. Any suggestions on brands? I'm going to camp in the Serengeti. Tks

My cpap setup is on solar power 100% of the time. PR cpaps ate native 12v so they can easily run directly off a car battery. I'm also using an inverter because I have other appliances hooked up to the same system.

Ancy wrote:I need a Cpap that can run on battery and re charge with solar power. Any suggestions on brands? I'm going to camp in the Serengeti

The surface area of solar panel(s) that you would need to be able to adequately recharge a battery during the day, so that you can can run a xPAP machine overnight may difficult to achieve in a camping situation

Cheers,

Bill

billbolton wrote:

Ancy wrote:I need a Cpap that can run on battery and re charge with solar power. Any suggestions on brands? I'm going to camp in the Serengeti

The surface area of solar panel(s) that you would need to be able to adequately recharge a battery during the day, so that you can can run a xPAP machine overnight may difficult to achieve in a camping situation

Cheers,

Bill

Why surface area? I would think weight is the biggest obstacle. They make flexible, 60 watt panels (60 inches x 24 inches) that fold up to about 15 inches x 12 inches. Two of those in a desert environment should be plenty of power to charge a CPAP battery.

The problem is the battery and associated weight required to take the charge to keep the CPAP going all night long.

DreamStalker wrote:
Why surface area? I would think weight is the biggest obstacle. They make flexible, 60 watt panels (60 inches x 24 inches) that fold up to about 15 inches x 12 inches. Two of those in a desert environment should be plenty of power to charge a CPAP battery.

The problem is the battery and associated weight required to take the charge to keep the CPAP going all night long.

Because the surface area determines the maximum number of instantaneous Watts generated by the panel(s) which in turn determines the maximum number of Watt-hours that the charge controller has available to charge the battery.

If the OP intends to use this setup for camping, then total number of Watt-hours generated the solar array must be at least 120% of the equivalent number Amp-hours drawn by their CPAP machine. (Assuming the charge controller is at least 80% efficient).

DiverCTHunter wrote:

DreamStalker wrote:
Why surface area? I would think weight is the biggest obstacle. They make flexible, 60 watt panels (60 inches x 24 inches) that fold up to about 15 inches x 12 inches. Two of those in a desert environment should be plenty of power to charge a CPAP battery.

The problem is the battery and associated weight required to take the charge to keep the CPAP going all night long.

Because the surface area determines the maximum number of instantaneous Watts generated by the panel(s) which in turn determines the maximum number of Watt-hours that the charge controller has available to charge the battery.

If the OP intends to use this setup for camping, then total number of Watt-hours generated the solar array must be at least 120% of the equivalent number Amp-hours drawn by their CPAP machine. (Assuming the charge controller is at least 80% efficient).

Ok so assuming he gets 5 hours of sunlight in the Serengeti (should be easy peasy) with two 120 watt panels ...

120 watt * 5 hours * 1/0.80 system efficiency * 1/12 volt battery = 62 AH per day

... your saying that 62 AH per day is not enough to run a CPAP?

I can run my CPAP on 60 AH for 2 nights at 11 cm pressure. Maybe my math is wrong?

I had solar panels on my old Travel trailer, and didn't bother adding them to the new one I bought last year because they tend to not deliver more often than not. For what you're looking to do, you'll need to leave your system in full sunlight for several hours a day, and you'll of course have to carry transport a fair amount of gear.

That said, I haven't got any better ideas. You can check the battery geeks for pre built systems that should fit your needs. You'll also want to verify that you can take the lithium battery pack on the aircraft as they have restrictions based on the size/type of battery.

Thanks to all that replied. When there is a will, there's a way!

And, please, please, please if you are using this mask, please remove it BEFORE exiting the tent. Last thing I need to read about is a fellow cpap user killed by horny rhinoceros after he tries to mount the "perfect" [albino] mate.

The calculations aren't necessarily easy.

If you have a 100W solar panel, it's only 100W

1) At noon
2) With the panel tilted at the right angle to the south.
3) If there is no shade from trees
4) It's not cloudy.

If you design a solar power system, you need several things

Solar panel.
1) How many watts.
2) Derate if you can't set it up at the right angle to the sun.
3) Derate if there is partial shade for part of the day.
4) Derate based on cloudiness. Guess how cloudy for how long for how many days in a row.
5) Derate based on lattitude and time of year for number of hours of sun and the effect of the changing angle of the sun.
6) Add capacity to handle the inefficiencies of the charge and discharge process. Not all the energy you put into the battery comes back out.
7) Add capacity to handle extra charging up the next day when you miss a day due to travel, clouds, shady camp site, etc. i.e. if you only get to charge every other day, you need 2x the charging power to charge enough for 2 nights during one good day.

Battery
1) Must have enough watt hours to run your CPAP for one night.
2) Add capacity to carry you through cloudy days. Guess how many cloudy days.
3) Add capacity to carry through days when you're moving and won't have the solar panel set up all day long.

Are you going to be at the campsite all the time? If you go out doing photography, is your equipment going to still be there when you get back?

You've already been given a ton of good information but I can give you some real world usage.

I've been taking my VPAP with me for years. I tried using the big marine 12volt battery and car inverter... it worked most of the night. I also blew 2 inverters from being hooking things up wrong! The battery was huge, heavy and embarrassing. My brother-in-law works for an emergency prep company (probably not allowed to plug his store) and he had a cool battery and solar panel that he used to watch tv and play around with when we would go on the big family camp outs. He MADE me borrow it one night after he saw me running the generator trying to recharge my 12 volt. I did...It lasted until about 2 am... not happy!

He charged it up on a small fold up panel that day and we tried it again the next night, but this time with the humidifier OFF... IT WORKED!!! I guess the tiny little heater uses a ton of power! I cant explain how cool this was. The battery wasn't that small, but it a lot smaller and lighter than the stupid marine battery I kept using. It didn't need an inverter so it was silent and it didn't spark when i hooked the cables to it

when I got home, I bought one from him with 2 of the solar panels. I wanted to be able to use it during the day to watch tv like he does I then went to my equipment supplier (Praxair) to see if they had a better humidifier (nope) but they did have the 12v adapter that made my machine use less power. I tested it, and then took the extra solar panel back.

This was 4 years ago! The solar panel is very light and yes, it works all day, (not just at noon) I don't even HAVE to put it in direct sun light, but it charges faster when I do. It works with clouds and trees... When it folds up, its about the size and weight of a hard back book.

I love it! Don't give up! I don't know if I can name the Company on the boards (I'm new here) but look around and I'm sure you can find it. if not or you want to know my setup, you can message me but only if that's ok with the moderators. No - I don't work for that company, but it's made a huge difference in my life, so I thought I would post.

Good luck!

Name the company, no one will object.

Yes, a solar panel will work at times other than noon. You just won't get the rated power out of it.

You usually get a LOT less power when it's cloudy, and if you're in any kind of shade.

Yes, the humidifier uses a lot of power, probably twice as much as just the blower.