TK Monster Explosion

[BentHeadTX]

LiMn is SAFER than regular lithium-ion but LiFePO4 it ain't!

Only lithium-iron-phosphate cells can be crushed, have a nail driven through them or shot with bullets and just vent. However! The LiFePO4 batteries I use (DeWalt 123 Systems cells) have a battery management system (BMS) board and a fuse built in to protect them and you from 10 cells in series throwing over 100 amps of pure hell output.

If you need 28.8V from LiMn, just use a Milwaukee 28V drill battery. It has the 8 cells but a BMS to prevent cells going nuts from being reverse charged by loading in dead cells with live cells. The BMS will signal the charger (when charging)that there is a problem and shut down. The BMS will also shut down the pack when discharging if any cell drops below a specific low voltage cutoff level.

I tested two drills, a DeWalt "36V" (actually 32V) A123 Systems LiFePO4 pack VS the Milwaukee 28V drill and we all preferred the DeWalt/A123 System packs. We noted that the LiMn cells would self-discharge very quickly (a week or two) VS the LiFePO4 holding their charge. Ironically, one of the 28V Milwaukee batteries popped, vented a little and the charger shut down fast!

If you want to play with powerful lights, get powerful battery SYSTEMS to power them. ANY lithium battery system will have cell voltage detection for EACH cell to shut down the pack if any cells drops below a specific voltage (around 2 to 2.5V depending) The BMS takes care of that issue.

It sounds like the LiMn cells self-discharged in shipping and were damaged from being dropped that low in voltage. (wonder how cold it gets in aircraft mail bays) When you "recharged" them, they were statically charged quickly since their mAH level approached zero. Amazing how fast dead batteries will charge when they have 1 mAH of capacity.

When 4sevens announced the S1200, I posted it better run a LiFePO4 battery pack to handle the current pulled by the SST-90 (it does) Although you can beat the crap out of a LiFePO4, put a nail through one etc...it will still vent some gas. If you decide to get the A123 Systems 18650 cells, run a BMS board and put some sort of vent in the tube. Venting through a rubber boot cover on a tail switch works well. I've had NiMH vent because I shorted a wire to an LED group and my switch did the balloon move (thankfully)

I am very edgy around batteries myself, it has to do with 25 years experience with medical equipment and the huge NiCad portable X-Ray packs from the 80s, gel-cell pack problems in the 90's and exploding primary lithium packs used in Automatic External Defibrillators (AED) from the last decade. When looking at a Cardiac Science AED, I asked what was inside the battery pack. The guy pulled out a clear plastic covered version of the lithium primary pack and I saw several large lithium cells inside, complete with a BMS with signal wires going to EACH CELL of the battery. The AED monitored the battery from the BMS and if it ever went weird on any cell, overheated or was getting low in voltage...it would shut down the AED and give a bad battery flash warning you there was a problem.

So I read about Surefires that use 6 CR123A cells in series/parallel under a heavy load with a runtime of 20 minutes. The S1800 SST-90 light uses 6 CR123A batteries...sorry folks, I'm not going to die for a flashlight! Give me LiFePO4 or NiMH so I'll have a gas vent and ballooned switch to live another day.

As far as the exploding Li-ion cells, I would use them if, and only if they have a battery management system board (protected) One cell, only one cell though and make sure the tail switch will vent pressure through it. Shorts happen so the BMS will shut the pack down if there is a problem with the light. The down side of BMS is it does not take into account of declining capacity of the cell so your "C" rate you pull off the cell goes up with age.

You can play nice with lithium and it will play nice back as long as the rules are followed. Battery management boards for protection, fuses backing up the BMS (usually they are on the BMS) Some way to vent the battery vapor just in case and thermal protection so the charger will shut down and warn you if the battery starts to heat up when charging. Exotic BMS systems for electric bikes/motorcycles/cars monitor the temperature of each cell when charging or discharging, I guess if I had (no way in hell!) a Tesla electric car, it would be a bummer if those 6,900+ 3.6V 18650 lithium-ion cells started going off like firecrackers.

Don't worry, the rest of the electric car world is going to LiFePO4 so no need to call Homeland Security to notify them your car's battery pack is starting to vent. (I want to see a Tesla battery pack in salt water from at least a mile upwind.)

