TK Monster Explosion

moldyoldy

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for your reference regarding Li-Ion safety, read the article in the Wall Street Journal from Monday 22 Feb on page R8 in the report on energy. The title of the article is: "Where Batteries Go To Be Tortured".

The lab tests only Li-Ion batteries....from single cells to automotive battery packs, even including the silver pouch batteries. The Sandia researcher causes all sorts of seemingly normal damage to the batteries. Quote: "Again and again, he watches them explode".

One of his favorite tests is to overcharge the battery if the electronics will somehow allow it. The Li-Ion cell goes in to thermal runaway and explodes. He admits that they test under worse-case scenarios, but the fires and explosions are real. His last comment about whether he would purchase a car powered by a Li-Ion battery: "...I am disinclined to buy the first of anything."

'nuff said.
 

John_Galt

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for your reference regarding Li-Ion safety, read the article in the Wall Street Journal from Monday 22 Feb on page R8 in the report on energy. The title of the article is: "Where Batteries Go To Be Tortured".

The lab tests only Li-Ion batteries....from single cells to automotive battery packs, even including the silver pouch batteries. The Sandia researcher causes all sorts of seemingly normal damage to the batteries. Quote: "Again and again, he watches them explode".

One of his favorite tests is to overcharge the battery if the electronics will somehow allow it. The Li-Ion cell goes in to thermal runaway and explodes. He admits that they test under worse-case scenarios, but the fires and explosions are real. His last comment about whether he would purchase a car powered by a Li-Ion battery: "...I am disinclined to buy the first of anything."

'nuff said.

Emphasis added... A Big +1

(On the other hand... Car accidents will become a thing of the past, as soon as everyone learns they'll be destroyed for the slightest fender bender. I jest, I jest...)
 

flasohollic

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TS: I was recently notify by a forum member of this incident. I'm glad you made it out of the incident w/o any serious injuries and the incident was outside so you didn't inhale the batteries outgas.

As for what happen. Here's my theory, hope you can chime in the detail to accurately recreate the case to prevent it from happening again.

1. The light is designed to be used as a 1-8 cells configuration. With four dead cells this indicate that the previous owner had reconfigured the battery pack for either 4S or 2S2P configuration. The batteries were left inside the light for an extended period of time. During which AW's driver drained slowly drained batteries to the point of zero voltage.
(Did you have to install the longer rod & spacer to reconfigure the pack when you received this?)

2. When you received this you tested with the ZTS tester and it indicate nothing. This indicates that the cell is completely dead.

3. The 4 bad cells were then placed in the charger for charging. They appear to take up charge and ready to go after ~1-2 hrs of charging. (What is the charger that you used?)

Many charger have detect dead cells, alarm, and refuse to charge these cells.

From my experience of over 1000s cell charge/discharge. Many dead cell can be revive to take charge provided that there is enough of a voltage potential applied. i]However the cell will always retain <70% of full capacity. And the self discharge rate of these cell are much faster compared to good cells.[/i]

4. Both the good & bad batteries were installed into the light.

5. First lightup seems to be operating fine. The light then rest for two hours. During this period the bad cell self discharge. The cell capacity is probably < 10%

6. Upon the second lightup, LOW appears to be functional. It is probably consuming the remaining 10% charge.

7A. Mode change to MEDIUM and HIGH. At this point the four bad cell is doesn't have any more capacity left in them while the other four still have >70% charge.

7B. The good cells will then attempt to dump all of their remaining power. Cell reversal occur.

7C. The cell then vents, pressure buildup within the light.
(did the switch boot pop out first and start venting from that port?)

7D. Not enough pressure relief within the light therefore pressure continue to build up and stress the light housing.

8. The weakest part of the light, the extension tube oring groove fails. Pressure release, propelling the two haves of the light in opposite direction.

The rest are just trivial afterward. Does this accurately recreate the scenario?

