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+--- Thread: Operating CPAP with battery.... (/Thread-Operating-CPAP-with-battery)
RE: Operating CPAP with battery.... - SuperSleeper - 04-26-2013
Yep, looks like there's risks in just about any alternative power source. For me, I'm quite familiar with lead-acid battery safety, so I stick with that. "A man's got to know his limitations." My experience as a ham radio operator is what gives me a bit of confidence with lead-acid deep cycles.
I do have a cheap small gasoline generator, but I'm very reluctant to hook that up to my CPAP machine, because it has spurts & surges that are worse than my standard household current. I'd have to use a very good quality surge protector if I did that. With 12-volt lead-acid deep cycles, I have no power surge worries, it's a very stable alternative power source, as long as I unhook the battery from any charging source while using it on CPAP.
RE: Operating CPAP with battery.... - robertbuckley - 04-26-2013
I spent $240 for kit to fly with (I use a resprionics machine). Check come of the on-line Cpap stores and they have charts to show how much battery life from a charge you will get at what pressures. some notes about heated humidifiers:
"Using a heated humidifier on a 12volt battery power source will significantly reduce the amount of power provided. In most cases, usage is reduced to less than half the estimated operational time. CPAPs or BiPAPs requiring inverters reduce the power time even more.
"For optimum performance of your battery pack, plan to use your CPAP without the heated humidifier. You may also have the humidifier connected and filled with water, but without the power turned on. This changes a typical heated humidifier into a passive humidifier."
I also have seen reports that at a pressure of 10 youwill get 8+ hours, but at 15 you will get 5 hours.
RE: Operating CPAP with battery.... - Sleepster - 04-26-2013
(04-26-2013, 01:43 AM)archangle Wrote: Lithium ion batteries tend to give you more Amp hours per pound of battery.
Right, but we don't see them sold with the same high amp-hour ratings as lead acid batteries. Probably because they'd be too expensive.
RE: Operating CPAP with battery.... - Sleepster - 04-26-2013
(04-26-2013, 10:27 AM)SuperSleeper Wrote: I do have a cheap small gasoline generator, but I'm very reluctant to hook that up to my CPAP machine, because it has spurts & surges that are worse than my standard household current.
Right, but if you were running that generator (anyway) you could use it to charge the battery that you'd later use to run your CPAP machine.
RE: Operating CPAP with battery.... - Sleepster - 04-26-2013
(04-26-2013, 10:10 AM)JJJ Wrote: Those were Lenovo Thinkpads (made in China now). They never set anything on fire, but they did melt the plastic of the laptop and destroy it.
Dell had to recall a bunch of its lithium ion laptop batteries a few years ago because they were a fire hazard.
RE: Operating CPAP with battery.... - robertbuckley - 04-27-2013
Well - then there was the problem with the Boeing 787... Can we get back on track here?
RE: Operating CPAP with battery.... - archangle - 04-29-2013
(04-26-2013, 08:32 PM)Sleepster Wrote:(04-26-2013, 01:43 AM)archangle Wrote: Lithium ion batteries tend to give you more Amp hours per pound of battery.
Right, but we don't see them sold with the same high amp-hour ratings as lead acid batteries. Probably because they'd be too expensive.
A larger lithium ion battery is a bigger fire/explosion hazard because there's more flammable material to burn if it does catch on fire.
It's also more likely to catch on fire because it's harder to dissipate the heat produced. There's a double whammy because the surface area for cooling doesn't grow as fast as the volume and weight, and the distance from the innermost part of the battery is further so the heat has to travel further.
Overheating is one of the things that's most likely to cause a lithium battery to catch fire.
From what I've read, the 787 battery problems had a lot to do with the problems of a big lithium battery.
Yes, cost is probably a factor, but I suspect safety may be a bigger factor.
RE: Operating CPAP with battery.... - archangle - 04-29-2013
(04-26-2013, 10:10 AM)JJJ Wrote:(04-26-2013, 07:48 AM)SuperSleeper Wrote: In the news a couple of years ago or so that there was a rash of Lithium-ion laptop batteries starting fires. That's why I suggested that they might not be as safe as lead-acid, (assuming one takes precautions).
Those were Lenovo Thinkpads (made in China now). They never set anything on fire, but they did melt the plastic of the laptop and destroy it. In this case the problem was in the "battery" because the charging controller circuitry was inside the battery, rather than in the laptop. It was the components of the charging circuitry that failed, similar to your story.
The problem with lithium batteries (including the cost) is the shortage of lithium supply. The largest known deposits are in Chile, but their law requires earth resources to be developed only with Chilean capital. They don't have the capital, so the deposits sit there unused. China has the second largest deposits, but they haven't been able to exploit them fully either. Industrialized countries have the capital, but mostly lack the deposits. The result is that almost all lithium batteries today are manufactured / recycled in China, and they are not famous for quality control.
