power draw difference in Resmed s9

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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palerider
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Location: Dallas(ish).

Re: power draw difference in Resmed s9

Post by palerider » Wed Jan 25, 2023 8:48 pm

polyborus wrote:
Wed Jan 25, 2023 6:57 pm
I have forwarded this entire thread to my girlfriend. I will ask her what color her humidifier light is. For running our resmeds on DC, We both use the 3 pin to barrel plug cord that Maxoak supplied (their Maxoak5 battery is geared to CPAPs). This cord id specifically labelled by Maxoak with an attached tag on the cord :"For Resmed s9".
I ask, because you can make an adapter cable that you can measure current draw, unless that's show on the maxoak display.
polyborus wrote:
Wed Jan 25, 2023 6:57 pm
We will trade CPAPs on this upcoming camping trip as we tried trading Maxoaks last camping trip. That should be an even better test than merely detaching and trading the humidity tank halves of our Resmed s9s.
Not really. If it's a faulty humidifier on her side, and she *thinks* it's on and heating, then swapping out the whole machine won't narrow down where the problem is.

And if you get her machine and change all the settings to be what you want, and it doesn't work for you, I guess you've proved it's your settings vs hers.
polyborus wrote:
Wed Jan 25, 2023 6:57 pm
My complaint was made clear, I believe, in my first post. To reiterate: it appears we have the same model Resmed on the same settings. We have the same Maxoak 5 battery. The difference between our set-ups is she has a heated hose and I do not. She truly gets 3 nights. I have seen her battery numbers. I get 8 hrs.
It is *IMPOSSIBLE* to get three nights of use out of one of those low watthour 'power banks' when using heated humidity.
You're getting what you should.
polyborus wrote:
Wed Jan 25, 2023 6:57 pm
Perhaps her CPAP is broken as a poster suggested. I have sent her a copy of this thread and a separate email about the light on her humidifier and the possibility her CPAP is broken, as this will be of concern to her health.
It's not a concern for her health if it's working for her, whether or not the humidifier is heating.
polyborus wrote:
Wed Jan 25, 2023 6:57 pm
Perhaps I am paranoid, but I'm getting a whiff of, at best, "one of you is lying" or at worst "Two bimbos who don't know what they are talking about".
There's a huge gap between "you're mistaken" and "you're lying" but if you want to go the paranoid route, I can't stop you.
polyborus wrote:
Wed Jan 25, 2023 6:57 pm
I would, however, like to close this reply with an observation I made very early in my own scientific career, solidified by a lot of reading in history of science: The words "This just can't BE", spoken either by the original observer or by would-be detractor scientific peers, have led to some of the most creative science and remarkable discoveries made by mankind.
er, sure. maybe your friend has discovered the secret to cold fusion in her turned off humidifier.

Zonker, please to be passing the popcorn.

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polyborus
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Re: power draw difference in Resmed s9

Post by polyborus » Wed Jan 25, 2023 9:08 pm

Thank you. You did make one good point...we will trade the whole CPAPs on one night, then try trading only the water tank half (easily detachable) the next night. Of course we will continue to use the same settings, as we have been doing thru this 'experiment' (with the exception of temperature. Resmed s9s elites don't even provide an option for temperature in the "Settings" unless the machine detects the contacts of a heated hose. I will not, as palerider suggested, be changing all the settings to my liking. It is fortuitous that the settings prescribed by our respective sleep docs are remarkably similar.

I hope my previous posting of Maxoak5 reviews from Amazon will lend some credence to the notion that a number of people can get a number of consecutive nights from this battery even on big newish model CPAPS like the Resmed airsense 10 ( and a number cannot). so there are many variables to twiddle. But it is not impossible, just challenging.

polyborus
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Re: power draw difference in Resmed s9

Post by polyborus » Wed Jan 25, 2023 9:32 pm

oops. Can't seem to find the amazon reviews I thought I posted about 15 minutes ago. I may have violated some policy by including a url link to Amazon reviews or perhaps my pasting in so much text exceeded my character limit (I'm new to the blog)...but if folks think a Maxoak 5 cannot last for multiple days, they can google "Amazon reviews Maxoak5" and find many happy purchasers enjoying multiple day use, even for larger, newer, more power-consuming CPAPs like the Resmed airsense 10. (They are not all air-mini users).These happy campers agree they don't get such results using heat...but I mention these reviews for the benefit of those on the blog who said I couldn't expect multiple days (I stated I don't have heat).

There are also users who don't even get the 8 hrs I get...so it is clear there are a lot of variables between battery and CPAP, but multiple days from a Maxoak5 can be and are achieved by numerous folks with standard CPAPs and I am seeking fellow bloggers' advice on how I can be among them.

