Deep Cycle Home Backup Supply

[archangle]

What are your thoughts on inserting a voltage regulator between the battery and the machine's DC-DC adaptor?

Sounds a lot more complicated. I'm trying to keep it simple for the non-geeks.

[archangle]

Here's the setup for an S9 CPAP/APAP/VPAP, humidifier, and Climateline hose.

It's the same as the PRS1 setup in the first post, just change the adapter.

Parts


1) Battery - Get a "Deep cycle" marine battery. Make sure it doesn't say anything about hybrid, starting, dual purpose, etc. It can mention trolling.

Here's one example. http://www.walmart.com/ip/EverStart-Max ... ifications

2) Battery box - Get one that your battery will fit in.

One example: http://www.walmart.com/ip/Snap-Top-Ever ... x/16781380 is one example.

3) Float charger. You need one that can stay hooked up to the battery all the time and not damage it. I've used several types and had several that are supposed to be a "float" charger, but they still ate the battery up over time. The one that's worked for me through several chargers and batteries is the Schumacher SE-1-12s. The last time I bought one, the cheapest and easiest place to get one was AutoZone. http://www.autozone.com/autozone/access ... 513702_0_0_

4) DC power adapter. For the ResMed S9 machines, use https://www.cpap.com/productpage/DC-Con ... hines.html. This comes with battery clips. For ResMed AirSense/AirCurve 10 machines use this adapter: https://www.cpap.com/productpage/resmed ... hines.html


Assembly


Put the battery in the box. I set the box inside another plastic storage box, just in case I get some kind of leak from both the battery and the battery box. Be sure you won't kick it over or trip on it.

Hook the charger up to the screw terminals on the battery. Clip the cigarette lighter/clip cable to the battery. Get the polarity right. Red to plus, black to negative.

Leave the ResMed converter unplugged from the cigarette adapter cable until you need to use it. It's an electronic device, so no need to have it running until you need it.

Check the water level. Note that the water level should not be at the top. It should be at the bottom of the little tube you look through. http://www.wikihow.com/Check-Car-Battery-Water-Levels. Distilled water is good.

Plug the battery charger into the wall. The green light should come on. Watch it for a few days, and the red light should come on when the battery is fully charged. It make take several days if the battery is new.

Put the top of the battery box on and strap it on. The top keeps you from dropping something on the top and shorting the battery out. Strap the cover on.

Check the water level after 1 month. Then about every 6 months or so. More often if you're using a different charger.

When the power goes out, unplug the AC adapter from the CPAP and plug in the ResMed converter into the cigarette lighter plug and the CPAP machine.

There are many other ways to do this with different levels of cost, portability, convenience, etc.

[123.Shawn T.W.]

Archangel:

What are your thoughts on inserting a voltage regulator between the battery and the machine's DC-DC adaptor?

I suspect both PR and ResMed are being conservative about their machine's voltage sensitivity, but since both recommend against using the DC-DC adapter while the alternator is running, I'm tempted to err on their side. My PRS1's power brick gives between 12.21 and 12.24 VDC under no load, so I'm not willing to subject it to the 13.5VDC or 14.2VDC that the float charger puts out in Float and Bulk charge modes unless others have done it with no ill effects.

Here's the setup I'm considering for home. If it works as planned, then the 60-watt PR power brick will go in the travel bag:

PSU:
300-watt AC->DC PSU from old PC @ +12VDC (could also use the -12VDC power rail for ground reference), but my DC Theory always references to earth ground & I doubt the common buss is isolated on the combination voltage regulator / charge controller)

Combo Charge Controller / Voltage Regulator:
Minibox Corp OpenUPS DC-DC voltage regulator and mixed-chemistry charge controller
The pics show 3 buck/boost transformers, so I should be OK using +12VDC in instead of +14VDC in. I can always swap out the PSU for a better one at a later date.

Battery:
28 Ah Sealed Lead-Acid bank (2x load-tested good 14Ah batteries from discarded UPSs, wired in parallel) Battery Cutoff voltage programmed for 70% max discharge gives ~20 Ah usable which should be plenty for 1 night with 8-11.5 cm/H2O APAP.

