Uninterruptible Power Supply for CPAP

Titrator wrote:We also carry the AeioMed Everest Battery Powered CPAP Machine. This gem has a built in battery and will run for 11 hours on a pressure of 10cm.

Check it out.

https://www.cpap.com/productpage/aura-t ... -pack.html

I talked to the wife about getting one of those.

I have a question: I got a prescription for a CPAP a while back. How long does it last?

Mine was almost 4 years old and was acceptable.

Derek is spot on. Run the cpap directly from the battery . Save lots of watts since the cpap runs from 12V CD anyway. Since most deep cycle batterys are 12V its as simple as pluging the m connector into the cpap and connecting to the battery. I use a 12V 115 amp hr battery. Its a bit large but lasts several days. For travel I use a jump starter . Good for 2 days with my 420e

:twis ted:

where did you get your battery pack. It is a great idea. Two days?? wow. what do you sleep 2 hours a night. LOL just kidding.

Derek,
Once again, thanks for your help!
plangster

I didn't want to start a new thread because there has been a lot of discussion on backup power supplies on this list already. But could someone please condense this into an electronics for dummies summary? I'm not particularly mechanically challenged, but electricity and I only get along so far as rewiring a lamp. So - my situation, and any help appreciated:

I currently have an F&P 234, integrated humidifier that can be turned off, but I really need some humidity so would rather not (but can if it's that or no CPAP at all). We have frequent power outages ranging from a quick blip to many hours. The F&P will not run on 12v. I will be getting something eventually that will run off 12v, probably an S8, but I read about the ones that "blew up." Perhaps those should go on AC current also rather than direct 12v? Anyway, I need something that can unobtrusively and safely (big concern of mine) sit near the CPAP ready to go at any time if needed, without overheating or overcharging. I do not need anything that would be considered portable. Convenience, ease of use, and reliability are primary concerns over cost.

As winter and frequent power outage season approaches, I really have been concerned about this situation. I would greatly appreciate some practical advice that would result in a set and forget arrangement. Many thanks for your help!

Prof,
If you have a machine that does not run on 12v dc, your best bet is to look at computer UPS (Uninteruptible Power Supply) systems. These allow you to plug into an ac socket on the unit. There is an automatic "switch" inside, and when your power is present you are connected to the ac directly, but when the power goes down, it switches to running on an internal battery through a dc-ac inverter.

Now here's a few things to consider:
1) These things are generally rated in watts, which reflects how "large" the internal inverter is. That's really of no consequence for cpap usage. They are designed to keep a computer system running for a short time in a power outage so that it can automatically shut down "gracefully" without losing data (the UPS usually sends the computer a message telling it to shut down).
2) The importand thing in choosing a UPS is the capacity of the internal battery in amp-hours, or Ah. I had great trouble determining that when I was looking into using a UPS; it's typically not listed anywhere in the specs. Usually the lower rated UPS's have smaller batteries but that does not always seem to be the case. Many of the manufacturers do list how long typical computer systems (with specified wattages) will run and you have to do some mental arithmetic to extrapolate to a, say 20 watt, xPAP. As a very crude estimate if a 200w computer system will run for x minutes, you might guess that a 20 w xPAP (1/10 the power) should run for 10 times that long, that is 10x minutes. (Don't quote me on that!)
3) I don't know about other manufacturers, but Respironics state explicitly that you must not run their humidifiers on a standard "modified sine-wave" inverter. These inverters have a horrible waveform that can burn out many types of electrical devices. So you must not run a Respironics humidifier from a UPS.
4) Some folk who have used a UPS have complained about the audible alarm that goes off in a power outage. There's an easy fix: locate the loudspeaker that's making the noise and cut or disconnect one of the wires .

I'll leave it to others who have used a UPS to comment further about choices of models for xPAP use, but a couple of brands to look at are Belkin and APC (American Power Conversion), Generally, the heavier the unit - the bigger the battery.

I have UPS units all over the house protecting 4 computers plus my audio/video equipment. APC and Tripplite are 2 brand names in use here.

