12v inverters----update

freshair · Post by **freshair** » Thu Jul 21, 2011 8:11 am

Has anyone used an inverter plugged into their cig lighter to power their cpap machine, if so, what wattage did you use...I don't need to pay 300-500 for a chique battery back up...my electric went off last week for a few hours and it was hot muggy and no cpap therapy....tks....FA

I am slower than the 7 yr itch and I wanted to add an update on my backup power system for my beloved PR1 machine---I bought the 12v lighter adapter from CPAP.com...bought the female socket with clips from Radio Shack...got one hell'va deal on 5 new 35AH deep cycle batteries off of Craigslist....going to buy a 2 bank Battery Tender from Amazon for now and later I will buy the 3 panel 45 watt solar panels from harbor freight..this is all taking time because I have to stay on my monthy budget..tks--FA

nanwilson · Post by **nanwilson** » Thu Jul 21, 2011 8:43 am

I only paid $40 canadian for mine...its an 300 - 400 watt inverter. Comes with the car plug in for the cig lighter and hook ups for a battery. I also have a 12 volt deep cycle marine battery that I use.

physicsbob · Post by **physicsbob** » Thu Jul 21, 2011 9:50 am

From your profile you list that you have a PR system1 Cpap this does not need a inverter to work. they will work with a 12 cable that you can make or purchase from Remstar. I have used mine that I purchased from our host (cpap.com) to run my MSeries cpap for over a year, and now my Intellipap. The Pr system 1 and the Mseries will power both the cpap and the humidifier off of 12 volts so there is no need for a inverter. The link is here for Cpap.com but you can order it from other sources as well https://www.cpap.com/productpage/respir ... -cord.html

davelikesbeer · Post by **davelikesbeer** » Thu Jul 21, 2011 10:20 am

freshair wrote:Has anyone used an inverter plugged into their cig lighter to power their cpap machine, if so, what wattage did you use...I don't need to pay 300-500 for a chique battery back up...my electric went off last week for a few hours and it was hot muggy and no cpap therapy....tks....FA

Are you suggesting you wish to sleep in your car when the power goes out?

You can make your own battery backup setup for under $200. Deep cycle battery + charger + 12 volt cable from Respironics and you are good to go.

freshair · Post by **freshair** » Thu Jul 21, 2011 10:48 am

tks for all suggestions---and yes I will sleep in my car or truck if my power goes out at the house again--4:30am one morning we had a temp of 80 degrees and a dewpoint of 88...i may have my numbers backwards but it was like a sauna outside-all the windows had a coating of moisture----its been real hot here with high humidity and the air conditioning works well in both my vehicles and I know to keep my windows slightly opened in the car/truck to prevent myself from going into an eternal sleep...tks..FA

Bob123 · Post by **Bob123** » Thu Jul 21, 2011 12:10 pm

QC604055-001 Rescue 3000 Booster Pack 12V Quick Cable Portable Jump Pack, get one of these add a 12v battery of your choice. It has the charger and the 12v cigarette plug built in. It's portable and if you add the right battery you can get 4 nights out of it like I do and go camping! Then you don't have to sleep in your truck...

archangle · Post by **archangle** » Thu Jul 21, 2011 12:20 pm

My PRS1 machine uses something like 20 watts average from the AC power when it's running.

In theory, you want a pure sine wave inverter. The so-called "modified sine wave" (MSW) inverters are not a sine wave at all, but a modified "square" wave. Electronic power supplies will see an effective voltage that is less than 120 from a modified sine wave inverter. Plus there are "spikes" when the voltage switches.

I wouldn't be surprised if the machine works fine off of a MSW inverter, but I wouldn't be too surprised if it causes problems, either. I suspect there are some people who have used MSW inverters without problem. Even if it does work, there's some theoretical possibility of damage to the machine long term.

I probably would risk using an MSW inverter in a pinch, but I'm not going to tell anyone it's "safe." If it did cause problems, it would probably be to the external power supply.

I would definitely not crank the engine with the CPAP plugged in through an inverter. On inverter power, I wouldn't be particularly afraid of using the CPAP while the engine is running. (Assuming someone else is driving.)

I wouldn't use a "square wave" inverter, be sure it's at least a modified inverter.

Be very careful about the humidifier if you're using the machine in the car. It would be really easy to forget to remove and empty the tank while you're groggily trying to get to the car after waking up in the middle of the night. Or to sit it somewhere in the car where you might accidentally move it.

