Pilot-24 CPAP Battery System from Medistrom

[sonicboom]

Happy Sunday Everyone!

I'm looking for feedback\reviews on the titled battery product to use with the Airsense 10 Autoset.

(I did a search and didn't find anything yet for this in this subforum but its certainly possible I missed it. If so, apologies in advance.)

[foss]

I hope to obtain one of these to power my Airsense 10 sometime in the future. I would be interested in results as well. If I run across any real world feedback, I will post here.

Jeff

[PaulaO2]

Moving this to the Main Forum where more people will see it.

[parkerdt]

I've looked into this battery quite a bit.

The Medistrom is a 100 watt hour battery per their specs.

If you have a 100 watt hour battery you divide by nominal voltage to get amp hours. 100 watt hours / 24 volts nominal = 4.167 amp hours.

The ResMed site has battery tables for their machines. My AirSense 10
running with 8cmH20 pressure and the slim line hose needs a 10 amp hour battery to run for 8 hours.

So - 10/8 = 1.25 amp hour per hour of run time.

Now - ResMed states this is with a 50% safety margin. So, if the battery were brand new, and you got 100% out of it, you could get 6.6 hours
out of it with no humidification or heat. I have no idea how realistic that is.

And 4.167 amp hours / 1.25 amp hours/hour = 3.3 hours run time.

Turn on the humidifier set to 4 with the slimline hose and you need 24 amp hours or battery to get 8 hours run time.

So, likewise, 24/8 = 3 amp hours per hour.

And 4.167 amp hours / 3 amp hours/hour = 1.389 hours of run time.

Throw in the Climate Air hose, or turn up the pressure, and run time deteriorates.

So, for me, this battery would NEVER be able to run my machine the way I like to use it for a full night.

If you are willing to run without humidity, without a heated hose, and have a low enough pressure requirement, you can get a full night out of this. Barely.

[GeoffD]

These 100 watt-hour lithium batteries that the TSA lets you carry aboard an airplane are kind of useless since they have such low capacity. You pay an enormous price for the portability.

I use a 35 amp-hour AGM wheelchair-scooter battery as my backup for power failure and on the boat to save my battery bank. You can buy them for $65 online with free shipping. They weigh 25 pounds so you're not going to toss it in a backpack and go camping but as a backup at home and for the boat or car camping, it's an inexpensive solution compared to a lithium battery.

You can buy a Resmed 12v to 24v DC-DC converter online for sub-$90. A Battery Tender Junior trickle charger is sub-$25 at Walmart or Amazon.

With the humidifier and heated hose off, I can get 3+ nights out of a 35 amp-hour battery. In the winter with a power failure where I need the humidifier, I can get a night out of it.

[foss]

Thanks for the info Parkerdt.

That explains a lot. I think I will just stick to my 55 amp hour AGM battery and Battery Tender.

Jeff

[Sleeprider]

Thanks for the info Parkerdt.

That explains a lot. I think I will just stick to my 55 amp hour AGM battery and Battery Tender.

Jeff

The problem is Parkerdt simply divided the claimed watt-hour rating of the battery by 24 volts, to get 4 hours of operation, which is wrong unless the machine uses 1-amp of power. What we need are the operating amps at 24 volts of the CPAP, and humidifier if that is to be left on. The output of Pilot is 24 volts (a 12 volt version is available). Note the battery is not rated in amp-hours which would be much better.

I don't know how many amps the Resmed machines require during operation, but 1-amp at 24 volts is 24 watts per hour. So whatever amps are required to run the equipment is multiplied by the 24 volt to derive watts. The maximum operating time is the result of 100/24*amps. This is not a very powerful battery, and when pitted against the inefficient 24 watts of a Resmed machine isn't going to go very far, especially considering the battery will likely fail to power the device once it is depleted below 40%. So this 100 watt-hour rated battery probably only has a functional output of 60-70 watt-hours tops. Score a point for 12 volt machines.

[sonicboom]

Thanks to all of you for the feedback. It sounds like the main advantage to this is the portability and use for short power outages - not overnights or camping trips. Here are the specs for whatever it's worth of the Airsense 10 Autoset:

AC Input Range - 90W Power Supply: 100 - 240V, 50 - 60Hz, 1.0 - 1.5A, Class II

DC Output - 90 W Power Supply: 24V --- 3.75A

Typical Power Consumption: 53W (57VA)

Peak Power Consumption: 104W (108VA)

[parkerdt]

Apparently you didn't read my thread closely:

If you have a 100 watt hour battery you divide by nominal voltage to get amp hours. 100 watt hours / 24 volts nominal = 4.167 amp hours.


If you don't believe this is the correct conversion from watt hours to amp hours, you can google it, which is what I did. Watts = Amps*Volts, so Amps = Watts/Volts. Unless you wish to reinvent Ohm's Law.


The ResMed site has battery tables for their machines. My AirSense 10
running with 8cmH20 pressure and the slim line hose needs a 10 amp hour battery to run for 8 hours.

So - 10/8 = 1.25 amp hour per hour of run time.

Thanks for the info Parkerdt.

That explains a lot. I think I will just stick to my 55 amp hour AGM battery and Battery Tender.

Jeff

The problem is Parkerdt simply divided the claimed watt-hour rating of the battery by 24 volts, to get 4 hours of operation, which is wrong unless the machine uses 1-amp of power. What we need are the operating amps at 24 volts of the CPAP, and humidifier if that is to be left on. The output of Pilot is 24 volts (a 12 volt version is available). Note the battery is not rated in amp-hours which would be much better.

I don't know how many amps the Resmed machines require during operation, but 1-amp at 24 volts is 24 watts per hour. So whatever amps are required to run the equipment is multiplied by the 24 volt to derive watts. The maximum operating time is the result of 100/24*amps. This is not a very powerful battery, and when pitted against the inefficient 24 watts of a Resmed machine isn't going to go very far, especially considering the battery will likely fail to power the device once it is depleted below 40%. So this 100 watt-hour rated battery probably only has a functional output of 60-70 watt-hours tops. Score a point for 12 volt machines.

[Sleeprider]

My apologies Parker. You did indeed convert watt hours to amp hours. My bad for mis-reading.