Battery Usage Time

I think it would be helpful to have a thread where battery usage times can be compared (for anyone contemplating backup power for their machine). If you have some sort of backup power device, please tell us what you use and how much time you can get from a full charge on that device (along with your pressure setting). Also let us know whether or not you're powering a heated humidifier with the backup power source.

I tested my backup battery (the C-222 from batterygeek.net) sometime last year and was able to get three nights out of it (with the heated humidifier), but I can't remember what pressure setting I had at the time. So I decided to retest the battery a couple of nights ago. Unfortunately, it occurred to me this morning that I'm now using the HC150 humidifier, and last year's test of the battery occurred while I was using the M-Series integrated humidifier; so the battery has not actually powered the HC150 for the past two nights, and the current results can't be fairly compared to my earlier experiment.

I exchanged the HC150 for my old integrated humidifier this morning, and I'm recharging my battery to full power today so I can re-start the test tonight. I'll post my results in a few days.

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So, if you use a backup power source:

1. What do you use?
2. What's your pressure setting(s)?
3. How much time can you get from a full charge?
4. Are you powering a heated humidifier, as well?

/JMMO/ - I think in most cases (power outages) one will be much better served to not use any power for any humidifier. Esp. if you don't know how long the power will be out. The humidifier can be used in the "Passover Mode" during these brief periods w/o commercial power. /Just My Meaningless Opinion/

Hi,

Just a couple of thoughts on what would be "useful information" to collect.

1. What Battery are you using?
2. How many nights did you use it between recharging the battery?
3. Number of Hours used per night while on Battery power?
4. What PAP device are you using?
5. What is your Pressure Setting(s).
6. What Humidifier are you using (if any)?
7. What is the Humidifier Setting that you used?
8. What Inverter (if any) did you use to convert battery power to AC power?
9. If an Inverter was used did it generate 110V or 220V AC Voltage?

Mseries auto /cflex 1 12cm(h2o implied)
Optima BlueTop 55AH
no HH /passover
straight 12v w/adapter
4 nights ~8hr/night

it would have gone another night maybe 2

I'm w/"I'm GumbyCT, damn'it" on this one,
the few nights I would need this I can live without HH.

I for one would like to give a BIG THANK YOU for this post. I am looking into buying a battery backup and this will be most welcomed info....

Might I suggest to the powers that be, Maybe even make a post like this a sticky so anyone in the future can easily lookup fact and figures on Battery Backups.

I agree that this is a useful exercise. However, a confounding question is how many times are you able to get that many nights out of your battery before the battery is damaged.

Batteries may be able to be discharged to a very low voltage a handful of times (that is, they may get you a full two, three, four or whatever nights use on one charge), but such deep discharge cycles are damaging to the battery. How damaging depends on the type of battery. But in any case, you will reduce the life of the battery, potentially significantly.

I really think everyone should periodically give thier backup battery an "acid" test. Differences between machines, changes in pressure, and age of the battery can all effect how much time you get out of it. I recharge the battery whenever I use it, it's my understanding that if the battery doesn't have a "memory", continually draining it will shorten its life. Part of your monthly maintennce should include "topping off" your backup battery. Also, remember that some humidifiers can not be run on DC.

My machine is a RemStar M Series. During a "power emergncy" (or camping) if I use the humidifer, it is in passover mode. Last time I tested, my pressure was 10. My nights are 6 to 8 hours.

I own both a Black & Deck 400 and a Battery Geek.

The Black & Decker on DC I got 4 nights and most of the 5th on DC, not quite 2 nights using the AC. I've never pushed the Battery Geek to the limit, but I can easily get 2 nights out of it.

I have the ResMed S8 Elite II without humidifier. I recently purchase what is called a gobe power system. It includes a 12V 14.5 amp battery with solar panels along with an AC power cord to charge the battery from the wall. It also comes with a DC cord with male and female adapters. Where I get the most benefit is from the gobe solar briefcase. When I camp/travel I can charge the battery during the day and get a good 10 hours of usage when I sleep at night. Pretty inexpensive when you consider that you get the whole kit for $180. From everywhere I researched the best price I found for this is at http://www.wattme.com.

