I did promise a review of progress re the CPAP machine did I not? Ok so I have a Resmed S8 lightweight that has several conflicting badges on it re power draw etc. "110, 240 volts 400hz (yes thats right 400 hz) 2.5 amps" Ok so I asked around I asked Resmed Techos (who I might add were cognisant of their vested interest in making money, not solving the problerm) I got the technical data sheet from Resmed et al........ Sooooooooooooooo I connected up my 150 watt inverter and ran it for over 6 hours with 12.53 volts still in the 80ah battery this is good enough for me, I don't usually keep the mask on for more than 6 hours a night anyway. This was with the humidifier attached but turned to 0, simple fix for the humidifier is to fill the water tank with hand hot water and it works without the heater which may draw heaps of power. Resmed say that I need a 600 watt inverter to run the humidifier WTF 600watts.. yeah blow in the other nostril....and they also claim that a "full genuine sine wave" is needed mine is just a simple $49.95 150 watt inverter and it did the job superbly. The cynic in me says that maybe Resmed don't like simple solutions...
dave06 said
06:10 PM Feb 20, 2009
in theory you should only be drawing about 30 watts (2.5w x 12volt =30w) from that unit with your numbers so a 150 watt inverter is using almost as much power to power itself than is needed for your machine,
basically overnight you used what maybe 1.5 - 2 volts so you're laughing, if you dont use it during the day the battery will "recover" that
the power needed for your humidifier, I assume, would be to power up some sort of heating element, if you can do without it all the better
a pure sine wave inverter is definitely not needed, like you I think a vested interest is at play here
but all in all happy that you can run it off an inverter, much more betterer than a genny
Basil Faulty said
07:27 PM Feb 20, 2009
Yes and to make the intrigue even better I peeled off a sticker that said "removal of this identity plate will void your warranty" and what did I discover underneath........Yes you guessed it "made in China" yes I jest not folks.... I may take this to the ACCC just to let them know that medical equipment is being rebranded as manufactured in the USA when it is Made in China....Though I did void my warranty (long since expired) to discover that. It is however a great relief to know I can now stop at unpowered sites for a night at least. I'll give the system a realistic test with the lights on, tv etc and the inverter and see how long the battery lasts. It has a 10.5 volt cut out in the van circuitry.
-- Edited by Basil Faulty at 18:30, 2009-02-20
BarbandDaz said
10:46 PM Feb 20, 2009
Hi Basil
Darryl uses a CPAP Resmed S6 without a humidifier and we got 12 days out of a 120AH AGM battery using a 300watt inverter.
Barb
Basil Faulty said
08:37 AM Feb 21, 2009
BarbandDaz wrote:
Hi Basil Darryl uses a CPAP Resmed S6 without a humidifier and we got 12 days out of a 120AH AGM battery using a 300watt inverter. Barb
With the S6 you would only need a 150 watt inverter and save some of the current needed to power the 300 watt inverter..... Darryl dosen't normally use a humidifier? Or he just suffers the dry air being pumped down his nose? Depending on the type of humidifier you have you may be able to use it with the 300 watt inverter. It is just a heater and I calculated by measuring the resistance across the 2 power pins ( crude) that at full power the H3i attached to my machine would draw 50 watts but then that is only intermittent. They do warn that some of their humidifiers can't be run via inverter, why they refused to tell me.I would have thought that if you normally plug the thing into 240 ac then plugging it into 240 ac from an inverter would be the same after all the first thing that happens to the power in any of these devices is that it hits the internal or in the case of some things eg Laptops, external power conditioner which converts it to dc anyway.... Here is a link to resmeds "Guide" it does have some good info but I think the best way to go is via practical experiment, try yours with the humidifier and see what happens....
I'd agree with all thay Basil!!! pity you couldnt wire direct into the 12 volt side of it and do away with the power hungry inverter, you dont have an old one laying around that could be sacrificed for the greater good by any chance!!!!!
Bridgee said
02:51 PM Feb 21, 2009
Apologies Basil.
It proves Mike and Judy's "Puzzle" post theory , where the human mind "reads" words it thinks looks right, even though spelt completely different.
When I first looked at your post CPAP machines revisited" I looked at the word CPAP I read it as CRAP and thought you were talking about Portaloos / Portapotties ......................... CRAP machines!!
jandas fun said
03:13 PM Feb 21, 2009
good Lord ! your right. i thought it was satrgne using inverters and dehumidifyers and wiring them up to to different power voltages. 1 was embarrased that mine was a cheapy plastic one with some coloured liquid thrown in.