Look at the instructions if you buy one of these (and probably can download a user guide on the web for either) and I believe you can shut off the alarm permanently on either without resorting to surgery on them. That solves the noise problem every time you get a 5 second power blip.

These have published sine wave and electronics data as well. One big advantage to using a UPS is that the device is protected not only from outages, but also from high voltage spikes (like when the power comes back ON) and also from "brownout" conditions. This is when the voltage SAGS but doesn't go out. Ever see your lights go dim for a few seconds? That's a brownout. And my opinion is that in areas with lots of brownouts, more damage to electronic equipment is happening that in areas with occasional high "spikes". The UPS supplies constant voltage throughout.

Many of the newer UPS units have "UPS" electrical outlets *AND* "protected" outlets. This means that in the same unit you have constant battery backup power supplied from some outlets and other outlets that are NOT on the battery backup but ARE protected against surge. If your heated humidifier can plug in separately, you could put THAT in a "protected" outlet and your CPAP in a "UPS" outlet and have battery backup to the CPAP itself while you lose the heat on the humidifier in case of an outage.

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): humidifier, CPAP, Power

http://www.costco.com/Browse/Product.as ... =&cat=&s=1

400 power supply mentioned for $89.95 plus they have the 300 for $79.95.

OK, I think I'm catching on. Here are the specs for the F&P:
Electrical Ratings:
Supply Frequency 50-60Hz
Voltage and Current 100-115V ~ (1.2A, 1.3A max)
220-240V ~ (0.8A, 1.8A max)

The Xantrex power supply looks interesting - I suppose the fact that it has multiple uses is appealing to me, although a computer UPS has some distinct advantages also. Since either would work, I'm wondering about capacity and being able to run the machine long enough to get some reasonable sleep Since I already have admitted to being electrically challenged, do the specs above make any difference? I noted one Belkin on their website that says it will power a computer system for 80 minutes (a high end UPS). What is the usual power draw of a computer compared to a CPAP? Is the 10/1 ratio a good standard to use in calculating? Is there any risk of frying things with either of these?

My continuing thanks
Beth (who wishes she had paid more attention to her engineer dad who tried to teach her these things before)

I don't know what the actual power requirements are of a CPAP. I mean... when they say things like "1.2amp MAX or 1.3amp MAX" does that mean that's *ACTUAL* power useage. I'm not sure I have the equipment here to measure what the machine is actually consuming as far as power while running.

Someone in another thread mentioned their machine using 9 watts I think. I believe that was without heated humidifier. That was on 12V power supply if I remember correctly. That'd be .75 amps. ( watts/volts = amps) if I'm remembering my equation correctly. If you take the information off the label .... 1.2amp at 120V then you'd get a VA number of 144VA.

Problem is... now I don't know what all those mubers really mean!

Does that mean a 650VA UPS will power a 144VA device for about 4 and a half hours? (That seems high)

And if you calculate VA using volts x amps ... on 12 volts that same device can be only 9VA? (That seems low) If so it'd look like it would run forever on a 650VA UPS.

I wish I was smarter.

Well, I thought I was catching on, but let me ask for the simple response again. Is there something that will run the CPAP for a full night, or at least a decent sleep? I was doing ok till I read about the sine waves and stuff and then the watts/volts/amps. HELP!

Good grief! That picture - somehow, I'm thinking of that Home Improvement sitcom. Any women on this thread?

momexp5 wrote:Good grief! That picture - somehow, I'm thinking of that Home Improvement sitcom. Any women on this thread?

You mean other than the one begging for help here?

There was a time I would have enjoyed learning all this stuff and getting into the nitty gritty of it all. Now, just tell me what to buy! (OK, along with a little bit- just a little- of why I should buy it). Life's too short....

If someone can tell me the amp information off their machine with heated humidifier running, I'll see if I can find a suitable, name brand, UPS that'll run it. I do this stuff at work for computer systems so this shouldn't be a big deal.

I'm going to use 1.25 amps at 120V for finding a UPS that'll run a CPAP with no heated humidifier. Because I don't know what the heater in the humidifier draws as far as current.