BTW-the battery has an integrated inverter so you can also run devices from it that require a USB, AC, or DC connection.

The blue and yellow top Optimas are AGM batteries that are designed to withstand deep discharge with little or no damage. The red top Optimas can also withstand deep discharge with little damage, but they are intended primarily as a starting battery. I have a red top Optima as my car starting battery and yellow top Optima in my car trunk.

The Battery Geek CPAP battery uses Li ion batteries that easily withstand deep discharge.

carbonman was using a 55 Ah battery for four nights, 8 hours a night, and I assume that his CPAP is drawing about an Amp. 4 * 8 * 1 = 32 Ah. His battery is rated at 55 Ah; 55 - 32 = 23 Ah reserve. That battery will take that sort of discharge without even breathing heavy. My guess is that he could run his CPAP for six nights without damaging the battery. 6 * 8 * 1 = 48 Ah and 55 - 48 = 7 Ah reserve (over 12%)

My results are in!

Using this battery: http://www.bestcpapprice.com/Owell-Indu ... 0-516.html
and this ResMed converter: http://www.bestcpapprice.com/ResMed-S8- ... 3-335.html

Machine: ResMed S8 Elite II
Pressure: 12cm, EPR=3 fulltime, no ramp
Humidifier: passover mode

I got 25.5 hours!

twokatmew wrote:My results are in!

I got 25.5 hours!

Good deal.

I'm sorry to report that my test has been derailed temporarily. I think my battery charger is faulty, as the power "brick" in the middle of the cord gets hot to the touch (too hot for comfort) within about an hour of plugging it in. So I need to replace that before I can effectively recharge my battery and repeat the test.

I hope it's just the charger that's defective...

I have a Battery Geeks 2200 and get two 8 hour nights use out of it, plus about five hours the third night -- 21 hours. I get the same with either an IntelliPAP or an Auto M set at 11 cmh2o.

This is an excellent battery solution and I have used it for 3 nights several times. It weighs about 13 lbs, will fit in my motorcycle saddlebag and allows me to go camping with the Boy Scouts. I remove the battery charger from the front pocket when I travel and my M-Series cpap fits right into the battery case. Cpap setting 8-12, no humidifier.

https://www.cpap.com/productpage/respir ... -pack.html

This is an excellent battery solution I just used for an overnight backpacking trip. Also provided excellent service and met my critical shipping date to make a Boy Scout trip. It weighs only 20 oz. and is the size of a crackerjack box. I used it for 8 hours at Cpap setting 8-12, no humidifier. I plan on this being for one night only.

http://www.batteryspace.com/polymerli-i ... arger.aspx

So, at 14 cm pressure how many amp-hours would I need to get three successful nights on a ResMed S8 with no HH (passover only)?

From the chart below, a CPAP set at 14 cmh2o should last about 12 hours with an 18.5 Ah battery and about 8 hours with a 12.5 Ah battery. You would probably be safe figuring that you need about 1.6 Ah per hour. A 12 Ah battery will be exhausted after 8 hours, I would conservatively figure that an 18 Ah battery would last one night. If using a lead-acid battery, I would figure at least 20 Ah per night. This is a starting point for testing, and your mileage may vary.

The following chart is adapted from
http://www.batterygeek.net/v/vspfiles/S ... _222Wh.asp

Estimated CPAP Lithium Ion Battery Usage Chart

CPAP Usage Time in Hours

Pressure.....Battery....Capacity
cm/H2O.....18.5Ah.....12.5Ah
................Hours......Hours
....4............25..........18
....7...........18.8.......12.7
...10...........14.3........9.7
...13...........12.1........8.2
...16...........10.5........7.1
...20............9.8........6.6

All Times Approximate, For lead acid batteries, allow at least a 25% reserve to help preserve battery life.