ROAR of the Pelican (CR123 Explosion during use, firsthand account)

Newbie,

Was it definitely the "100%" cell that vented? I've been looking at the pictures (brilliant, btw) and it seems to me that the visual evidence points more to the back end of the front cell giving way, than the front end of the rear cell, in spite of the front end of a cell being the expected route.

I'll try to explain what I'm thinking based on your recent photos...

This picture:



makes me think that the cell on the right is the one that was at the front (big round clear spot in the middle, where the button from the other cell was in contact with it).

So I'm thinking that this picture:



(front cell now on the left, if my thinking is correct) might indicate that the rear of the front cell gave way.

For example, their is no pattern of debris (I'm focusing on the black stuff) that suggests two vent holes at 180 degrees (to be expected, if the batteries in the pictures vented through their vent holes). In fact, some of the patterns (I'm just looking at the back of the left cell for this...) suggest a force applied from the outer of the cell to the inner. The bottom-left quadrant shows the black stuff accumulating not under the plastic wrapper, but about 1mm away from it. Also, the top-left quadrant, where the button from the other battery has left a thin "silver" arc at the button's perimeter, shows the black stuff very reliably accumulating at the innermost point of this thin arc, not the outermost point.

Granted, the forces at play could cause all sorts of unpredictable havoc, but I think the visual evidence is enough to justify the question. I suppose another way of addressing the question is how do both cells perform electrically? If the one on the right in the last picture I quote from you still performs, then this would suggest it was indeed the one on the left that failed, quite likely through its rear.

Newbie, I think you were lucky? in that the venting didn't ignite. The electrolyte components appear to be self oxidizing, and if ignited, result in a ~5" "roaring jet" like a blowtorch, lasting several seconds! (Based on events I've observed from a safe/armored distance. :green: ) The electrolyte itself possesses a fair amount of chemical potential energy, whether fresh or depleted!

Are PTCs made from thermoplastic materials? at what temperature do they soften sufficiently to be rendered ineffective/short through the cell crimp? Stored electrical potential energy is obviously raising a system component's temperature sufficiently for it to vent and sometimes ignite. If ignition occurs, the switch boot is going to do more than inflate!

:thumbsup: for some good science which will hopefully lead to avoidance awareness!

Larry

I know everyone is busy doing tests, but lunarmodule hassnt been on CPF (that i know of) lately
"Last Activity: 06-18-2006 07:40 AM"
Anyone know how he is doing, hopefully this isnt related to his cr123 accident...

OutdoorIdiot said:

Newbie,

Was it definitely the "100%" cell that vented? I've been looking at the pictures (brilliant, btw) and it seems to me that the visual evidence points more to the back end of the front cell giving way, than the front end of the rear cell, in spite of the front end of a cell being the expected route.

I'll try to explain what I'm thinking based on your recent photos...

This picture:

makes me think that the cell on the right is the one that was at the front (big round clear spot in the middle, where the button from the other cell was in contact with it).

So I'm thinking that this picture:

(front cell now on the left, if my thinking is correct) might indicate that the rear of the front cell gave way.

For example, their is no pattern of debris (I'm focusing on the black stuff) that suggests two vent holes at 180 degrees (to be expected, if the batteries in the pictures vented through their vent holes). In fact, some of the patterns (I'm just looking at the back of the left cell for this...) suggest a force applied from the outer of the cell to the inner. The bottom-left quadrant shows the black stuff accumulating not under the plastic wrapper, but about 1mm away from it. Also, the top-left quadrant, where the button from the other battery has left a thin "silver" arc at the button's perimeter, shows the black stuff very reliably accumulating at the innermost point of this thin arc, not the outermost point.

Granted, the forces at play could cause all sorts of unpredictable havoc, but I think the visual evidence is enough to justify the question. I suppose another way of addressing the question is how do both cells perform electrically? If the one on the right in the last picture I quote from you still performs, then this would suggest it was indeed the one on the left that failed, quite likely through its rear.

Click to expand...

If you look carefully at the blackened bottom, you will see a circle, with two divits in it, this is where the stuff came out from the venting cell, which is on the bottom.

I am *absolutely* certain it was the 100% cell that vented, zero question there.




On my first run tonight, I just caused another venting, this time I depleted the cell by 33%, to 67% remaining. I'm currently waiting for things to cool off. It looks like it didn't vent as much, as the switch cover didn't budge out as far.

So, basically, I am looking at 2 for 2. Proves nothing really, until I get the test count and see if they keep venting.

Remember, the cells are designed to vent, which is better than bursting on us.

A key thing, if you look at the photos, you will see there are no dent marks in the cells. Which discounts all the dent theories we had, in my results.