Charge controller can handle single parallel banks at up to 24V battery bank (30V bulk charge) at 3A max and can also be configured for up to 6 single cells batteries (2V or 4V cells) in a modified serial config, so I can always slip a flooded deep-cycle or AGM trolling battery in there later.

I have the PR S1 Auto ... My brick puts out 12.3vdc, my cig lighter in my semi puts out 12.9vdc with it shut off, running it is 13.9vdc ... I have only used my APAP two nights with the truck running, and no harm has come to my APAP ... I use to use an invertor, but my new company I work for (Heartland Express) forbids invertors in their trucks ...

[Guest]

i seriously doubt that any harm will be caused by using the cpap while the truck is running. as long as you arent driving of course.
we are caught in a world with too many lawyers and corporate cya

[chrissv]

Great post! This is almost exactly what I have, except my battery box has built-in voltage indicator and cigarette lighter sockets:
http://www.amazon.com/MinnKota-Trolling ... 001PTHKMG/

A little more expensive, but worth it for the extra bells and whistles.

I would change one thing in the original post:

When power goes out, unplug the AC power adapter from the CPAP and plug in the battery cord.

I plug my CPAP machine into the battery and run it from there all the time. The trickle charger keeps the battery topped off. That way if/when the power goes out, you don't have any interruption.

I take this on campouts also to power my machine. One time I returned from a campout and put things back into my bedroom, but forgot to attach the trickle charger. I ran my machine for over a week before I noticed the missing trickle charger; the battery worked great for that whole time. So I know I can go at least a week with no power. Due to last year's October Surprise New England storm, I have a backup generator I can use to charge my battery for protracted power outages.

Good luck!

-- Steven

[archangle]

I plug my CPAP machine into the battery and run it from there all the time. The trickle charger keeps the battery topped off. That way if/when the power goes out, you don't have any interruption.

The charger isn't "safety designed" for medical use. There's the possibility that it could do something dangerous like fail and have a 115V AC bias on the output side.

There's a slight risk you might have a charger that does weird things or fails and damages the CPAP. I have a "battery minder" brand (Not battery tender) charger that is intended to "desulphate" batteries, and it puts a 14MHz high frequency high current pulse into the battery. It's good for the battery, but might not be good for the CPAP. There are a number of other battery chargers that do "weird" things that I wouldn't connect to a CPAP machine or other electronics.

The risk is probably small, but that's part of why I don't recommend that.

I have another device I run from battery all the time that way, but I don't think my favorite, trustworthy, charger model would pump out enough amps during the day to keep up with what my CPAP uses during the night.

[Guest]

The charger isn't "safety designed" for medical use. There's the possibility that it could do something dangerous like fail and have a 115V AC bias on the output side.

then there is the real possibility it will work as he described it
the medical use does not matter it is not a special medical use only battery either

There's a slight risk you might have a charger that does weird things or fails and damages the CPAP.

then there is the very real possibility that after a year of use it will never fail as you described or think or want it to

stop the worry and get some sleep

[DiverCTHunter]

I plug my CPAP machine into the battery and run it from there all the time. The trickle charger keeps the battery topped off. That way if/when the power goes out, you don't have any interruption.

The charger isn't "safety designed" for medical use. There's the possibility that it could do something dangerous like fail and have a 115V AC bias on the output side.
...
...
The risk is probably small, but that's part of why I don't recommend that.

This was my concern too. One of our big-rig driving members says his PRS1 is comfortable with the 13.9Vdc charging voltage as is, but I still think the OpenUPS board is the most idiot-proof solution I've found after a week's worth of Googleing. If the manufacturer ever emails me back on a couple of spec questions, I'll probably put the order in late next week and let you all know how it goes.

For the record, I could probably get away with just a 12-14Vdc UPS board, but this one is supposed to keep the output voltage steady no matter what the input voltage does. Since it's specifically designed to keep in-vehicle entertainment computers happy, it should be overkill for our purposes.

