TK Monster Explosion

[IMSabbel]

First : Even if the original poster was not careful enough, he at least checked the batteries and charged them when he found them to be 0.00V. The fact that the voltage was is no sign of dead batteries anymore, as any kind of protected cell will show 0V if it was shorted for a moment or discharged to fast. One should not expect any more care from a user.

Ok, after going through the accident again, this would have been absolutely no issue with any kind of venting design:

The first sound of problems was seemingly a single cell venting. This was followed by additional vents some moments later (probably accellerated because of temperature and pressure buildup). That lead to a cascade that eventually produced enough pressure to RIP OUT THE THREADS.

Which means that there was absolutely no weak point for pressure release in the design than _ripping apart metal_. People have been talking about pipebombs pretty often, but this really fitted the definition. Have a slow deflagration and contain it long enough for a pressure vessel burst.

What I find curious is the fact that the battery chamber seems to be toally contained. Not even the switch or the glass window worked as a release (people say bad things about glass fagments going anywhere, but it really is preferable to pipebomb shrapnell).


And for those who make those analogies about guns, cars, etc. Yes, users have to be careful. But that does not mean that the products is allowed to be a deadtrap.
Just try selling:

- a gun without any safety and a hairtrigger
- a car which has no upward shielding around the transmission that will send gears through the driver if it fouls up
- a chainsaw that has a on/off switch instead of a dead-man button (would it not be much more convenient?)
- a hairdryer without a protection sieve on the fan inlet

And hope there wont be any backlash if it goes south.
I mean, following that argument, you would KNOW that you have to be carefull when working a chainsaw. So why do you need a saw-brake and two operation buttons? Would it not be the users fault if he isnt carefull?

No, that wont work for a chainsaw. And a chainsaw is a thing that earns enough respect that people put it into horror movies.

Flashlights, no matter how big, are NOT in the same class of respect. Because one does need to assume that if you are not put into a situation of potential danger.

Just imagine that light would have been used in a crowed to show of its power. The shrapnell would have hit somebody. Around here, there was a death some years ago because somebody put fireworks in a tincan and a metal sliver ripped through somebodies artery.

PS: There is nothing really wrong with the batteries. They behaved nicely. Reverse-charging with 20A+ WILL result in venting, thats what they are designed for. Putting them where the venting gases cannot go anywhere is the problem.

 

[timberwolf]

PS: There is nothing really wrong with the batteries. They behaved nicely. Reverse-charging with 20A+ WILL result in venting, thats what they are designed for. Putting them where the venting gases cannot go anywhere is the problem.

Yep, I just read this thread oo: and you are absolutely right!

We CPF users should definitely check high power flashlights for this feature, just using IMR Cells doesn't save your butt if you put them into a pressure vessel.

 

[fyrstormer]

Wow, that's crazy.

I have to ask, though; if you knew that Li-Ion batteries can explode when abused, and you had a set of Li-Ion batteries that seemed to go from zero charge to full charge in a few minutes, why did you try to use them? Didn't it seem like maybe there was something wrong with those batteries?

 

[fyrstormer]

dcaprilia - that explosion damage looked like it was reaching the mythical
star trek phaser overload blam! Glad you're alive.

Holy crap. oo: Now I get it. Star Trek phasers run on lithium-ion batteries!

Seriously though, considering the amount of power released by this light when it went ****-up, any device capable of vaporizing solid rock would go up like a nuclear bomb if it self-destructed. I guess it's a good thing for us that phasers don't exist, huh?

 

[fyrstormer]

Just imagine that light would have been used in a crowed to show of its power. The shrapnell would have hit somebody. Around here, there was a death some years ago because somebody put fireworks in a tincan and a metal sliver ripped through somebodies artery.

...and that is why I carry a bag of CELOX in my attache. There are a few things in this world that, by the time you realize you need them, it is far too late to go get one. One of those things is hemostat -- if you have a torn or severed artery, you have about 5 minutes left to live, on a good day.

