Uninterruptible Power Supply for CPAP

GoodKnight · Post by **GoodKnight** » Fri Nov 18, 2005 12:18 am

Sorry for jumping into this thread a little late, but I have not been online for a little while.

I have also been interested in this problem and have been gathering parts to make an UPS for my Remstar APAP and here is a little gem I have found that when used with an appropriate sized battery will work great.
At this link http://216.71.88.83/ look for the model PST-SP12AS. It is a power supply that trickle charges a 12 volt battery while supplying 12 volts at a terminal that can be hooked up to the 12 v DC input to the Remstar. If the 120v fails, it will pass through the battery power to the 12 v terminal and continue to run the Remstar until the battery runs down.

It requires some wiring and hookup so you have to be comfortable doing this, but you can put it into a nice looking cabinet along with the battery and it will look nice in the room. It is only about 4" x 3" x 3" and weighs about half a pound. It supplies a maximum of 3 A which is what the Remstar draws at maximum.

You have to power the humidifier from AC and not hook it to this. So it will only be a passover if the power fails. It will be hooked up similarly to the photo Derek shows.

I am awaiting the Remstar DC cable from CPAP.com to hook the whole thing up.
I'll post how it works after that.

Take a look at it and please let me know if you see any reason that it won't work.

ProfessorSleep · Post by **ProfessorSleep** » Tue Nov 22, 2005 2:34 pm

I just have to resurrect this thread one more time. I now have a PB 420E, which does run on 12V. That problem solved. After re-reading all this discussion and product specs, I'm leaning toward the Xantrex PowerPack 400Plus. Just wondering if Derek or anyone else using a similar setup keeps the CPAP running off the 12v of the powerpack all the time, with the powerpack charging off the AC, or is the powerpack connected to the CPAP only when needed and kept charged separately? It wasn't clear in previous posts whether the powerpack was connected to the CPAP all the time. Thanks for indulging me with one more, and absolutely final question about power! I promise!

jcobb607 · Post by **jcobb607** » Tue Nov 22, 2005 4:03 pm

While we are at it....how long will the Xantrex powerpack 400 power a PB420 series before recharging?

Guest · Post by **Guest** » Tue Nov 22, 2005 4:31 pm

I have a 420E that is connected permently to a 115 amp hr deep cycle battery . The battery is connected to a 12 amp smart charger that keeps everything charged. I also connected my heated hose to the battery.

The heated humidifier is pluged into the mains .

I made this system after being left without sleep after a few power outages last year. I owned a Resmed spirit then and used a 350 watt pure sine wave inverter. I recently addad another 115AH battery just before hurricane rita arrived .

My system will power the 420E for over a month if needed . It has been tested on 1 battery for 15 days. NO problems. Battery was 50% discharged.

PM for more info.

:twis ted:

Chrisp

Guest · Post by **Guest** » Tue Nov 22, 2005 4:50 pm

I forgot to answer the Xantrex 400 ? A guess would be 8-12 hours depending on your pressure and if you ran it continuously or divided it into 4-6 hr periods. It will get HOT.

My reasoning :

It has a 20 amp hr battery

20/2 =10 the usable amount (50%) = 10 amp hr

10 amp hr / .75 . The amp used by my 420e at my pressure of 9-13

10/.75 =13 thats hours.

What you get in theory isnt always what you get in the real world.

Like I said earlier , my 115 amp hr Wal Mart deep cycle battery lasts over 2 weeks. A bargain at $57 !

A battery must be charged and discharged (never below 50%) up to 25 times to reach its full capacity so use it.

I also have a few K&K jump starteds that I have used for a nite .

If in doubt give it a try !

:twis ted:

jcobb607 · Post by **jcobb607** » Tue Nov 22, 2005 5:28 pm

Chrisp

I would like more information on your setup, but I cant PM you as you are logged in as guest. Can you PM me or something? Thanks! JC

chrisp · Post by **chrisp** » Tue Nov 22, 2005 6:54 pm

now you can !

:twist ed:

jcobb607 · Post by **jcobb607** » Tue Nov 22, 2005 8:17 pm

Thank you very much!

Oh 2 breathe · Post by **Oh 2 breathe** » Wed Nov 23, 2005 4:47 am

My poor non-techie brain is sore from trying to understand all this. If someone can provide a simple answer to these questions I'd be very grateful.

