? For the battery powered gurus

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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CapnLoki
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Re: ? For the battery powered gurus

Post by CapnLoki » Sun Dec 21, 2014 9:57 am

Finster63 wrote: I run the S8 at pressure level 9, and I need 1 night at a bare minimum - would prefer 2 or 3 (8 hours of sleep each night).

I was thinking that the DC 12 adaptor caused the inefficiency?
The adapter inefficiency should be low (especially since the S8 is a 12v machine) and its built into the Resmed figures.
Finster63 wrote: So if the S8 draws about 5 amp-hours per night, and the PowerAdd has 32 amp-hours (32,000mah), it should last 6+ days???
Not sure about the math on this.
Amps and AmpHours are meaningless unless the voltage is stated. In this case, 32000 refers to the total milliAmpHours of the individual 3.7 volt Lithium Polymer cells. This totals 118 Watt-hours (volts X amps X hours), but then dividing by 12V you have something under 10 AmpHours. It get worse because some electronics have to somehow reconfigure the component cells to a useful voltage, and this voltage drops steadily as the battery discharges, so if you select 12V, you might only have 11v when its half discharged. Also, it seems the PowerAdd shuts down if the current draw is too high, and CPAP tend to draw a lot (2-4 Amps) when starting up, which may explain one report of needing to run two PowerAdds in parallel. I can't explain the one user report of 4 nights from a PowerAdd, but that user did say he uses a pressure of "6" and has only contributed several posts in one thread.
Finster63 wrote: Based on your recommendation, I've started researching LiFePo4 batteries, but I ran into this review:
One problem with all Lithium batteries (as far as I have seen) is that they cannot be discharged too far or they will be not be rechargeable. I checked Battery Tender's warranty and if the battery is discharged below 8 volts it cannot be recharged and the warranty will not cover replacement. Most manufacturer's of conventional Lead-Acid, AGM and Gel batteries for similar applications will replace a discharged or dead battery that cannot be recharged if it is under warranty.
The review was for this battery:
http://smile.amazon.com/Battery-Tender- ... dp_product

Would my CPAP discharge the battery below the 8 volts? or would it stop as soon as it went below 12v?
Most electronics that have a built-in regulator will shut down at low voltage = usually around 10.5 to 11 Volts. So it seems unlikely that a CPAP would run it down to zero, but because LiFePO4 has a very flat discharge voltage curve, it will still be be above 3V/cell, or 12V for the battery at near 100% discharge. This may lead to some harsh language in the warranty. To be honest I've never had this type of battery, but I think we've all had experience cell phone or laptop or power tool batteries that at some point refuse to take a charge. So I would take claims like "1000 cycles" with a grain of salt and avoid spending too much on something that will die from abuse or obsolescence long before you can wear it out. If this issue is a major concern, get something like:
http://www.amazon.com/Watts-Meter-Analy ... 001B6N2WK/
so you can accurately track the battery performance.

As for the Battery Tender battery - I have been a big fan and promoter of the Battery Tender charger for many years. However, the marketing of the new line of batteries seems rather despicable to me. Instead of listing the actual AmpHours of the batteries, they post "lead acid equivalent" which presumably inflates their ratings by the 50% safety often used for traditional batteries. In the FAQs, they confuse the matter more with marketing gibberish about how their batteries might have 4.5 times the power. This is all nonsense since there are standard, meaningful ways to measure AmpHours and they are just trying to justify inflated prices with misleading specs. I would look for another vendor. (And I feel a nasty-gram to the manufacturer coming on ...)
Finster63 wrote: I doubt that I would go with Respironics due to their larger size, but the DeVilbass IntelliPAP looks promising!
https://www.cpap.com/productpage/devilb ... ptions-tab
I don't know why you think the Respironics is larger - the 560 and 460 pump measures 7" x 5.5" x 4" or 154 cubic inches and weighs 2.8 (although I just weighed mine at 2.3 lbs) while the Devilbiss is 4.2" x 6.5" x 6.9", or 188 cu in, and also weighs 2.8 pounds. Unless I've missed something, the Respironics is the clear winner.

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Machine: DreamStation Auto CPAP Machine
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Additional Comments: Pressure 9-20, average ~9.5; often use battery power while off-grid
Hark, how hard he fetches breath . . .  Act II, Scene IV, King Henry IV Part I, William Shakespeare
Choosing a Battery thread: http://www.cpaptalk.com/viewtopic/t1140 ... ttery.html

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Finster63
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Re: ? For the battery powered gurus

Post by Finster63 » Sun Dec 21, 2014 11:28 am

You're correct - the Respironics are smaller! I was going off the pics, didn't read the specs...

I appreciate you pointing me in the right direction.

