If unprotected 18650 batteries are dangerous, why are they on sale ?

[Ragiska]

Just to put it into perspective: With an annual production of several hundred million cells, there has not been a _single_ count of dead or severe injury by a failing 18650 cell.

actually there have been many hundreds world wide outside of the flashlight community (which is minuscule compared to general 18650 usage). and those failures were with engineered battery systems, not loose cells, which are an order of magnitude more dangerous in the hands of rechargable battery noobs who don't even know what a DMM is.

 

[45/70]

The unprotected cells are clearly meant for using in packages where it's up to the guy who build the packages to provide the protection and balancing.

I think your analogy is a bit misleading. Li-Ion cells in general, were never intended to be used individually. The protection circuits are added by distributors, not the manufacturers, as most of them (all?) don't sell individual cells, except to pack makers. The exception here, is distributors like xxxxxFire et al, that buy up loose cells from manufacturers in China, and then sell them separately with, or without a protection circuit which they add onto the cell.

The problem with protected cells is that the addition of the protection circuit is, in itself a hazard. Protection circuits are prone to failure and may, or may not actually work, giving users a false sense of security. I might add here that the added protection circuit is provided to protect the cell, not the user. Anyone with a beginner's knowledge of protected Li-Ion cells should know that the protection circuit should never be tripped. It's there as a safeguard for the cell, not as a convenience to the user.

And that thin metal strip (+) running down the side of the cell, with only a very thin piece of plastic tape separating it from the cell body (-), and the shrink wrap separating it from the flashlight body (-), is all that's preventing a short circuit, or . Have you ever dropped your light, or skinned the wrapper, when installing your cells?

With proper care and knowledge, unprotected cells could be considered safer than protected ones. I'm not advocating that those unfamiliar with Li-Ion cells start out with unprotected cells, but really, they are no more dangerous than protected cells, with proper knowledge of how to use them. You could say that Li-Ion cells with the added protection circuit have additional hazards "built in", compared to unprotected cells.

Also, I'm not sure what you're getting at regarding balancing. Balancing protected cells in no way differs from balancing unprotected cells.

Dave

 

[Bullzeyebill]

45/70, +1!!!!!!!!!!! :thumbsup:

Bill

 

[McAllan]

I think your analogy is a bit misleading. Li-Ion cells in general, were never intended to be used individually. The protection circuits are added by distributors, not the manufacturers, as most of them (all?) don't sell individual cells, except to pack makers. The exception here, is distributors like xxxxxFire et al, that buy up loose cells from manufacturers in China, and then sell them separately with, or without a protection circuit which they add onto the cell.

Can't individual cells be considered being a pack?
After all that's the biggest problem with LiIon. Every time you buy a new camera etc. you need one again buy new batteries, chargers, everything. If only we could get standardized forms. An why not the cell with protection?

The problem with protected cells is that the addition of the protection circuit is, in itself a hazard. Protection circuits are prone to failure and may, or may not actually work, giving users a false sense of security. I might add here that the added protection circuit is provided to protect the cell, not the user. Anyone with a beginner's knowledge of protected Li-Ion cells should know that the protection circuit should never be tripped. It's there as a safeguard for the cell, not as a convenience to the user.

Can't strongly disagree here. Except for the over discharge protection. A lot of stuff seems to rely on that one. And I believe the circuits are far less likely to fail than you're implying. You just have to admit nothing is 100% sure. But when is it good enough?
As an aside I tell you that I'm relying on one. Lets just call it an item bought from DX. Although used with 3 NiMH with which it is perfect since it'll cut before any chance of a cell reversal and the cells for all purposes empty. Originally it used a Nokia knock-off battery but run time was much too short.

And that thin metal strip (+) running down the side of the cell, with only a very thin piece of plastic tape separating it from the cell body (-), and the shrink wrap separating it from the flashlight body (-), is all that's preventing a short circuit, or . Have you ever dropped your light, or skinned the wrapper, when installing your cells?