-----

Okay, Update:

Waited for the light to cool down to 65F. The boot didn't buldge nearly as far this time. Put on the protective gear and went back out to open up the light. Carefully opened it, much less of a hiss of gas comming out. The one of the cells vented, not sure which one, as there is zero debris, marks, etc.

Obviously this one was much less violent, which is a good thing.


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Good to see the protection mechanism doing what it's supposed to. Any ideas why the stronger cell vented?

Okay, started a third run on the partially depleted cell, another 30% depletion (70% remaining in cell) run with a new 100% cell.

The fireworks from the rodeo started, so I turned off the porch light.

I'm standing there watching the fireworks, and noticed the PM6 in the bucket, went out.

Cool, I figure, it takes a bit after the light goes out, and I can turn the video camera back on, and maybe catch it in action.

All of a sudden, kablamo, a sharp pinging, *BING*, not like the fireworks sound, but sharper, like a richocet.

Wife asks, "Whats that", I'm looking around wondering what just hit what from where and how.

Oh! I fire up my EDC, and look in the bucket. Aw, crap. I missed it, and now my PM6 is messed up.

This occured this time, within 41 minutes of starting the test, and within minute or two after the light went out.

After cool down, I'll don my protective equipment and go take some pictures.


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In the last picture, you can see what is a chunk of the bulb assy spring, that partially unwound, and in other pictures, you can see it looks like it cut/fractured/snapped on the bulb assy itself. The bulb spring is shorter now...thats one hot exhaust, velocity, or both. Thanks Beamhead, for noticing this!

The threads don't work all that great anymore, in the tail assy, I think they got reformed or something. They used to be smooth, and work good, it was *pretty* darn hard to unscrew. Possibly it jumped a thread or two, during the bang.

Notice how the cell bases are now dented after the explosion and buldged.


For now, that will terminate any further testing.

I'll have to run to the store to get another one (after boxes of batteries over the past month, and having to get a new light, this testing stuff gets *really* spendy)

Thanks again to Kevin of Battery Station for providing free cells for testing purposes!

Does anyone know if the new PM6's are sealed? Maybe if I am lucky, I'll find an old one at the store. Any way from the outside of the package to tell the difference?

Nice work NewBie! My congratulations.
Was it the fully charged cell that let go again?
If so, it begins to look as if the strong cell tries to dump so much energy into the weak cell plus the lamp that it is over-heating. Mixing used and new cells is really a no-no despite whichever way it happens.
Greg

Newbie,

This is brilliant stuff! I really hope you can get hold of another old style PM6. We (as in you) could well be on the verge of discovering something which is not only of great benefit to flashlight users, but also potentially to flashlight and/or battery designers. It would be more than a bit of a shame if you had to stop now...

I'm wondering what exactly happened in LunarModule's case. The results you've been getting seem very similar to his first explosion, where he described his tailcap rupturing, causing him to drop the flashlight. Then he described another explosion, this time involving venting with flame. Perhaps the initial build up of gas from one of the batteries placed a lot of pressure on battery components, then the sudden decompression when the tailcap ruptured caused something else to rupture, maybe exposing the lithium to the moist atmosphere, eventually resulting in the rapid venting with flame?

I'm also still very interested in which of the two batteries vent, if there is indeed a consistent pattern...

from the pic's new cell in bottom position vented for first test.

second venting occured on top cell, next to bulb. So cell being located next to bulb's heat may not be a factor?
Which cell was 100% in second venting?

Newbie, would you post your paypal? so cpf'er can send PP to help defray costs. This risky testing benifits everyone.

would be really cool if testing data isolates failure mode. repeatabilty of failure mode is golden!

Now What's your paypal?

NewBie said:

Notice how the cell bases are now dented after the explosion and buldged.


For now, that will terminate any further testing.

I'll have to run to the store to get another one (after boxes of batteries over the past month, and having to get a new light, this testing stuff gets *really* spendy)

Thanks again to Kevin of Battery Station for providing free cells for testing purposes!

Does anyone know if the new PM6's are sealed? Maybe if I am lucky, I'll find an old one at the store. Any way from the outside of the package to tell the difference?

Click to expand...

I can send him an old style Pelican M6 as I have a few donated here by CPFers and Pelican.

My tests here have involved an almost completely depleted cell along with a fresh cell and NewBie has been using a slightly depleted cell along with a fresh 100% cell. I shall alter some experiments here to that effect. It would appear that using a slightly depleted cell still allows for enough heat energy to be generated by the lower cell where my dead cell just begins reverse charging but does not get as hot.