I think you are wrong, even an completly worn out lithium sell would not self discharge that way, and if he dident notice any unusual thing during chariging those cell were probebly "fine".

the 4 cell he thinked were fine accually dangerous empty and he only charged the 4 cell that was comletly empty, so in fact it was the one off the 4 cell you think was ok that exploded.

I still think it is the seller responsible as the cells was delivered in that state. I would claimed the seller for the responsiblity for the damage.
 

Mdinana

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The manufacturer didn't sell the light to the OP. Even if the manufacturer included further warnings/documentation/etc with the light, there's no guarantee they'll still be with the light when it's resold.
True. But the OP said someone else brought it to him. It's not clear if it was used/opened by the actual purchaser and brought to the OP in "New in package" condition, or not.

But I'm a bit suprised that there's not more attention being put on the manufacturer. In the US, that'd be a nice little lawsuit. (rightly or wrongly)

To the OP - glad that you had the sense to drop and dive! Hope you remain OK, and don't get any late symptoms.
 

cmacclel

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True. But the OP said someone else brought it to him. It's not clear if it was used/opened by the actual purchaser and brought to the OP in "New in package" condition, or not.

But I'm a bit suprised that there's not more attention being put on the manufacturer. In the US, that'd be a nice little lawsuit. (rightly or wrongly)

To the OP - glad that you had the sense to drop and dive! Hope you remain OK, and don't get any late symptoms.

There is no real manufacture and those lights where sold months ago. I guess everyone that puts a light together these days needs to have people sign a waiver :(

Max
 

gswitter

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I think you are wrong, even an completly worn out lithium sell would not self discharge that way, and if he dident notice any unusual thing during chariging those cell were probebly "fine".
Re-read what modamag wrote. He didn't say they self-discharged. He suggested they were left unattended in the host and were over-discharged by the incan driver - a known "feature" of the driver that the seller probably wasn't aware of.

Edit: I take it back. He did say they later self-discharged. I still think his assessment is likely correct.

True. But the OP said someone else brought it to him. It's not clear if it was used/opened by the actual purchaser and brought to the OP in "New in package" condition, or not.
The OP said someone else sold it to him, and provided a link to the sales thread. The seller's previous posts indicate he did use it. (I probably shouldn't even point out his preceeding post.)

I agree with modamag's assessment of what probably happened.

There is no real manufacture and those lights where sold months ago. I guess everyone that puts a light together these days needs to have people sign a waiver :(
Maybe, sad but true.

I give credit to the OP - he's handled this very well - and I'm glad neither he nor anyone else was badly hurt.
 
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Bullzeyebill

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I am sort of glad that some people are opting out on the use of Li-Ions, or not getting into them in the first place. I for one will continue using them but will do what I usually do, keep monitoring, monitoring, monitoring them, and never consider an added protection circuit for Li-Co as the end all for safety. You have to be some kind of nut to be a flashaholic anyway, and nuttier yet if you take the time it takes to take proper care of rechargeable cells. I've got the time and the will.

Bill
 

LuxLuthor

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Thank you again for the concern guys.

I know Im at fault for not carefully checking the batteries. I assumed that if there was something wrong that the seller knew about, he would have informed me. I was caught up in the excitement of having one of the strongest lights and I just wanted to light up the night... a very very expensive lesson. Honestly though, I never knew it was this dangerous. Had I read anything like this on the forum, I would have been way more careful. Hopefully, Im the last in the CPF family that this happens to.

Just saw this thread. This is likely the most dramatic reminder to date on battery safety, the preparation and learning that should take place by lithium battery users, and the importance of adequate planning/forethought of possible safety issues by modders/sellers. Despite best of intentions, accidents and problems will still occur from a myriad of sources. Hopefully, like this thread they can be used to learn from.

dcaprilia, first and foremost, it is great that you did not sustain serious injuries, and have recently learned that your insurance coverage is excellent. Secondly, it is truly amazing how well you have handled this situation and how you contributed the facts for the benefit of the community, given what you went through. Seriously, I would nominate you for CPF Member of the Year if there was such a category.