That's more hypothetical than practical if done properly. If manufactures allowed devices that take 18650 cell to accept cells that are 19655 or so then there's plenty of space for making a safe route to the positive terminal and a safety circuitry as good as many other packs.
Or (wonder why nobody thought of that) you can put the circuitry at the positive end of a flat top cell. Yes - more difficult and you still need a wire to go along to the negative end to provide power to the circuitry since I presume it's not safe to spot weld the negative connection to the side of the battery (they've made them with spot welding in mind at the ends). But the connection doesn't need to be insulated. And you'll need a top as a the positive terminal. So a little bit more difficult but much better technical wise.

With proper care and knowledge, unprotected cells could be considered safer than protected ones. I'm not advocating that those unfamiliar with Li-Ion cells start out with unprotected cells, but really, they are no more dangerous than protected cells, with proper knowledge of how to use them. You could say that Li-Ion cells with the added protection circuit have additional hazards "built in", compared to unprotected cells.

And the ones you buy today - protected or not. If you scratch the wrapping at the positive end you can short the cells. If designed properly a PCB at the positive end would greatly reduce that risk since an item in order to create a short will need to it at bigger distance - and of course you can design the PCB with that dual purpose in mind.

 

[LeifUK]

Gasoline is dangerous
Knives are dangerous
Cars are dangerous
Motorcycles are dangerous
Chainsaws are dangerous
Ladders are dangerous
Water is dangerous

If you want to remove all kinds of danger from your life, the only way is euthanize yourself.

It sounds like you have not read through the thread, as that point has been made several times. However, I guess the thread is long. So I give a brief answer as I see it.

People know that petrol (gasoline) and knives are dangerous. We have regulations about the sale of petrol, such as requiring the use of special cans when buying in small quantities. We teach children not to play with knives, and restrict their sale to people over a certain age. And we force people to take car tests. These are all precautions to protect people. To sell unprotected Li cells without any warnings would be grossly irresponsible as people would not realise the very real dangers. Were they to go on sale in mon and pop stores, rest assured there would be serious injuries, and enough law suits to keep the legal profession in champagne and caviar for a long time.

Just to put it into perspective: With an annual production of several hundred million cells, there has not been a _single_ count of dead or severe injury by a failing 18650 cell.

So just dont by into the hysterics.

PS: Yeah, there is stuff like the TK-Monster explosion that could hurt somebody badly. But that is not the fault of the cell. NO more than its the fault of a Chainsaw if you try to shave with it.

The vast bulk of Li cells are used in packs with protection circuits, and dedicated chargers with protection circuits. Very very few are and/or used sold loose.

I don't understand your last point. The owner turned it on. Is that not expected use?

 

[LeifUK]

The problem with protected cells is that the addition of the protection circuit is, in itself a hazard. Protection circuits are prone to failure and may, or may not actually work, giving users a false sense of security. I might add here that the added protection circuit is provided to protect the cell, not the user. Anyone with a beginner's knowledge of protected Li-Ion cells should know that the protection circuit should never be tripped. It's there as a safeguard for the cell, not as a convenience to the user.

That is the most topsy turvey logic I have ever read. I have heard the same argument justifying the riding of motorbikes without helmets. The truth is that helmet laws lead to significant reduction in head injuries among bike riders.

The same would be true for Li cells. Your argument might apply to a small number of well educated people who take proper care of their cells. There are millions of Li packs in use and few problems due to high quality design and manufacture. What you say might apply to cheaply made protected cells i.e. the QC is so low that the protection circuits often do not work, and as you suggest, mislead people into taking risks. Perhaps that is what you meant.

I think the problem is that a lot of these cells are from places like DX with crap QC. Were they to be made to the standards of the protected cells sold with cameras, quality would be high.

As an side, it is not unheard of for third party camera batteries to catch fire while charging. I can recall a couple of accounts, where the fire brigade needed to intervene. That is why I would never buy third party Li batteries for a consumer good.

 

[45/70]

That is the most topsy turvey logic I have ever read. I have heard the same argument justifying the riding of motorbikes without helmets.

Motorcycle helmets have certain specifications that have to be met before they are approved for use. There are no such regulations for individual Li-Ion cell protection circuits. Would wrapping a paper towel around a motorcyclist's head work? Again, in case you are not aware, manufacturers of Li-Ion cells, do not make or sell protection circuits for individual Li-Ion cells. From their viewpoint, it is too much of a liability, and refuse to do so.

The truth is that helmet laws lead to significant reduction in head injuries among bike riders.

