C-PAP machine and a TC?

jmckelvy wrote:
This is a very timely thread. My wife will be getting a CPAP machine soon. I have been researching the available machines with an eye on power requirements as we mostly camp off the grid. I do have 200 AH of AGM batteries and a built in generator.

I would appreciate it if some of you with 12 volt compatible models would list the manufacturer and model #.

There are 15-20 manufacturers of CPAP machines. I'm not familiar with all of them, but Phillips Respironics & ResMed are the two most common. The 12 volt adapters for these two machines are proprietary, the adapter for one will fry the other.

I've also used both above models plus DeVilbiss and Fisher & Paykel. Your medical provider will walk you through the various models. Most today are 12 volt compatible. One particular note, there is no need to purchase the "12 volt power pack" available for these machines, it's typically expensive & not necessary, just get the right 12 volt adapter.

On a side note: I have three machines, one in the RV, one in home & a back-up. If you need or want a second machine, Craig's List is a good source. I purchased the one for my RV with 47 hours on it for $115 & set the pressure myself. The back-up has 117 hours on it. My original machine was used nightly for 12 years straight, roughly 35,000 hours.

jaycocreek wrote:
My 12 volt compatible is a Phillips Remstar One, System One. I use a stand alone 12 volt group 27 battery for it and charge it about every 3~4 days of nightly use.

jaycocreek,

Are you using a heated humidifier ?

Dakota

I am new to the CPAP world, just got mine three days ago. I have a camping trip (dry camping) next week, for three days and two nights. I ran my CPAP machine connected to a cheap 100 watt Blacker & Decker inverter that plugs into a cigarette lighter, to see what I needed to run it.

My CPAP is a 120 volt unit, that operates at 24 volts as I recall. It does not run off 12-volt. This is what I have:

RESMED Airsense 10 Autoset. It has a built in humidifier. I need 18 PSI with the humidity set at 4.


I have a Trimetric in my TC. Among other things, I can see at a glance the AHs (amp hours)/amps I am using. I connected my CPAP machine to my inverter, and did a couple of quick test. The following are the results:

1 At 18 psi, Humidity set at 4. My amps varied from 1.6 to 2.02.

2 At 18 psi, Humidity set at 6. My amps varied from 3.25 to 3.75.


It was obvious there was a substantial jump in amp requirements simply be raising the humidity from 4 to 6. You could see the amps raise and lower as you listened to the humidity cycle on and off. I have more testing to do, but the indications for my (number 1) use is 1.6 to 2.02 amps. That translates into 1.6 to 2.02 AH. So, if I sleep (run CPAP) machine for eight hours, I can expect to use 12.8 to 16.16 AH.

Typically, I rarely use 20 or more AH per day. This is for TV, laptop, and all L.E.D.s for lighting. I have one 100 AH AGM (50 AH usable). That total, with the CPAP should be less than 35 AH. My 120 watts of solar has replace 35 AH on more than one occasion. Even without the solar, my 55 amp Iota charger will replace most of the 35 AH pretty quickly.

What the reader should get from this post is that with the same CPAP as mine, on the settings I posted above, is the AH they will need. The loss in AH due to the efficiency of the Blacker & Decker inverter is not really that great in my opinion. I would not change my CPAP simply to get a 12-volt unit.

I will do a bit more data collecting. Being I have a TC, it is seldom I do not dry camp.

Wayne

Thanks for the info guys. Appreciate it.

Reddog1 wrote:
My CPAP is a 120 volt unit, that operates at 24 volts as I recall. It does not run off 12-volt. Wayne

Quote from ResMed:

The 24 Volt 90 Watt DC Converter allows you to hook your ResMed AirSense™ 10 machine up to a 12 Volt or 24 Volt battery power source.

What's nice about Respironics machines is the 12 volt adapters are about $20. Not so with ResMed machines.


DC Adapter

Dakota98 wrote:

Reddog1 wrote:
My CPAP is a 120 volt unit, that operates at 24 volts as I recall. It does not run off 12-volt. Wayne

Quote from ResMed:

The 24 Volt 90 Watt DC Converter allows you to hook your ResMed AirSense™ 10 machine up to a 12 Volt or 24 Volt battery power source.

What's nice about Respironics machines is the 12 volt adapters are about $20. Not so with ResMed machines.


DC Adapter

Thanks for the link. As long as my $20 inverter works, I'll not spend $90 on their adapter.

I'm still learning.

I'm still learning.

I'm always still learning..I have read and read about this and came up with what works for me so far.I don't use the humidifier,I set it at 0, when in the hills without AC.I don't notice any issue doing that but do at home..I guess it's all in the humidity where your at?I always keep the reservoir full even though it is set at 0.So far so good,I keep waking up.

A portable C-Pap with battery pack large enough for 8 hrs of use cost more than a good used Lance camper.Not in my budget.With a Honda Gen and a couple newer group 27 stand alone batteries I take with me for the extra 12 volt stuff for over and above the unit needs works well with a travel trailer but I'm selling the pickup for a 1 Ton of some sort to get back into pickup camping instead where carrying extra batteries is not as easy without a trailer in tow.

I'm all ears to what works best in a pickup camper.With my ATV trailer in tow I see no issues but without..Hummm..Except a good charge every day...

Lots of people using C-Paps without electricity and there is know substitute for there experiences doing so,so I'm listening and learning.:B

More info:
Resmed Fisher & Paykel Icon + unit
110VAC ONLY
TC has one battery

Probably won't be dry camping no more than 2 nights in a row.

Individual who supplied C-PAP suggested using 400 watt inverter and no heat on the C_PAP.

Thanx for all the info to all that have contributed!:B

My wife has a CPAP and uses a humidifier on hers when we are at home but she does ok without it when we are on the road. She has many machines from over the years and the one she travels with is a 12VDC unit. When we took our trip to Alaska in 2013 we decided to break down and buy a battery just for it. So we purchased the Lithium Ion battery. Expensive but small and compact. This little battery would run my wife's CPAP for 3 nights without the humidifier. Then when driving during the day I would plug it into the truck to charger it back up. After 3 days of discharge one day driving charges it back up.

I have used a CPAP for years and I only dry-camp. You might want to consider looking into some solar to replenish your batteries. I had a smaller system (185 watts) and it kept my batteries charged without ever running the generator.
This would allow you to stay out much longer without having to "drive around to charge".

Good luck

Bill