So the next time you take your uber-cool and ultra-bright twisty li-ion powered flashlight out of your pocket...think what that sealed tube with Lithium-Cobalt-Oxide battery is snuggled up to. I prefer to remain a bull...not a steer.

Now back to my 2AA NiMH Eneloop powered XP-G R5 goodness....

 

[sledhead]

This is just an unbelievable event! Thank goodness you are okay Derrick. Hopefully the building insurance will come through! I would take several other members advice and get checked out by a Doc for sure. Health is priority.

 

[Databyter]

looking at the damage to the building, and reading another newer post where 6 glass roof panels are also cracked,

im *guestimating* a repair bill of $6000 or more.

but that is nothing compared to the loss of a hand or a childs life.

Wow, that's alot of money!
My main point about the waiver is that when someone sign a liability waiver at the bottom of a serious warning, with some instructions, it opens the eyes to the possiblities that, hey this thing is serious! If on the other hand buyers have no responsibility and it's all fun and games, this does not promote safety, knowledge, or responsibility in handling potentially dangerous appliances around the house, the hand and the kid, and in cases like this the buyer was innocently not aware there was any reason for concern about balancing the cells beyond the attempt to charge them..

I know it would make me think twice If I bought say a candy bar and there was a liability waiver for eating it. I would think, hey what's in this thing, how does it work, why the warning. See what I mean? It's not about the money, its about the responsibility to yourself, family and neighbors, that's what the waiver should remind us of. And as I said, it's just a suggestion, to know that if someone has signed it, then they have read your descriptive instructions and warning. It's a responsible solution imho.

Good guess on the damage cost, I had no idea Wow.

 

[Databyter]

Very true.... You are close to the estimate as well. One of my neighbors panels broke and he had to pay P73,000 or about $1,500/ panel. So thats $4,500 for my glass and another who knows for the panels downstairs. I really hope Ill get help from the building insurance. Ill be putting up some of my lights for sale within a week or so to pay for the damage (hopefully just the deductable).

I again invite you to think about taking donations, this thing is just a terrible blow and all your intentions were good.

I think a little bit from a lot of us could really help you out. I hope for the insurance as well, but I doubt they will cover all of your expenses, but who knows :thinking: hopefully. Maybe you wouldn't have to have a "fire sale" with your other lights.

Include in expenses, taking the wife out to dinner, I hope she is an understanding lady

Wives are so much more dangerous than flashlights when mad!

 

[LightChaser]

I skipped this thread yesterday thinking it wasn't an actual explosion, but now I know better. I'm glad to know nobody got badly hurt, but I know all that property damage is painful too. Here's hoping your building's insurance covers most of the damage.

 

[Juggernaut]

Using the car analogy, not that the driver could or would crash because he doesn't know how to drive it and went to fast around a turn, but that in turning on the engine the car blew up, this would not be considered an acceptable product. If this were a commercial product from a major corporation it might have been submitted to Underwriter's Laboratories for safety testing. It may have failed or they may have deemed it as potentially unsafe simply in the fact that it uses 8 unprotected Lith Ion batteries and has no venting.

Not trying to be argumentative, or anything, but using the car analogy: nonflashaholic light cost: $10, average car buyer's car: $16,000. Super flashaholic light: $550+ dollars that's a ratio of 55. How many average Joe's are buying $880,000 cars!? If you had $880,000 to spurge on a car and didn't realize that putting low octane in it would make the car turn into a thermonuclear weapon, then I don't think this would be a problem for most users.

Flashlights like anything, can be extremely dangerous once they begin to push the envelope for what is, and what isn't possible. Living on the edge is just one of the factors that come into the "want" when it comes down to this sort of stuff. Look at most extreme motor sports, at any moment the user may end up dead, but that's half of the excitement. If we play it safe all the time, life is just to dull. Something like this would never turn
me off from a product, it would just earn more respect.

I'm happy the user got away with no serious harm:thumbsup:, but look at it this way: for a few thousand dollars in expenses Dcaprilia will have some Epic bar stories! I'm mean how cool does this sound: "Yea, I had this flashlight so powerful the moment I turned it on the thing detonated like a bomb, leveling my patio, while taking out the roof on an adjacent building!". That's a pretty sick story, and one that's not made-up to boot, I'd like to see any of his friends beat that one out:bow:!

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

 

[fiftycalibre]

I havent had any problems with my TK Monster at all. All my cells have never showed any indication of a problem. My cells look like the ones pictured but with a full length sleeve.