I have a hard time with this comparison, although I agree. Here, there is no helmet requirement, but I wear one. Protection circuits installed on individual Li-Ion cells is more of a custom application, as manufacturers do not approve of the sale of individual Li-Ion cells period, regardless of whether or not they have protection circuits installed.

Your argument might apply to a small number of well educated people who take proper care of their cells.

Um, yes, that would, or should be the flashlight/torch community.

What you say might apply to cheaply made protected cells i.e. the QC is so low that the protection circuits often do not work, and as you suggest, mislead people into taking risks. Perhaps that is what you meant.

Yes, as you hopefully know, there is a big difference between, for example, AW cells, and xxxxxFire cells.

I think the problem is that a lot of these cells are from places like DX with crap QC. Were they to be made to the standards of the protected cells sold with cameras, quality would be high.

Again, camera battery packs are built with the builder's plans for the means of protecting the packs, having been approved by the actual manufacturer of the cells before production. There is no such approval for individual cells, that distributors such as xxxxxFire, install their own protection circuit on. Remember, these are produced in China, not Japan, the UK, or the US. Good luck with any legal action.

Back to my last post, my point is that physically, there are more components that can fail on a protected Li-Ion cell, than an unprotected cell. That is just the nature of the beast. The more components, the more likely a failure. In addition, the protection PCB's, being an "add on", to cells not intended for them, are more vulnerable to dropping etc. by their very nature.

I am not saying that unprotected cells are better, just that safety wise, they are closer than you might think. I also consider "a small number of well educated people who take proper care of their cells" much preferable to "Big Brother" intervention, as well. Reading through the forums though, I find many are still clueless as to the proper care and maintenance of Li-Ion cells. Unfortunately, I see an outright ban of individual Li-Ion cells being preferable to the "powers that be", as opposed to regulation. Then we'll be scrounging around breaking apart laptop and tool packs, and all cells will be unprotected. I'm not supportive of that, at all.

Dave

 

[LeifUK]

Motorcycle helmets have certain specifications that have to be met before they are approved for use. There are no such regulations for individual Li-Ion cell protection circuits.

Earlier I said the following:

"What you say might apply to cheaply made protected cells i.e. the QC is so low that the protection circuits often do not work, and as you suggest, mislead people into taking risks. Perhaps that is what you meant. "!

It does indeed seem to be what you meant.

I would say that the protection circuits in batteries for consumer goods from established names such as Nikon are of significant value, and are not worse than useless, or marginally useful. As I have said, I have read several first hand accounts of 3rd party Li cells for cameras (Nikon) catching fire during charging, probably due to over-charging. I have never heard of a fire when charging a Nikon brand battery. My guess (no evidence, just a guess) is that the number of Nikon brand batteries in Nikon cameras far outnumbers the number of cheap 3rd party units.

Of course if you have statistics for how often batteries from big names such as Nikon fail, that would be of interest.

 

[45/70]

Earlier I said the following:
"What you say might apply to cheaply made protected cells i.e. the QC is so low that the protection circuits often do not work, and as you suggest, mislead people into taking risks. Perhaps that is what you meant. "!

It does indeed seem to be what you meant.

Yes, fair enough.

My concern is flashlight/torch oriented. What I think possibly you, and I know others on the Forums don't understand, is the difference between a Nikon pack's protection circuitry, which is more than likely well thought out, tested etc., as compared to the homemade type that xxxxxFire et al installs onto individual cells, that were never meant by the actual manufacturer, to have a protection circuit installed onto the bottom, made in somebody's garage when they aren't at their day job. I will exclude AW from this last group, as whoever does his cells seems to be on top of things. :thumbsup:

There are two points that, to me anyway, are safety concerns here. First, the protection circuit installation on the bottom of the cell. This is a vulnerable location to mount a PCB. It can be crushed, torn, or broken, any number of ways, leading to the circuit's failure. I don't have any suggestion as to a better place to mount the PCB, but then again, neither do the manufacturers of the cells. That more than likely has a lot to do with why the actual cell manufacturers don't manufacture, or sell individual cells with protection circuits installed.

