Resmed S8 and Battery Power

[5aces]

Inverter type Products:
Modified sine wave -
150 watt
• S6 • AutoSet CS™ 2/
VPAP™ Adapt SV
• AutoSet T
• C-Series Tango™ • S7 Series • S8™ series
• S8™ II series • VPAP™ III series • VPAP™ Auto
• VPAP™ Malibu • VPAP™ series.

It is not that confusing,where does it say not to use the modified inverter,other than if you are going to attatch the ResMed Humidaire3i or 4i?

I own this unit and it works...save yourself a few $$$

[rise&shiner]

I called up Resmed and asked them where to go for a battery for the Resmed S8 and they said to go to Battery Power Solution online. That they have the correct one to run our equipment. I think they also said with the humdifier as well. I haven't gone to the website yet so let me know what you think.

[5aces]

Here are two CPAP user consumer reviews from the CanadianTire website regarding the PowerBox 800A 600W:

1//---Use with CPAP for 2 nights Date: May 28, 2009

"I have sleep apnea so I am a CPAP user. I have used the Eliminator Power Box 800 many times for 2 nights in a row with a Remstar Auto at 16 lbs pressure. It did deliver easily 18 hrs of continuous use without humidifier for each weekend .

Great product for camping!

It also can remain on the charge for ever without over charging. I recommend it to you!"

2//--Camping with a CPAP Machine Date: October 28, 2008

"I have Sleep Apnea, and use a CPAP machine at night. This battery system gave me power for the CPAP machine for two nights camping without having to recharge.

I waited until the Powerbox 800 came on sale to buy it. It appears to come on sale regularly.

The one drawback is that it is heavy. It is fine for a standing camp, but would not be useful for a mobile camp. That said, the CPAP machine would be awfully bulky for a mobile camp anyway!

In looking for a battery system for my CPAP machine, I had to write to the manufacturer, and get the technical specs for the machine and compare them to the specs for the battery system. The manufacturer was very helpful and recommended the Powerbox 800 for my ResMed S7 Elite, without humidifier. This review hopefully saves someone else that trouble. The battery system worked GREAT!

There is also a solar charger, available separately, that will recharge the unit using the AC charger input, for longer camps."

Anyway,this product is out there if you choose,I really have nothing more to add,there it is...

[jnk]

Bill, 5aces, and other experts:

So let's say I buy one.

If I plug the AC plug from my VPAP Auto into it but leave the humidifier attached for passive humidification and accidentally turn the humifier on, would that fry the humifier? If so, then I guess I should only plug my VPAP Auto's AC plug into it if I disconnect the humidifier completely, right? Or am I confused?

Is that a deep-cycle battery? How many amp-hours is it? How many times can it be used and how long will it last?

Sorry I am so dumb when it comes to this stuff. I really like the idea of $150 instead of $300, so this has really got me curious. But my brain gets all twisted up. It all scares me because of statements like this one from cpap.com:

"Do not run this machine on a regular DC to AC inverter."--https://www.cpap.com/cpap-machine/resme ... chine.html

Why would cpap.com make a statement like that? Does that statment only apply to using the machine with the humidifier, or something?

At first I read this post to mean that the humifier could be attached when using the regular AC plug with this battery, but I think that would not be a good idea right?:

. . . Confirmed safe to use with a ResMed cpap by ResMed,just use the regular plug.
Also,it has a pair of booster cables to jump start your car,a digital power output display,AM/FM Radio with Alarm Clock,emergency light and can be hooked to another battery for longer run time.
I purchased this unit on sale at Canadian Tire for $149.99
More than enough to run your cpap for a few nights.
(more limited run time with humidifier,of course)

[billbolton]

If so, then I guess I should only plug my VPAP Auto's AC plug into it if I disconnect the humidifier completely, right?

If you run off 12V DC, there's simply no way you can accidently turn the AC humidifier on.

the humidifier could be attached when using the regular AC plug with this battery, but I think that would not be a good idea right?

Correct, that would be a BAD idea.

Cheers,

Bill

[jnk]

. . . If you run off 12V DC, there's simply no way you can accidently turn the AC humidifier on. . . .

Running an S8 off 12V DC would require the additional purchase of a ResMed converter, though, right?

"CPAP.com Comments
"This is the only product that you should use to power the S8 machines from a DC source. . . . Other cables may fit, but will blow out the S8 power supply (no kidding, we have found out the hard way). The polarity is different from most 12 volt cables and the inverter provides needed power smoothing." --https://www.cpap.com/productpage/DC-12-Inverter.html

I read all that to mean that the battery 5aces is pointing to can be used for powering an S8 either (1) by plugging the machine into the battery using the machine's AC cord (but, importantly, WITHOUT THE HUMIDIFIER ATTACHED) or (2) by using the ResMed 12V DC converter and cord (allowing the humidifier to be used passively, if desired), which costs an additional $80.

Sorry to be a pain, I'm just trying to make sure I have this all sorted out in my head this time.

jeff

[5aces]

JNK,my experiment for you:



In this picture from last night you will see that I did in fact leave the Huimidaire H3i connected to the ResMed S8 Elite II.
The humidifier control knob was always in the 'OFF' position.
I did push the "humidifier warming" button on the S8 blower just to "see what would happen"

I then masked up,turned on the straight cpap (8 cmh2o,EPR 1) and let 'er rip for 6.25 hours with no break.

Nothing remarkable happened.
The plug on the Humidaire looked good,nothing melted.
I checked the PowerBox digital display and it was still at 70% charge.
Plenty of juice left for tonight.
So,even if you make a 'mistake' you will not fry everything up.
You're welcome.Remember those scary homemade heated cpap tubes all melted?
Not happening.



