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Last nite with thunder storms moving thru my area I decided to try something different. I had already tried my Jump Starter over nite to make sure it would last, it did. But having read on here a number of people wanting to use a UPS so they were not awakened during the power outage I thought I would use my Jump Starter while it was plugged in and charging. Remember the UPS sounds an alarm when the power goes out, this won't.

This is the Jump Starter I used -
viewtopic.php?f=1&t=47625&p=434501&hilit=+1150#p434501

First you will need a DC power plug to fit your machine. I recommend you fully charge the battery, then use it overnite to ensure it will last the nite at your pressure. My bipap pressure is 18/15 sometimes going up to 20/18 but did last for me. This model has a 22AH battery, the largest I have seen.

I plugged my bipap into the DC power outlet which is always ON and not switched by the power switch. Then made sure the 1 amp charger was plugged in and charging. Keep in mind it is against the manufacturer recommendation to operate the starter while it is charging. This unit displays the percent of charge on a display while it is charging and keeps a float charge. I initially kept an eye on this display, it never moved from 100. Then I took a nap for about 30 min. and evaluated things. Later, when the lightning and thunder started I was set to go down for the nite.

Before all the naysayers show up to tell me I'm off my rocker, I am here to say "Try it BEFORE you knock it". To me, this is the way to go. When the lights go out you won't have to go looking for anything or even wake up

Isn't that what so many have been asking for?

Some here may remember I was nearly roasted at the stake when I suggested using a car jump starter to run a cpap. So now I say give this a test driver before you knock this time.

Here is a link to an earlier roast -
viewtopic.php?f=1&t=47625&p=434501&hilit=+1150#p434501

The Black & Decker jump starter is another good one to use. I don't have one but know that it, unlike my Sears, keeps the jump leads live; luckily they are easily unplugged from the unit. I am not yet sure if the DC power outlet is unswitched or not.

However, because the jump leads remain live this B&D jump starter is ideal to build a larger battery into. Simply connect the jumper leads to whatever battery you have and it is connected in parallel, which is what you want to increase the battery capacity (hours of use). Then use the charger built into the B&D to charge the external battery also.

In fact, the B&D Jump Starter could easily be used in the JBF Battery Backup Design -
viewtopic.php?t=49115

This link will take you right to the Halloween Snowstorm UPDATE part of this thread -
viewtopic.php?f=1&t=64943&p=652397#p652397
With a Salute to My Friends who encouraged me all along.

I think you have a great idea there. In fact, I would probably use that except that I backpack and need something smaller. Thank you for sharing this idea.

There are a few drawbacks with this system. That doesn't mean it's "wrong," just some drawbacks. Any battery system you use will have some drawbacks.

If you run the battery way down, it reduces the lifetime of the battery. i.e. it dies a little with each discharge, the more discharge the more death. The jumper you have is probably a "gel cell." These are reasonably resistant to damage from deep cycling, but still suffer a little.

We need to figure out how many amps your machine actually draws when you're using it. I think it's fused and speced as 5 amps. If it really draws 5 amps, even if you're pumping in 1 amp, the battery will be "dead" within 5 hours or so, even if the charger is working. You need to measure the current draw of your machine with your machine running.

If you're trying to run the CPAP machine this way all the time, the charging may or may not stay ahead of the discharge. For instance, if you're putting 1 Amp in for 24 hours a day, and the CPAP is pulling 5 Amps out for 8 hours a day, you'll slowly lose ground and the voltage will droop over a long period of time, even if you have a larger battery. If you're only running the CPAP off of it on bad weather days, that's probably OK.

The battery charger probably isn't "safe" to run the CPAP, but since it's a low current charger, the battery will smooth things out considerably. If the charger tries to put out a higher voltage, the battery will tend to soak it up. If the charger tries to drop voltage, the battery will tend to fill in. It's one of the kind of things I would not officially recommend in a professional capacity, but I might be willing to risk doing it myself, and I wouldn't be surprised if it works well.

archangle wrote:If it really draws 5 amps, even if you're pumping in 1 amp, the battery will be "dead" within 5 hours or so, even if the charger is working.

