Cpap on DC/ 12v or invertor

[Patrick A]

I have a question My wife and I own a Motorhome which we use for business travel and pleasure. to make a long story short.....
There are times that we do not have AC current available I have a 12v DC cord for my machine. There is a 12v.DC plug near the bed (for a TV) being as I do not watch TV when I try to sleep I could use that but I am also looking into getting an inverter, does anyone know which inverter is good for the job or should I just use the DC plug I got from Resmed?
I do not want to run down the house batteries.

I realize that I can turn on the generator, but a lot people with horses that go to bed to get up at about 0400hrs. to go out and do a 25 or 50 mile endurance ride or enven a 100 mile endurance do not like to hear a generator all night long.

Thanks in advance. I have had some severe health problems lately and I have not been on line much and have not been here in the forum for a couple of months. Seems I keep forgetting my password. Seems like I have more passwords than I know what to do with.

[Guest]

I think it all depends on what your really going to run off the inverter. If its a computer or an expensive cpap machine you need clean power so that means you probably need to spend more for the inverter (>$350). The more expensive inverters put out cleaner sine wave AC power than the cheap ones, they are also more efficient.

I have a cheapo 1500-watt (2000-watt surge) Xantech from Costco, for my travel trailer, paid only $89 bucks for it. I can run drills, lights fans etc. from it but it really sucks down a battery pretty quick with extended use. I use a single heavy duty marine battery with it. I have a battery isolater that isolates the inverter battery from my main RV battery so it does run the main battery down but then I don't have to worry about charging it either. It gets recharged when I fire up my Honda generator or connect the trailer to street power. My travel trailer also has a 1000-watt inverter/charger built-in but I only use it for charging the batteries. With iPods, cellphones and the like I have several 12vdc cigarette sockets available.

Power inverters by nature are NOT very efficient, they consume lots of battery current and create lots of heat for what little AC power they produce. I run my cpap straight off the 12-vdc battery, as it is much more efficient.

In my opinion, your better off running your cpap straight off the clean 12vdc power and using a humidifier in only the passover mode then use a heated Aussie hose. Doesn't make much sense to convert 12vdc to AC then convert it back to 12vdc again where it goes into the machine. The Remstars and PB420x can all run directly off the 12 volts. Same for the newer Resmeds using their proprietary cable.

[jkeene]

I'm agreeing with what the Guest said. Plug it straight into 12v DC, don't power the humidifier, and snooze away. Just got back from a two night camping trip, my Remstar Plus at 10cm used 60% of a 20 amp-hour battery, running the humidifier in passover mode, pulling current only through the 12v connection. I also unplugged the Remstar every morning so as to not waste current on lighting up the buttons all day.

[twillson]

I am not an expert on whether you need a "clean" signal form an inverter, but limited experience with a Respironics Rem-Star suggest that it works well with any inverter. Sounds like you have a ResMed unit so YMMV.

The only reason to prefer using an inverter is if you have enough battery capacity to keep it going all night with a humidifier. If you are not going to power the humidifier, I would definitely use the DC.

Inverters are supposed to be pretty efficient (>90%) but that may be under ideal conditions. I have noticed that they vary considerably with respect to their low (DC) voltage tolerance. Mine has an alarm that goes off at 11.5 volts, which only gives me about 2 hours on a full charge when I try to use a heated humidifier.

[jkeene]

Just make SURE that if you power up a humidifier with an inverter that the inverter is making pure sine wave AC. The modified sine wave AC produced by the more common, lower-priced inverters will fry most humidifiers.

[Nitro Dan]

My Rem Star will not produce enough pressure on 12 volts DC, so I have to use the inverter. Using the heated humidifier is out with any kind of inverter due to damaging the heating unit, so I use my old larger non heated pass-over one. All is good.

[Patrick A]

My Rem Star will not produce enough pressure on 12 volts DC,

That's odd, I have used my CPAP plugged into the 12v plug for the TV in the other motor home we had and it worked great, but when we are out in the motorhome i don't use my humidifier. (as a mater of fact i have yet not used it)

My sleep doctor said that if I didn't need to use it all the better my machine is set @20

[notsorested]

I agree with the advice of not using a humidifier. I haven't gone out in my 5th wheel since being on cpap, but I have used a pretty cheap inverter with many things, including a computer. (I know that may not be wise, but it hasn't given me any trouble yet.) My best advice--and what has helped me out immensely when dry camping--is to add another battery. I've got three--holps up a lot of heavy use.
How I wish I were on the road already. . . .

[LocoLouie]

I just got off the phone with Respironics. I asked the Support Dept. what I needed to run my Bi-PAP Plus and intragrated humidifier off my motorhome battery. They told me that they recommend a Xantrex 300 Prowatt inverter. I asked if I needed to have a pure sine wave inverter and the reply was " No ".