The second safety concern, is that a Nikon pack's protection circuitry is tested and designed from the ground up for a specific device, with specific demands, and is tuned to the battery pack. The circuits provided by xxxxxFire et al, that the guy makes in his garage, most likely are composed of similar components, but at best, they are not designed for a specific light's use of the cell, or battery. If they are, then there are going to be some lights in which the protection circuit works well, and many others that it really isn't suitable for. You can't make a catchall protection circuit that works for every application. Actually, you probably could, but the cost to manufacture it would likely be more than the cost of the bare cell.

And I'll say one more time, I am in no way suggesting that anybody use unprotected cells, rather than protected ones, in particular those new to Li-Ion cell use. I am just pointing out that with an unprotected cell, there are actually fewer things to go wrong, again, with a proper understanding of their use. You know the "small number of well educated people who take proper care of their cells" group.

Dave

 

[march.brown]

.
Instead of protecting the battery itself , would it be possible to ----

A/ ... Have a drop-in protection circuit that fits in the anode end of the torch ... This would be connected to the outer casing of the torch and would also be connected between the battery anode and the LED ... This would be the same as adding the protection circuit to the bottom of the battery and would eliminate the thin insulated metal strip connecting the protection circuit to the battery anode ... So the battery would have discharge protection/undervoltage protection taken care of ... Thermal (over-temperature) protection could be built in if required ... The insert needs only to be the same basic thickness as the one fitted to the bottom of the protected cells ... Since there would be less of these devices , they could be made from better quality components.

B/ ... Also a similar item to be inserted when charging , at the anode end of the battery ... A lead could be inserted between the negative end of the battery to the protection circuit to monitor charging voltage ... This protection circuit could even be built into any charger (even the cheapest) quite easily ... This circuit would protect against over voltage and excess charging current ... It would be possible to have different values of charging current protection to cater for the different capacities (18650 or 123)

These protection circuits would enable unprotected cells to be readily used ... There again , with care and experience , unprotected cells can be used anyway.

Unfortunately , this protection would not protect against the occasional Li-Ion cell falling into the chain-locker of a sailing boat and consequently having a short-circuit applied ... But you can't protect against every possible problem.

I don't know whether the above idea is viable , but it was just a thought.
.

 

[march.brown]

.
I have a Panasonic camera and the battery is a rectangular one built from thick hard plastic ... The protection circuit is inside the plastic case and is not in the same vulnerable position as those on the 18650s etc.

It does worry me somewhat that , on protected Li-Ion cells , there is a thinly insulated length of metal strip running the length of the cell connecting the battery anode to the protection circuit ... I am beginning to wonder whether I should be using non-protected cells instead.

I take great care in charging my 18650s and check the off-load voltage regularly to ensure that they never go over 4.20 volts ... I also take great care when inserting the cells into my torches ... I never remove the torch head and replace it whilst the batteries are in ... I (so far) never over-discharge my cells and tend to err on the top-up charges rather than a full charge.

I also do not own any multi-Li-Ion devices , as I think that I am paranoid enough with just the single Li-Ion cell torches ... I even unscrew the torch end caps occasionally and listen for a hiss , just in case there in a slight build-up of pressure in the torch body.

I must admit though that the performance of the 18650 torches is worth the extra care and effort ... I still prefer the single AA for my EDC though as it is the right form factor for me ... I am slightly tempted now by a single 123 torch with a primary cell as it could be left alone till 2019 and still be useable ... Mind you , by then I would be 81 and might have to get a torch mount for a Zimmer Frame ... Time will tell.
.

 

[45/70]

I don't think your suggestions are very practical, march. The ultimate solution, thinking about it in the way you're looking at it, is to just buy lights that have the protection built in, rather than adding an additional component.

Owning these type lights, is why half of my Li-Ion cells are unprotected cells. That and owning a couple proper chargers, and I'm good to go.

Dave

 

[LeifUK]

Yes, fair enough.

