ResMed S9 and external power/UPS supply

[Physician]

Twice we had a power outage and waking up to the smothering sensation of no CPAP is not an idea of fun. One solution is a marine battery (33 amp = $90, 80 amp = $200) attached in parallel to the lead-acid battery inside the UPS device, BUT

1. It's inefficient to have the ResMed transformer plugged into the UPS because of the voltage conversion of 12V --> 120V ---> ResMed.

2. Most of the UPS units "beep" when the home electricity goes off. APC's units can be software programmed to not do this.

3. Home UPS units have not been certified for medical/hospital use.

4. The UPS unit may not have the capability of recharging BOTH the internal lead-acid battery and an external battery attached in parallel.

Tech support for two UPS companies alleges that their 1500 model UPS will run the ResMed unit for only 30 minutes because it is 900 watts.

QUESTIONS: Someone please explain the easiest and most understandable way to have a back-up system so that if/when the house electricity goes off my S9 will contunue uninterrupted for seven hours use.

Does any company make a non-interruptible quiet power supply for CPAPs ? Quiet fan, no beeping, and lasts at least six hours would all be nice ?

Is there a special cord to bypass the brick transformer and plug directly into the S9 so that a lower voltage can be used for more efficiency ?

[chunkyfrog]

1: I read the bottom of the brick on my S9 Elite:
--the voltage to the machine is 24 volts
--The wattage drawn by the whole business is 90, not 900 (just a typo, I'm sure--nobody's perfect)
2: Looks like the 24V plug is proprietary; If you find a source, let us know.
3: CPAP.com has Resmed's new 12v to 120V inverter in the New products section--for $44!--I might get a couple.
4: IMHO, energy efficiency is secondary to need in an emergency use situation.
You breathe--even if it wastes electricity--if Resmed cared; they wouldn't make it so difficult for us.

[Physician]

1: I read the bottom of the brick on my S9 Elite:
--the voltage to the machine is 24 volts
--The wattage drawn by the whole business is 90, not 900 (just a typo, I'm sure--nobody's perfect)
2: Looks like the 24V plug is proprietary; If you find a source, let us know.
3: CPAP.com has Resmed's new 12v to 120V inverter in the New products section--for $44!--I might get a couple.
4: IMHO, energy efficiency is secondary to need in an emergency use situation.
You breathe--even if it wastes electricity--if Resmed cared; they wouldn't make it so difficult for us.

Thank you, Chunky. But that is only for pure use with a 12V DC battery. How could it possibly interface with anything to give aa seamlessly functional S9 if the house power is interrupted ?

Here is the inverter link: https://www.cpap.com/productpage/resmed ... erter.html

Some company must make a non-interrupt type back up unit for continuous use of a CPAP for at least six hours in the event of a power failure to the home. Anyone know ?????

[cortez356]

As for finding a special cord: Why? Where are you going to find a lower voltage for your unit?? Using an inverter in your house would be a real pain. You need a 12 volt battery that is charged and ready to go. Are you going to keep a lead acid battery in your bedroom?

Bob

[billbolton]

1. It's inefficient to have the ResMed transformer plugged into the UPS because of the voltage conversion of 12V --> 120V ---> ResMed.

The end-to-end efficency loss with a contemporary and appropriately sized inverter plus the S9 switch mode power supply is about 10%, all up. For a fixed location solution, that is insignificant.

[billbolton]

3: CPAP.com has Resmed's new 12v to 120V inverter in the New products section--for $44

Its manufactured by Tripp-lite (http://www.tripplite.com/) and is their standard PV150 model (http://www.tripplite.com/en/products/mo ... delID=2553), so the CPAP.com web site is wrong on it being "manfactured by Resmed".

However, it seems to be appropriately fit for the purpose of use with an S9.

Cheers,

Bill

[reitzell]

I seriously over killed this problem.

I think a UPS provides backup power but doesn’t increase availability.

I used a APC7750 switch and with it you can dual source power.

House power ->switch->cpap.
House power->charger->battery->inverter->switch->cpap

I use the aims 300watt pure sine wave inverter. It needs to be clean power for the switch because some PMW inverters don’t produce clean enough power for the switch to ever consider it as a source. This also works with the idea I have no idea if a future device will or will not require clean power so I just wanted to go with clean power.