It appears that most of the salient, causative factors, reasonable speculations, and lessons learned have already been done. It is obvious that secondary to improper cell condition/use, there was a cell(s) reversal, multiple cell short, venting within a closed pipe, followed by a catastrophic pressure buildup and explosive release at tube section joint, with enough force to strip off those threads and do all the subsequent damage.

This is also not the only "Elephant" (4 wide 18650) style light that had issues with shorts developing. You are on the bleeding edge with such high power lights here, but that should not be taken literally (poor attempt at humor).

LiMn cells are safer than LiCo cells in that it takes a higher temperature to bring them to thermal runaway, and a higher overcharge voltage before they rapidly vent (sometimes with flame). They are safer, but not "safe" in the absolute sense of the word.

While they can endure more abuse, they can still rapidly vent, sometimes with flame.

LiFePo cells are safer yet. They can take even more abuse and only seem to vent, rather than "vent with flame." However, a rapid vent is still very close to an explosion.

Tom

A year and a half ago, when I wrote about various lithium ion categories here, and did my testing of various Lithium Ion 18650 cells here, I spent quite a bit of time researching all that I could find.

I was careful to put the categories of "Safe" Lithium Ion chemistries in quotes, as there was not enough clear cut information since they were so new. As Tom has said, "Safe" chemistries is relative.

These new "Safe" chemistries were mainly being developed to address and fix the Lithium Cobalt Ion runaway 1300°F fires and toxic fumes that were being seen with computer laptop batteries, leading to devastating fires, and tens of millions being recalled. There was also a need for safe, high energy batteries for power tools and electric car designs.

I think it is quite noteworthy despite the explosive venting of gases, that these Sony Konion cells did not in fact lead to a runaway 1300°F fire in this case. The flashlight tube's aluminum is not melted, and recovered battery shells still have green color label visible. So in that regards, these cells are safer than Lithium Cobalt.

I could not find out if the vented gases from Lithium Manganese (Emoli), Lithium Nickel Cobalt Manganese (Sony/Konion) and Lithium Iron Phosphate had the same ultra-toxic hydrofluoric acid that Chrontius mentions--seen in Lithium Cobalt cells.

I also did not find evidence at the time I posted those threads 18 months ago that the "Safe" Lithium chemistries had the potential of venting with flame, nor leading to the 1300°F fire causing the cascading thermal runaway spreading to all other cells like you see with "unsafe" Lithium Cobalt cells.

Perhaps more testing and documentation has come available since then. Tom, do you have a source that documents the specific issue of high temp flames scenario with Lithium Manganese--would be good to read and update old threads?

Certainly the Lithium Iron Phosphate have had the best safety track record thus far.
 

LuxLuthor

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Tom, is that single page the whole report, or just the summary page? If you have the whole report, or other sources--that would be useful and interesting to read. I'm not sure that extrapolating from this single page is valid since there is not enough information to make much out of it.

In particular, I don't know the objectivity and credibility of this reference "research institute," nor what exactly is the "40113 Lithium Ion," and how they changed only the cathode and kept all other variables the same, which the single page seems to imply. I like to question things like could they be a "paid plant" by a company that primarily produces LiFePO4 ?

I was hoping to find actual tests of name brand company 18650 cells like those I reviewed in my post (i.e. Sony/Konion).
 

Databyter

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I also did not find evidence at the time I posted those threads 18 months ago that the "Safe" Lithium chemistries had the potential of venting with flame, nor leading to the 1300°F fire causing the cascading thermal runaway spreading to all other cells like you see with "unsafe" Lithium Cobalt cells.
I know you are addressing this from a different angle, but I was wondering if you considered the fact that a battery wouldn't need to in fact vent with flame to cause an explosive flash under certain conditions that I believe existed in the OP's light.

