Choosing a Battery

[palerider]

Just wondered if anyone has tried the .....

There's not a chance that will run your AS 10 (with humidifier and heated hose) all night.

You've estimated your nightly requirements to be 19 Ah without Humidifier and H.H. and 46 Ah with.

That power station's capacity is 13.8 Ah

Pretty much, bit "Ah" is meaningless unless you also spec a *voltage*, then multiply the Ah by voltage to get watthours, which is how much power, thus usage, you can get out of a thing.

It's clear that you, DS know this, but mcanoehead doesn't, so I'll lay it out.

Marketeers, whose job is to lie to you in order to separate you from your money are having a field day with these lithium battery banks.

First, they state capacity in thousands of thousandths,, because 45,000 of something sounds so much more impressive compared to 45. So this piece of rubbish is 45Ah of... something... But, what?

The other misleading thing they do is quote that Ah at the lithium battery nominal voltage, or 3.6 volts. So, you have to take the 45 and multiply it by 3.6, which comes out to 162 watthours.

Watthours is the *only way* to properly compare power banks that use different battery chemistry.

Cpap battery usage Ah is specified at *lead acid* voltages, or 12.6, so for example, a 35Ah scooter battery provides 442 watthours of power.

Beware the deception of marketing wank.

The piece of junk posted by canoehead is further bad because it has an *inverter* in it, which is very inefficient (and adds weight), and thus wasteful of battery power. For maximum life the cpap needs to run off 12 volts directly, with the appropriate 12 volt cord.

Also, maybe mr canoehead won't need humidity in the great outdoors, which would extend runtime considerably.

[Dog Slobber]

Just wondered if anyone has tried the .....

There's not a chance that will run your AS 10 (with humidifier and heated hose) all night.

You've estimated your nightly requirements to be 19 Ah without Humidifier and H.H. and 46 Ah with.

That power station's capacity is 13.8 Ah

Pretty much, bit "Ah" is meaningless unless you also spec a *voltage*, then multiply the Ah by voltage to get watthours, which is how much power, thus usage, you can get out of a thing.

It's clear that you, DS know this, but mcanoehead doesn't, so I'll lay it out.

You do bring up a good point though, when ever posting Ah, one should also reference the voltage used to calculate the Amp hours.

Add to that, I get lazy and use 12v instead of the 12.6v, that probably better reflects the actual voltage.

The piece of junk posted by canoehead is further bad because it has an *inverter* in it, which is very inefficient (and adds weight), and thus wasteful of battery power. For maximum life the cpap needs to run off 12 volts directly, with the appropriate 12 volt cord.

Probably also worth pointing out to him, that to run off battery, one should be using the DC-to-DC converter, and *NOT* the AC converter plugged into an inverter.

[mrCanoehead]

Understood. Very grateful to you for explaining that the capacities of these products is referenced to a lithium cell voltage. I was trying to figure out why it weighed so little.

I am going to make my own battery. Any idea of the best number and configuration of Samsung 18650 batteries, to achieve a) 20 and b) 50 Ah referenced to 12 V? I can't be the first person who's attempting this. I am thinking of making the battery voltage as close to 24 V as I can, to minimize losses in the Resmed DC-DC converter.

[palerider]

Look into lifepo battery cells (I think I got that right).

They're more expensive, but with better voltages,and less explody compared to the li-ion cells.

[Dog Slobber]

Understood. Very grateful to you for explaining that the capacities of these products is referenced to a lithium cell voltage. I was trying to figure out why it weighed so little.

I am going to make my own battery. Any idea of the best number and configuration of Samsung 18650 batteries, to achieve a) 20 and b) 50 Ah referenced to 12 V? I can't be the first person who's attempting this. I am thinking of making the battery voltage as close to 24 V as I can, to minimize losses in the Resmed DC-DC converter.

Here's a topic where the creator built a CPAP power station from 18650 cells.

A lot of good information in there.

viewtopic/t176763/Homemade-Resmed-A10-c ... ttery.html

[mrCanoehead]

I tried a 45 Ah deep cycle 12V battery with the resmed converter, worked all night and charged with my 15 A charger in less than a half hour. I don't think it discharged very deeply. I was running the AS 10 around 10 cm of water pressure, climate line hose, humidifier set to "1".

I am going to try to get a logging clamp ammeter and see what the true Ah requirement is, in my case.

[mrCanoehead]

Here's a topic where the creator built a CPAP power station from 18650 cells.

A lot of good information in there.

viewtopic/t176763/Homemade-Resmed-A10-c ... ttery.html

This is gold, Jerry! Thanks for fishing it up for me!

[Air Jordan]

My Backup Battery Setup
Components of my current home setup copied from a recent post, with a few edits:
UPDATED 5/17/2018

Is there a current update?

I'm wanting something very simple for an occasional one-night power outage. My machine is a ResMed AirSense 10 AutoSet and the humidifier is not a firm requirement. Currently, I am living in the city in a small third-floor walkup that was built around 1910 - closet space nearly non-existent, and storage space, in general, is very tight.

The landlord's daughter and her family live on the first two floors. The daughter sees everything that gets delivered to me. If she would see what looks like a car battery and battery box being delivered, she might unhinge.

[palerider]

My Backup Battery Setup
Components of my current home setup copied from a recent post, with a few edits:
UPDATED 5/17/2018

Is there a current update?