I used a Optima blue AGM 34M deep cycle battery and put that in a battery case that straps closed. because:
Doesn’t vent
Long life
Low internal resistance
Doesn’t spill
Thumb screw terminal on the top easy to attach
Deep cycle
Etc…

The charger I use is:
CTEK Multi US 7002 12V Battery Charger
(CTEK sells a bunch of stuff that will make connecting all of this up easy.)

The charger is overkill too. You could easily go with the next one down… I set it to supply at night and turn it off during the day. If you have to recharge it, it has a "Optima" charge which is faster @ 15.8 volts up to 7amps.

I test it at least once a month when I clean it I have it blow everything dry. I let it run off the inverter for 4 hours… overkill for just drying but also testing the backup power/inverter/switch…etc.. It could easily do 8 hours.

Also if the power goes off, a light under my bed comes on.. a very subtle indicator that the power has gone off but I would only notice if the power is off and I am awake.

Also plugged into the switch:
A light that cuts on if I lose power.
An alarm if I lose power.

I built this for a friend and this weekend he lost power in the middle of the night and didn’t know till he tried to make coffee.

From a “CPAP”systems thinking perspective, it’s overkill and pricey.

This is not "hospital" grade but you want to talk pricey... look into some of that...good lord.

I'm not saying do this. This is just what I did and it only proves I need medication.

Good luck,
Rob

[Physician]

3: CPAP.com has Resmed's new 12v to 120V inverter in the New products section--for $44

Its manufactured by Tripp-lite (http://www.tripplite.com/) and is their standard PV150 model (http://www.tripplite.com/en/products/mo ... delID=2553), so the CPAP.com web site is wrong on it being "manfactured by Resmed".

However, it seems to be appropriately fit for the purpose of use with an S9.

Cheers,

Bill

Geeez. Not this is too confusing for my feeble mind. I don't want to have batteries go to an inverter to run my S9. Ideally I'd like a non-interruptible power array whereby if and when the house electrcity goes off then at least six hours of power will go to the S9.

There seems to be two ways to do this:

1. A switching device which uses house AC, but then in the event of a power failure, the switching device uses the DC batteries and an inverter to supply up to six hours

OR

2. Use a standard UPS as used for computers and monitors, but attach suffucuent batteries in parallel to the internal battrey circuit of the UPS, so that at least six hours of use can be obtained.


At the ResMed site under travel, an S9 Autoset with full time EPR of three and no humidifier and with a pressure of 15 requires 0.98 to 1.14 amps, thus six amp hours. As of now, ResMed does not make a NON-interruptible supply.

I'll contact some electrical geniuses, but perhaps there are some here who have the solution #1 above - - - - a switching device. My concern is altering a UPS by adding external battery(ies) as the changing circuit would not handle the extra draw of the additional battery(ies).

[dtsm]

Topic discussed many times in the past, do a search on backup power. Here's a thread to review: viewtopic/t57663/viewtopic.php?p=517165#p517165

If you want to use humidifier, try JohnBFisher's in depth step-by-step here: viewtopic.php?f=1&t=49115&st=0&sk=t&sd= ... ery+backup

If you don't use humidifier, the duracell 600 will work just fine. I've used it twice with my S8 for 8 solid hours. Can be purchased from amazon.com delivered for under $150 -- http://www.amazon.com/Duracell-DPP-600H ... 287&sr=8-1

[BanjoPaterson]

One solution I was thinking of was that I don't necessarily want a UPS, but I want to know when the power's off so I'm not breathing CO2 into my mask. So instead of a UPS, I was thinking of getting something that would generate an alarm when the power cut off so I can take the mask off. That, IMHO, would be the simplest, cost effective solution (provided ones power isn't cut off every 2nd day or something daft like that - in which case I WOULD want a UPS).

[dtsm]

but I want to know when the power's off so I'm not breathing CO2 into my mask.

Masks are designed so that won't occur. In most cases, you'll wake up within a minute or so. You either switch to backup power [eg duracell 600] or just take off your mask and roll over back to sleep.

[Physician]

Topic discussed many times in the past, do a search on backup power. Here's a thread to review: viewtopic/t57663/viewtopic.php?p=517165#p517165

If you want to use humidifier, try JohnBFisher's in depth step-by-step here: viewtopic.php?f=1&t=49115&st=0&sk=t&sd= ... ery+backup

If you don't use humidifier, the duracell 600 will work just fine. I've used it twice with my S8 for 8 solid hours. Can be purchased from amazon.com delivered for under $150 -- http://www.amazon.com/Duracell-DPP-600H ... 287&sr=8-1

Maybe discussed before, but not completely resolved. Thank you for that link, but those Duracell specs (copied below) disclose that the unit is only 480 watts continuous @ $140.