My concern is flashlight/torch oriented. What I think possibly you, and I know others on the Forums don't understand, is the difference between a Nikon pack's protection circuitry, which is more than likely well thought out, tested etc., as compared to the homemade type that xxxxxFire et al installs onto individual cells, that were never meant by the actual manufacturer, to have a protection circuit installed onto the bottom, made in somebody's garage when they aren't at their day job. I will exclude AW from this last group, as whoever does his cells seems to be on top of things. :thumbsup:

There are two points that, to me anyway, are safety concerns here. First, the protection circuit installation on the bottom of the cell. This is a vulnerable location to mount a PCB. It can be crushed, torn, or broken, any number of ways, leading to the circuit's failure. I don't have any suggestion as to a better place to mount the PCB, but then again, neither do the manufacturers of the cells. That more than likely has a lot to do with why the actual cell manufacturers don't manufacture, or sell individual cells with protection circuits installed.

The second safety concern, is that a Nikon pack's protection circuitry is tested and designed from the ground up for a specific device, with specific demands, and is tuned to the battery pack. The circuits provided by xxxxxFire et al, that the guy makes in his garage, most likely are composed of similar components, but at best, they are not designed for a specific light's use of the cell, or battery. If they are, then there are going to be some lights in which the protection circuit works well, and many others that it really isn't suitable for. You can't make a catchall protection circuit that works for every application. Actually, you probably could, but the cost to manufacture it would likely be more than the cost of the bare cell.

And I'll say one more time, I am in no way suggesting that anybody use unprotected cells, rather than protected ones, in particular those new to Li-Ion cell use. I am just pointing out that with an unprotected cell, there are actually fewer things to go wrong, again, with a proper understanding of their use. You know the "small number of well educated people who take proper care of their cells" group.

Dave

Actually I do understand that Nikon et al make batteries specifically designed for a given product, and that the quality is high. That is why they usually have a specific form factor, and simply cannot be used in other devices. And they have a dedicated charger. These measures ensure that Nikon cannot be sued for someone accidentally using/charging the cell in the wrong device. That also explains why they are expensive, though cost is also due to being sold through high street retailers. In addition the product can have protection circuitry built in thereby achieving very high standards of safety.

The reason for my disagreeing with your earlier posts was that you did not qualify what you meant, and simply stated that protected cells are worse than non-protected. I do not disagree that a lot of Chinese stuff is poop, for want of a better word. That is why I have chosen not to use rechargeable Lithium cells.

I have no first hand knowledge of AW cells. But I still wonder about how easy it is to break the protection.

The problem is clearly that Chinese makers have to bodge unprotected cells, which were designed for use in packs, but which are already almost filling the available space in the torch (flashlight). It would be nice if manufacturers produced protected lithium cells with the form factors suitable for torches. But, either they concluded that demand would be too low to justify it, or possibly that even with protection, it would open them to law suits, as then their beautifully made cell could be used in a poop torch, or charged in a poop charger. So they would have to design their own form factor, and then get torch makers to sign up to the required standards. That would be too expensive by half.

But your key point that (poor quality) protected cells may lull the user into a false sense of security leading to accidents is no doubt a good one.

 

[IMSabbel]

actually there have been many hundreds world wide outside of the flashlight community (which is minuscule compared to general 18650 usage). and those failures were with engineered battery systems, not loose cells, which are an order of magnitude more dangerous in the hands of rechargable battery noobs who don't even know what a DMM is.

Give me a single link to a casualty or case of bodily harm bigger than "ouch i burned my finger"

And those were engineered battery packs used by people for years, with no care for the battery at all

Which in many of the devices sits right next to the hot parts of the motherboard, getting steamed at 60C+ during use.

 

[Ragiska]

Give me a single link to a casualty or case of bodily harm bigger than "ouch i burned my finger"

And those were engineered battery packs used by people for years, with no care for the battery at all

Which in many of the devices sits right next to the hot parts of the motherboard, getting steamed at 60C+ during use.

http://www.techtree.com/India/News/Exploding_Battery_Kills_Chinese_Man/551-98463-547.html

http://www.lifeofguangzhou.com/node_10/node_37/node_82/2007/07/05/118360232622937.shtml

http://www.neowin.net/news/man-killed-after-phone-explosion

http://www.cbc.ca/consumer/story/2009/08/26/bc-overheating-laptop-fire-death-vancouver.html

this article cites several deaths to his recall, including the above:
http://www.boston.com/business/tech...th_man_sues_hewlett_packard_over_laptop_fire/

with the most casual of searches you find hundreds (if not thousands) of reports of house and business fires started by lithium batteries. several fires started in airplane cargo holds led to current air transportation restrictions.