battery backup?

[btaylor]

I am going over seas to work for the government, and i am supposed to have a battery backup for my cpap, can anyone recommend a good one?

[PaulaO2]

I moved your thread to the main area where it will be seen by more folk.

While waiting for more comments, check out these threads:
http://www.apneaboard.com/forums/Thread-...r-goes-out
http://www.apneaboard.com/forums/Thread-...Backup-UPS
http://www.apneaboard.com/forums/Thread-...wer-outage

[trish6hundred]

Hi btaylor,
WELCOME! to the forum.!
Best of luck to you on finding a battery backup.

[trish6hundred]

Hi btaylor,
WELCOME! to the forum.!
There is lots of great information on this as Paula posted.
Best of luck to you on finding a battery backup.

[ConnCarl]

Welcome to Apnea Board, btaylor!

I'm not sure what the power requirements of your RemStar Auto are, but I'll share with you what I did during the hurricane when we lost power.

I bought two items, an Evercell Heavy-Duty 12V/5A Power cord at Radio Shack (part number 270-048, $12.99), and a Die Hard 750 portable jump starter from Sears (item number 02871486000, $58.99). The DC adapter has a "cigarette lighter" type of plug and terminates in a small barrel which accepts various plugs, depending upon your needs. The purchase price of the adapter includes the plug...I brought my ResMed S8 in with me and matched it up.

Based on the power consumption of the S8...it's a pretty power-frugal little beast...I figured that I'd need at least a 7 to 9 AH 12-volt source to run the whole night (no humidifier, of course) without interruption. I selected a Die Hard unit with a 12 AH battery. They had 15 and 22 AH units as well, but they were out of stock.

Now, this was a bit of a leap of faith. ResMed says that if you run the S8 on 12 volt DC power without their proprietary adapter with the secret toasted-in frosting, you'll turn into a frog or something. For one thing, 12 volts DC is 12 volts DC, and I wasn't about to drop $75.00 on a handful of magic beans. For another, in the aftermath of the hurricane, nobody had the ResMed adapter in stock, just some goofy bag-battery thing (apparently, CPAP manufacturers think that hoseheads can't resist anything in a nylon bag) that sells for hundreds of dollars.

I configured the plug for the ResMed (which means plugging it into the cord with the correct polarity, which is negative-tip as opposed to the more common positive-tip, a little trick which keeps you from using most cheap and readily-available 12 volt cords), plugged it in to the jump starter, and presto...a night of blissful, wonderful sleep.

A couple of caveats, though.

The Radio Shack cable was tagged $12.99 but rang up at $17.99. When I pointed that out, they charged me $12.99, but YMMV. If you have trouble getting the lower price, though, you can always order a Chinese copy on eBay, since you're in the preparing stage and not in immediate need. Probably run you about $5.

The Die Hard 750 worked well, and is on sale right now for $49.99. It has the more desirable AGM battery (I didn't want a "leakable" battery in my living space), a charge indicator, a light, and an integrated dual-stage charger so it can be left plugged in all the time without issue. It weighs 12 pounds which is easily carried by almost anyone. I did a lot of comparison shopping, and I think it's a good value.

You can probably get away with a cheaper unit...I've seen them as low as $29.99 elsewhere. Check Wallyworld, Home Despot, Amazon, Pep Boys, AutoZone, Parts America, etc. Just be sure it has a DC outlet! Some don't, since they're dedicated jump starters. Be careful to check the AH rating, some units have a battery that's only 5 AH or so. That might run your unit all night, but it's not likely to repeat that performance many times, because the more deeply you discharge the battery, the shorter its lifespan. If you don't get a unit with an AGM battery, consider a plastic tray or some other method of containing possible spills. Note, too, that some units come with a cumbersome, "wall wart" charger that can easily be lost. And even units like mine with built-in chargers will need a simple one-outlet extension cord (not included) for charging. And charging is slow.

There are units with huge batteries, dual outlets, USB charger ports, even 110 volt AC outlets (really!) and an air compressor built-in. Tim "The Tool Man" Taylor would love that, but I sure wouldn't want to lug that baby through an airport. Plus in my case, I had to take the thing to work with me every day to charge it, since I didn't want to go two nights and risk killing the battery completely. I wanted something handy and compact and I was pleased with the 750. But it only has four LEDs to show the battery condition. One is pretty much fully discharged and one is fully charged, so that only leaves two to indicate a partial charge. Other units have a digital readout, which I think would be really handy.