I have the PR S1 Auto ... My brick puts out 12.3vdc, my cig lighter in my semi puts out 12.9vdc with it shut off, running it is 13.9vdc ... I have only used my APAP two nights with the truck running, and no harm has come to my APAP ...

[archangle]

then there is the real possibility it will work as he described it

Go play a game of Russian Roulette, guest. There's a real possibility you'll live.

[DiverCTHunter]

My PicoUPS arrived this afternoon and after a quick visit to Radio Shack for a longer roll of wire it's been a success.

Running the machine on it tonight as a burn-in and if things behave I'll post pics later.

[avi123]

then there is the real possibility it will work as he described it

Go play a game of Russian Roulette, guest. There's a real possibility you'll live.

Comment,

That Guest is most likely Den Wulfman who has posted here since 2005. But often he is a pain in the ass.
Deleting his posts as a Guest should be regarded OK as deleting SPAM, b/c you can't send PMs to him.
He posts here illegally!

[avi123]

Great post! This is almost exactly what I have, except my battery box has built-in voltage indicator and cigarette lighter sockets:
http://www.amazon.com/MinnKota-Trolling ... 001PTHKMG/

A little more expensive, but worth it for the extra bells and whistles.

I would change one thing in the original post:

When power goes out, unplug the AC power adapter from the CPAP and plug in the battery cord.

I plug my CPAP machine into the battery and run it from there all the time. The trickle charger keeps the battery topped off. That way if/when the power goes out, you don't have any interruption.

I take this on campouts also to power my machine. One time I returned from a campout and put things back into my bedroom, but forgot to attach the trickle charger. I ran my machine for over a week before I noticed the missing trickle charger; the battery worked great for that whole time. So I know I can go at least a week with no power. Due to last year's October Surprise New England storm, I have a backup generator I can use to charge my battery for protracted power outages.

Good luck!

-- Steven

Comment,

I think that having a generator is a good idea especially for those living near the coast or in Tornados prone areas and have ventilated places to locate it.
Two generators that come to my mind are:


1) http://www.wisesales.com/eu1000ia-honda-generator.html




and this Propane Generator:

2) http://www.northerntool.com/shop/tools/ ... _200481615

[JohnBFisher]

avi123, I completely agree with you. Folks who live in an area where power is all too likely to be lost, should consider a generator. However, I think you will agree that there are some safety concerns that anyone with a generator should address:

http://news.consumerreports.org/home/20 ... -tips.html

Additionally, if you intend to run more than just an extension (properly sized wire, please!!) to an appliance, then I *highly* recommend the use of a generator electric subpanel. The idea is that it helps detach the house from the electric grid. This makes it safer for power company employees who won't be endangered by a hot line outside of your house. Second, it allows you to automatically select circuits that you can automatically charge - without the need to run a bunch of extension cords. For example, we can drive our fans and refridgerator and freezer and even our microwave. But our subpanel does not drive things that it can not support - such as our air conditioner units. It really simplifies the use of a generator and makes the use of it much safer for everyone.

It costs more, but the safety of others and your own home is at stake. Sometimes spending money to "do it right" is the best thing to do.

[archangle]

I've been told by several people who have worked with generators to avoid Generac.

Propane is an interesting idea. Modern gas self destructs quickly and can't be stored for long. Propane doesn't have as much of a problem as this. I think propane burns cleaner than gasoline. However I wonder how hard it is to get more propane during an emergency event.

As always, pluses and minuses.

[Burkebang]

For CPAP use, I would only consider a generator as a means of recharging a battery backup solution during the day. Then even the smallest Honda generator, which in my oppinion is the best, would be fine. But this is only nessecary for people that have a fair chance of being without power for weeks.

If we say that a CPAP without humidifier draws in the neighborhood of 0.8 amps when in use, a 100 AH battery will last allmost 16 days with 8 hour of sleep. So I don't think many needs to consider generators.

If the power to the home is so unstable as to consider a generator, then I think they should do it the way JohnBFisher describes, with a large permanently mounted generator and a generator electric subpanel that can take care of the basic needs of the whole house.