A Little Accident. W/123's and a Peli. M6

Re: A Little Accident. Enjoy.

Well, according to a Website: (i'm not sure if this is an official website)
Pelican Page Safety Features

"An additional safety related attribute of Pelican flashlights is the built in patented hydrogen purge valve that allows explosive gases to harmlessly leave the battery compartments. <font color="red">In addition to this patented safety feature, pellets have been encapsulated into every Pelican flashlight</font>. These tiny catalyst pellets combine outgasing hydrogen discharging from batteries with ambient air trapped inside all flashlights, changing the mixture to harmless water droplets. This serves as an additional "backup" fail-safe not found in other lights. Battery powered flashlights are potentially dangerous due to the hydrogen gas given off by over heated battery cells exploding as the unit is turned on.

This has resulted in occasions where the flashlight can explode, causing bodily harm. To combat this potentially dangerous situation, Pelican flashlights now incorporate a special one-way valve that allows small amounts of hydrogen gas to harmlessly escape, yet prevents the ingress of ambient explosive gases..."

I am not a pelican expert, but it says so right there...

Re: A Little Accident. Enjoy.

Ummm... I don't think that is Pelican's official home page. AFAIK (I could be wrong) their official home page is at http://www.pelican.com/

EDIT: I did some more digging and found that the M6 is still listed as pending as far as approvals.

http://www.pelican.com/small_lights/li_2320_m6_lithium.htm

Re: A Little Accident. Enjoy.

DC:
Lol, i do not know if it is the official homepage. Let me edit my post to reflect that.

However, if you go to pelican.com and look for the M6, it does have the 'you break it, we replace it' guarantee!

Re: A Little Accident. Enjoy.

The PM6 does not have that I'm aware of the obvious safety valve that my Super Sabrelite and StealthLites have.
The UK-2L does not have a safety valve either (I've lent mine out but I'm pretty sure it doesn't).

Al

Re: A Little Accident. Enjoy.

I still have this UKE-2L that exploded , along with all the parts and the two batteries in a little tupperware container.

I'd be happy to mail it to someone in the USA that would like to do a post mortem. Free, including postage.

Just say you want it here and then PM your shipping info to me, I'll get it in the mail Monday morning. The first to do both of those things will get it.

Britt

Re: A Little Accident. Enjoy.

True, Pelican does have the "You break it, we replace it... forever." tagline. Would be interesting to find out just how far they will hold true to that.

FWIW, I own a Pelican M6 (Xenon) and it does not have any safety valve that I am aware of.

Re: A Little Accident. Enjoy.

The UKL2 has a hole under the first O-ring (the one near the body) to vent.

Re: A Little Accident. Enjoy.

[ QUOTE ]
RY3 said:
Hi. Thanks for all the comments and suggestion. I didn't even think of corrosive when we did the cleaning. Opps.

I learn later from my wife's confession /ubbthreads/images/graemlins/smile.gif that before she use the PM6, she did turned on the UK2L but it was very dim.
So I was incorrect when I originally thought it has no batteries in the UK2L.

In other words, there were 4 batteries involved here. A Surefire, a Duracell, a DP and one unknown.
So at least one of the flashlight had mixed brand of batteries.

I am not sure about the theory that the UK-2L started the accident.
The battery compartment of UK2L was clean. There wasn't any residues that I can see.
The picture that I posted looks like there was burn mark and a hole at the tail but there wasn't. It was just the camera angle.
On the other hand, the inside of the PM6 was full of black residues.

Also, the inside of the Surefire was relatively clean when compare to the unknown one. I believe the unknown cell was the cause.

I look under my microscope but still can not identify it. It "seem" to have some blue tint but I also seeing some red.

http://img9.exs.cx/img9/6130/p1020270c9km.jpg

http://img179.exs.cx/img179/2880/p1020276c3hw.jpg

The other side..
http://img179.exs.cx/img179/9822/p1020277c8fa.jpg

Images replaced with links due to size. Please do not post pics wider than 800 pixels.

B@rt

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The two top battery contacts, can you get us photos of those, and or count the vent holes?

On the base of SureFire and Engergizer cells, dead center, you will see a small circular dimple. Could you look for that?

Re: A Little Accident. Enjoy.

[ QUOTE ]
NewBie said:



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Newbie, if Im not mistaken, every CR123 battery in existence has those two vent holes.

Re: A Little Accident. Enjoy.

I currently have both a titanium battery and a SF 123 battery in front of me. When I look at the wrappings in the pictures, I can see that the wrapping is a darker color of red, unlike the Titanium battery which is a more lighter hue of red. Also, the titanium battery has a different design under the + contact button. I wish I can post pictures, but I cant find any of my cameras or the USB connectors. Others who own these will probably understand. On SF cells, you can see that there is black plastic surrounding the vent hole. The surrounding plastic is a complete circle with no hole in it. On a titanium cell however, that plastic circle is really a sort of + shaped design with the + contact button in the middle of it. This picture I made in paint should fit the description.
http://img133.exs.cx/my.php?loc=img133&image=untitled7ph.png
When I looked in the given pictures, the top of the battery looked a lot like an SF battery. But I may be mistaken. The battery might have been a Titanium battery, and the black surrounding plastic might have fused together into one piece from the heat of the explosion. Then again... I wont make any assumptions since I am not sure of anything.

Re: A Little Accident. Enjoy.

[ QUOTE ]
Mags_despiser said:
[ QUOTE ]
NewBie said:



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Newbie, if Im not mistaken, every CR123 battery in existence has those two vent holes.

