Using a Resmed S8 on 12V power

Anonymous wrote:I own a ResMed S8 Elite and was told I needed to buy the adapter in oder for it to work on a sail boat I'll be cruising on in June. I was told the boat has 12&24 watt power, so will this adapter from ResMed be enough?
Any/all help greatly appreciated

The Resmed DC-12 adapter will work with both 12 Volt and 24 volt power sources to provide regulated 12 Volt DC power to your S8, and it is basically all you need.

The power input to the DC-12 is a cigarette lighter type plug, so you need to check what the power sockets are on the boat. You may need a "patch" cable to match the boat outlet socket to the DC-12 input plug.

Cheers,

Bill

Thanks Bill! (I was the Anonymous that asked the question and I've since registered for this site having first discovered it today!)
I am not sure what is meant by a patch cable?
I'll ask the boat (sail) captain what sort of outlet they use to be sure, but just in case, what's a 'patch'?

The 12 volt system on the boat should be large enough (wattage) to handle your S8 through the night. The Resmed adapter will work OK but is a bit overpriced. I made mine out of an adapter that I found and modified from an Auto parts store.

Have a nice trip.

Shadowatcher

billbolton wrote: I'm facing a 7 week vacation trip around Europe soon . . .

Poor boy, hope it does not take too much out of you. It's been 33 years since I spent 6 weeks driving around Europe. Have fun!

To anyone interested.

I have photos on my web site of me running an S8 Escape off my cars 12v direct.

Works fine.

Issue is that if running direct, the voltage should not drop below 12 (as in a slowly discharging battery) also if the car engine is running & the alternator is charging at say 15 VDC, this I believe may have some effect.

The plus & minus 12 vdc variations are the obvious issues.

Cheers

Doug


http://www.internetage.com/cpapinfo/
Go to 'cpaps & software' menu (left list) & choose item 8 off that menu

Also see Bill Bolton's home built battery pack under the contributed items section.

D

Shadowatcher wrote:The Resmed adapter will work OK but is a bit overpriced.

It depends on what risks you want to take.

The DC-12 provides isolation between the input and output sides, noise filtering, low voltage sensing/cut out (to prevent over discharging a battery), accepts nominal input voltages up to 24 Volts while providing a regulated and very stable 12 Volt output.

Your modified autostore adapter probably only does one of those things, and typical autostore devices don't even handle the regulation of the output voltage very well on the whole.

Cheers,

Bill

Help. DC-12 Converter For S8 Machines. 12V DC output of the correct plug polarity (+),(-)to an S8 ?

Hi Please for information on the DC voltage polarity on the CPAP ResMed S8 Autoset Where is the + and where - on the outside and inside the plug?
Thanks in advance for your help and waiting for an answer
Regards
Stanislaw

From the 4th post in this threadP

billbolton wrote: The S8 is wired for NEGATIVE voltage on the centre pin of the low voltage power connection, which is the opposite of the normal wiring convention for that type of low voltage connector.

I suggest that you read the entire thread as there is a lot of good info about powering an S8 from alternative power sources.

I tried wiring up my S8 escape 2 to direct 12 volts - Disaster, one totally fritzed cpap machine. Most DC appliances here in the UK using that type of hollow pin are positive centre, negative outside. From bitter experience I take it that my S8 model is the reverse. I haven't tried it wired the other way round yet, but would like to confirm from someone who has wired it negative centre, positive outer, that it will work. All the other stuff in Resmed's DC coverter are voltage stabilization (13.5 volts?) and a low voltage cut out to stop your battery being drained completely.
I'm spending around three nights in a campervan at the moment, so would like to sort this out soon-ish.

billbolton wrote:Does anyone have any technical details on the Resmed DC-12 adapter for the S8 CPAP machine??

The DC-12 is the adapter that is supposed to go between an automobile cigarette lighter outlet, or airline seat low voltage power socket (etc) and the S8.

I'm facing a 7 week vacation trip around Europe soon and it looks like I will end up carrying several different power supplies/adapters for CPAP, laptop, camera battery recharger, mobile phone etc, and I'd like to see if I can rationalise the number I really need to carry.

Does anyone have any experience is powering an S8 from a nominal 12 Volt DC power supply without using a DC-12 in the circuit?

Cheers,

Bill

Is anything here for you by John Fisher:


viewtopic.php?f=1&t=49115&st=0&sk=t&sd= ... Ft%3D49115+...

Bill Bolton started this topic in 2006 - over five years ago:
Using a Resmed S8 on 12V power
by billbolton on Wed Jun 07, 2006 9:06 pm

avi123 wrote:Is anything here for you by John Fisher:

Feb 10 2010 subject: Battery Backup Design
JohnBFisher's detailed design description with pictures.
viewtopic.php?p=449334#p449334

I think it's a safe bet to say Bill is definitely aware of John's topic which was started in 2010. Bill posted several times in John's thread.

Both this thread and John's are good for new people to see.
New readers can also find more discussions here:
LINKS to Battery operation, camping, power outage
viewtopic.php?t=9682

Tickety-Boo wrote:Most DC appliances here in the UK using that type of hollow pin are positive centre, negative outside.

As I've discovered along the way , in fact it is pretty much a 50/50 call whether the centre pin is positive or negative on barrel style connectors used with commercial power supplies.

Tickety-Boo wrote:but would like to confirm from someone who has wired it negative centre, positive outer, that it will work.

You already have the answer to that in this thread.

Cheers,

Bill

avi123 wrote:Is anything here for you by John Fisher:

Feb 10 2010 subject: Battery Backup Design
JohnBFisher's detailed design description with pictures.
viewtopic.php?p=449334#p449334

I think it's a safe bet to say Bill is definitely aware of John's topic which was started in 2010. Bill posted several times in John's thread.

Both this thread and John's are good for new people to see.
New readers can also find more discussions here:
LINKS to Battery operation, camping, power outage
viewtopic.php?t=9682[/quote]


Thanks RG. By any chance do you know the link to John Fisher's file in PDF?

Did you ever get your S8 repaired & what did you find?

I am considering making a mod inside to accomodate either + or - center pins.

I just tried to "CHECK" my S8 in preperation for a trip and inadvertantly grabbed the wrong 12v cord from my other cpap & the S8 is now dead..

I plan to put on the bench tomorrow & take a look inside..

Tickety-Boo wrote:I tried wiring up my S8 escape 2 to direct 12 volts - Disaster, one totally fritzed cpap machine. Most DC appliances here in the UK using that type of hollow pin are positive centre, negative outside. From bitter experience I take it that my S8 model is the reverse. I haven't tried it wired the other way round yet, but would like to confirm from someone who has wired it negative centre, positive outer, that it will work. All the other stuff in Resmed's DC coverter are voltage stabilization (13.5 volts?) and a low voltage cut out to stop your battery being drained completely.
I'm spending around three nights in a campervan at the moment, so would like to sort this out soon-ish.