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zonker
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Re: power draw difference in Resmed s9

Post by zonker » Wed Jan 25, 2023 9:47 pm

palerider wrote:
Wed Jan 25, 2023 8:48 pm


Zonker, please to be passing the popcorn.
okay, boss-Image

also, too, got a new one for ya-

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but that's enough about them.
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tyrinryan
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Re: power draw difference in Resmed s9

Post by tyrinryan » Thu Jan 26, 2023 2:21 am

The Maxoak k5 specs show 82.5 amp hours at 3.7 v. which is 25.4 ah at 12 volts. which is 8.5 ah over 3 nights. approx reduced by lithium, i suggest, 75% maximum draw-down = 6.4 ah per night AT 12 VOLTS.----just an approximation!

divided by 8 hrs of sleep =.79 amp draw AT 12 VOLTS. which is more or less (in the ballpark of) what the Resmed battery guide calls for an S9 to draw at 9 cm AND at 12 VOLTS without heat with room to spare.

so it is quite reasonable for the Maxoak to last 3 nights.

If you add any sort of normal heat, you would be lucky to get even one 8 hr session even at a 90% draw-down, I think---ymmv!

Does the Maxoak put out 24 volts directly to the S9 Along with the trigger? wire at a lower voltage? That might increase its efficiency?


The question is, i think, why is the op's unit drawing more juice than his friend's unit or why is his friend's battery so much better.

When I was buying a vrla (lead acid) battery for my UPS, I was offered the original 7ah at one price but for a fistful of dollars more, I could get a 9 ah or 10 ah ---in the same case. If it has the same number of cells--how can one vrla battery be "better", "better ah" and of course more expensive than another? Do you think this is a bit of a scam to get you to pay more? Are there the same discrepancies in lithium batteries?

as10fh
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Re: power draw difference in Resmed s9

Post by as10fh » Thu Jan 26, 2023 5:51 am

polyborus wrote:
Wed Jan 25, 2023 9:08 pm
...we will trade the whole CPAPs on one night, then try ...
start with the heated hose, you will be amazed.

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ChicagoGranny
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Re: power draw difference in Resmed s9

Post by ChicagoGranny » Thu Jan 26, 2023 8:32 am

polyborus wrote:
Wed Jan 25, 2023 6:57 pm
My friend is retired from law enforcement and later, the ministry.
I'm not accusing your girlfriend or you of lying, but come on, cops and ministers are well-known for lying. :lol: :lol: :lol: :lol:

polyborus
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Re: power draw difference in Resmed s9

Post by polyborus » Thu Jan 26, 2023 9:42 am

to as10fh...thank you for responding. I'm not quite sure I understand your suggestion. Could you clarify? I am not currently using a heated hose on my camping CPAP though my girlfriend is

polyborus
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Re: power draw difference in Resmed s9

Post by polyborus » Thu Jan 26, 2023 9:53 am

To lyrinryan: Thank you ever so much for your detailed response. This is exactly the sort of thing I was hoping for when I posted here. I'm currently buried in snow , but will soon shovel my way out to the van, retrieve my camping CPAP, unearth my voltmeter and have a look. Will relay the info to my friend as well (currently camping)..her husband brings a huge toolbox even to the boonies (the benefit of a towed set-up)

as10fh
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Re: power draw difference in Resmed s9

Post by as10fh » Thu Jan 26, 2023 10:54 am

polyborus wrote:
Thu Jan 26, 2023 9:42 am
I'm not quite sure I understand your suggestion. Could you clarify?
I don't have a S9 but with the AirSense 10 the temperature set with the heated hose is the maximum temperature. If the ambient temperature is high enough the hose is not heated at all. The humidifier is a much stronger heat source than the hose. You said your girlfriend has the hose temperature set to about 20°C. Which is not that much and can easily be accomplished by just the humidifier on its own. If you tell the machine that it should not be over 20°C there is only one option: less power or heat to the humidifier.

Just use a heated hose with your machine and those settings and your girlfriend should use a normal hose. Than just compare the power drainage and you actually know if that is indeed the case. That simple.

polyborus
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Re: power draw difference in Resmed s9

Post by polyborus » Thu Jan 26, 2023 11:18 am

Thanks as10fh. I have an airsense 10 w/ heated hose for home use. Not sure what you mean that the "temperature set with the heated hose is the maximum temperature". When I go to dial in my temp on that CPAP I see options through a large temperature range. I usually do about 68 degrees in a 55 degree bedroom....I mean, this is an aside from my Resmed s9 (camping CPAP) power draw problem (no heated hose for me on that one), but I'm always interested in learning about CPAP use in general.