GumbyCT wrote: I had already tried my Jump Starter over nite to make sure it would last, it did.

If I wasn't clear that was without a charger.

archangle wrote:if you're putting 1 Amp in for 24 hours a day, and the CPAP is pulling 5 Amps out for 8 hours a day, you'll slowly lose ground and the voltage will droop over a long period of time, even if you have a larger battery.

See above and below.

GumbyCT wrote:This unit displays the percent of charge on a display while it is charging and keeps a float charge. I initially kept an eye on this display, it never moved from 100. Then I took a nap for about 30 min. and evaluated things.

AndyCelt wrote:I think you have a great idea there. In fact, I would probably use that except that I backpack and need something smaller. Thank you for sharing this idea.

You are quite welcome. After the second consecutive nite, I am prematurely prepared to call this a success especially for those who want or need to use DC or are in areas where the power is served in spurts.

This method is not only easy but everything can be bought right off the shelf and put together by even those not-so-techy types. Probably less expensive than a UPS and without the power OFF alarms.

WARNING: You will have to be able to read

Gumby, you still don't know how much current the CPAP draws, or how far down it draws the battery over night. The charge indicator on this type of device is not very accurate in terms of remaining capacity. They measure voltage, which doesn't give you a good estimate of remaining capacity on most rechargeable batteries.

It may draw the battery down too far each night for the battery to be able to survive this level of discharge every night. Even if it works for one night, you may be still be discharging the battery enough to shorten its life cycle.

It's possible that if you use it every night, with it on a 24 hour charge, it will not charge back up to a full charge level and the voltage will droop over time.

It's also possible that your setup will work fine. Whether a particular setup will work fine depends on the battery, the charger, the CPAP machine, the therapy settings, humidification, mask leaks, auto adjust, etc.

Yet another problem is that the charger for such devices may not be good to be connected to the battery 24/7/365. Many chargers will shorten the lifetime of a lead acid battery if you leave it connected all the time. I've personally ruined several lead acid batteries by leaving them connected for several months to chargers that were supposed to be safe to leave connected all the time. I also have 3 or 4 batteries that I've kept connected to a charger for 5 years or so with the right charger. These car jump starter batteries are designed to be charged occasionally and then put into the car trunk for emergency use. It's possible the charger is smart enough to not slowly eat the battery, but I'd be surprised if it really will maintain the battery for years on constant charge.

One other risk I see is what does a low voltage do to the CPAP machine? As the DC voltage on the CPAP machine drops, does the machine become less effective? As the voltage droops, does the pressure drop? Does it shut down suddenly with no warning to the user? Does operating on a lower than normal voltage put some sort of strain on the machine and shorten the lifetime?

I know some people have run their CPAP machine on emergency batteries for a while. Has anyone run their battery down to the point where it didn't work any more? How precisely did the machine die on a dying battery?

The setup you propose is an excellent way to run something like a CPAP machine if the battery and charger are large enough for your usage. I have a gadget (non-CPAP) sitting next to me that I've used this way for 10 years or so. Simply running your CPAP successfully overnight or even several nights without any measurements doesn't tell you it will work long term.

I will note here that the first 2 nites the humidifier was set to 1 (accidentally) while I thought it was set to 0. That means it was drawing more current than I thought. But is good news for those who might need or want to also use the humidifier while on battery. The display hasn't moved off 100.

Mark your calendar. We'll have to see how long this battery can take the abuse. It has remained on the float charge since Dec. 29, 2009. I used it only twice I think to jump a car and several times to inflate things like tires and an exercise ball. Oh and prob twice on my bipap overnite w/o a charger. I put it into daily bipap service two days ago.

In a car you replace the battery every 3-5yrs. So eventually this will also need replacement. Is there someplace I can send it for an autopsy when it dies?