Lead acid batteries have problems that are just as bad. For example, it is against US federal law to take a lead acid battery on any public transportation vehicle. Why? Because the acid is not very friendly to human life. But we have been using lead acid batteries for a century and everyone understands the dangers. If the public was as familiar with the electronics in lithium batteries they might be just as safe.
Personally, if the power goes out I will power my CPAP with the generator out in my garage. That is, if I can keep from burning the house down with the gasoline.
One of the biggest and earliest examples of flaming laptops was with batteries manufactured by Sony. I think Dell laptops with Sony batteries were the brand of laptop that got the most publicity, but many manufacturer's used Sony lithium cells in their battery packs.
Here's some of many recall notices.
http://www.cpsc.gov/en/Recalls/2007/Sony-Recalls-Notebook-Computer-Batteries-Due-to-Previous-Fires/
4 million Dell laptop batteries in this recall:
http://www.nbcnews.com/id/14350403/ns/technology_and_science-tech_and_gadgets/t/dell-customers-respond-recall/#.UX8m-dd7NRQ
There was a lot of finger pointing, but the best explanation seems to be that the problem was not a quality control problem in the batteries, but a combination of the cell, the charger, and the protective circuitry in the battery.
Note: A "battery" is a collection of individual cells. A car battery is 6 cells, a laptop battery is a collection of around 6-12 cells. Technically, an AA, AAA, or D cell "battery" is not a "battery," it's a "cell."
While you definitely want the correct charger for your lithium battery, by far the most important safety measure is the protection circuitry within the battery itself. These sense when the battery has been overcharged or over discharged and "blow a fuse" and permanently disable the battery. This is the only reason lithium batteries are safe enough to use in consumer devices at all.
When a rechargeable lithium battery is overcharged, overdischarged, overheated, or otherwise "abused," chemical changes happen and it becomes dangerous and prone to a fire. The circuitry in the cell is programmed to watch for these conditions and shut the battery down for life. It's critical that the "protection" circuitry is permanently attached to the individual cell that's been damaged.
That's why you need protection circuitry in the battery, not just the charger. If you put it in the charger, the customer will try to reuse that battery in another computer, or put it back into the same computer after resetting the charger.
I remember for many years when lithium rechargeable batteries were far too dangerous to use in consumer devices. While there were some improvements in the safety of the cells themselves, it's the per-battery protection circuitry that's allowed them to be sold relatively safely to consumers.
RE: Operating CPAP with battery.... - archangle - 04-29-2013
(04-26-2013, 10:10 AM)JJJ Wrote: Lead acid batteries have problems that are just as bad. For example, it is against US federal law to take a lead acid battery on any public transportation vehicle.
Are you just making this stuff up?
Please provide a citation.
There are some restrictions on lithium batteries, but I've never heard of any restrictions on lead acid batteries.
(04-26-2013, 10:10 AM)JJJ Wrote: Because the acid is not very friendly to human life. But we have been using lead acid batteries for a century and everyone understands the dangers. If the public was as familiar with the electronics in lithium batteries they might be just as safe.
No portable lead acid battery pack you buy is likely to be spillable. It will probably be gel cell or AGM, which won't leak much if any acid even if you make a hole in the case. It's really hard to find any liquid electrolyte lead acid batteries in smaller than car or motorcycle batteries. A car battery sized liquid electrolyte marine battery is good for home use in some cases, but you wouldn't want to haul around one or even haul around a liquid electrolyte motorcycle battery.
RE: Operating CPAP with battery.... - archangle - 04-29-2013
(04-26-2013, 10:10 AM)JJJ Wrote: Personally, if the power goes out I will power my CPAP with the generator out in my garage. That is, if I can keep from burning the house down with the gasoline.
That's the STUPIDEST!!! and most dangerous advice I've heard here in a long time
Sorry for being blunt, but every time there's a widespread power outage, some idiot kills himself or his kids by running a generator in his garage. Even running it on a carport can be dangerous.
I'm tired of it, and I'm tired of hearing people recommend it.
A generator running in the garage is at least a hundred times as dangerous as a lead acid or lithium battery in the house.
Yes, I know, you're going to use it with the door open. That's what the dead kid's dad said.
Yes, you've done it before with no problems. You may not run the same number of hours this time. The wind may be different. Windows are open one time and not another. The engine makes very different amounts of carbon monoxide when the running conditions change, as the fuel system gets dirty, as the air filter gets dirty, as gas or temperature change. The weatherstripping may seal differently, etc.
5 out of 6 people playing Russian roulette come through OK, too.
Gasoline powered gadgets are deadly if used wrong. Treat them with respect.