Yet Another Battery Q - Resmed Autoset 10

I live in an earthquake-prone area and need a way to run my CPAP even if power grid goes down for a week or two.
According to my CPAP manual, my CPAP needs 24V, DC.
I know battery questions have been done to death, but I'm confused by all the variables.
I need a portable rechargable battery (why do they call them generators?) like this:
https://www.amazon.com/Aeiusny-Portable ... 01IW408R0/

Does anyone use a unit like this?
ResMed has a cute little rechargeable battery pack, but it costs as much as the CPAP unit itself did! Anyway, I need something I can recharge using solar panels in a pinch.

I bought the Resmed DC power adapter from our sponsor. It uses 12 volts. I them bought the 100 watt solar panel kit and 35 watt hour battery from Harbor Freight. Somebody here estimated usage at 5 watt hours per night if you turn off the humidifier and heated hose.
I used mine for 2nights as a test and the battery worked well. I will put it back on charge this weekend.
I got an email this week saying the solar panels are on sale.

dvejr wrote:I live in an earthquake-prone area and need a way to run my CPAP even if power grid goes down for a week or two.
According to my CPAP manual, my CPAP needs 24V, DC.
I know battery questions have been done to death, but I'm confused by all the variables.
I need a portable rechargable battery (why do they call them generators?) like this:
https://www.amazon.com/Aeiusny-Portable ... 01IW408R0/

Does anyone use a unit like this?
ResMed has a cute little rechargeable battery pack, but it costs as much as the CPAP unit itself did! Anyway, I need something I can recharge using solar panels in a pinch.

Here's all you need to know, lots of reading, but why start from scratch when it's all been done by others?:

viewtopic.php?p=449334#p449334

viewtopic.php?t=9682

This one is the most on point for your situation: viewtopic.php?f=1&t=156100&start=0

https://www.ebay.com/itm/DC-Tip-7-4x5-0 ... 1438.l2649

https://www.ebay.com/itm/New-Waterproof ... 1438.l2649

https://www.ebay.com/itm/LM2596-Buck-St ... 1438.l2649

Hi

Cap'n Loki is our resident expert on batteries. He lives off of them for a couple of months. Here is his battery setup.

viewtopic/t114012/Choosing-a-Battery.html#p1129137. The entire thread is an excellent tutorial, but for around $200~$250 it looks like it would be long term (over a week) battery solution.

-Bill

Thanks very much - a lot to digest. It is mostly 6-10 year-old info, and there are few mentions of the large modern portable lithium-ion rechargeable battery packs. I did learn enough already from the links you gave me that I'll skip the 12V DC (battery output) - to - 120V AC (from an inverter) - to - 24V DC (which can use my existing home power cord). I'll limit myself to 12V DC (battery) - to - 24V DC (buying a simple step-up transformer like this http://a.co/dG4kxw3).

As you've probably already gathered for AGM type lead acid batteries like some automotive or many/most scooter batteries, running them down below 20% capacity will shorten their lifespan, and on the other side getting them from 80% charged to 100% charged can take longer than you might expect. For these reasons I like to have extra capacity on hand.

dvejr wrote:I live in an earthquake-prone area and need a way to run my CPAP even if power grid goes down for a week or two.
According to my CPAP manual, my CPAP needs 24V, DC.
I know battery questions have been done to death, but I'm confused by all the variables.
I need a portable rechargable battery (why do they call them generators?) like this:
https://www.amazon.com/Aeiusny-Portable ... 01IW408R0/

Does anyone use a unit like this?
ResMed has a cute little rechargeable battery pack, but it costs as much as the CPAP unit itself did! Anyway, I need something I can recharge using solar panels in a pinch.

dvejr wrote:Thanks very much - a lot to digest. It is mostly 6-10 year-old info, and there are few mentions of the large modern portable lithium-ion rechargeable battery packs. I did learn enough already from the links you gave me that I'll skip the 12V DC (battery output) - to - 120V AC (from an inverter) - to - 24V DC (which can use my existing home power cord). I'll limit myself to 12V DC (battery) - to - 24V DC (buying a simple step-up transformer like this http://a.co/dG4kxw3).