Now this is how I will proceed tonight and how you should hook your cpap up to this PowerBox when using the AC outlet.
No Humidaire 3i.Simple.
Perhaps there are other stand alone humidifiers that you could plug into the box but I haven't looked into that.
Yes,there is a 12V DC outlet on the side of the PowerBox but I opted to keep the $80 it costs for the required ResMed converter.
Easier to use a can of Nasal Mist Saline Spray than fumble around with a humidifier in the dark,if only for a couple nights.

Let's face it,we're not talking about going off the grid like SurvivorMan.
Emergency backup power,like it says.
One or two nights,maybe never...

Anyhow,I'll run the cpap until the low power warning sound comes on and report back in the other battery thread.

[bearded_two]

I had incorrectly assumed that the S8 would run directly from 12 volts. RedMed says that to run an S8 Escape from 12 volts, a ResMed DC-12 converter must be used. This is odd, because other CPAPs, such as Puritan Bennett, DeVilbiss IntelliPAP, and Respironics will operate directly from 12 VDC.

[swknight]

Maybe I missed it being mentioned but have you considered just using a battery backup/UPS (something by APC perhaps)? It might give you an hour or so and the alarm would wake you up to let you know the power was out.

This is the route I plan on taking.

[jnk]

5aces,

Thanks for the experiments. You always come through for me.

I would assume that the humidifier warmup button does nothing if the humidifier knob is in the off position. My worry for frying the humidifier with your first setup is if someone were to accidentally turn that control dial, thus turning the humidifier on with a modified sine wave. For that reason, I don't think it worth the risk of trying to use the humidifier in passive mode while using the AC cord to plug everything in. But hey, that's just me. I like your second setup. My only problem is that I use autobilevel at around 15/11, which increases my juice use and my need for humidity (because of the high vent rate). I'm still thinking of going your route anyway, though, once I know what my financial situation is in a few months.

Thank you VERY much for explaining all that and linking to that product. Very helpful indeed!

jeff

[5aces]

From an old TalkAboutSleep thread:

The advantage of a UPS is that it will even out momentary losses of power, without your machine thinking it's been turned off.
Also, it gives the electronics in your machine better protection from surges.
Another advantage is that most UPS's sound an alarm when power is lost for any length of time.
Since most UPS's won't provide power for more than a *few* minutes, this will warn you to take your mask off.
If you are driven out your home,some UPS's are not that versatile in the field.
The objection is that you are paying for the complexity and comparative
high cost of a UPS for only brief relief and dubious reliability.

I think you have to choose what you want:

A power-off alarm that wakes you up?
A power supply that automatically cuts in and powers the cpap?
A power supply that also powers the huge drain of a finicky humidifier?
A back up power supply that will power your machine for a few days until the power is likely to be restored,or just a few hours?
Some people simply can not go without their humidifiers; many can if they really have to.
Some people live in areas with reliable power companies; some don't.
Its best to decide what you want and how important the humidifier really is to you during a power blackout.

@JNK:
For your humidifer, the gotcha is the heating circuitry.
Most are based on MosFets which switch on and off when the AC signals reverses.
The problem with some inverters is that the reversal is too short for the
MosFets to detect and switch in time to be switching zero current.
If this happens, you are effectively getting a mini electronic version of
the mad scientist switches with sparks arcing and the MOSFET runs hot,
which they are not designed to do.
The likely result is one busted machine, you end up with a lung full of toxic smoke and if you are really
unlucky,a fire.
By now,you know getting around this means buying a $$-PURE SINE WAVE-$$ inverter for safety.

Again http://www.xantrex.com is a leader of backup power supply,from the $139 portable power pack to the more expensive true home UPS backup systems.
I like the versatility of the PowerBox and for the price,it's hard to beat.
You could do better by just running full time off a good deep discharge battery with an auto charger and
appropriate inverter but it's an aquired look for the bedroom...

[billbolton]

Re the Resmed DC-12 and S8 flow generators.....

The DC-12 is designed to make 12V DC operation (from any possible source up to 24V DC, in any possible usage situation) as foolproof as possible, for users who have no particular skill with electrical matters.... and it works very well in doing that.

If you are absolutely sure that you know what you are doing, an S8 flow generator can be operated from a reasonably steady 12V DC power source without using a DC-12. I do that with my NiMH battery packs.

The most significant thing to be aware of is that a Resmed S8 has negative polarity (-) on the centre pin of the DC barrel connector. Since there is no standard or convention for wiring these connectors, there's a 50/50 chance that any general purpose DC connection cable may be wired incorrectly for use with an S8.

Cheers,

Bill

[bearded_two]

Thanks for the information about the DC-12. I would say that there is a very great chance that a 12 V power plug will be wired backward for a ResMed, almost all of the DC coaxial connectors that I have seen have a positive center pin.

[jnk]

. . . If you are absolutely sure that you know what you are doing . . .

I have no idea what that would even feel like.

[LyleK1]

"The most significant thing to be aware of is that a Resmed S8 has negative polarity (-) on the centre pin of the DC barrel connector. Since there is no standard or convention for wiring these connectors, there's a 50/50 chance that any general purpose DC connection cable may be wired incorrectly for use with an S8."

Now, I'm confused!
I talked to the business I purchased my Resmed S8 Autoset II from and he said the center pin is positive!
Any chance of some clarification? I'm fine with buying a regular 12 volt set-up and I have defined 12 volt power source (on my boat) but who do I believe!!?
I can wire the the pin either way by changing the wires attached to the plug.
Or am I better off buying the $80 DC converter and being able to use the 12 volt plug for charging other devices when I'm not sleeping?