I think there might be a possibility that the spring tension is affecting the PTC circuit so that as it gets hot it cannot function properly. Otherwise every time we shorted a cell here in a vise it should do the same thing. This has to have a lot to do with trapped heat. Could the heat be softening up the metal in the battery to the point where it flexes the PTC?

This all still makes me wonder why I ever got into the battery business. They are all dangerous.

If Newbie is willing and in fairness to Battery Station cells.

I'd like to send paypal and/or other major brands cells like Energizer CR123 to see if this can be repeated.

there's a thread offering Energizers CR123 cells right now...

cy said:

If Newbie is willing and in fairness to Battery Station cells.

I'd like to send paypal and/or other major brands cells like Energizer CR123 to see if this can be repeated.

there's a thread offering Energizers CR123 cells right now...

Click to expand...

I would be happy to supply him with anything he needs.

cy said:

from the pic's new cell in bottom position vented for first test.

second venting occured on top cell, next to bulb. So cell being located next to bulb's heat may not be a factor?
Which cell was 100% in second venting?

Newbie, would you post your paypal? so cpf'er can send PP to help defray costs. This risky testing benifits everyone.

would be really cool if testing data isolates failure mode. repeatabilty of failure mode is golden!

Now What's your paypal?

Click to expand...

Actually- this time, it was the top cell that vented, which is the depleted cell. I am certain of this too, first time it was the bottom cell, the middle run was a minor venting.

As far as my assurance which cell it is, I have been doing the depletion, inserting it into the light, then going into the house to get a fresh cell.

One pattern I realized, was the explosions/venting all happened in late evening, with the worst occuring the latest in the evening, this last one I started a bit after 10 PM.

All my previous tests were during the daytime, in the heat of the day.

Not sure yet, I need to run more of these tests with the BS cells during the heat of the day. What may be happening is in the heat of the day, more of the heat is comming from an external source, and the battery has to add less energy before the PTC kicks in. There may be a pretty long thermal time constant before the heat from the depths of the cell reaches the PTC. I have watched the PTC kick in during a run, in the direct sun on a 100 degree day, watching the body temp of the flashlight hit 148-160F, and the light going dim or out, and then comming back on when things cool off. I saw no venting then, but I haven't done it with this same type of mismatched cell test. Who knows, I need to do more testing...

My PM6 was depleting a fresh set of cells in an hour to an hour and a half, and it would pull from 1.29A to 1.5A (fresh cells), depending a bit on the cell, and this would drop a bit during the run- as the cells depleted. Kevin, to partially deplete the cell, I am discharging it for 20 minutes at 1.5A- before inserting it into the light.

When I get a chance, I'll look and at the PTCs, I have a few here.

Cmoore has donated one of his old flashlights for testing, having a back up one would be nice. Kevin should probably keep his lights, for his own testing.

3 for 3 is quite a record here Newbie!! It would sure seem that you are the way to identifying a set of event conditions!! Good job! Your speculation on ambient conditions and their possible contribution is very interesting and seemingly contrary to what one would expect. From some of my own investigations, ambient humidity with the same temperature had significant impact on the steady state operating temperatures of the light and the efficiencies of the cells, with runtimes noticibly impacted.

If I can be of any service or support, you know how to reach me! Perhaps a special battery tube or tail cap with a fitting mounted on the tail with a pressure gauge attached? Thermacouple?

Kevin, I feel your pain and understand your concerns!!! There is the oft used justification that If I didn't provide this to folks, someone else would. Well this is true in your case but the someone else might not be as forthright or concerned and wanting to get to the bottom of any possible safety risks!! I aplaud your concern, and responsible, proactive approach here! Your support and willingness to seek the truth even if contrary to personal vested interests sets you above the typical and in the realm of the special, IMHO. I hope the community will in turn show you support.

McGizmo said:

3 for 3 is quite a record here Newbie!! It would sure seem that you are the way to identifying a set of event conditions!! Good job! Your speculation on ambient conditions and their possible contribution is very interesting and seemingly contrary to what one would expect. From some of my own investigations, ambient humidity with the same temperature had significant impact on the steady state operating temperatures of the light and the efficiencies of the cells, with runtimes noticibly impacted.

If I can be of any service or support, you know how to reach me! Perhaps a special battery tube or tail cap with a fitting mounted on the tail with a pressure gauge attached? Thermacouple?

Kevin, I feel your pain and understand your concerns!!! There is the oft used justification that If I didn't provide this to folks, someone else would. Well this is true in your case but the someone else might not be as forthright or concerned and wanting to get to the bottom of any possible safety risks!! I aplaud your concern, and responsible, proactive approach here! Your support and willingness to seek the truth even if contrary to personal vested interests sets you above the typical and in the realm of the special, IMHO. I hope the community will in turn show you support.

Click to expand...