 

[ozner1991]

i think i speak for everyone on this forum when i say HOLY SH**

just shows how dangerous rechargebles can be :sick2:

 

[dcaprilia]

Wow, that's crazy.

I have to ask, though; if you knew that Li-Ion batteries can explode when abused, and you had a set of Li-Ion batteries that seemed to go from zero charge to full charge in a few minutes, why did you try to use them? Didn't it seem like maybe there was something wrong with those batteries?

It charged for over an hour possibly even close to 2 hours. I was expecting more in the range of a couple hours. In hindsight, yes that should have been a red flag. But I guess I was too excited to see the darn thing. I also figured that the seller (had he known) would have warned me or stated in the sale that the batteries were bad.

Question- If the batteries I used were protected and didnt carry a charge? Would the battery still explode? Since its protected, doesnt it mean it shorted already and therefore harmless? That means that the live 4 other live batteries were the one that shorted and blew up... is this correct?


Update on the damage- The insurance inspected my balcony and the rest of the damage on the building this afternoon. They will give their assessment early next week. Im keeping my fingers crossed that it will be covered.

 

[Databyter]

First : Even if the original poster was not careful enough, he at least checked the batteries and charged them when he found them to be 0.00V. The fact that the voltage was is no sign of dead batteries anymore, as any kind of protected cell will show 0V if it was shorted for a moment or discharged to fast. One should not expect any more care from a user.

Ok, after going through the accident again, this would have been absolutely no issue with any kind of venting design:

The first sound of problems was seemingly a single cell venting. This was followed by additional vents some moments later (probably accelerated because of temperature and pressure buildup). That lead to a cascade that eventually produced enough pressure to RIP OUT THE THREADS.

Which means that there was absolutely no weak point for pressure release in the design than _ripping apart metal_. People have been talking about pipebombs pretty often, but this really fitted the definition. Have a slow deflagration and contain it long enough for a pressure vessel burst.

What I find curious is the fact that the battery chamber seems to be toally contained. Not even the switch or the glass window worked as a release (people say bad things about glass fagments going anywhere, but it really is preferable to pipebomb shrapnell).


And for those who make those analogies about guns, cars, etc. Yes, users have to be careful. But that does not mean that the products is allowed to be a deadtrap.
Just try selling:

- a gun without any safety and a hairtrigger
- a car which has no upward shielding around the transmission that will send gears through the driver if it fouls up
- a chainsaw that has a on/off switch instead of a dead-man button (would it not be much more convenient?)
- a hairdryer without a protection sieve on the fan inlet

And hope there wont be any backlash if it goes south.
I mean, following that argument, you would KNOW that you have to be carefull when working a chainsaw. So why do you need a saw-brake and two operation buttons? Would it not be the users fault if he isnt carefull?

No, that wont work for a chainsaw. And a chainsaw is a thing that earns enough respect that people put it into horror movies.

Flashlights, no matter how big, are NOT in the same class of respect. Because one does need to assume that if you are not put into a situation of potential danger.

Just imagine that light would have been used in a crowed to show of its power. The shrapnell would have hit somebody. Around here, there was a death some years ago because somebody put fireworks in a tincan and a metal sliver ripped through somebodies artery.

PS: There is nothing really wrong with the batteries. They behaved nicely. Reverse-charging with 20A+ WILL result in venting, thats what they are designed for. Putting them where the venting gases cannot go anywhere is the problem.

Your point is well taken, maybe there should be a vent solution made or added to a containment this big, and under this load. I really don't know enough about this type of battery to be sure, do you? However I think there was more than venting going on. There was shorting, and a chain reaction, no practical vent short of a breakaway body ring could have mitigated something like that unless you want a 500 dollar flashlight full of half inch holes that you can't take out in inclement weather. Furthermore under normal conditions with a balanced and maintained pack any normal venting would be able to sneak out without building up too much pressure, these are water resistant, not dive lights. Positive pressure can and does escape through the O rings and switch housing.

