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+--- Thread: 700 or 1000 watt power inverter for Resmed S9? (/Thread-700-or-1000-watt-power-inverter-for-Resmed-S9)
700 or 1000 watt power inverter for Resmed S9? - Lanco - 09-08-2017
Now that hurricane Irma is possibly going to hit our area in Florida I found my 700 watt inverter I bought years ago and thought I'd use it with my Respironics at the time but never used it. Also have a 1000 watt available.
The guy that has the 1000 watt version said he thought that these would run my S9 for around 3 or 4 hours. Is that correct? I'd be using the battery from a Dodge Caravan so I guess it's a 12 volt battery. What can you tell me about this?
We do have a power generator ready to go to but thought it good to know about the time for inverters.
RE: 700 or 1000 watt power inverter for Resmed S9? - trish6hundred - 09-08-2017
Hi Lanco,
Hopefully your inverter is a pure-sign wave as they work the best on medical devices.
Hang in there for more answers to your questions.
RE: 700 or 1000 watt power inverter for Resmed S9? - OMyMyOHellYes - 09-09-2017
CPAPs don't care if it is a sine or stepped wave form. Either is fine as far as the modern machines go. (ResMed says exactly that in its Battery Guide).
Now, no, car batteries are not good to use for this. They will work, but they are not built for deep discharge uses. And inverters are a terrible way to go because they are so blasted inefficient. Much better to go direct DC. But if you are due for a visit from your Aunt Irma soon, then, well, you are probably gonna have to do with what you got on hand right now. But looking at your profile where you are at in Florida, probably not.
If you have to use a battery supply, then totally ditch heated humidification. I mean, if you are in the path of a hurricane, chances are your air is pretty wet anyhow and heated humidification would be superfluous.
It would be helpful to know what your average pressure runs. Sleepyhead would be a useful tool to find that.
If we guess your average pressure is 12, about halfway between your min and max pressures, the Resmed battery guide shows it will pull 12 V current at around 1.1 amps. Multiply that by 1.5 to establish a power draw estimate with a 50% safety factor built in (in this case around 1.65 A) Assuming the battery is fully charged, you would divide its Amp Hour (Ah) rating by that 1.65 to see how many hours of used it would provide. Don't know what the Ah capacity of your truck is - it probably doesn't even list an Ah rating as it is a starting battery. Most deep cycle batteries roughly the same size as an average car battery is probably somewhere between a 50-70 Ah rating. Again, wouldn't have a clue as to what a car battery would offer in Ah. In any case, deep discharge of a starting battery is a lot harder on that battery than it would be on a deep cycle battery and may considerably shorten its life.
But being Pensacola area, you not likely be hit that hard by Irma. But you are definitely subject to hurricane hits. While you are thinking about it, it might be a good time to order ResMed's 12-24 V converter, a couple of deep cycle batteries (I like 35 Ah AGM/SLA size) and a Deltran Battery Tender smart charger to keep them charged and coindtioned. I just did a multi day measurement and determined that without heated humidification I can safely get 8 nights out of the 35 AH AGM battery with my S9 at an average pressure of 9 cm. Your mileage will vary.
in any case, an inverter is a really bad idea if you want to get the most hours out of a battery.
See http://www.resmed.com/us/dam/documents/articles/198103_battery-guide_glo_eng.pdf and it will give you a good idea what to expect using your S-9 with a battery.
OMMOHY
RE: 700 or 1000 watt power inverter for Resmed S9? - OMyMyOHellYes - 09-09-2017
BTW, if someone is hell bent on running with an inverter, the Battery Guide shows 150 W modified sine wave (stepped, not pure sine wave) is fine with the S-9 (as the minimum).
OMMOHY
RE: 700 or 1000 watt power inverter for Resmed S9? - OMyMyOHellYes - 09-10-2017
Ooops..... She is shifting westward. P'cola may get some. Good luck.
OMMOHY
RE: 700 or 1000 watt power inverter for Resmed S9? - Sleep2Snore - 09-10-2017
Be careful using Inverter power supplies, the ones that DO NOT supply a pure sine wave not only can be bad for your health, but some electronics can be damaged by the cheaper ones and the square wave ones can cause things not to run properly, hot, or become noisy due to the modified sine wave.
I will have a look to see if I can fine some videos to show you what I mean.
RE: 700 or 1000 watt power inverter for Resmed S9? - Sleep2Snore - 09-10-2017
That didn't take me long, perhaps I was just lucky!
What is the difference between a pure sine wave Ac inverter and a Modified sine wave inverter.
How it affects your electric components and how they work.
RE: 700 or 1000 watt power inverter for Resmed S9? - Sleep2Snore - 09-10-2017
How it affects your electric components and your health long term.
The Difference Between a Sine Wave Inverter and a Modified Sine Wave Inverter
Watch them full screen by clicking the cross on the bottom right when the video starts.
RE: 700 or 1000 watt power inverter for Resmed S9? - OMyMyOHellYes - 09-10-2017
(09-10-2017, 09:35 AM)Sleep2Snore Wrote: Be careful using Inverter power supplies, the ones that DO NOT supply a pure sine wave not only can be bad for your health, but some electronics can be damaged by the cheaper ones and the square wave ones can cause things not to run properly, hot, or become noisy due to the modified sine wave.
I will have a look to see if I can fine some videos to show you what I mean.
All this stuff about pure sine wave vs modifeid sine wave (stepped wave form) is simply not applicable. It is garbage as it relates to modern CPAP/APAP machines. The machines just do not care. ResMed, point in fact, says if using an inverter, a 150 W modified sine wave is totally fine. Reference ResMed Battery Guide.
Better yet, don't use a dad-gum inverter AT ALL. They stink from an efficiency standpoint. But if someone is hard-over to use an inverter, then you don't need to worry about waveform.
OMMOHY
RE: 700 or 1000 watt power inverter for Resmed S9? - Sleep2Snore - 09-10-2017
(09-10-2017, 10:22 AM)OMyMyOHellYes Wrote:Strange that because when they were at a conference in Scotland they were very explicit that you use ONLY good sine wave inverters.(09-10-2017, 09:35 AM)Sleep2Snore Wrote: Be careful using Inverter power supplies, the ones that DO NOT supply a pure sine wave not only can be bad for your health, but some electronics can be damaged by the cheaper ones and the square wave ones can cause things not to run properly, hot, or become noisy due to the modified sine wave.
I will have a look to see if I can fine some videos to show you what I mean.
All this stuff about pure sine wave vs modifeid sine wave (stepped wave form) is simply not applicable. It is garbage as it relates to modern CPAP/APAP machines. The machines just do not care. ResMed, point in fact, says if using an inverter, a 150 W modified sine wave is totally fine. Reference ResMed Battery Guide.
Better yet, don't use a dad-gum inverter AT ALL. They stink from an efficiency standpoint. But if someone is hard-over to use an inverter, then you don't need to worry about waveform.
OMMOHY
They came from the manufacturer of the machines. So if you don't mind I will follow their advice. They said they would not cover a machine if it were used with a modified sine wave inverter.