DC cpap suggestion?

[Dive Apnea]

I have had my cpap for 7 years. I believe I am eligible for a new cpap every 5 years. Does anyone hve a DC cpap they like, and would suggest? I am looking for something to run off a deep cycle battery, w/o an inverter. (Just one extra failing point) I camped with my lithium ion battery, inverter cord from cpap.com. If the temp is below 70° at night forget about it. Shuts off after 30 secs. Had 3 of the worst nights of my life a couple weeks ago, never again, or I just will camp warm sunny baja!

My battery is below from a camping thread.

https://www.amazon.com/gp/product/B00DN ... ge_o07_s00

[Doug_Nightmare]

Mine. Will run fine off a 24 VDC battery pack.

With humidifier off it draws 4 amps; times 8 hours per night is 32 AH @ 24 VDC. Use a 50 AH 24 VDC AGM battery pack for extra capacity for Peukert Effect and aging.

Charge them separately with a CTEK 4.3 MUS that will not overcharge an AGM while charging at the maximum proper rate. An 12 volt nominal AGM must not be quick charged or charged with greater than 14.7 VDC or at more than 4.3 amps.

[CapnLoki]

I have had my cpap for 7 years. I believe I am eligible for a new cpap every 5 years. Does anyone hve a DC cpap they like, and would suggest? I am looking for something to run off a deep cycle battery, w/o an inverter. (Just one extra failing point) I camped with my lithium ion battery, inverter cord from cpap.com. If the temp is below 70° at night forget about it. Shuts off after 30 secs. Had 3 of the worst nights of my life a couple weeks ago, never again, or I just will camp warm sunny baja!

My battery is below from a camping thread.

https://www.amazon.com/gp/product/B00DN ... ge_o07_s00

The Respironics brand cpaps run on 12V and you can get an inexpensive 12V cord for them. The slightly more expensive (and perhaps slightly better) ResMed products run on 24V and they sell a 12/24 volt converter for about $85 (making them slightly less efficient). So if 12 volt operation is important, I'd go with the Respironics products (I did!).

I favor lead acid batteries, primarily AGM for camping, but people have had success with the PowerAdd 32000; there were several threads on them a few years ago. Interesting that you had temperature issues. Probably that, coupled with the inefficient inverter tripped the undervolt circuit prematurely.

I run a lot on battery power (golf cart batteries) on my boat during the summer, but I also use a smaller AGM for home backup and recommend that for up to a week of car camping. For info on my setup, check out the thread linked in my sig. Towards the bottom of the first page are description on parts for wiring up an AGM battery.

[palerider]

Mine. Will run fine off a 24 VDC battery pack.

Or a 12volt pack, the resmed converter doesn't care.

[CapnLoki]

Mine. Will run fine off a 24 VDC battery pack.

With humidifier off it draws 4 amps; times 8 hours per night is 32 AH @ 24 VDC. Use a 50 AH 24 VDC AGM battery pack for extra capacity for Peukert Effect and aging.

Your number are way off - you''re saying that without humidity you're using a whopping 768 watt-hours a night! My Respironics uses 4 AH a night at 12 volts, which is only 48 Watt-hours. Your Resmed probably uses a bit more, depending on settings, but it shouldn't be over 60 Watt-hours for a night. And why go to the hassle of using 24 volt gear when you can get the 12/24 converter and probably save money? An advantage of having a big 12V AGM around is that it can be charged with any regular charger and also used for charging phones or jumping a car!

[palerider]

Mine. Will run fine off a 24 VDC battery pack.

With humidifier off it draws 4 amps; times 8 hours per night is 32 AH @ 24 VDC. Use a 50 AH 24 VDC AGM battery pack for extra capacity for Peukert Effect and aging.

Not even close. Or, maybe you've completely broken your setup... who knows.

https://www.resmed.com/us/dam/documents ... lo_eng.pdf

Airsense 10 autoset, no humidiication, 10cm pressure. 0.93 amps @ 12 volts, 12AH battery needed for 8 hours with 50% safety margin.

using a heated hose and humidity, the thing would only use *half* of what you're alleging.

[palerider]

I have had my cpap for 7 years. I believe I am eligible for a new cpap every 5 years. Does anyone hve a DC cpap they like, and would suggest? I am looking for something to run off a deep cycle battery, w/o an inverter. (Just one extra failing point) I camped with my lithium ion battery, inverter cord from cpap.com. If the temp is below 70° at night forget about it. Shuts off after 30 secs. Had 3 of the worst nights of my life a couple weeks ago, never again, or I just will camp warm sunny baja!