I only use mine outdoors and in controlled conditions.



That is INSANE what happened. Good to hear you are fine.

 

[hopkins]

Suggested before that there needs to be a 'blow out' vent hole in all our
indestructible metal flashlights. Perhaps a small hole plugged with candle
wax would be enough for a DIY safety mod. Maintains waterproofness
but hopefully would pop out. Probably there exists some off the self 'putty' that is made for this kind of emergency vent application .

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

 

[Databyter]

Suggested before that there needs to be a 'blow out' vent hole in all our
indestructible metal flashlights. Perhaps a small hole plugged with candle
wax would be enough for a DIY safety mod. Maintains waterproofness
but hopefully would pop out. Probably there exists some off the self 'putty' that is made for this kind of emergency vent application .

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

Good idea, I was thinking of something along the same lines for a do it yourself one way vent mod.

In my idea I would drill a small hole in the tail-cap shaped to push out under extreme pressure (like a 60 % countersink angle), then I would fill it with a drop of 100" pure silicone clear caulking /sealant, perhaps tinted to the color of the light.

This dries clean would pup out of the angled hole under pressure as long as you don't get any on the inside face and just in the hole sides itself.

And here is the best part, stick a thin pin through the center of the silicone drop so that it enters the other side. remove pin carefully (grease it first). Under most conditions this will still be virtually water resistant, but under any internal pressure the elasticity would allow gasses to vent thru your pin hole. Under catastrophic failure and fast venting the entire plug would popout of your 1/16th hole.

Whaddaya think?

p.s. there are also small one way valves designed for this of course that would do the same, but how much and would you have to buy more than one I don't know. This would probably be more for a manufaturers consideration than a home modder, I like the tailcap thread slot mod sylanthie mentioned as well, but for smaller than that monster I would like to retain some water/moisture resistance. I think a pin holed silicone drop would work decently. Might have to re-do it every year or so.

None of my lights really requires this at all, so far.

 

[dcaprilia]

I again invite you to think about taking donations, this thing is just a terrible blow and all your intentions were good.

I think a little bit from a lot of us could really help you out. I hope for the insurance as well, but I doubt they will cover all of your expenses, but who knows :thinking: hopefully. Maybe you wouldn't have to have a "fire sale" with your other lights.

Include in expenses, taking the wife out to dinner, I hope she is an understanding lady

Wives are so much more dangerous than flashlights when mad!

Hahaha very true on the wifee bit I will get the exact amount of the damage and post it here. If its just the deductable, Ill sell some my lights to shoulder it. If I have to pay for everything, god knows... Ill need all the help I can get....Thanks again

I'm happy the user got away with no serious harm:thumbsup:, but look at it this way: for a few thousand dollars in expenses Dcaprilia will have some Epic bar stories! I'm mean how cool does this sound: "Yea, I had this flashlight so powerful the moment I turned it on the thing detonated like a bomb, leveling my patio, while taking out the roof on an adjacent building!". That's a pretty sick story, and one that's not made-up to boot, I'd like to see any of his friends beat that one out:bow:!

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

After explaining to the security last night that a flashlight exploded and seeing their expressions (the yeah right look?! ). I think Ill keep the story between us flashaholics.

More pictures...

 

[cmacclel]

All I can say is WOW!

What exactly did you mean by the other 4 batteries had "No Charge" what was their voltage?

After explaining to the security last night that a flashlight exploded and seeing their expressions (the yeah right look?! ). I think Ill keep the story between us flashaholics.

Show them the remainder of the burnt up parts of the flashlight.


Mac

 

[hopkins]

One small vent hole may not be enough. The pressure build up
could be so fast that several small vents would be needed to pop
to prevent this pipe-bomb effect of TK Monster.

Datab- yes I like the silicone, needle pierced vent plug idea.

Anyone guess what the psi range would be to cause the kind of
damage in the dcaprilia's photo's? Are we talking 1000's psi ? 10,000?

 

[dcaprilia]

Im using the ZTS- Pulse load battery tester- it uses percentages in telling how much voltage is left. When I checked them, no indicator light turned on so I assumed they were drained under 10%. Ive checked and charged other batteries like this just recently and they work fine.

All I can say is WOW!

What exactly did you mean by the other 4 batteries had "No Charge" what was their voltage?