Ok, after going through the accident again, this would have been absolutely no issue with any kind of venting design:

That's a pretty confident assertion, I have to disagree though, when you hear popcorn in a light there is more than venting going on, there is failure and bursts, the events would cause even more heat from instant discharge and affect the adjoining cells causing them to fail, at some point the vapor would just flash from the heat whether it is flammable or not under the heat/pressure conditions. The flash causes explosive pressure which no vent would be able to handle at that point in the event. The burst of catostrophic failure from a short or heat would occur even in an open charger or a perfectly vented light using an pack with dead cells next to charged ones under that load, granted it wouldnt be as damaging, but might cause a fire instead of a blast..

There is nothing really wrong with the batteries. They behaved nicely. Reverse-charging with 20A+ WILL result in venting, thats what they are designed for.

They are not designed to be reverse charged, that is why they fail when not balance conditioned and charged.

If someone can post the basic dimensions for the battery tube (diameter, length, and wall thickness) then there's a pressure vessel equation to calculate what it took to rupture the tube; and from that photo that showed the tube split apart, it looks like it DID rupture the tube itself, unless I'm looking at it wrong.

BTW, I'm guessing this was aluminum? 6061-T6?

Take into consideration also the heat, Hopefully the OP will let us know if there was any signs of melting or welding on the inside, but assuredly there was some incredible heat at some point before the aluminum failed. I'm also curious what charger was used.

 

[cmacclel]

The battery's in this light are not protected type battery's. Currently there are no *High Current* protected cells available on the market.

Mac

 

[Sabrewolf]

WOWSERS!
I just read through most of this thread, And have to say..
I hope you are okay!!

Maybee we should start a little donation fund to help you out
in case the proverbial feces hits the fan with the insurance company..

Subscribing to this thread for sure

 

[Chrontius]

That's a pretty confident assertion, I have to disagree though, when you hear popcorn in a light there is more than venting going on, there is failure and bursts, the events would cause even more heat from instant discharge and affect the adjoining cells causing them to fail, at some point the vapor would just flash from the heat whether it is flammable or not under the heat/pressure conditions. The flash causes explosive pressure which no vent would be able to handle at that point in the event. The burst of catostrophic failure from a short or heat would occur even in an open charger or a perfectly vented light using an pack with dead cells next to charged ones under that load, granted it wouldnt be as damaging, but might cause a fire instead of a blast...

First, to quote Demoman, "ka-boom!"

Holy poop dude, I'm incredibly glad you set that thing down and got a bit of cover. I can only hope I have as much presence of mind should such a thing ever happen to me... incidentally, I think my Pelican M3 LED has just such a burst disk in the tailcap.

Second, emphasis mine. Are you implying a diesel-style combustion event happened after the batteries vented?

Edit: I'm reconsidering using my Pineapple body with my IMR-E2 configuration. Talk about a pipe bomb, that's practically a hand grenade.

Edit2: You know, my chainsaw actually *does* have a latching on-switch. It's required to start the engine. I can see how it's dangerous, and how they tried to make it inherently safe, but I can also see how to bypass those safety mechanisms. YMMV. Hope I didn't kill your metaphor.

 

[Nightstalker1993]

To think, Electrolumens makes a 12x 18650 light:devil:!!!

OT a bit,

My friend owns it and its now in my bedroom, right after reading this thread, immidietly stripped off all the batteries and did a voltage check. 8 of the batteries checks in at 3.87v while 4 checks in at 4.03v. Any idea? I remembered all the batteries were at 4.2v when i installed it! :shrug:

anyway, to the TS, glad you're safe! Now i'm wondering if i should give back the Kong to my friend! :thinking:

 

[Bullzeyebill]

Going back to my former assertion, a ZTS tester is no substitute for a good voltage meter, or a DMM when using Li-Ion's. Being suspicious of the four cells that tested O with the ZTS, a voltage meter could/should have been employed to see what the actual voltage of those cells was, and then when recharged what the voltage was after charging, and then again used to see if they would hold the voltage.

