AirSense 10 units won't run on an inverter? Screwed again?

[archangle]

If you read the [urlwww.resmed.com/us/dam/documents/articles/198103r3_batteryguide_glo_eng.pdf]ResMed battery guide[/url], they imply that the A10 units can't run off of inverters at all, not even off of pure sine wave inverters.

I wonder if this is just poor editing or if it's correct.

[RogerSC]

I'm guessing they missed adding the AirSense 10 to the tables and charts for use with an inverter. There's no reason why they wouldn't design a new cpap to be powered by an inverter that puts out a pure sine wave, that's just bad design if true. And they don't specifically say that you shouldn't use the AirSense 10 with an inverter, which they should say if that's the case. The only device they list that can't be powered by an inverter is an old one.

Just guessing, though. I'd verify this by calling ResMed customer support or looking for other documentation on this before actually doing it, but design-wise just doesn't make sense to me *smile*. I'm not going to comment on ResMed customer support, since I've never used them.

Personally I use the converter since it is more efficient power-wise, and makes less noise *smile*.

[JDS74]

I'm not an electrical engineer so take this discussion with a large grain of salt.

Invertors that change from DC to AC do so in a variety of ways some of which don't play well with some electronic equipment. The "doesn't play well" types do generate AC but the wave form has lots of very sharp edges that can look like significant noise to the device.

The "pure sine wave" devices put out AC with a really smooth wave form. That means no "noise" to disrupt the device. Normal line voltage is not as smooth as that generated by such devices.

I suspect the the Airsense devices can't tell the difference between ordinary line voltage and pure sine wave invertors and will be just fine.

Just to be safe, check with ResMed to be sure.

BTW Respironics can run directly from battery but you are warned never to use them in a running vehicle. Alternators on vehicles have noise and voltage spike problems so this issue is not limited to ResMed.

[TangledHose]

If you read the [urlwww.resmed.com/us/dam/documents/articles/198103r3_batteryguide_glo_eng.pdf]ResMed battery guide[/url], they imply that the A10 units can't run off of inverters at all, not even off of pure sine wave inverters.

I wonder if this is just poor editing or if it's correct.

I have a 12v battery and inverter, I will plug my Airsense into it tonight and let you know what happens, but I can't report back until sometime tomorrow. My guess is it will run just fine. I do know that the Airsense does draw a bit more power than the S9 did if you compare the specs. When I run my Airsense on 12v due to power outage I use the ResMed DC power cord because it uses less power that way, but I'll try the inverter tonight.....its modified sine wave.

[wm_hess]

Hi archangle.

I use a BPS battery for my S9, and checked their site regarding the Airsense and found this page. Look near the bottom where the Accessories not included blurb is. It says a power sine wave inverter is optional.

http://www.batterypowersolutions.net/do ... EVICES.pdf

-Bill

[TangledHose]

I will still try my inverter tonight, but in the mean time from cpap.com under the power tab for the Airsense:

150W Modified Sine Wave Inverter Compatibility: The 150W inverter combined with the C-100 Travel Battery Pack will provide an AC outlet to plug the AirSense machine into the C-100 battery, however will provide a very low run time. It is NOT ADVISED to use this inverter to power the Airsense machines with the C-100 battery. Use instead the 24V converter.


So it sounds like it will run on an inexpensive modified sine wave inverter. But it will use a lot more power with the inverter as opposed to simply using a DC converter.

[TangledHose]

OK,

I ran my Airsense off 12v battery with a modified sine wave inverter and it worked just fine, had the ClimateLine air heated hose and humidifier running as well, no issues, worked just as it would had it been plugged into the wall socket. With all running, blower, heated hose, and humidifier the inverter was indicating a draw of 111 watts.

The inverter is probably not of extremely high quality, it's the one that's built into the Sears 1150 jump start package, so with a relatively inexpensive inverter the Airsense worked fine. As I said above I would normally not run it this way because it will shorten the available battery life considerably compared to running the Airsense with the ResMed DC power converter/cable. And before everyone jumps on the band wagon to bash the Sears 1150......I use it as a backup for occasional power outages that typically only last an hour or two at the most, so that's all the umpf I currently need for battery power and it's super convenient. I am just reporting to the OP that the Airsense runs just fine with a more or less standard off the shelf modified sine wave inverter - that's all - I am not endorsing any kind of battery setup.

[chunkyfrog]

Not surprised.
Science vs BS.
Under bright lights, the BS doesn't have much chance.

[archangle]

Hi archangle.

I use a BPS battery for my S9, and checked their site regarding the Airsense and found this page. Look near the bottom where the Accessories not included blurb is. It says a power sine wave inverter is optional.

http://www.batterypowersolutions.net/do ... EVICES.pdf

-Bill

Yes, but that's from a third party company, not ResMed.

[palerider]

OK,

I ran my Airsense off 12v battery with a modified sine wave inverter and it worked just fine, had the ClimateLine air heated hose and humidifier running as well, no issues, worked just as it would had it been plugged into the wall socket. With all running, blower, heated hose, and humidifier the inverter was indicating a draw of 111 watts.

not surprising, the modern units use switched mode power supplies, and those actually *like* the cheap stepped wave inverter output, though they're also happy with sine wave... the harmonics in the stepped wave power causes the old linear power supplies (with the big heavy transformers) to overheat.