John
BarbandDaz said
09:54 PM Feb 21, 2009
Hi Basil, Daz has NEVER used a humidifier and he has used the CPAP for 6 years now. Will have to check out the draw of the inverter. When we first went camping we went to a battery store and they calculated that for 8 hours CPAP use we would use ~20amp hours per night?????? So to get 12 nights out of a battery that we were tod would last 6 - was brilliant. Barb
-- Edited by BarbandDaz at 20:55, 2009-02-21
Basil Faulty said
07:43 AM Feb 23, 2009
BarbandDaz wrote:
Hi Basil, Daz has NEVER used a humidifier and he has used the CPAP for 6 years now. Will have to check out the draw of the inverter. When we first went camping we went to a battery store and they calculated that for 8 hours CPAP use we would use ~20amp hours per night?????? So to get 12 nights out of a battery that we were tod would last 6 - was brilliant. Barb
-- Edited by BarbandDaz at 20:55, 2009-02-21
That is amazing, if my humidifier is off I get a very sore nose.... I think it's the very confusing info on the bottom of the machine that caused the error in your favour, plus unless Daz is a long sleeper he may not be getting a full 8 hrs each night. I retire at around 10:30, read for a bit then put on my mask, I'm awake around 4:00am and don't put it back on after that so I only use it for around 6 hours a night. Each person will have different usage patterns and this is one case where practical experimentation is really the only way to get an accurate answer.
dave06 said
10:38 AM Feb 23, 2009
thats funny Basil, if I snore I get a sore ear, thats where the dragon thumps me
BarbandDaz said
08:35 PM Feb 23, 2009
Hi Basil,
Darryl goes to bed about MN or 1 am an sleeps til ~ 8 so get about 7 hrs sleep. When we are camping it is different and he is in bed by ~10 and up at ~6 heheh
Ok so I have a Resmed S8 lightweight that has several conflicting badges on it re power draw etc. "110, 240 volts 400hz (yes thats right 400 hz) 2.5 amps" Ok so I asked around I asked Resmed Techos (who I might add were cognisant of their vested interest in making money, not solving the problerm) I got the technical data sheet from Resmed et al........
Sooooooooooooooo I connected up my 150 watt inverter and ran it for over 6 hours with 12.53 volts still in the 80ah battery this is good enough for me, I don't usually keep the mask on for more than 6 hours a night anyway. This was with the humidifier attached but turned to 0, simple fix for the humidifier is to fill the water tank with hand hot water and it works without the heater which may draw heaps of power. Resmed say that I need a 600 watt inverter to run the humidifier WTF 600watts.. yeah blow in the other nostril....and they also claim that a "full genuine sine wave" is needed mine is just a simple $49.95 150 watt inverter and it did the job superbly.
The cynic in me says that maybe Resmed don't like simple solutions...
It is however a great relief to know I can now stop at unpowered sites for a night at least. I'll give the system a realistic test with the lights on, tv etc and the inverter and see how long the battery lasts.
It has a 10.5 volt cut out in the van circuitry.
-- Edited by Basil Faulty at 18:30, 2009-02-20
Darryl dosen't normally use a humidifier? Or he just suffers the dry air being pumped down his nose? Depending on the type of humidifier you have you may be able to use it with the 300 watt inverter. It is just a heater and I calculated by measuring the resistance across the 2 power pins ( crude) that at full power the H3i attached to my machine would draw 50 watts but then that is only intermittent. They do warn that some of their humidifiers can't be run via inverter, why they refused to tell me.I would have thought that if you normally plug the thing into 240 ac then plugging it into 240 ac from an inverter would be the same after all the first thing that happens to the power in any of these devices is that it hits the internal or in the case of some things eg Laptops, external power conditioner which converts it to dc anyway....
Here is a link to resmeds "Guide" it does have some good info but I think the best way to go is via practical experiment, try yours with the humidifier and see what happens....
http://www.resmed.com/en-au/products/service_and_support/documents/19825r2_battery_guide_english.pdf
Looking at the S6 it draws at top flow rate around 2.2 amps@ 12 volts
It proves Mike and Judy's "Puzzle" post theory , where the human mind "reads" words it thinks looks right, even though spelt completely different.
When I first looked at your post CPAP machines revisited" I looked at the word CPAP I read it as CRAP and thought you were talking about Portaloos / Portapotties ......................... CRAP machines!!
1 was embarrased that mine was a cheapy plastic one with some coloured liquid thrown in.
John
Daz has NEVER used a humidifier and he has used the CPAP for 6 years now.
Will have to check out the draw of the inverter.
When we first went camping we went to a battery store and they calculated that for 8 hours CPAP use we would use ~20amp hours per night??????
So to get 12 nights out of a battery that we were tod would last 6 - was brilliant.
Barb
-- Edited by BarbandDaz at 20:55, 2009-02-21
Each person will have different usage patterns and this is one case where practical experimentation is really the only way to get an accurate answer.