powering up ResMed S9 via a car battery

[Gabe in Jax]

I would like to power up my ResMed S9 bipap with a car battery via an adapter that uses alligator clips. I will not have any AC power nor a vehicle that will take a lighter adaptor. I would like to get the authorized part from ResMed but they tell me they cannot sell directly to patients. If anyone has any information that would be most helpful. Thanks much.

[Krelvin]

This link is a little old, but a lot of info there related to using a battery with an S9

https://sleep.tnet.com/resources/batter ... collection

[ChicagoGranny]

Gabe in Jax

This is a good thread to read and post questions - viewtopic/t114012/Choosing-a-Battery.html

CapnLoki is our resident expert on batteries.

[CapnLoki]

I would like to power up my ResMed S9 bipap with a car battery via an adapter that uses alligator clips. I will not have any AC power nor a vehicle that will take a lighter adaptor. I would like to get the authorized part from ResMed but they tell me they cannot sell directly to patients. If anyone has any information that would be most helpful. Thanks much.

First you need a ResMed 12/24 volt converter to run any S9 from a 12V battery. DO NOT use a car battery unless its a last resort; get a proper deep cycle battery. Don't use alligator clips, get a cable with the socket. The converter can be found on cpap.com, everything else on Amazon.

refer to:
viewtopic/t114012/Choosing-a-Battery.html

[AirPump]

Thanks for the tips CapnLoki!

Is it not the case that one can get much much more life out of a car battery by just using the CPAP and leaving the Hi5 humidifier in the bag? The CPAP itself doesn't draw that much power. It's the heater that sucks the juice.
And of course, there's always the more portable CPAP batteries that sell for about $325 out there, purportedly good for two nights per charge. Have you had success with those?

[Uncle_Bob]

I think this is what you maybe looking for

https://www.cpap.com/productpage/DC-Con ... hines.html

[palerider]

Is it not the case that one can get much much more life out of a car battery

but, it's bad for the battery, they're not designed for that kind of usage.

[Gabe in Jax]

Thanks for all the responses, I will inquire about the deep cycle battery but not sure that it would be available in Africa. My S9 is about six years old and the heater doesn't work, which is ok with me since we live in FL and keep our house at a somewhat high humidity level. What is the problem with using a regular car battery And alligator clip? Are we talking about potential harm to the S9 or the danger of a battery explosion?

[palerider]

Thanks for all the responses, I will inquire about the deep cycle battery but not sure that it would be available in Africa. My S9 is about six years old and the heater doesn't work, which is ok with me since we live in FL and keep our house at a somewhat high humidity level. What is the problem with using a regular car battery And alligator clip? Are we talking about potential harm to the S9 or the danger of a battery explosion?

extended discharge of a starting battery greatly reduces it's life.

[CapnLoki]

Thanks for the tips CapnLoki!

Is it not the case that one can get much much more life out of a car battery by just using the CPAP and leaving the Hi5 humidifier in the bag? The CPAP itself doesn't draw that much power. It's the heater that sucks the juice.
And of course, there's always the more portable CPAP batteries that sell for about $325 out there, purportedly good for two nights per charge. Have you had success with those?

Its quite true that the pump alone should be well under 10 Amp-hours, which doesn't seriously deplete a new car battery, which is rated at 65 to 100 Amp-hours. However, why lug around a 70 pound battery filled with corrosive acid, when you can get the same useful power from a much lighter, cheaper battery that's designed to run upside down? And if anyone is thinking of running of their car's starting battery, remember that these are best case numbers, for a new battery. An old battery run down 10 AH (about the same as a door left open) may not be able to start the car on a cold morning.

As for batteries that cost $325, it may be reassuring to some that it has a Resmed logo, I'd rather just carry a few extra pound and get the same power for $20. Even in the lithium world there are options close to $100.

[CapnLoki]

Thanks for all the responses, I will inquire about the deep cycle battery but not sure that it would be available in Africa.

Ah-hah! You want to buy , and presumably use the battery in Africa. You might have mentioned that first. And Africa, being the 2nd largest continent, covers a lot of ground, so exactly where you're going may have a bearing on the conversation.

New AGM deep cycle batteries will be available in any city because they are used to power scooters and wheelchairs, as well as a variety of larger battery packs such as jump starters and uninterruptible power supplies. And old style deep cycles are used to power golf carts and floor buffers, as well as all sorts of battery backup systems, such as emergency lights in any building. Obviously car batteries are ubiquitous, but deep cycles should be available in any larger city.

What is the problem with using a regular car battery And alligator clip? Are we talking about potential harm to the S9 or the danger of a battery explosion?

The S9 should be safe, especially if there's a fuse. And explosions are most commonly from high power chargers. One problem with alligator clips is that they fall off. If I was using them, they would probably fall off on a daily basis.

EDIT: Actually, alligator clips could be a problem if put on reversed. Although most devices should be protected, there's certainly no guarantee.

But the bigger issue is that using them implies that the battery posts are unprotected, meaning that they can be easily shorted out. A large battery holds roughly one kilowatt-hour, or enough run a normal household outlet full power for 30 minutes. If shorted out (by a metal tool, or tool box, etc) it would dump all that power in a few seconds. In other words, total meltdown! Full size batteries should be protected, either in a box or at the very least, with terminal post boots.

And what is the problem with permanently mounting a small cable on the battery? The system I recommend uses a cable (supplied by the charger company, but available for a few bucks) that can plug into the charger or a cigarette socket (another cable for a few bucks). Leave the alligator clips for the amateurs.

BTW, car battery accidents send several thousand people to the emergency room every year in the US. Charging issues are the biggest culprit, followed closely by jump starting. Alligator clips are usually involved!