My battery is below from a camping thread.

https://www.amazon.com/gp/product/B00DN ... ge_o07_s00

Get a 12v lead acid battery, 35ah will give you 5 nights without humidification.

Inverters are bad, the 12v cable for resmeds is not an inverter.

The lithium battery you're using is iffy.. some people say it'll work for them, some say it doesn't, it seems that it's borderline about supplying the power needs of a cpap.

[CapnLoki]

Airsense 10 autoset, no humidiication, 10cm pressure. 0.93 amps @ 12 volts, 12AH battery needed for 8 hours with 50% safety margin.

Why does the Airsense use so much more power than the Airstart? Does it do that much more when it has the same settings? If its true that makes a pretty big argument to never buy ResMed if you intend to run on battery power!

[palerider]

Airsense 10 autoset, no humidiication, 10cm pressure. 0.93 amps @ 12 volts, 12AH battery needed for 8 hours with 50% safety margin.

Why does the Airsense use so much more power than the Airstart? Does it do that much more when it has the same settings? If its true that makes a pretty big argument to never buy ResMed if you intend to run on battery power!

That's a good question, and I don't have any idea.
But, it's only 60 watts a night, not that much more than yours.

[CapnLoki]

Airsense 10 autoset, no humidiication, 10cm pressure. 0.93 amps @ 12 volts, 12AH battery needed for 8 hours with 50% safety margin.

Why does the Airsense use so much more power than the Airstart? Does it do that much more when it has the same settings? If its true that makes a pretty big argument to never buy ResMed if you intend to run on battery power!

That's a good question, and I don't have any idea.
But, it's only 60 watts a night, not that much more than yours.

Actually its almost 90 Watt-hours! That's a huge difference.

[palerider]

Airsense 10 autoset, no humidiication, 10cm pressure. 0.93 amps @ 12 volts, 12AH battery needed for 8 hours with 50% safety margin.

Why does the Airsense use so much more power than the Airstart? Does it do that much more when it has the same settings? If its true that makes a pretty big argument to never buy ResMed if you intend to run on battery power!

That's a good question, and I don't have any idea.
But, it's only 60 watts a night, not that much more than yours.

Actually its almost 90 Watt-hours! That's a huge difference.

Yup, you're right, I musta hit something wrong. twice as much.

That's why I refer people to you for battery stuff

[CapnLoki]

Actually its almost 90 Watt-hours! That's a huge difference.

Yup, you're right, I musta hit something wrong. twice as much.

That's why I refer people to you for battery stuff

I tried to dig a bit deeper into this. Philips Respironics is quite stingy with their specs but they are clear that their lithium battery pack, which is airline safe (i.e. 100 watt-hours), lasts for over 14 hours with the Series 50, Series 60, and Dreamstations. This is consistent with my 4AH, or 48 watt-hours, a night for the 560 at pressure 10, and means the load didn't increase for the new Dreamstation line.

Resmed S9 is a bit less efficient but their latest battery doc seems to say the AirSense 10 line is much less efficient, and is almost twice the power load of the equivalent Respironics pump! This means, for instance, that a U1 AGM (35 amp-hours) that would power a Dreamstation 6 nights with a fair margin, would only go 3 nights with an Resmed Airsense. And curiously, the new version of the ResMed doc doesn't even list the new pumps on an inverter - it must be too embarrassing!

https://www.resmed.com/us/dam/documents ... lo_eng.pdf

[Rob K]

Are you set on getting a different machine than what your used to? From what I've read over the years the S9 is one of the best units on the market. The simplest thing would be to run your S9 from two 12v batteries in series to get the needed 24 volts.

[Rob K]

I did a parts search for the S9. From what I could find, I see Resmed doesn't accommodate a simple 24v deep cycle battery hookup. That's not very nice of them. Their basic dc cable has a special connector that only allows you to connect the S9 to the costly Resmed Power Station. The other option is to use the converter to be able to connect to a 12v battery. The best thing would be to make cables for a 24v battery system, but that's not simple for many people.

[palerider]

Are you set on getting a different machine than what your used to? From what I've read over the years the S9 is one of the best units on the market. The simplest thing would be to run your S9 from two 12v batteries in series to get the needed 24 volts.

You can't just hook them up to 2 batteries, there's a sense pin that tells the unit what kind of power supply it's hooked up to. Without that, it won't turn on, just like many modern computer notebooks.