Energy Can't figure out how to run CPAP off grid, long term

I am not a CPAP user. I thought 40 watts sounded like a lot for a device that basically blows air, so I did a quick search and was surprised to find that 40 watts is actually on the low end of the scale. Some of them run over 100 watts. So I just got schooled on that one.

Anyway, 40 watts by itself isn't much for a short term load. But 40 watts consumed for 6-10 hours every single night does add up to a lot of juice.

Forty watts at 12 volts is a little over 3 amps. So a standard 100 amp-hour battery providing 3.5 amps (rounded up) would last about 11-12 hours assuming you do not let it discharge below 60%. On the recharge side, a 10 amp charge would refill that battery in about three hours.

So to answer your question, a 100 amp hour battery and 200 watt panel will almost get you there. I say almost because it assumes full output from the solar panel, which never happens. You would need to add solar capacity to compensate for lower light conditions.

That's what is needed to get you through one night, and it assumes you'll have enough sun to recharge the battery every day.

To give yourself more run time, scale up the batteries and solar as needed.

I've tried to explain this without going heavy on the math or being too wordy. Your problem is not too hard to solve. I think you can do it.

 

I've used these folks for almost 20 years. They may have what you need. CPAP Machines, Masks & Resources for CPAP Therapy | CPAP.com

 

What are T105s? What is a 12Vdc system? And what is a 120 Vac/12Vdc 12 amp battery charger? Remember, I know very little about electricity or electrical equipment. I appreciate the time you've taken to tell me about your setup, but I don't understand a lot of what you said.

 

Tell me where I can find the nameplate rating (I have no idea what it is) and I'll do my best to get it for you.

 

I don't need extra oxygen. There are CPAP users who do, but they usually have very severe sleep apnea. For most users, their CPAP machines just provide pressurized air, which keeps their air channel open all night and prevents apnea episodes -- that is episodes when the person stops breathing. (Repeatedly stopping breathing for short periods of time isn't immediately dangerous but it can severely degrade sleep and has been linked to various chronic diseases such as heart disease.)

My CPAP supplies is just that -- a supplier. They really know shockingly little about...anything. However, I have asked around on one of the main CPAP user boards for information about how people run their CPAPs off the grid. It's amazingly hard to get this info and I'm not sure why. There's one guy on these boards who has put together his own acid battery solution with a deep cycle battery. He provides a very long thread on how he's put this together and related subjects, but it's way, way over the head of someone like me who is, as, as has been pointed out above, a neophyte.

 

I think this means 12 volts? Not sure what the 6.67 A stands for.

There's no way for me to tell just by wearing my mask if I'm getting enough pressure. CPAP machines have pressure settings that are very specific -- you can't just spitball it. And in my case, my machine is an auto PAP, which means it varies the pressure from the inhale to the exhale. How would a hair dryer be able to do that? And I also use a humidifier (which is why the CPAP uses so much power.) The hose plugs into the humidifier chamber, so how would that work with your setup?

 

Respironics System One Auto CPAP with Humidifier

 

• No landlord -- I own the house.
• I'm pretty low income. Mainly live on disability income. But I put aside a little money each month to do prepping stuff and I saved $500 of my stimulus money to invest in this project. I realize that doesn't cover the costs of what I need, especially since I'm leaning in the direction of a solar battery.
• See my original post for my issues with a generator.
  
• I don't quite understand your question about unshadowed insolation?

 

I recently got some feedback on another forum that's given my first inkling on how this might all come together. As I said in my original post I've been most puzzled about how to charge whatever solution I come up with in a reliable way. All this time I was thinking of getting a battery that would hold me for one night only, but the suggestion is for me to get a bigger battery that can hold me for my CPAP use for maybe three nights. I would also need solar panels. Then I would have three solid days to snag enough sunshine to recharge the battery. Hopefully the power outage won't fall on a stretch of weather that's all rain. The extra benefit of that is that, if I want to take a short camping trip I wouldn't have to recharge at all.

So, I'm now thinking I need a 1000W battery. That seems to me to exclude using an acid battery because it would be super heavy. I would have to go with lithium, which I realize is a lot more expensive.

 

Gents , I bow

 

Somebody in this thread mentioned that these meters aren't accurate, but I don't see that anywhere in the reviews on the Walmart site. My measurements came out about in line with this guide: https://www.resmed.com/us/dam/documents/articles/198103_battery-guide_glo_eng.pdf. It's for Resmed machines, not Respironics, unfortunately, but I looked up the Resmed machine (S9 VPAP Auto) I also have, which is comperable in age to my Respironics one. If you check the listing for humidifier setting of 3 it's actually lower than my measurements. My humidifier settings are at 2.

 

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New and my first post here.

My CPAP machine is through the VA and works well, annually checked out by them. My first VA advisor tried to tell me I didn't own the CPAP, but could only possess it after years of use. It seems CPAPs you get through Medicare are owned by them and only loaned to you, but with VA you do own what they issue.

So it is that I have become interested in its upkeeps and how to operate its programming features. Found a couple CPAP forums that explore all that.

My interest now is 1) how to use the CPAP to treat seasonal virus infections, even survive Covid-19; and 2) about how to possibly modify the CPAP for greater versatility.

1,a: About combatting infections, I'm interested in possibly buying one of the cleaning machines at Amazon, maybe one of the ozone generating boxes that could also be used to clean virus masks.

1,b: I also notice the machines that poot out oxygen into tubes for nostrils, and wonder if CPAP machine tube could allow oxygen input that way? I have read that CPAP machines can be used in Covid-19 treatment, where the ventilator machines are in short supply. Could be back-up if infected and doing treatment in isolation?

2, a: On the electrical supply backup front, I imagine carrying a deep-cycle battery in a vehicle for charging, then plugging the battery into some 12 volt wiring in home? (Have also read that you could connect vehicle water circulation to a radiator inside home for sub-zero conditions?) Not sure if CPAP 120-12 volt converter could just have a switch added at the plug to go directly to 12 volt.