I was thinking that even if the battery chemistry was such that it would vent without flame, under conditions of a short in a confined space with pressure build up, heat, vapor, melted plastic, and oils can cause an explosive flash of the vapor ignited by sparking/shorting regardless.

In fact under the conditions in the tube the particulate vapor wouldn't even need to be flammable at all to be explosive under the right conditions.

My theory is that regardless of the inherent chemistry of the cell, conditions were met that led to a flash exasterbating the already dangerous chain venting heat and pressure. It's my opinion that this was not just an explosive venting, but a detonation. Ignited not from a flaming cell necesarily but an electrical short of some kind within the tube. The cells might indeed be flameless, and still indirectly cause ignition.

So the cells might be comparatively safe and as advertised, certainly not like the ones they were compared to that had a history of fire starting.

Whaddaya think?

It would be interesting if the OP could let us know if there was a visable flash of light when the tube failed.
 
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Locoboy5150

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Dear Members- Good news! The building was able to source out another supplier for the damaged glass. Total damage is P398,000 (previous quote P515,000) or around $8,600. The best part is that the insurance will cover the damage. The deductible is roughly $100 which I will gladly pay for.

That's *great* news indeed! :)
 

LuxLuthor

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I know you are addressing this from a different angle, but I was wondering if you considered the fact that a battery wouldn't need to in fact vent with flame to cause an explosive flash under certain conditions that I believe existed in the OP's light.

I was thinking that even if the battery chemistry was such that it would vent without flame, under conditions of a short in a confined space with pressure build up, heat, vapor, melted plastic, and oils can cause an explosive flash of the vapor ignited by sparking/shorting regardless.

In fact under the conditions in the tube the particulate vapor wouldn't even need to be flammable at all to be explosive under the right conditions.

My theory is that regardless of the inherent chemistry of the cell, conditions were met that led to a flash exasterbating the already dangerous chain venting heat and pressure. It's my opinion that this was not just an explosive venting, but a detonation. Ignited not from a flaming cell necesarily but an electrical short of some kind within the tube. The cells might indeed be flameless, and still indirectly cause ignition.

So the cells might be comparatively safe and as advertised, certainly not like the ones they were compared to that had a history of fire starting.

Whaddaya think?

It would be interesting if the OP could let us know if there was a visable flash of light when the tube failed.

I don't know enough about the potential flammability of the vapors you posed vis-a-vis if they could have supported a spark-induced detonation akin to the concept of an automotive engine chamber filled with a compressed, flammable air-gasoline vapor detonated by the spark plug.

Making an educated guess...I would doubt there would be such a likely scenario based on the idea that all of these "safe" chemistries were trying to address the Lithium Cobalt disasters, while keeping some degree of their higher, lightweight energy density. They are all looking for the "Holy Grail" of being able to effectively and safely power various hand-held tools, electronics, and electric vehicles.

I think the rapid build up of any gas in a closed metal tube, even including pneumatic air tools can have enough force to cause deadly damage, and alone explain the OP's events without the necessity of a spark induced combustible detonation. If these cells sizzled, popped, dropped and vented over the few seconds that are described, just a non-volatile build up of vented gases would eventually reach enough force to strip away the section threads and propel the ends in opposite directions.

There is not enough evidence in his photos of significant heat damage, nor deformity of the sides of the former TK Monster body to explain a spark detonation. The best tell tale sign, if he can find them would be looking at the condition of the Delrin battery holders. If they are melted, then that is one way to peg the actual event temperature reached prior to "missile launch."

I'm pretty sure despite some posts correctly stating that Lithium Iron Phosphate are the safest Li-Ion, that they also could have been sufficiently abused and misused to cause an abrupt reverse/short heating up and release of gasses in a closed container to result in a similar event. There is no way out of the user needing to understand his components, and designers/modders/manufacturers needing to put safety first and if necessary, restrict sales to the inexperienced.