Bill

 

[modamag]

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?

 

[Databyter]

First, to quote Demoman, "ka-boom!"
Are you implying a diesel-style combustion event happened after the batteries vented?

Not Diesel, because in a diesel the rapid increase of pressure itself is so high that it ignites the fuel (although it is worthy to note that any rapid rise in pressure does cause alot of heat in itself).

What I'm saying is the failure quickly created a high pressure high temperature condition filled with gaseous and particulate vapors from the battery chemistry, melted plastic and oils etc, and that particulate vapor at some point flashed obviously due to the extent of the damage, the ignition source was undoubtedly related to electrical discharge..

 

[fyrstormer]

The battery's in this light are not protected type battery's. Currently there are no *High Current* protected cells available on the market.

Mac

You can get around that by running cells in parallel though.

 

[dcaprilia]

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.

Im glad I got out of it ok too. It could have been really bad. I kind of inhaled the outgas in the balcony for the duration of the incident. How bad is it? I was thinking of going to the doctor like the other members advised but I feel it will be a waste of time. They will look at me and see no physical mark and say "your free to go".

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?)

Sorry, I dont know what 4S or 2S2P configuration looks like. I didnt rearrange the batteries. I placed them back the way it came to me. The four cells that I charged were placed at the bottom of the battery holder.

Correction- I do know what 4 series or 2 series 2 parallel looks like. I just didnt know the lingo.

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?)

I used 2 ultrafire rapid chargers. I placed them in the charger and plugged them in. The light turned red and I left it.

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.

Correct


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%

correct

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

Correct

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?)

I didnt notice the switchboot. As soon as I heard a fizz and a pop, I dropped the light turned and jumped on my bench

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?

Yes.

 

[Chrontius]

The battery vented anhydrous hydrofluoric acid. This is formed by the reaction of the lithium hexafluoride electrolyte with water.

The following stage is to fill the cell with the electrolyte and seal it. This must be carried out in a "dry room" since the electrolyte reacts with water. Moisture will cause the electrolyte to decompose with the emission of toxic gases. Lithium Hexafluoride (LiPF6) for instance, one of the most commonly used electrolyte materials, reacts with water forming toxic hydrofluoric acid (HF).

Hydrofluoric acid is an extremely corrosive liquid and is a contact poison. It should be handled with extreme care, beyond that accorded to other mineral acids. Owing to its low dissociation constant, HF penetrates tissue more quickly than typical acids. Because of the ability of hydrofluoric acid to penetrate tissue, poisoning can occur readily through exposure of skin or eyes, or when inhaled or swallowed. Symptoms of exposure to hydrofluoric acid may not be immediately evident. HF interferes with nerve function, meaning that burns may not initially be painful. Accidental exposures can go unnoticed, delaying treatment and increasing the extent and seriousness of the injury.[7]

The danger in handling hydrofluoric acid is extreme, as skin saturation with the acid in areas of only 25 square inches (160 cm2) may be relatively painless, yet ultimately fatal. High concentrations of hydrofluoric acid and hydrogen fluoride gas will also quickly destroy the corneas of the eyes.

At the very minimum, contact your poison control center.

 

[dcaprilia]

The battery vented anhydrous hydrofluoric acid. This is formed by the reaction of the lithium hexafluoride electrolyte with water.


At the very minimum, contact your poison control center.

Ok, thats bad. Thank you for the info Chrontius. I will try and go now.

 

[Flashlight_Bug]

Wonder if airlines will start banning these kind of flashlights from aircraft. Doesn't seem to take much for Osama's boys to turn a 12 X 18650 light like the Kong or this particular light into a bomb, ship it onboard unsuspectingly via USPS and . This is a matter of international security.