OK, Good. You've discovered that a 12 to 24 volt converter is the best way to power your pump. but the converter you've listed is for a particular battery setup. You'd do better with the official ResMed converter. Its efficient and reliable, heavy duty, fused, works of a variety of voltages, and plugs into a common "cigarette lighter socket." Easily worth the few extra bucks.
https://www.cpap.com/productpage/resmed ... hines.html

Next is the choice of battery. For applications where low weight isn't needed, AGM batteries are favored. These are the sealed lead-acid batteries developed for jet fighters and now commonly used in mobility scooters, uninterruptible power supplies, and jump starters and are safe for in house use. They come in a variety of sizes from 7 amp-hours (one night) to over 100 AH (several weeks). I favor the 35 AH size, but for your application you might want to go up to 100 AH. These batteries can be charged with normal car chargers - I like the BatteryTender brand. You could easily setup several batteries to provide power for several weeks. Details of this type of system are discussed in the thread linked in my signature.

As for Lithium, there are new power packs, sometimes called "generators" that provide a fair amount of power, but at a high price. The pack you list is 288 Watt-hours, which translates to about 24 Amp-hours at 12 volts, which would run your pump for about 4 nights. This is less power than the small 35 AH AGM I recommend at $65. The lithium "generator" is $260 - for this kind of money you can setup a 100 AH system with money left for a small battey for camping. If lithium is within your budget, please feel to get one, test it out, report back! Its a bit outside my needs. Perhaps in a few years these will be a lot cheaper.

dvejr wrote:I live in an earthquake-prone area and need a way to run my CPAP even if power grid goes down for a week or two.
According to my CPAP manual, my CPAP needs 24V, DC.
I know battery questions have been done to death, but I'm confused by all the variables.
I need a portable rechargable battery (why do they call them generators?) like this:
https://www.amazon.com/Aeiusny-Portable ... 01IW408R0/

Does anyone use a unit like this?
ResMed has a cute little rechargeable battery pack, but it costs as much as the CPAP unit itself did! Anyway, I need something I can recharge using solar panels in a pinch.

I do not know how long you have lived in the L.A. area.
I lived in Hollywood for the 1987 UPLAND earthquake
Hollywood for the 1990 Whittier quake
PASADENA for the 1992 Big Bear quake
Mid-Wilshire area ( near the La Brea Tar Pits George Page Natural History Museum ) 1994 Northridge quake...I left SOUTHERN CALIFORNIA in 2009 and at no time in the 22 years that I lived there did I experience a power outage of the magnitude you are talking about.
I would suggest going to a computer superstore like Fry's or Microcenter and look at UPS systems ( Uninterruptable Power Supply). They are designed to allow businesses to power
their computer systems for specific amounts of time in the event of a power outage. They may be what you are looking foŕ.

45011ohio wrote: I would suggest going to a computer superstore like Fry's or Microcenter and look at UPS systems ( Uninterruptable Power Supply). They are designed to allow businesses to power
their computer systems for specific amounts of time in the event of a power outage. They may be what you are looking foŕ.

The affordable UPS systems usually have a 7 AH battery and are intended to be used with an inverter, which reduces the useful output to about 4 AH. This might not cover one night even without humidity running. They are best used when brief outages are expected, perhaps under half an hour, where you don't want to wake up to switch power. For anything longer, a bigger battery would be appropriate.

I agree that long outages are uncommon and are often "luck of the draw." In the last major outage in my town (storm related) half the town was out for several days, half was unaffected. This was common throughout the region. My home backup system will quite possibly never be used for that purpose.

CapnLoki wrote:

45011ohio wrote: I would suggest going to a computer superstore like Fry's or Microcenter and look at UPS systems ( Uninterruptable Power Supply). They are designed to allow businesses to power
their computer systems for specific amounts of time in the event of a power outage. They may be what you are looking foŕ.

The affordable UPS systems usually have a 7 AH battery and are intended to be used with an inverter, which reduces the useful output to about 4 AH. This might not cover one night even without humidity running. ...

The only thing I count on running for any length of time off a UPS is some network equipment, and then only for a few hours at most. Computers are set up to shut down if power goes out for more than a minute or two. If needed the CPAP will be run off a separate battery of some kind with bigger reserve.

I appreciate all the input. I have twice endured extended power outages, but both were from severe winter storms (in other locales, needless to say.) So this may be a personal problem - an earthquake related outage is unlikely, but I can all-too-easily imagine it and am inclined to prep for something that isn't going to happen. But is it really so that all those high-tension lines that fold like a house of cards in an ice storm merrily laugh at earthquakes? I'm kind of surprised that earthquakes don't destroy utility poles and pylons....