The best thing about this and other similar safety threads is the increased awareness it brings to the subject.
 

VegasF6

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Indeed any battery is capable of venting. Look at these pics of an A123 cell that exploded on a charger that was turned off.
http://www.rcgroups.com/forums/showthread.php?t=709190

NiMH explosion:
https://www.candlepowerforums.com/threads/239520

Have read tales of nicad as well and don't even have to talk about sla.

I guess the size of the explosion is of course proportionate to the amount of stored energy, but this could have quite possibly happened with a 2 cell light as easily as an 8 cell light. Determining the cause, or at least a good a guess as possible is fine, but there is no need to point fingers, be it at the manufacturer, the previous owner or the OP.
 

dcaprilia

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It would be interesting if the OP could let us know if there was a visable flash of light when the tube failed.

As soon as i dropped the light, i turned my back. On the floor, I heard a couple small pops from the light then a huge boom after about 3-5 seconds. Is it possible the bulb acted as an ignitor? The light was still on the high setting when i dropped it.
 

Databyter

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As soon as i dropped the light, i turned my back. On the floor, I heard a couple small pops from the light then a huge boom after about 3-5 seconds. Is it possible the bulb acted as an ignitor? The light was still on the high setting when i dropped it.
I guess the preponderance of opinion says it was an explosive venting and not a detonation. I doubt the bulb itself caused ignition if there even was one since that is the one part of the light that is designed to be hot and is also somewhat separated from the Batt. Compartment.

I still believe that a detonation is possible, regardless of safe chemistry even dust can cause a huge explosion, but Ihave to lean towards Lux Luther and others on this who have spent alot more time reading and testing batteries.

I know alot about fire, and explosions, but very little about batteries :thinking:
 

Mr Happy

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Whether it detonated or simply exploded may be a moot point. However, it is worth bearing in mind that a mixture of flammable vapors and air in an enclosed tube can explode with many times more energy than the same weight of a high explosive like dynamite. The only thing that stops it actually being a stick of dynamite is the low density of gases and air so that very small weights of flammable material are involved.

The comparison with the combustion cylinder of an internal combustion engine is apt. Remember that minuscule amounts of gasoline in a little tiny cylinder can propel your 1 ton car along the road at 70 mph.

Honestly, only a fool would put such potentially explosive systems in a sealed metal tube and screw the end on tight.
 

download

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Glad you did the right things to drop and run.
Could not imagine the electrical or mechanical failure of flashlight is life or dead.
It totally changed my mind of treating the li-ion battery.
Including cell-phone, digital cam, notebook computer and our flashlights.

This is one of the most important post I read here!!!
Thanks a lot for sharing.
 

Data

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dcaprilia, I am so glad you and your family are OK. The battery failure could have been prevented but hindsight is 20/20. That is easy for us to say now, but as I ask myself, would I have stopped you from testing the light had I been there? I might not have but I do not know for sure.

I love my TK, the quality and care that went into it's build are amazing. It can start a fire faster thank you can shake a stick and that is something to see in person. :nana: However . . . :thinking:

Clearly we have a problem here that still needs addressing. When these batteries fail by venting gas at a high rate, like an automotive air bag device does, the gas needs to get out quickly. The fix is to provide for a pressure release. The TK Monster and many many other light designs are pressure chambers, capable of holding back extreme forces and therefor the buildup of extreme potential energy before the vessel fails and releases said energy.

My TK Monster is going to be drilled through the end cap. I recommend you all do the same to yours. Simply fill the hole with silicon glue. I suspect that a 1/4 hole in the battery cap would suffice but only testing would tell for sure, I am not testing mine! :D

Secondly, these ultra power flashlights should not be stored with the batteries in them and you may want to think twice about using them indoors. Simple rules that I have read here on the forums many times before but they must be repeated.

Finally, take care to charge these batteries under supervision only. High power chargers and batteries can fail and cause a fire.


Cheers
Dave
 
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