Thanks. I have alot more testing that I'd like to do, and I'd even like to "instrument" a flashlight up, to monitor internal temps, voltages, currents, etc. But it all takes time, and this is a spare time hobby type thing.

First thing is to do a few more tests, and see what the failure ratio under these conditions is. Then I'd like to change one condition at a time, and keep the others as close as I can (I'm at the mercy of mother nature here at home...)

I've devoted a rather decent amount of personal time over the past month, recently running tests into the midnight hours, and probably too much cash on Lithium 123 Primary cells. The cells that Kevin provided were a nice relief.

The reason why I've done this of my own accord, is it really bothers me, when a fun hobby ends up hurting the hobbyist. So, I've been doing a bit of research for awhile now, running several tests each night, and more on the weekends, for about the past month.

I was about to give up, and consider the actual failures we have seen, more as a fluke, one of those one in a million type things. But there have been too many failures for that, but the doubts were piling up. The additional cells Kevin provided, kept me going, the least I could do for something I got for free, and allowed me to finally uncover something.

At the moment, it seems fairly repeatable- so far.

The partial cell depletion, coupled with cooler evening ambient temperature (65F-70F), appears at the moment to be the proper combination. What is a little bothersome about all this is that many folks around here have gotten cells which didn't last very long, some cells leaking while in their original packaging, so the scenario might not be as uncommon as one would at first think.

There have been examples in the past, where folks mixed cells of various brands, or put a new one in with a partial depleted one, and they have had venting or other issues.

At the moment, Kevin of Battery Station, seems to be expending extra effort to actually test his cells, the best way he knows how, to assure that the cells are matched in as full up battery (not depleted at all) as well as he can. This step, after finding 3 out of 3 venting incidents in the partial depletion scenarios, in hind sight, was a *very* prudent move on his part.

The good thing, is in all the failure tests so far, is that the cells vented as designed. They didn't not vent, which would lead to build up of pressure within the cell, and lead to a explosion of the cell itself.

My hats off to you Kevin, thank you very much the free cells for testing purposes!


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Newbie,

Is that a thermometer in post #613? If so, is that reading in Celsius or Fahrenheit? It appears that's a flashlight body reading of 86. Hence my question.

From what I've been newly introduced to by the fine work done on this forum, CR123's internally gas at 80C/176F. To get the flashlight's body to reach 86 the battery(s) must be considerably hotter. Possibly hot enough to reach the approximate cell venting temp of 140C/285F.

As you mentioned fully instrumenting/installing sensors is highly desirable.

Your good work is appreciated.

g36pilot said:

Newbie,

Is that a thermometer in post #613? If so, is that reading in Celsius or Fahrenheit? It appears that's a flashlight body reading of 86. Hence my question.

From what I've been newly introduced to by the fine work done on this forum, CR123's internally gas at 80C/176F. To get the flashlight's body to reach 86 the battery(s) must be considerably hotter. Possibly hot enough to reach the approximate cell venting temp of 140C/285F.

As you mentioned fully instrumenting/installing sensors is highly desirable.

Your good work is appreciated.

Click to expand...

It is 86 F. The hottest I've seen the body of the flashlight is 155 F on a 100 degree day, in the sun.

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..
...
.... . The Final chapter to this ... so far - 637 Post Thread ....


...... Can be found .... in THIS > Cheers'N'Jeers ForumTHREAD . !




This part is a shocker ................................ at least to MANY !




( Many didn't know about this lost episode )


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TooManyGizmos said:

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The Final chapter to this ... 637 Post Thread ......
...... Can be found .... in THIS > Cheers'N'Jeers Forum THREAD

Click to expand...

No, that's *not* the final chapter.

The significance of this thread goes far beyond the reported incident that sparked it off. This incident led to people experimenting with CR123's in various configurations, and some of these experiments (like the ones conducted by Newbie) may well be the key towards a much better understanding of what makes CR123's vent. And that in turn may help people avoid such incidents in the future.

We're not yet there, there's still much that isn't really clear, but already many people are more aware of the potential dangers of CR123's and the things they should *not* do than ever before.

If that's the end result it was all worth it.

Hans

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.. Some people in that Cheers'N'Jeers thread are wondering if there was ever a legitimate reason for the tests to be done .


I admit ..... I am BEWILDERED by this !


And I don't know why the topics and situations raised in that Cheers'N'Jeers thread , have not been divulged here in this thread. I hope Kevin of BatteryStation is aware of that thread. It casts doubts. Kevin has not posted in that thread - so I wonder if he is aware of all the controversy . I only found the thread 2 hours ago , myself. I was amazed at what I was reading ........ now I'm suspicious .


This is all "Twilight Zone" stuff .


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