So now this is my plan of attack:
Buy the Respironics https://www.cpap.com/productpage/pr-sys ... chine.html Hopefully insurance will cover most of the cost, if not, my FSA will.
Test with PowerAdd to see if I can get 1+ nights out of it
If I can't, I'll return the PowerAdd and start researching LiFePo4 batteries

I've also been a fan of Battery Tender - use their trickle charger for my motorcycle, and another trickle charger for my deep cycle 12 volt (for car camping with the CPAP) - but I agree if they are going to artificially inflate the numbers, I'm not going to buy from them.
THANK YOU VERY MUCH FOR THE HELP!!!
Home: ResMed S8 Escape II
Backpacking: PR System One REMstar 60 Series Plus with the PowerAdd 32000mAh battery:http://www.cpaptalk.com/viewtopic.php?f=1&t=103170&st=0&sk=t&sd=a
Travel: Zzz-PAP 'Silent Traveler'

Sleeprider
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Re: ? For the battery powered gurus

Post by Sleeprider » Sun Dec 21, 2014 9:37 pm

It will be interesting to hear the results of your test.

I have some experience with LiFePO4 batteries and if you go that way it is important to know that they usually list the amp-hr rating as "lead equivalent" (Pb-eq). The real life use of these batteries when used in deep cycle applications is that real usable amp hours are about 1/3 of the Pb-eq. So you need a 36 amp hour battery pb-eq to get the 12 actual amp hours for something like your CPAP. If you buy a battery rated at 14 to 18 amp hours, I guarantee it will have a short life and will not be adequate. Also, they are crazy expensive.

A 36 amh hr (pbeq) battery will run about $330 and will weigh just under 4 lbs. http://earthxmotorsports.com/shop/etx36c/
For comparison, the 14.4 amp-hour AGM lead battery pack by Respironics weights 13.7 lbs. https://www.cpap.com/productpage/respir ... ations-tab

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Kellman
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Re: ? For the battery powered gurus

Post by Kellman » Thu Jan 07, 2016 3:00 pm

I got to thinking this same thing last night, so I went and got my Energen P6 http://myenergen.com/sgproduct/power-jumper-a/ and hooked the 12v 2a output to my PR REMStar Auto A-flex to it. Starting at 11.0 cmH2O it ran for over 4 hours and automatically shut off when the battery was completely depleted. I am going to try getting a matching jumper pack to see if I can run them in parallel to get more than 8 hrs. The jumper pack takes ~3 hrs to recharge from 120v outlet with included wall wart. On the CPAP side I had the humidifier completely disconnected from the machine to assure that it didn't try to kick on at any point during the the test as this is how I usually run it when I am running off an inverter while camping.

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jagzoo
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Re: ? For the battery powered gurus

Post by jagzoo » Thu Jan 07, 2016 7:52 pm

Hi,
I can only speak from my experience.

I would recommend picking up a gently used Respironics APAP System One (if your APAP is a ResMed) to use for camping. Now that the DreamWeaver is out, they can be found quite reasonably. That is what I use camping. With it I use a foldable solar panel :Instapark® Mercury27 Portable & Foldable 27 Watts Solar Battery Charger with DC 12V Output (also has USB and other ports) it plugs into a Poweradd Pilot Pro 32000mAh Monster Capacity Multi-Voltage Portable Charger External Battery Pack.

All I have to then do is plug my System One directly into the charged battery pack. I used it for 3 months, off and on as we were dry camping, and at a pressure of 10.5 I was able to get 3 nights (8-10 hrs each). I did try to recharge before the 3rd night, either by electric power (generator or we could plug in) or solar but could have made a 3rd night. The battery couldn't cold start the CPAP to a pressure of 10.5 - I did a 5 min. ramp starting at 9 and then there wasn't any problem running at 10.5. I did use straight CPAP, not APAP but I tolerated that well. And, needless to say - no humidification, although pass-over would probably not be a problem. Didn't do any more experimenting with it.

This also works well for backpacking, as the System One does not have an integrated humidifier, I just left the humidifier at home and then the battery and solar panels weigh only 3.75 lbs together.

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CapnLoki
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Re: ? For the battery powered gurus

Post by CapnLoki » Fri Jan 08, 2016 11:06 am

Kellman wrote:I got to thinking this same thing last night, so I went and got my Energen P6 http://myenergen.com/sgproduct/power-jumper-a/ and hooked the 12v 2a output to my PR REMStar Auto A-flex to it. Starting at 11.0 cmH2O it ran for over 4 hours and automatically shut off when the battery was completely depleted. I am going to try getting a matching jumper pack to see if I can run them in parallel to get more than 8 hrs. The jumper pack takes ~3 hrs to recharge from 120v outlet with included wall wart. On the CPAP side I had the humidifier completely disconnected from the machine to assure that it didn't try to kick on at any point during the the test as this is how I usually run it when I am running off an inverter while camping.
A few points: the energen is inexpensive but also is rather low power - you should be able to find devices that will carry you through a full night or maybe more (such as the PowerAdd mentioned by Jagzoo). Also, inverters tend to by only 60% efficient (if that) so I'm not sure why you use one when your cpap can be powered directly by 12V.
jagzoo wrote: I would recommend picking up a gently used Respironics APAP System One (if your APAP is a ResMed) to use for camping. Now that the DreamWeaver is out, they can be found quite reasonably. That is what I use camping. With it I use a foldable solar panel :Instapark® Mercury27 Portable & Foldable 27 Watts Solar Battery Charger with DC 12V Output (also has USB and other ports) it plugs into a Poweradd Pilot Pro 32000mAh Monster Capacity Multi-Voltage Portable Charger External Battery Pack.

