Cpap and 12v power (1 Viewer)

Affiliate links here may earn MHF compensation
Jan 9, 2022
242
585
Colchester, UK
Funster No
86,183
MH
Pilote G732
Exp
Total Newbie
So following on from previous comments on another thread, I did the maths and bought the Resmed 12v adaptor. I have 2 x 12v fag lighter sockets, 1 in the kitchen and 1 next to the wc ( really not the best place to put electrics surely? ) both will run a phone charger but neither will run the power adaptor.
Not understanding life, let alone electric stuff, can anyone suggest what I might need to look at or do?

Confused of Colchester
 
Feb 9, 2008
4,134
6,007
SW Scotland
Funster No
1,453
MH
LP Coachbuilt
Exp
Since 2008 after caravanning for 20 years
A Cpap power supply can use between 2.5A and 5A, that's a lot for a 12v socket. Better off just using the brick on mains supply. For comparison a phone charges at about 1A.
 

Neckender

Free Member
Oct 15, 2007
3,221
5,923
Neckend or North Wales.
Funster No
635
MH
VW T6.1Kombi day Van
Exp
Since 2004
I had a dedicated 12 volt 10 amp supply fitted in the rear of our VW T6.1 for my CPAP machine and it works just fine off 12 volt. I also fitted the same in my last 2 motorhomes with no problems.

John.
 

pappajohn

LIFE MEMBER
Aug 26, 2007
43,601
51,605
Dark side of the moon
Funster No
172
Exp
Since 2005
I don't see why it won't work.
If a dedicated supply is rated at 10 amps and works then a cig lighter socket should work.
Cig lighter sockets are rated at 10amp (120w) or 15amps (180w)

Subscribers  do not see these advertisements

 

tonka

LIFE MEMBER
Jul 2, 2008
10,942
21,890
Cannock, Staffs
Funster No
3,141
MH
A class Burstner 800
Exp
Since 2000
I know nothing about CPAP but after a quick google it seems they can run anywhere from 60-100watts.
As the two replies state, most 12v cigarette sockets are usually rated at 120 or 150w so should run it ok.
Maybe look at making a direct feed from the battery and into a new 12v socket, fused with appropriate cable.
If there is still issues check the batteries.
 
Nov 5, 2013
3,212
101,128
Shropshire
Funster No
28,900
MH
Carthago chic e-line
Exp
Since 2013
I ran a dedicated fused socket direct from the battery in our last two vans,S8 and S9 but no humidifier,no problems.
 
OP
OP
S
Jan 9, 2022
242
585
Colchester, UK
Funster No
86,183
MH
Pilote G732
Exp
Total Newbie
This is from the booklet that came with it, so should work?
 

Attachments

  • IMG_2525 Large.jpeg
    IMG_2525 Large.jpeg
    238.1 KB · Views: 47
Apr 27, 2016
7,126
8,395
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
From the data in the picture, I'd say the CPAP unit works at a steady state of 7.5A (2 x 3.75A) and it has a startup current of 13A. That is not unreasonable for a cigarette-lighter socket to provide. However it's possible that the existing sockets are not really up to it, perhaps with a maximum limit of 8A or even less.

You could install a new socket, with nice thick wires and a 20A fuse, going direct to the leisure battery. I'm sure that will solve your problem and be an investment for the future. It's sure to come in handy for lots of other uses too. Like running an tyre inflater pump to top up the tyres. I have over a dozen of these sockets all around the MH, including in the garage at the back.

Subscribers  do not see these advertisements

 
Oct 27, 2007
1,856
2,494
Near Dartford
Funster No
726
MH
Hymer
Exp
Since 2005
I have a CPAP machine and run it off a cigarette lighter socket in the back of the van. I use a resmed 12volt cigarette lighter adaptor ( wasnt cheap £90 5 years ago) and also an extension lead (12 volt cigarette lighter type) as the plug is too far for my machine to reach.

This has worked absolutely fine for the last 5 years.

Sonja
 

Lenny HB

LIFE MEMBER
Oct 18, 2007
54,931
157,311
On the coast in West Sussex
Funster No
658
MH
Carthago Compactline
Exp
Since 2008 & many years tugging
Probably not working due volt drop due to the cable to the socket being under size. Rewire the socket with heavier cable and I would change the socket and the plug on the device for a a Hella plug & socket, cigar lighter sockets often have a poor connection and not much good for high currents.

Cable size calculator on this page aim for less than 3% volt drop.
 
Oct 27, 2007
1,856
2,494
Near Dartford
Funster No
726
MH
Hymer
Exp
Since 2005
Probably not working due volt drop due to the cable to the socket being under size. Rewire the socket with heavier cable and I would change the socket and the plug on the device for a a Hella plug & socket, cigar lighter sockets often have a poor connection and not much good for high currents.

Cable size calculator on this page aim for less than 3% volt drop.
Forgot to mention ours is a hella socket.
 
Apr 11, 2015
5,605
57,870
hull
Funster No
35,812
MH
Laika Ecovip 300
Exp
since 1988 with breaks until 2009
John runs his through a cigarette lighter type socket, proper resmed cable, recently had a problem but was prtly because extension lead fuse was borderline ok (he had used it for several years) it also shorted out that light systwm which knocked out our truma heating, no idea why they are on the same master fuse, all sorted now and seems to be working fine. He has been using CPAP in the motorhome since we got our first in 2009, first time we have hd a problem although he has also, in the past, used an inverter. We can do several nights off grid, have 1 leisure battery and 180W of solar.

Subscribers  do not see these advertisements

 

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top