I'm wanting something very simple for an occasional one-night power outage. My machine is a ResMed AirSense 10 AutoSet and the humidifier is not a firm requirement. Currently, I am living in the city in a small third-floor walkup that was built around 1910 - closet space nearly non-existent, and storage space, in general, is very tight.

The landlord's daughter and her family live on the first two floors. The daughter sees everything that gets delivered to me. If she would see what looks like a car battery and battery box being delivered, she might unhinge.

Battery technology doesn't change rapidly.

A lead acid scooter battery is still the most economical backup power source.

[zonker]

My Backup Battery Setup
Components of my current home setup copied from a recent post, with a few edits:
UPDATED 5/17/2018

Is there a current update?

I'm wanting something very simple for an occasional one-night power outage. My machine is a ResMed AirSense 10 AutoSet and the humidifier is not a firm requirement. Currently, I am living in the city in a small third-floor walkup that was built around 1910 - closet space nearly non-existent, and storage space, in general, is very tight.

The landlord's daughter and her family live on the first two floors. The daughter sees everything that gets delivered to me. If she would see what looks like a car battery and battery box being delivered, she might unhinge.

Battery technology doesn't change rapidly.

A lead acid scooter battery is still the most economical backup power source.

would this be a good example?-

https://www.amazon.com/Mighty-Max-Batte ... B00K9Q3D18

[SleepGeek]

You have to get the right DC power cord for your cpap, first. cpap.com has many selections.

I keep mine plugged into a car jumper battery and slept right thru a power outage nite before. When I woke up I knew something happened but I was not disturbed,

I know from experience that I wake up when the cpap shuts off but then what you gonna do? Can't watch TV? So sleep right thru.

[palerider]

My Backup Battery Setup
Components of my current home setup copied from a recent post, with a few edits:
UPDATED 5/17/2018

Is there a current update?

I'm wanting something very simple for an occasional one-night power outage. My machine is a ResMed AirSense 10 AutoSet and the humidifier is not a firm requirement. Currently, I am living in the city in a small third-floor walkup that was built around 1910 - closet space nearly non-existent, and storage space, in general, is very tight.

The landlord's daughter and her family live on the first two floors. The daughter sees everything that gets delivered to me. If she would see what looks like a car battery and battery box being delivered, she might unhinge.

Battery technology doesn't change rapidly.

A lead acid scooter battery is still the most economical backup power source.

would this be a good example?-

https://www.amazon.com/Mighty-Max-Batte ... B00K9Q3D18

It *could* but having three small ones is a little more complicated, wiring wise, than one larger, the 35ah are what I've usually seen recommended, like this: https://smile.amazon.com/Battery-Scoote ... 678&sr=8-1 (that is a two pack, but it's the first listing I saw).

(that $134 would give you something like 10 nights (without humidity)) a tiny fraction of what lithium power packs would cost.

[zonker]

It *could* but having three small ones is a little more complicated, wiring wise, than one larger, the 35ah are what I've usually seen recommended, like this: https://smile.amazon.com/Battery-Scoote ... 678&sr=8-1 (that is a two pack, but it's the first listing I saw).

(that $134 would give you something like 10 nights (without humidity)) a tiny fraction of what lithium power packs would cost.

my friend, could you take the time to find one (or more, if you want) that you would recommend?

air jordan did a good thing and actually sought the post explaining batteries. but damn, this is a long thread!

but i would like to have a link to hand to let people know who come in and ask the question. it doesn't happen all the time, but often enough. i'm here more often than you are and would like to be able to help a person out (with all due credit to you of course) without forcing them to go through this thread.

thank you!

[SleepGeek]

IMO the easiest way is to call cpap.com so they can help you get the *correct* DC power cord to fit your CPAP.
From their web page...
Need Help? Call 1.800.356.5221
M-F 8AM-8PM|Sa 8AM-5PM (CST)

Then with that cord you can simply plug into *any DC outlet* (aka cigarette lighter* plug)* and if you already have a car jump starter you are golden.

IF not you can order one online from Amazon, Sears, Walmart, etc. or drive to Walmart, Target, or any auto parts store to get your car jump starter.

iirc - Sears has one that has an 18ah battery. That will get you started and is easily portable to take camping or just use wherever you normally sleep.
IF you need longer run times before charging buy more than one but I would suggest starting with one to see how much time you get.
IF/when you have more than one you can charge one while using another.

Keep in mind any battery you buy *OFF The Shelf* you should read the directions and *CHARGE* Before use - you have No Idea just how low it has been sitting on the shelf waiting for you to come along.

This is the most plug*N*play way I can think of for anyone who doesn't understand how to wire their own battery.

It is safe, portable, and is not all that expensive. Prob less costly than many other ways to accomplish the same thing.

1 Other note for those thinking about using a computer UPS - every UPS I've seen has alarms that sound when the power goes out.
Sleeping without any battery backup you will wake-up when the cpap turns off - I know I do.
Using a car jump start battery (or any battery) you can sleep right thru any power interruption, period.
I use a jump start battery and just keep it plugged in.
It has been flawless for over a year now.

HTH

[Pugsy]

Attention ResMed users....ResMed machines run off 24 volt...not 12 volt so you all need the converter as well as any special plug to attach to a battery. There is no way around it.
So Respironics users...when you advise a ResMed user what connections that they might need....don't forget that converter thingy...and it costs around $80 or so and this is one time I would NOT go with aftermarket because I have heard too many times that aftermarket didn't work so great.