WARNING to CPAP Users: PREPARE for the Unexpected - When the power goes out

[SuperSleeper]

I don't own the humidifier so I can't say. You're right though... using the humidifier would draw a lot more.

[SuperSleeper]

But, I've run my S9 AutoSet CPAP on my Wal-Mart Marine Battery for 3 nights in a row and it only got down to around 12.5. Haven't tested beyond that.

But, you do not use a humidifier.

Using a humidifier would run the battery down a lot faster.

Edited to say: I see you already told that to Paula.

Another reason why one should read all the way down to the bottom of the discussion before responding to 1 specific post!

[SuperSleeper]

We lost grid power in 2008 for about a week because of Hurricane Ike. That happens only once every couple of decades or so. I couldn't imagine trying to go through that without power to my CPAP machine. If that were to happen today, I'd pull the battery out of my car, cut the wires to the CPAP machine, and hook them up directly to the battery. I think I could find a way to put a fuse in the circuit, too.

[SuperSleeper]

If that were to happen today, I'd pull the battery out of my car, cut the wires to the CPAP machine, and hook them up directly to the battery. I think I could find a way to put a fuse in the circuit, too.

Just remember that you can't just plug 12-volt power into the CPAP connector that is designed for 110 volt power, or the other way around. Some CPAPs have a specific second connector that is to be used with 12 volt power, others don't, so you'll have to purchase a separate 12-volt power supply brick (converter) that is made for your specific machine.

If the CPAP manufacturer does not offer an OEM 12-volt power supply option, you can always purchase a pure sine wave DC to AC power inverter that will change 12 volt battery power to 110 volt standard home power. But keep in mind that any time you use an inverter, you're going to lose anywhere between 20-30% of your battery power in the conversion process. Using an OEM converter designed specifically for your CPAP machine will usually save battery power over using a AC to DC inverter.

[SuperSleeper]

Just remember that you can't just plug 12-volt power into the CPAP connector that is designed for 110 volt power, or the other way around.

There's a 110-volt wire that runs from the wall outlet to the transformer, then a 12-volt wire that runs from the transformer to the CPAP machine. It's this 12-volt wire that I'd cut and connect to my car battery.

Of course, it would be much better to plan ahead and purchase a separate (deep cycle sealed) battery and the proper connecting cable. I'm just sayin', in a pinch, cutting the wire would be better than going for a week without PAP therapy.

Right now I do have my machine plugged into a computer back-up power supply. I don't think it would last more than one night, though. It'll handle the typical short outages that we have maybe a few times per year.

[SuperSleeper]

There's a 110-volt wire that runs from the wall outlet to the transformer, then a 12-volt wire that runs from the transformer to the CPAP machine. It's this 12-volt wire that I'd cut and connect to my car battery.

Not on ResMed S9 machines. S9 machines don't run off 12V. ResMed's not very open about what the voltage is, but they'll sell you an expensive converter to produce the needed voltage from a 12V battery.

I believe S9 uses both 12 and 24, but I'm not sure.

ResMed S8 apparently uses 12V, but the plug is wired backwards from Respironics. ResMed tells you not to run it off 12V without their expensive DC converter that somehow turns normal 12V into ResMed approved 12V.

If you decide to cut the power cord and make a 12V plug for your CPAP when the power goes out, how do you know which wire is plus and which is minus?

Buy or make yourself a DC cord before the power goes out.

[SuperSleeper]

I have an inverter I use in my vehicle to run my laptop from. It plugs into a 12v outlet (cigarette lighter) and has a standard plug. That's what I will be using. I got an adapter that has two clips on one end and the outlet on the other.

I went four or five days last winter without my CPAP. Never ever again. I was such a freakin' grouch! We were packing my gear to go to a hotel so I could sleep when the power came back on.

[SuperSleeper]

If you decide to cut the power cord and make a 12V plug for your CPAP when the power goes out, how do you know which wire is plus and which is minus?

I checked with a volt meter. On the plug that goes into the PRS1 machines, the center conductor is positive, the outer conductor is negative. If I ever have to do this I'll use a continuity tester to figure out which wire goes to the center conductor. My guess is that the wire with the white stripes on it is negative, but I wouldn't go on a guess.

Buy or make yourself a DC cord before the power goes out.

I do plan to make a cord, or purchase the two cords needed (they make a cable that goes from a cigarette lighter to the CPAP machine, and another that goes from the cigarette lighter socket to alligator clps that attach to a battery -- together they cost almost $50).

[SuperSleeper]

Hello, :Hi:

Here is my setup for Electrical Blackout...




I use a cheap Stanley plastic toolbox on wheel with folding handle to put my Optima 12VDC sealed battery, my charger, the DC/AC Inverter, wires, tester, fuses, etc. well everything I need concerning my DC Power Backup.

I leave it in the closet and when I need it, I just have to roll it near the bed, open the sliding bottom door and plug my CPAP on the 12 VDC plug..This is it and that's all!

And for more security I use a AGM Type Deep Cycle Sealed battery, those batteries does not suppose to exaust gas or acid but in case of...all acid spilling will stay in the plastic box (door close)

For maintenance:
Twice a year, I discharge completly the battery and recharge. I use a 300 W DC to AC inverter, full load with 3 X 100 Watts bulbs to discharge it. It's take about a hour to reach the auto-shutdown point on inverter. In this way you protect your battery from a too deep discharge. After I charge it with Automatic Marine Deep Cycle battery charger at 10 Amps, set on "GelCell Batteries".,It takes a few hours.

Then I can sleep with peace of mind all the night regardless of weather!

"Au revoir!"

Gustave

[SuperSleeper]

I do plan to make a cord, or purchase the two cords needed (they make a cable that goes from a cigarette lighter to the CPAP machine, and another that goes from the cigarette lighter socket to alligator clps that attach to a battery -- together they cost almost $50).

I bought some DC connectors for my Respironics CPAP machines.

They are 2.5 mm ID, 5.5 mm OD barrel connectors. The tip is positive. This is also referred to as a “size N coaxial DC power connector.”

Tip/center conductor/pin = positive.
Barrel/outer conductor = negative.

Some ResMed machines may use the same connector, but are reversed polarity. ResMed claims you must use their DC-DC converter. Don't plug the cable into the wrong machine.

I can confirm they fit the Repironics PRS1, M Series and Legacy CPAP machines.

I ordered from DigiKey. Good company to buy from.

Part number CP3-002BH-ND $1.79 each fits all three machines perfectly. I haven't actually soldered wires and powered it up yet, though.

Part number CP-2200-ND $3.42 each fits the M series and PRS1 machines fine. It doesn't fit well into the legacy REMstar machine. It makes connection, but tends to fall out. The uninsulated part of the barrel is a little longer on the connector that fits and on the official Respironics DC cable.

I like the CP-2200 ND connector a little better because it's a preassembled molded connector with a 6 foot 18 gauge wire. Sometimes, it's difficult to make a good, neat solder connection to those small connectors. It's also right angle with a strain relief. For my particular project, it should work out well.

Don't neglect to add a fuse as close to the battery as possible.