All I have to then do is plug my System One directly into the charged battery pack. I used it for 3 months, off and on as we were dry camping, and at a pressure of 10.5 I was able to get 3 nights (8-10 hrs each). I did try to recharge before the 3rd night, either by electric power (generator or we could plug in) or solar but could have made a 3rd night. The battery couldn't cold start the CPAP to a pressure of 10.5 - I did a 5 min. ramp starting at 9 and then there wasn't any problem running at 10.5. I did use straight CPAP, not APAP but I tolerated that well. And, needless to say - no humidification, although pass-over would probably not be a problem. Didn't do any more experimenting with it.

This also works well for backpacking, as the System One does not have an integrated humidifier, I just left the humidifier at home and then the battery and solar panels weigh only 3.75 lbs together.
I'm a bit surprised you got three full nights - my research pointed to about 16 hours with that battery pack. Of course there are lots of reasons why it might go longer but I'm curious about your comment "could have made a 3rd night." What is this based on?

_________________
Machine: DreamStation Auto CPAP Machine
Mask: Quattro™ Air Full Face Mask with Headgear
Humidifier: DreamStation Heated Humidifier
Additional Comments: Pressure 9-20, average ~9.5; often use battery power while off-grid
Hark, how hard he fetches breath . . .  Act II, Scene IV, King Henry IV Part I, William Shakespeare
Choosing a Battery thread: http://www.cpaptalk.com/viewtopic/t1140 ... ttery.html

dtsm
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Re: ? For the battery powered gurus

Post by dtsm » Fri Aug 05, 2016 10:14 am

Drowsy Dancer wrote:Try Paul C. Buff Vagabond Mini (designed to power strobe lights):
http://www.paulcbuff.com/vm120.php
My standby backup battery has died. In the 4 yrs I've had it, used it maybe 4-5 times (which is good news to me!). I wonder how your vagabond is holding up a couple of years later as thinking to get this battery pack.

SAlan

Re: ? For the battery powered gurus

Post by SAlan » Tue Sep 20, 2016 6:44 am

I've been trying to follow all this but I am completely helpless at understanding this thread. I'm trying to find a very cheap solution for my husband's CPAP so we can go camping. He uses the Respironics S8 but I don't know at what setting. I think fairly high. We only need one night's usage from the battery since we would have the ability to recharge it during the day. Would something like this work... Suaoki 24V 25000mAh Portable Jump Starter Car Jumper Power Bank Battery Booster with 12V/19V DC Output USB Charging Port Built-in Flashlight Perfect for Automotive Truck Motorcycle Boat -- sorry I can't post a link to Amazon but I'm not a registered user.

Thanks!

Sleeprider
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Re: ? For the battery powered gurus

Post by Sleeprider » Tue Sep 20, 2016 8:32 am

SAlan wrote:I've been trying to follow all this but I am completely helpless at understanding this thread. I'm trying to find a very cheap solution for my husband's CPAP so we can go camping. He uses the Respironics S8 but I don't know at what setting. I think fairly high. We only need one night's usage from the battery since we would have the ability to recharge it during the day. Would something like this work... Suaoki 24V 25000mAh Portable Jump Starter Car Jumper Power Bank Battery Booster with 12V/19V DC Output USB Charging Port Built-in Flashlight Perfect for Automotive Truck Motorcycle Boat -- sorry I can't post a link to Amazon but I'm not a registered user.

Thanks!
First if your husband has a S8 model, it is a Resmed and operates at 24 volts DC. Get the Resmed DC Adapter. This Resmed document tells you everything you need to know about battery size using either an inverter or converter. http://www.resmed.com/us/dam/documents/ ... lo_eng.pdf

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D.H.
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Re: ? For the battery powered gurus

Post by D.H. » Tue Sep 20, 2016 8:39 am

My old machine is an AEIO med - Everest 3 with interrogated battery. The company went out of business 2011ish when their factory in China burnt down. Even with the battery and the humidifier, it has a very small footprint.

You can still get this machine used, but I don't really recommend it as you might have issues getting even maintenance parts for it. Also, it does not have any tracking except for an "odometer."

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Julie
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Re: ? For the battery powered gurus

Post by Julie » Tue Sep 20, 2016 8:49 am

Then why in hell are you posting - to not-recommend a machine that's not even available except if you get lucky somewhere? Do you just like to see your initials in print?

Gawd!

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palerider
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Re: ? For the battery powered gurus

Post by palerider » Tue Sep 20, 2016 8:57 am

D.H. wrote:You can still get this machine used, but I don't really recommend it "
more useless drivel from dunderhead.

"I've got old crap, you might be able to dig one out of a landfill, but I wouldn't if I were you".

why would anybody even be looking?

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Accounts to put on the foe list: dataq1, clownbell, gearchange, lynninnj, mper!?, DreamDiver, Geer1, almostadoctor, sleepgeek, ajack, stom, mogy, D.H., They often post misleading, timewasting stuff.