I don't yet have a back-up system for my Remstar Auto CPAP machine but
there's currently a sale on at my local Canadian Tire offering a Powerpack 300 battery at 60% off the regular price. ($55 Canadian, the equivalent of about $45 in U.S. dollars).

If I run my CPAP without the humidifyer, how many hours do you think this 300 powerpack will run it?

Remstar recommends using a special shielded power cord. Is this really necessary? Would it be a good idea to run the CPAP machine from a power surge bar plugged into the battery pack?

If you have any advice let me know. I have to decide whether to buy this battery by this upcoming Saturday.

~ Oh 2 breathe

derek · Post by **derek** » Wed Nov 23, 2005 6:27 am

Oh 2,
I presume you are talking about the Xantrex 300 Powerpack??

I took a look at the specs. It uses a 20 Ah battery, the same as the Powerpack 400, so you might expect to get at least one night, and probably two at a pinch.

The problem I see is that the charger is only rated at 500 ma (1/2 amp) max, compared to the 700 ma on the 400. This will not quite keep up with the apap during the night, and the question is whether that charger will be able to top off the battery during the day. I really can't answer that without trying it, all I can say is maybe!!!

The 300 is quite tall (11.8") and narrow, but would probably run on its side to fit under a bed.

Re the cables: surge protectors are designed for ac. There is no need for one on a battery circuit because the battery itself acts as a huge surge absorber. There is no real need to use a Respironics cable, either - any cord with a cigarette lighter plug on one end and the appropriate co-axial plug on the other end will work (I think I saw others post that they had bought a cable at Radio Shack) I bought a Respironics cable from cpap.com just for the convenience.

ProfessorSleep · Post by **ProfessorSleep** » Wed Nov 23, 2005 10:11 am

I am assuming, then, that you run your xPAP off the DC adapter and the powerpack, with the powerpack plugged in to AC all the time? In which case, if the AC goes off, you're still running without interruption. Is that your daily setup? Thanks!

Oh 2 breathe · Post by **Oh 2 breathe** » Thu Nov 24, 2005 8:11 pm

Derek
It sounds like the 300 powerpack would not be powerful enough. It might be better to hold off and wait until I can get a 400 or higher power pack. I could probably wait until the summer to get one. Meanwhile I'll watch for sales.

~ OTB

chrisp · Post by **chrisp** » Sat Nov 26, 2005 8:05 pm

ANy ol deep cycle battery rated above 20 amp hrs will work for a nite or 2 . Nonspillable preferred, and smart charger. This works fine with the 12 volt direct capable units such as GK420 and Remstar. All you need is an "M" style connector. Resmed needs a Pure Sine Wave Inverter.$140 at http://www.invertersrus.com . Y'all are making this reallty more complicated than it needs to be.

:twis ted:

jcobb607 · Post by **jcobb607** » Sat Nov 26, 2005 9:28 pm

Followng Chrisps advice, I purchased a 12 volt deep cycle marine battery, 75 AH, an accesory outlet that had the clamps already installed and a charger---total was right at but less than $100 from Autozone. First night using it was last night and had no problems whatsoever. Im going to see how many nights I can get without having to recharge the battery. Will let you know when I figure it out.
Jay

derek · Post by **derek** » Sun Nov 27, 2005 6:51 am

Prof,
Yep, I leave the Powepack plugged in all the time...

For everybody contemplating buying a deep-cycle battery: Remember that batteries contain very strong acid. Even the cases can have strong corrosive residues that can eat through carpets and damage flooring. Make sure you have the battery fully contained in a suitable plastic (acid resistant) box. Even the fully sealed (AGM or gel) batteries should (must) be in a suitable container. In addition the box will keep the terminals protected. A short circuit could be disastrous,

I speak from experience, after working with batteries in boats for many years. I have had several instances of mysterious holes appearing in clothing after carrying what appeared to be completely dry batteries. Makes wives quite unhappy

You can buy battery boxes at marine stores for just a few bucks, but any plastic container should work.

For use inside, I thoroughly recommend the maintenance-free AGM or gel deep-cycle batteries, even though they are more expensive. The Optima series are compact, but expensive. Consider the Optima D34M 55 Ah (not the 34M - which is a pure starting battery)

Optima Deep-Cycle Batteries

I use Optimas for starting my large diesel engine on my boat. They have worked flawlessly for five years without any attention.

Mask	Humidifier