12 volt invertor

Hello William
I run my Cpap from a 12 volt adaptor similar to a computer adaptor from a 12 volt cig plug on a 30 amp fuse from the battery setup in my camper. I bought it when I purchased my Cpap because I asked for a camping setup and wanted to run from 12v not an invertor.

William, I'll send a mate a message with link to here.
He's been running one on trips and only uses 1amp a night, easily run from 12v, though think his is 12v unit with 240v to run at home.
Anyway, he's looked into this a lot so should be able to advise his experiences.

I also have a CPAP machine with heated hose. I use 240V at home and when camping use a Resmed 12v inverter. I think the CPAP actually operates at 19V or some similar odd voltage.
I have a 240V inverter but found that using it through this inverter uses a fair bit of power during the night so I went 12V. When camping I usually turn the humidifier off and this saves quite a bit of current draw. (approx 3 amps down to 1 amp)
Cheers

I've used CPAP's for 15 + years while camping.

My experience has been different models have differing power consumption rates and if using a humidifier, power increase goes up significantly. Read details on the name plate of your device and if you haven’t purchased one yet hunt down one with lowest power use and preferably with a 12 volt outlet as well as normal 240v.

Also note that if using 240 volt from an inverter, be aware of electrocution risk; this is why I sleep in a tent.

Happy sleeping.

Wow there appears to be a huge take-up of cpap machines.
Many people on them have been recommended to do so by the agents of the machines and their "free" tests.
"Come in and we will test to see if you should be using one of our machines".
They wouldn't recommend against using one would they?

Basically a bigger inverter will be better as its not flogging its guts out generating 240v. Reduces heat etc.
Cheap smaller units running close to their max often start whistling or squealing.
Actual battery power used really comes down to design (quality) of the unit. Cheaper ones tend to use more.

You don't say what make/model cpap.
The different machines offer different features which use differing amounts of power. Sometimes you can turn bits off and save power.
The Resmed AirMini uses very little power but I use a Resmed Autoset 10 with heated hose and humidifier. It consumes some 90 watts at 24v = around 4 amps, my 80L Waeco on 12v uses about 4amps with its compressor running so that effectivly 2x 80L fridges.
Turning off the humidifier and heated hose drops that enormously but its still a very hungry device.
Resmed make a 12 to 24v inverter/adapter which I also have but that still pulls near 8 amps at 12v with all cpap functions turned on.

Using an 240v inverter has some overhead losses. You have to convert 12v up to 240v just so you can drag it down to 24v again via its 240v adapter. Much more efficient to use the 12-24v inverter.
Bottom line is that in this example, you still need to supply at least 90w (8 amps) of 12v plus the inverter overhead.

Are you heading for the bush or powered camping sites?

Bruce uses a Resmed cpap machine with heated hose and humidifier. He uses 240 volt at home and when we have it away camping he uses a 12volt DC to DC converter available from Resmed. Works a treat and use little power and both of us get a good night's sleep! :)

Di

Don't buy a cheapie inverter; they don't cope well with corrugations in my experience.

If you're going to fix an inverter in your camper keep it away from shock and spring mounts.

Inverters draw a base current when idle and that figure should be available.

Best wishes with the plan.

William, mate just sent this link to the ResMed Battery Guide

Gives a lot of good info . . . they mention 'converters'.