Show them the remainder of the burnt up parts of the flashlight.


Mac

 

[cmacclel]

I just spoke with a friend that also has a ZTS pulse battery tester and he said even a 1.5v battery will light up the tester when placed in the li-ion section so your battery's must have been completey dead with 0v. The rule with Lithium cells is generally if they go below 2.5v then you should retire the cells.

Mac

 

[dcaprilia]

I just spoke with a friend that also has a ZTS pulse battery tester and he said even a 1.5v battery will light up the tester when placed in the li-ion section so your battery's must have been completey dead with 0v. The rule with Lithium cells is generally if they go below 2.5v then you should retire the cells.

Mac

I never knew that. Thanks Mac

 

[Stress_Test]

Anyone guess what the psi range would be to cause the kind of
damage in the dcaprilia's photo's? Are we talking 1000's psi ? 10,000?

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?

 

[Bullzeyebill]

I am trying to make some sense out of this thread. OP used a light that a friend had brought to him, and used 18650 cells that were not his own, that came with the light. I have been using protected and unprotected 18650's, and other length Li-Ions for several years in my lights. Have not used more than three in series, but, the Li-Ions I use in my lights are cells that I have maintained and have monitored closely.

As noted earlier, the clue the OP had early on was the four cells that were at 0 voltage, a condition that can occur when the low voltage protection circuit in an unprotected is triggered, usually a temporary condition that is easily remedied by placing the cell back on a charger as soon as possible to bring the cell back to a readable voltage, and that voltage should move up to 3.6 volts or so fairly quickly, and there will be no damage done to the cell. However, if left at the 0 voltage reading for a long period of time the cell may degrade, and become damaged, and give an unreliable voltage reading if returned to a charger. I have noticed this phenomena on several occasions.

Bill

 

[hoongern]

I am trying to make some sense out of this thread. OP used a light that a friend had brought to him, and used 18650 cells that were not his own, that came with the light. I have been using protected and unprotected 18650's, and other length Li-Ions for several years in my lights. Have not used more than three in series, but, the Li-Ions I use in my lights are cells that I have maintained and have monitored closely.

As noted earlier, the clue the OP had early on was the four cells that were at 0 voltage, a condition that can occur when the low voltage protection circuit in an unprotected is triggered, usually a temporary condition that is easily remedied by placing the cell back on a charger as soon as possible to bring the cell back to a readable voltage, and that voltage should move up to 3.6 volts or so fairly quickly, and there will be no damage done to the cell. However, if left at the 0 voltage reading for a long period of time the cell may degrade, and become damaged, and give an unreliable voltage reading if returned to a charger. I have noticed this phenomena on several occasions.

Bill

I don't believe the OP knew that the cells were at 0V as the ZTS battery tester he said he was using just didn't show a charge - and didn't realize that 0% meant 0V, or whether it could be 1V or 2.8V etc.

I'm still very surprised at the force of explosion given that these are supposed to be relatively safe chemistry cells.

 

[Bullzeyebill]

I don't believe the OP knew that the cells were at 0V as the ZTS battery tester he said he was using just didn't show a charge - and didn't realize that 0% meant 0V, or whether it could be 1V or 2.8V etc.

I'm still very surprised at the force of explosion given that these are supposed to be relatively safe chemistry cells.

My error, I did not know that a DMM, or some kind of voltmeter was not used, a real necessity with Li-Ions. Do not use Li-Ion cells, unless you have read, read, and then read some more about them. CPF provides the info you need via researching the dozens of threads on the subject. Do not just ask a question here on CPF in a single thread and expect to get the answers that you need. That pertains to this thread too, as this thread will not make you qualified to use Li-Ions properly. Go beyond that and spend several hours researching here.

Bill

 

[dcaprilia]

I am trying to make some sense out of this thread. OP used a light that a friend had brought to him, and used 18650 cells that were not his own, that came with the light. I have been using protected and unprotected 18650's, and other length Li-Ions for several years in my lights. Have not used more than three in series, but, the Li-Ions I use in my lights are cells that I have maintained and have monitored closely.

Bill

Apologies for being vague.

I purchased the light from this thread.

https://www.candlepowerforums.com/threads/261216

Since I dont live in the US, I had the light sent to a friend who came back to the Philippines the other day. 8 Sony 18650 cells originally came with the light. These are the same cells that I charged and placed back into the light.