If you need to go more than one night on a charge, that should also figure into your purchase decision.

Anyway, it worked for me! It's a cheap, clean, portable and relatively elegant solution (only two components). However, if you blow up your CPAP, you're on your own.

Good luck! Carl

Edited to incorporate archangle's correction of VA to AH

[archangle]

Based on the power consumption of the S8...it's a pretty power-frugal little beast...I figured that I'd need at least a 7 to 9 VA 12-volt source to run the whole night (no humidifier, of course) without interruption. I selected a Die Hard unit with a 12 VA battery. They had 15 and 22 VA units as well, but they were out of stock.

"VA" is the wrong unit. You're probably thinking about Ah (Amp Hours.)

For the OP's PRS1 unit, you can buy the Respironics official cable from many of the online suppliers.

If you roll your own plug, be sure to get the polarity right. If you get it wrong, your CPAP goes boom. If you use the Radio Shack adapter thing, be careful about the tip. If it falls off and you (or someone else) puts it back on wrong, the polarity gets reversed. Mark it very carefully such that you can plug it back in correctly even in the middle of the night with severe brain fog, or secure it somehow with something like heat shrink tubing or glue.

Note that ResMed S8 and many of the Respironics units use the same plug, but the polarity is reversed.

If you use a jumper battery solution, and many others packaged battery packs, they may take a long time to recharge. If you're in a situation where you have a few hours power each day, you may not be able to get enough charge into the battery during the few hours you have in order to keep it running at night.

Airlines may have restrictions on carrying batteries on airplanes, especially lithium batteries. Even if you meet the airlines restrictions, you may have problems getting it through security, customs, and the pinheaded local airline employees.

Power consumption varies a lot with pressure, humidification level, and your leak rate. I suspect Flex may increase power consumption, too.

If you discharge the battery fairly deeply, it does a little damage each time you do it. "Deep cycle" batteries are less susceptible to this, but they are still harmed a little. A bigger battery pack will last for a lot more months simply because it doesn't get discharged as deeply each time you use it.

Plan on how you replace the battery if it goes bad. Even the best batteries go bad, sometimes without a lot of warning. Learn how to check your battery to know if it's slowly dying like an old car battery often will.

If you're working from a fixed location overseas, you may get a larger deep cycle battery about the size of a car battery and get a lot more capability. If you want something easily carried for travel, that's a lot more limited, and more expensive.

[btaylor]

Yea I was just looking for bare minimum and as light weight as i can get it. i have limited weight requirements for travel to remote locations.

[archangle]

Yea I was just looking for bare minimum and as light weight as i can get it. i have limited weight requirements for travel to remote locations.

How lightweight? Nothing very lightweight is going to give you much time on battery backup.

Lithium batteries will give you considerably more hours per pound, but are more expensive, and more of a problem with airline travel due to the risk of fire. Lithium batteries also have a tendency to die with no warning, while lead acid batteries tend to die slowly over time.

[btaylor]

Well I see all the suggestions for battery backups and everyone says get a deep cycle marine battery... well I can't because that is way more weight than I can take with me. I need something in the 3-5 lbs range. if it only holds enough charge for 4-8 hours that is fine. it is more of a requirement for traveling than a severe need for me. I have no problem sleeping without the cpap for awhile.

[PaulaO2]

There are some smaller, more compact battery packs. I'm trying to remember what they were called. They were like little torpedoes.

There's a lot of lightweight solar options but they're for running/charging stuff during the day, not holding a charge to run something at night.

There is the lithium ion battery system made for CPAPs. Go to Secondwind (Supplier #2) and click the 'accessories' link. It weighs 4.5lbs. But if you were out for more than just a few days, you'd need a way to recharge it. Google Blue Pacific Solar to find their site then look at the backpacking options.

Using something like that with the pressure lower than usual would be better than nothing at all. Your profile says 8 which would get you, according to their chart, about 14-19 hrs. The lower the pressure, the longer it lasts.

Another source to look at is The Battery Geeks. They have a page of options for CPAP machines.

Whatever you choose, get one soon enough to test out before hand. Going without your CPAP for more than a few nights is going to make you feel miserable. And noisy!