cpap machine

[Tayls]

Hi all, I have a cpap machine, bugger. What options do we have for using these on 12 volt?.

[Lt4vette]

I don't know anything about them but I would think a relatively small inverter would be the easiest, maybe not the cheapest, solution.
Thanks,
Russell

[MYT150]

Depending on which machine you have there is a number of options.

Easiest one is probably a sine-wave inverter as it can be used to also charge other things safely.
There is also 12volt systems available for some of the makes of CPAP machines.
Or some of them also have battery packs which can last one or two days but then need to be recharged.

[Alien]

Hi all, I have a cpap machine, bugger. What options do we have for using these on 12 volt?.

I'm going through this at the moment as the better half now has one.
We have not been away with the cpap yet but below is where I'm at with setting up for it.

I've got a Dick Smith 300W invertor on a merit plug that is used for laptop, camera/torch batteries etc..
It will be plugged in at the yellow box(research has shown this is the best plug for high current applications).
With the cpap plugged in and running I draw 2amps from the inverter(measured across the inline fuse holder).
This is a Philips System One without the dehumidifier attached.
We got a extra hose so the aim is to have the machine on top of the radio panel and run the hose along the roof net.
This should still allow us to sleep at the pointy end.

It has been recommended to add a 240volt 7amp charger to the circuit.
The idea is the invertor will power the cpap and charger with the charger feeding back to the Tvan's battery.
One of todays jobs is to hook it all up and do the testing to see what amps/volts I get.

Update....
At 6.0cmH2O I'm drawing 3.6 amps.
After 1 hour I've gone from 11.44v(measured while running) to 11.25v cpap only(rubber mat over the solar panel so no input from it).

With the charger plugged in only I use 3.08 amps and get 1.3 into the battery.
With both the charger and cpap I use 4.6 amps and still get 1.3 at the battery with no voltage gain.

I've left the cpap only on and the invertor cut out due to low voltage after 1 hour of running.
This is with the 1 year old house battery, heavy cycle CCA 100.
The van sits outside so the solar keeps things toped up.

I thinking that SHMBO could use something like this unit for trips.
https://www.cpapaustralia.com.au/shopping/transcend-ii-really-small-travelling-cpap-machine-p4-battery.html
I've yet to look into it's power consumption either on it's own or to charge the battery pack.

[Caveman26146]

I have had a CPAP for some years now and while it has never stopped me going bush I have learnt a few things.
If you have a humidifier with your CPAP a 300w inverter will not keep up as they do draw a fair amount of juice.
My old machine did run ok if I turned the temp on the humidifier right down or off completely, but the Resmed S9 I now use has a 12v to 24v step up power convertor which plugs into a normal 12v cigarette socket. I think it costed around the $140 mark but well worth it.
Our Ranger runs a 3 battery setup with 2 start batteries and a 60amp Thumper pack which works quite nicely all night with out the voltage dropping much over night with the temp dropped down to 18degrees instead of the 25 I set it at while home.
Hope this helps you out .

[MYT150]

I have the Resmed S9 autoset and use it without the humidifer and with a 150Watt sine wave inverter it runs all night and take the battery in the Tvan down from 100% to about 85% over night, with nothing else running other then the lights some times.
I also have the Transcend machine as I used to do a lot of travel for work and it is so much smaller, it also does about the same level of battery usage.

Slightly off topic, but I would recommend having a look at http://1800cpap.com/ if you are looking at buying a machine or masks, they are less then half the cost of getting the same thing in Australia. I have used them a few times and happy to recommend them. One order I submitted on a Friday night Sydney time and had it delivered the Monday afternoon, so less then 3 days and including a weekend, which isn't bad from the states.

[rogtj]

Know people with sleep apnoea who use CPAP, the Resmed S9 with 12V adaptor works very well, as does the Transcend auto with battery, or via 12 adaptor.  Sine wave inverter is another option, but get one the right size, i.e. slightly bigger than the draw from the power supply.  It is part of the cost of recreaction, at least there are options.

[Slick]

Hi Troops!

SWMBO reports that the 300w inverter in our TVan isn't up to the task for her ResMed S9 with Humidifier. Apparently me aguing the point didn't help either  Luckily for us, i also have a 600w inverter mounted in the car too so with the addition of an extension lead the problem just went away 

All things being equal, i am happier running it off the car anyway as the brute (CPAP - not wife ) will chew 40+ Ah overnight. I have good options for charging batteries but, at the end of the day, my preference is to preserve the camper  batteries where possible.

Vince.

[Tayls]

Thank you for all the great advice. I will follow up on 12/24 converter.