This is the post from the day I got it. Who knows how long it was on the shelf. Have I already got my moneys worth?
viewtopic.php?f=1&t=47625&p=434501&hilit=+1150#p434501

GumbyCT wrote:It has remained on the float charge since Dec. 29, 2009.

You may very well have the magic combination of the right battery and the right charger. They'll last a very long time if the combination is right.

If you want to test the health of the battery, charge it fully, find a predictable current load, and then run it down to something like 11 volts and calculate the amp hours you get out of it. Use a load that will discharge the battery in something like 20 hours. I have a 60 Watt DC lightbulb I use. Don't do this test too often. Every 6 months or so is enough.

When the battery starts dying, the number of amp hours will drop.

It's also useful to fully charge it, let it sit unused without the charger for a week, then measure the voltage and make note of it. When the battery starts dying, the voltage drop. You can also do the same test for a shorter "rest" period, even a few minutes, but the shorter the period, the less likely it is to show you a problem.

You can also put a heavy load on the battery for a few seconds and measure voltage right away, but this usually requires something like a commercial battery load tester. ($20-$80)

Yup, that's the one we talked about. Good to hear your UL(home edition) worked
still have not managed to purchase despite all the reasons for. $99 smokin deal !

deerslayer wrote:Yup, that's the one we talked about. Good to hear your UL(home edition) worked
still have not managed to purchase despite all the reasons for. $99 smokin deal !

What I like is you can use it for so much more than just cpap.

Time for me to go charge my battery

Glad to hear that worked for you, Gumby.

For other readers who might need additional solutions:

LINKS to Battery operation, camping, power outage
viewtopic.php?t=9682

Gumby, This sounds like a winner. My power went out again last night. The lack of pressure woke me up right away and I took the mask off and went back to sleep. My O2 dropped about 2-4% for that 90 minutes. The nice thing is the S9 started blowing when the power was restored so I heard it and put the mask back on.

You mentioned a DC connector. Why can't you plug into the AC outlet? Would that deplete the battery faster?

Lizistired wrote:You mentioned a DC connector. Why can't you plug into the AC outlet? Would that deplete the battery faster?

Yes, it would. You could plug it in AC inverter but I did not.

If you do let us know how it worked out. Resmeds are much fussier there with inverters so to me DC is a much safer approach.

For those who want to try/use the AC inverter, this is from page 9 of the manual,
found at [*]http://www.managemylife.com/mmh/lis_pdf ... 904777.pdf

• Make sure the device you are using is compatible with a modified sine
  wave inverter.
  
  It is important to know the continuous wattage of the device you plan to
  use with the inverter. The Portable Power 1150 must be used with devices
  drawing 400 watts or less. If the wattage is not marked on the device, use
  only devices that draw less than 4 Amps of AC.
  
  Devices like TVs, fans or electric motors require additional power to start
  (commonly known as the "starting or peak power"). The Portable Power
  1150 can supply a momentary surge in wattage; however even devices
  rated less than the maximum 400 watts can exceed the inverters surge
  capability and cause an automatic overload shutdown.
  Make sure the device you are using is compatible with a modified sine
  wave inverter.
  
  CAUTION: Always run a test to establish whether the inverter will operate
  a particular piece of equipment or device.

You can charge your cell via USB or AC.
HTH

Lizistired wrote: You mentioned a DC connector. Why can't you plug into the AC outlet? Would that deplete the battery faster?

If you're working from a battery, it's much better to run DC than AC. Going from DC to AC, through the CPAP power supply and back to DC is inefficient. Also, cheap inverters don't produce a proper sine wave AC voltage and may damage or stress your machine, or simply not operate it correctly. Your S9 ResMed actually works from DC from the power brick anyway.

Be SURE!!! to have the right power adapters for battery operation. I've heard ResMed DC cords will blow up Respironics CPAP machines and vice versa. The connector may be the same, but the polarity is reversed.

PRS1 machines will operate the humidifier off of the DC adapter. I think ResMed S9 machines will, too, but I'm not sure. Some other machines won't operate the humidifier unless you use an inverter.