[archangle]

I'm guessing they missed adding the AirSense 10 to the tables and charts for use with an inverter. There's no reason why they wouldn't design a new cpap to be powered by an inverter that puts out a pure sine wave, that's just bad design if true. And they don't specifically say that you shouldn't use the AirSense 10 with an inverter, which they should say if that's the case. The only device they list that can't be powered by an inverter is an old one.

Just guessing, though. I'd verify this by calling ResMed customer support or looking for other documentation on this before actually doing it, but design-wise just doesn't make sense to me *smile*. I'm not going to comment on ResMed customer support, since I've never used them.

Personally I use the converter since it is more efficient power-wise, and makes less noise *smile*.

I notice that they left the A10 out in two places in the "Minimum Inverter Requirements" section, and in the "ResMed devices powered with inverter" section, and lists the A10 in the "Converter" section and in the "ResMed devices powered with converter" section.

Normally, I'd expect a device with an external power brick like this to work even off of a modified sine wave inverter. However, there are some recent environmental laws about power factor, and manufacturers have had to change their power supply designs. I've heard some newer PC power supplies, for instance, won't run off of a MSW inverter, even though earlier designs would work just fine.

Even a pure sine wave inverter isn't a 100% sure bet, because it's "pure sine wave" when driving a simple resistive load, and a power supply is more complicated than that. There are considerations like power factor and switching and non-linear loads.

Why didn't ResMed list this in their battery guide? Maybe they just forgot. Maybe they just didn't get all the necessary testing and research done. Maybe they just want to sell the pricey DC-DC converters, which are the best solution. Maybe there is an actual problem with some inverters.

It sure would be nice if ResMed had said whether the A10 machines worked OK with inverters.

OK,

I ran my Airsense off 12v battery with a modified sine wave inverter and it worked just fine, had the ClimateLine air heated hose and humidifier running as well, no issues, worked just as it would had it been plugged into the wall socket. With all running, blower, heated hose, and humidifier the inverter was indicating a draw of 111 watts.

Thanks TangledHose. It's good to know that it worked in at least one case. There's still the possibility that there is some risk, but it just didn't happen that one night. Also, that it might vary with different inverters.

Anyone else run their A10 off of an inverter or UPS? More data would be good.

For now, I think we can say that it appears to work, but we can't say for sure it's safe, and the manufacturer doesn't say.

My best guess is it's OK, but I can't say for sure. I'd probably risk my own A10 machine if I had one and needed it. I'd probably try to find another solution if possible.

I'd also guess that, if anything, it would only damage the power brick or maybe the unit would refuse to run.

Anyone have a way to feed info to ResMed where they might actually update their manual?

[RogerSC]

Hi archangle.

I use a BPS battery for my S9, and checked their site regarding the Airsense and found this page. Look near the bottom where the Accessories not included blurb is. It says a power sine wave inverter is optional.

http://www.batterypowersolutions.net/do ... EVICES.pdf

-Bill

Yes, but that's from a third party company, not ResMed.

And it says the inverter is used to run the battery charger, not the cpap...you got to read this stuff carefully *smile*.

Like I said, looks like a documentation updating problem to me. Happens all the time when new products are added to existing documentation, things get missed.

[davecpap]

Anyone try contacting ResMed?

I am surprised by the draw of the Airsense 10 in the battery guide - I wonder if they tested in Airplane mode on or off.

[archangle]

Anyone try contacting ResMed?

I am surprised by the draw of the Airsense 10 in the battery guide - I wonder if they tested in Airplane mode on or off.

Airplane mode shouldn't make much difference. It only transmits once a day or so. Cell phones go for days on a tiny battery.

[wm_hess]

Hi archangle.

I use a BPS battery for my S9, and checked their site regarding the Airsense and found this page. Look near the bottom where the Accessories not included blurb is. It says a power sine wave inverter is optional.

http://www.batterypowersolutions.net/do ... EVICES.pdf

-Bill

Yes, but that's from a third party company, not ResMed.

And it says the inverter is used to run the battery charger, not the cpap...you got to read this stuff carefully *smile*.

Like I said, looks like a documentation updating problem to me. Happens all the time when new products are added to existing documentation, things get missed.

Archangle I understand Resmed is not the people saying this so it's the operators choice and responsibility to use the equipment.

Roger:

I also saw this on the page...

Battery Power Solutions’ 24V Power Converter was specifically designed for use with ResMed AirSense 10
PAP devices and the C-100 CPAP Battery Pack. ResMed’s AirSense 10 DC Converter or a sine wave power
inverter may also be used to complete the connection between the AirSense 10 device and the Battery Pack

From reading that, it appears that an inverter can be used to run the device?

I looked at Resmeds site and don't see that they sell an inverter but they do sell converters. Would they want to suggest you purchase something that don't carry at the expense of something that does the job and that they sell? I doubt Firestone Tires is going to suggest I go and purchase Michelin tires down the street instead of buying from them. Maybe I'm a little cynical.

If I may ask though why would you want to use an inverter instead of a converter? Doesn't a inverter use more energy than a converter, thus draining a battery faster?

Have a good day!

-Bill