Battery Back up for Airsense 10

[Sleeprider]

This is an older thread, and when it started, the BixPower Super High Capacity CP170-S10 battery was not available. This is a 159 watt-hour li-ion battery with the Resmed converter included at $249 on Amazon. That is at least 2-3 days of use without the humidifier, and it is designed for use with the Resmed Airsense 10. Lightweight with a lot of capacity. I know what I would get.

[OMyMyOHellYes]

The problem is having a ResMed machine.  In addition to the battery, you have to use their monster big 12-24 V DC to 24V DC converter.  Sorry.

They made it that way.  So you have to buy their converter.

OMMOHY

Can't you just use two 12v batteries in series, so you have native 24v and avoid the converter?

Nope.  That's the evil in their plan.  For the machine to run, it has to see a signal running on the third wire  from the converter.  I don't recall off the top of my head, but I want to say it is a specified electrical resistance that the machine looks for.  If it is not found, the machine will not start up. Other than that, there is no reason why you couldn't run one off of a 24 V battery.

That kind of behavior is one of the reasons I consider ResMed evil and am secure in my position that the S-8 and S-9 products that I have will be the last of their CPAP products that I  will ever have.  Other options with equal or better performance out there.

OMMOHY

[srlevine1]

Matza you can also use the Poweradd Pilot Power li-ion 32000 mAh power bank sold on Amazon for $109.  If you use a Resmed, you will have to get the Resmed DC Voltage adapter. Respironics and other 12 volt machines do not require an adapter.  This battery has enough output power to run most CPAPs over 2-days on a single charge, and is relatively small and light. It is multi-voltage and comes with a variety of cords and tips and can be useful to run a laptop and other electronics.  A few units have failed to power CPAPs and the return policy allows for an exchange.  Most work, but a few have tripped due to the load.  Some people start the machine in ramp to avoid startup surge demand.  Once running, it's no problem.

Have you ever figured out what machine you are using? Maybe update the profile?

Have you used the Poweradd unit?
Is it a deep cycle battery?  
At 32ah, ResMed's battery guide says I can power my Airsense 10 for about 16 hours with a 50% safety margin.
Way better price that anything else I have seen -- if it works? Of course, one needs to account for any loss in the DC-DC converter.

[OMyMyOHellYes]

The loss in the 12-24 V DC converter is not significant.

And ResMed's Battery guide figures are listed as if using a 12 V source, not a 24 V source so there is no need to consider any loss (and I suspect that their numbers in the Battery Guide are sandbagged some just to be conservative.)

Converter is greatly different than an inverter in this regard.

OMMOHY

[Sleeprider]

For the Resmed there is a new battery on Amazon now called the BiXPower Super High Capacity (159 Watt-hour) Rechargeable Battery for ResMed AirSense 10 CPAP Machine CP170-S10. This new battery is the equivalent to 59,000 mAh and includes the 24 volt DC converter for Airsense 10. This should give about 2-1/2 to 3 days of use with 50% reserve, and it includes all adapters, AC and DC chargers. At $250 it's not cheap, but since it is a complete package, it is pretty competitive and is designed to work with the Resmed CPAP and Aircurve.

[srlevine1]

For the Resmed there is a new battery on Amazon now called the BiXPower Super High Capacity (159 Watt-hour) Rechargeable Battery for ResMed AirSense 10 CPAP Machine CP170-S10.  This new battery is the equivalent to 59,000 mAh and includes the 24 volt DC converter for Airsense 10.  This should give about 2-1/2 to 3 days of use with 50% reserve, and it includes all adapters, AC and DC chargers.  At $250 it's not cheap, but since it is a complete package, it is pretty competitive and is designed to work with the Resmed CPAP and Aircurve.

Thank you for the information. It sounds like a great deal. Unfortunately, the numbers make no sense to me.

From BixPower ...

This package comes with a BiXPower AP170 super high capacity (159 Wh) lithium ion rechargeable battery pack and a 24V DC converter specially designed for a ResMed AirSense 10 CPAP machine. It can add 6-10 hours of extra running time for most laptop/notebook computers and 15-30 hours for most ultra-books & tablets. It can also power ResMed AirSense 10 CPAP machines for 2-3 nights with the humidifier turned off. This battery has a capacity of 159 Watt-Hours (44,100mAh). For comparison, most laptop internal batteries only have around 40-60 Watt-Hours.

According to my calculations ...

159 wH = 13,250 mAh at 12 volts

to get to 159 wH  and 44,100 mAh the voltage would have to be approximately 3.6 volts which may be the nominal voltage of a single  battery cell itself -- not the combined output capacity.

The formula is Q(mAh) = 1000 × E(Wh) / V(V) 
Q = 1000 x 159/12 = 13,250 not 44,100

THERE MUST BE SOMETHING I DO NOT UNDERSTAND OR THE NUMBERS ARE WONKY!

[Sleeprider]

Interesting. Will have to look closer at the claims.

[OMyMyOHellYes]

The numbers are wrong for 12 V.

OMMOHY

[srlevine1]

The numbers are wrong for 12 V.

OMMOHY

How are the numbers wrong?
Please clarify which numbers and why.

[Sleeprider]

Resmed is a 24 Volt machine...would that fix it?