The UPS I just purchased (Cyberpower CP1500AVRT for $120) is listed as 900 watts. So for $20 less the CyberPower has almost double the "run time". Is this not correct ?



CYBERPOWER 900 Watts: http://www.cyberpowersystems.com/produc ... 0AVRT.html

Is the Duracell still a better choice than the CyberPower ? if so, why ?

Cyberpower UPS 900 watts $120
Duracell 480 watts $140




Product Features of the Duracell
Contains three three-pronged AC outlets (480-watt continuous / 600-watt peak) to power multiple devices, appliances and tools
Contains one DC outlet which can be used to both power devices and recharge the HD600 unit
Built-in 600-watt power inverter, 5-watt flashlight, overload/over-temperature protection and reverse polarity detection
Sealed, non-spillable 28 amp hour AGM battery and detachable alligator clamps for jump-starting cars (up to 8-cylinder); refer to users' manual for charging instructions
Built-in AM/FM radio and digital alarm clock

[jazzer4]

I've been reading on here about back up power for a year and still have not initiated anything because it's all so complicated.

I wish Resmed would just work on this. Come on Resmed step up to the plate.....make it easy. (for dummies like me)

[idamtnboy]

There seems to be two ways to do this:
1. A switching device which uses house AC, but then in the event of a power failure, the switching device uses the DC batteries and an inverter to supply up to six hours
OR
2. Use a standard UPS as used for computers and monitors, but attach suffucuent batteries in parallel to the internal battrey circuit of the UPS, so that at least six hours of use can be obtained.

#2 is exactly what you want in #1.

A UPS, mine at least which is ~10 years old, bypasses the battery when house power is available. The battery is in 'float' mode being kept charged but no current is being drawn from it.

From your later post.

but those Duracell specs (copied below) disclose that the unit is only 480 watts continuous @ $140.

The UPS I just purchased (Cyberpower CP1500AVRT for $120) is listed as 900 watts. So for $20 less the CyberPower has almost double the "run time". Is this not correct ?

No, it is not. The wattage rating only tells you how much instantaneous power the unit will put out. It says nothing about how long it will put it out. The battery size/capacity and the connected load controls that.

If I were looking to do what you want I would buy a UPS that can handle at least 120 watts, since the max draw of the S9 is 90. 90 is only 3/4 of 120 so that gives a good margin of safety for long term, i.e. several hours, running on battery power. I would then remove the UPS battery and find some other use for it. Connect the battery wires to a 12v deep cycle battery like you mention in your first post. Getting rid of the internal battery will avoid any recharging and monitoring conflicts that might be caused by two dissimilar batteries in parallel. The UPS will keep the big battery charged when house power is on. It is possible that a small UPS such as 120 watt, or even a 500 watt, would take days to recharge a discharged deep cycle marine battery. The current draw might even be great enough to overload the UPS. The only way to know for sure is try it. I don't think there will be any danger of frying the UPS by doing so because it will have circuit breakers in it. If by chance you ever run the big battery down completely you may need to recharge it with a regular car battery charger.

Since you already have the 900 watt UPS just disconnect the battery inside it and connect it to a marine battery. If you don't have a marine battery yet use a battery from of your cars and run the S9 off the UPS with the UPS unplugged from the wall outlet. See what happens after you've run the car battery down and plug the UPS back in.

[jlk]

Idamtnboy quote;
{"If I were looking to do what you want I would buy a UPS that can handle at least 120 watts, since the max draw of the S9 is 90. 90 is only 3/4 of 120 so that gives a good margin of safety for long term, i.e. several hours, running on battery power. I would then remove the UPS battery and find some other use for it. Connect the battery wires to a 12v deep cycle battery like you mention in your first post. Getting rid of the internal battery will avoid any recharging and monitoring conflicts that might be caused by two dissimilar batteries in parallel. The UPS will keep the big battery charged when house power is on."}

Excellent idea! I recently tossed in the garbage a ups due to battery failure, the replacement battery was more than I originally paid for the whole unit. I didn't even keep the cord. (man joke) For around $300 you can get that set-up with a safe gel type battery, nothing made for medical use will come close to that price. We don't lose power very often or I would own that set-up. john