Bob123 · Post by **Bob123** » Thu Jul 21, 2011 1:30 pm

The battery I used is the Werker WKDC12-33J, a 33 ah (amp hour) battery, the largest battery that will fit . Drawback is it weighs in at 26 pounds, advantage is that it lasts 4 nights and I can go down to my car and recharge it from my $24.00 Costco non-sine wave inverter box while I'm driving to get supplies. Then I'm ready for another 4 nights. For camping overnights I have the same box with a 15ah battery in it that gives me a total of 15.8 hours of therapy and can serve for a two night camping/hiking trip, at half the weight. You can go cheaper and buy any of the jump packs at Sams, Costco or Walmart pre made, they all have 14.5ah or 15ah batteries in them, just make sure it has the cigarette lighter plug in and get the 12v cord from Respironics and you'll be good to go.

GumbyCT · Post by **GumbyCT** » Thu Jul 21, 2011 4:50 pm

freshair wrote:Has anyone used an inverter plugged into their cig lighter to power their cpap machine, if so, what wattage did you use...I don't need to pay 300-500 for a chique battery back up...my electric went off last week for a few hours and it was hot muggy and no cpap therapy....tks....FA

I think DC is the preferred way to go. Read this ... Another Battery Option!

billbolton · Post by **billbolton** » Thu Jul 21, 2011 5:01 pm

freshair wrote:the air conditioning works well in both my vehicles and I know to keep my windows slightly opened in the car/truck to prevent myself from going into an eternal sleep...tks..FA

If you are implying that you would leave the engine running to keep the air-conditioning going, while using your CPAP to sleep.... keep in mind that with an alternator actively feeding the electrical system, the DC voltage in the vehicle can get significantly above nominal 12V DC levels.

So, running an xPAP machine directly from the vehicle's nominal 12V DC electric system without a voltage regulator in the power line to the xPAP could result in unpredictable behaviour by the xPAP, or even damage to it.

Cheers,

Bill

freshair · Post by **freshair** » Sat Aug 13, 2011 8:22 am

I finally got the 12v cig lighter power cord from cpap...I need to build a system that I can use during an extended black out (power failure) and be mobile because I do go to Florida in November ( hurricanes) and come back the following April (tornadoes)---I want to use one of my vehicles to recharge the cpap 12v battery after its use...what would be the best way to recharge the 12v battery using a 12v automotive system....i don't want something that looks like a Dr. Frankenstein's Laboratory....fewer the parts the better...I'm not paying for the Respironics fancy battery pack---its the price...any suggestions...tks-FA

archangle · Post by **archangle** » Sat Aug 13, 2011 11:20 am

freshair wrote:what would be the best way to recharge the 12v battery using a 12v automotive system...

What kind of 12V battery do you have? Car battery, marine battery, jumper battery, etc.?

Jumper batteries direct to the car battery would be the usual arrangement. Be sure to follow proper jumper cable procedures.

If you're looking for something to charge the battery from the cigarette lighter plug, that turns out to be more difficult than you might think. You need some sort of current limiting device, or the discharged battery will draw more current than the plug can supply.

freshair · Post by **freshair** » Sat Aug 13, 2011 11:56 am

archangle wrote:
freshair wrote:what would be the best way to recharge the 12v battery using a 12v automotive system...
What kind of 12V battery do you have? Car battery, marine battery, jumper battery, etc.?

Jumper batteries direct to the car battery would be the usual arrangement. Be sure to follow proper jumper cable procedures.

If you're looking for something to charge the battery from the cigarette lighter plug, that turns out to be more difficult than you might think. You need some sort of current limiting device, or the discharged battery will draw more current than the plug can supply.

the only battery I have is in my vehicles...I havn't bought the other battery yet.....was leaning toward jumper battery for simplicity....I was hoping to make this a simple "do" but in the back of my mind I was also thinking why not just turn my truck into a power plant.....add another battery with larger output alternator ?..your thoughts ?..tks--FA

archangle · Post by **archangle** » Sat Aug 13, 2011 12:39 pm

The jumper battery option will work. Hook it up to your car just like you're jump starting the car, except you're "jump starting" the jump starter. If it has a shutoff switch, hook it up with the switch off just like you do when you jump start the battery. Then crank the car. Then throw the switch to on.

Are you thinking about permanently mounting two batteries in your car? That is a good idea in a couple of ways. Unfortunately, it's not a good idea to simply wire the two batteries in parallel. One battery will tend to hog all the charge and the other may not get charged fully. There are some other problems that can crop up. You need to have some sort of an isolation setup. There's a lot of info on the web about "Dual battery isolation." Some of the advice is bad advice, too.

I think there might also be some problems with more modern cars where they try to manage everything with the computer and isolating the batteries from the alternator might upset the computer and cause it to go Skynet on you.

freshair · Post by **freshair** » Sat Aug 13, 2011 2:53 pm

I think i'll start with the jumper battery option---will do some research to find one that can be fully charged that will work for 8hrs w/humidifier on-----MY ac just quit on me here at the hse an hour ago -----fan not working---no service call till monday---bummer---archangle tks for all your help sir--FA

12v inverters----update

12v inverters----update

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