[/ QUOTE ]


You are mistaken:




Furthermore, amongst the two vent hole cells, the placement of where those two holes are on the side of the "nipple" (up towards the top as in the SureFire/Energizer cells, vs. lower with other cells) further helps identify who's cell it is. There are also differences in crimping, the bottom plastic ring, the top plastic disk, and plenty of other things.

Re: A Little Accident. Enjoy.

Thanks for fixing the pictures Bart. Sorry about that.

When I first posting this thread, my intention was just to share my experience, not to blame or pointing finger to anyone or anything. As someone mentioned, what's life without some sort of dangerous and excitement although I am not sure if my wife will agree. Now like some of you, I am interested to find out what is the brand of the unknown cell.

Anyway, here are the pictures. The one on the left has two parts. I include the botton part that "I think" belong to the one on the right. Also, I can't see any marking on the bottom of the cells.

Re: A Little Accident. Enjoy.

What about other lithiums, like AA and AAAs?

Hydrogen venting only occurs after useage right? So keeping cells in a pelican case (like batterystation's package deal) is ok?

Re: A Little Accident. Enjoy.

I think I'll have a look at how I've got my cells stored. I think CSI will need to check this one out. I've got these and other batteries stashed all over the place!

chiphead

Re: A Little Accident. Enjoy.

[ QUOTE ]
SilverFox said:
The vent is supposed to relieve the pressure build up in a controlled way.


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A vent on a battery isn't going to do a blind bit of good if the battery is inside a sealed container such as a flashlight body. The flashlight tube will turn into a pipe bomb when it can no longer contain the gas pressure.

Store lithium-powered lights with the tailcaps off.

Re: A Little Accident. Enjoy.

Lithium batteries discharge sulfur-dioxide gas. There is a slow industry trend toward a safer lithium-manganese composition. Many lithium batteries for modern military application are of lithium-manganese composition. Example;
http://www.ulbi.com/ and http://www.ulbi.com/market-display.asp?ID=7

Re: A Little Accident. Enjoy.

This is dangerous, man!! Good thing you weren't EDCing it when this happened,RY3. I happen to have a 12 pack SFcr123s in my dehumidifying box now, and it worries me. /ubbthreads/images/graemlins/eek.gif Will the cells blow only when they are in a light? I am also interested in what response SF gave you on the batts, i mean, this isn't just you average problem, someone could probably even sue them for this. Anyways, just glad that no one got hurt.

Re: A Little Accident. Enjoy.

WATER DIFFUSION IN LITHIUM-MANGANESE CELLS

This episode has been so scary to me that I have found compelling to explain it thoughtfully. I rely so heavily on my primary 123s that any safety based on excess of precaution would have brought me one era back…

Let me state first that the violence of the explosion requires more energy than the energy chemically stored in the battery.

Also, there is to explain why the overpressure and the PTC protections of the 123 battery haven't kicked in.

The only viable scenario, and a reproducible one, is a defective cell. Let me explain in what manner it was defective.

As you all know, the 123s are based on a non-water chemistry. They use an organic solvent, with a volatile compound (sulphur based) as electrolyte. This is because the electro-negativity of the lithium, used at the negative electrode is so high that it spontaneously decomposes the water into hydrogen and oxygen.

Assume that a 123 cell with a defective crimp was produced, and stored. The highly volatile electrolyte vanishes first, and this raises the internal resistance of the cell - so it has a flash-amp reading is 1 – 2 Amps instead of the usual 7+ Amps.
Subsequently the ambient water, normally contained in the air, is adsorbed through the defective crimp seal, by the manganese dioxide, and rests there. The manganese dioxide has an affinity with water.

So far, the cell is in a meta-stable state, just as a sleeping pipe-bomb.

Let's now assume the above cell is placed in a two cells light, totally sealed, in series with a good 123 cell.
The light is activated. It produces some light, since the defective cell will initially pump some current, for the first five minutes (tested), while heating up quickly due to the increased internal resistance.
After the first five minutes, the cell is being reverse charged from the good cell, and the stray water contained in the manganese dioxide reaches the hot lithium metal. It decomposes in hydrogen and oxygen very fast, while the lithium heats up some more.
This chemical reaction produces an explosive gas mixture that self-ignites soon after, shooting away the tail cap of the flashlight like a projectile.

The PTC (Positive Temperature Coefficient) protection, and the membrane piercing overpressure relief have no mean, or reason, to intervene in this process.

Based on my previous experience, I had a similar occurrence of defective crimped 123 cells with some DP brand cells, sold by a manufacturer no longer in business. Knowing the danger of water diffusion in lithium cells, I throw them away promptly. I strongly doubt that a SF or DL cell was the initiator of this small disaster.

As morale, if you are scared from this story, the only precaution I advice is to flash-amp your cells. Cells with defective crimps, that can present the risk of water diffusion, show a short-circuit current, otherwise called flash-amp, of 1- 2 Amp.
Another valid suggestion is to buy only cells built from a ISO certified factory!

Hope this helps

Anthony

Re: A Little Accident. Enjoy.

[ QUOTE ]
show a short-circuit current, otherwise called flash-amp, of 1- 2 Amp.

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/ubbthreads/images/graemlins/huh2.gif

How does this present itself on a DMM?

Re: A Little Accident. Enjoy.

To measure flash-amps, set your DMM on 20 Amp scale, and measure the current flowing through the 123 cell.
Remember to keep the reading shorter than one or two seconds.

Anthony