Dingo ate my tailcap!

Bimmerboy

Flashlight Enthusiast
Joined
Dec 30, 2004
Messages
2,091
Location
Long Island, NY
That's my story, and I'm sticking to it. :whistle:

Problem is, there are no Dingos on Long Island. Even if there were, there's no record of one that can safely discharge 8C of electric current, so that kinda' hurts my defense, as does the photographic evidence.

Your honor, the prosecution presents to the jury, exhibit A:

Notice the area of discoloration on both sides of this washer. Looks like it got awfully hot. It also looks like someone tried to clean it up in an attempt to conceal the evidence.
burntwasher1.jpg


burntwasher2.jpg



And, exhibit B:

Obviously, that spring has seen better days. It appears it was, at one time, flattened, then pulled out to act as if nothing happened. More signs of a cover up going on here!
burntspring1.jpg


burntspring2.jpg


Ladies, and gentlemen of the jury... this clearly shows the effects of dead shorting Lithium-Manganese batteries, caused by user error!

*Bimmerboy breaks down on the witness stand*

:mecry: I confess! I accidentally shorted my AW IMR16340's for approx. two seconds! :mecry:

I throw myself upon the mercy of the court. Here's how it happened...

I wanted to try two of these powerful, new rechargeables on a FM1794 with a FM-D26 socket/reflector in a SF C2. When it failed to light up, I figured it a contact issue, and needed the bent washer treatment. My negligence forthwith, lies in the fact that I left the batteries in the body after taking off the bezel, removing the socket, and simply dropping the washer into the body, assuming it would flip nicely into place, like a coin going into a wrapper.

Well, it didn't, and the results are displayed above. One side of the washer touched the inside flashlight body, the other side touched the positive button of the topmost batt. Faster than one could say "that wasn't supposed to happen", the washer started glowing bright red around where it was touching the battery. Now, this wouldn't have happened if not for the following... in the interest of saving time, I left the tailcap tightened so as to quickly test the drop-in for proper focus by simply pushing it down into the body.

What I didn't realize is that the poor tailcap spring got it worse than the washer. This was later discovered upon swapping the FM D26 with an M60, and wondering why it didn't work. That sucker was not only burnt, but squashed flat! It must've gotten so hot, that it lost it's temper. The only reason it could still work with the FM D26 is due to the extra long spring on the drop-in. The picture was taken after I stretched it back out a bit so it could work with the Malkoff. Wonder if Surefire can send me a spring, or if I can find a suitable replacement.

So, there you have it. This is what happens when you're not careful with high discharge energy stores. If two, little IMR16340's can practically melt a SF tailcap spring, I almost shudder at the thought of what my 26700's are capable of. At least they won't went with flame... lol.

I encourage others to have fun, but be sure to treat these batteries with respect... or the dingos will come for your tailcap too.
 
Wow, nice narrative and even better good fortune...

A BatteryUniversity description of IMR manganese chemistry says it takes 250° for that type of chemistry to spontaneously combust as opposed to 150° for cobalt. The 8C thing is a recommended continuous discharge limit. Not what happens when paper clips glow in the dark.

Our first real world successful test without protection circuits.:)
 
to Bimmerboy --


A very eloquent posting.

(and photos)

:goodjob:




And i totally Laughed Out Loud

when i read yer' thread's title !


:lolsign: <----- just like that ! ! !
_
 
Nice story.

That poor spring looks quite sick. It's good to see industrious members testing these cells to their max (be it intentionally or otherwise) :cool:
 
That nice flat spring will never dent another battery, and you will get a nice firm flat contact with the battery that might even reduce resistance, one of your goals in life. LOL

Bill
 
Giving the new multi-quote feature a workout. :D

First time using it. Great feature, and I discovered that it will remember the order of posts in which you click the button. For example, if you want to group quotes from posts two and four together, then from post three after that, just click the multi-quote button in the order you want, hit "post reply" at the bottom of the page, and presto. How cool is that?!

Anyway...

Wow, nice narrative and even better good fortune...

A BatteryUniversity description of IMR manganese chemistry says it takes 250° for that type of chemistry to spontaneously combust as opposed to 150° for cobalt. The 8C thing is a recommended continuous discharge limit. Not what happens when paper clips glow in the dark.

Our first real world successful test without protection circuits.:)

Thanks, Al. I didn't know there is a temperature at which the IMR's will combust. Time to do some brushing up at Battery University.

In keeping with that note...

To the gallows!!!!!!!! :grin2:
You are lucky there was no BOOM!:candle:

Haha... every time I read that, I CANNOT stop from hearing Marvin the Martian in my head. "What happened to the kaboom? There was supposed to be an earth shattering kaboom?!"

to Bimmerboy --


A very eloquent posting.

(and photos)

:goodjob:




And i totally Laughed Out Loud

when i read yer' thread's title !


:lolsign: <----- just like that ! ! !
_
:crackup::crackup::crackup:


Gr8 title there....


Any damage to the cells at all ??

Glad ya' both liked it! Made me laugh when I thought of it, so I went with it.

I suspect there's no damage to the cells, as the short was literally for two seconds. My hand was already starting to move toward grabbing the washer as it began glowing, I haven't given them another good test yet (just running them with a P90 in a 6P right now), but will at some point. Probably with a H1499.

LOL! How to weld a tailcap with 2x IMR16340s!

LOL... great idea for a tutorial dedicated to the criminally reckless flashaholic. :ohgeez:

If this was, indeed, caused by my accidental shorting (which still seems the likely scenario since no one else has reported melting SF twisties), them I'm still really impressed by how fast it happened. These little bad boys are powerful!


Nice story.

That poor spring looks quite sick. It's good to see industrious members testing these cells to their max (be it intentionally or otherwise) :cool:

Awww, it's not sick. It's just made of pwetty cowors now! :crazy:

That nice flat spring will never dent another battery, and you will get a nice firm flat contact with the battery that might even reduce resistance, one of your goals in life. LOL

Bill

Hahaha... you got that right. Shoulda' seen it before I stretched it back out. Flatter than Twiggy!

BTW, I'd very much like to thank Surefire customer service. I called up, hoping against hope to get the proper spring out of 'em so I can do a fix. I started by saying "What I've done to my tailcap spring is probably not covered under warranty. I was messing around with...", and before telling the rest of the story, the very pleasant, friendly rep told me not to worry, and they'll get a new tailcap out to me right away... along with a light-hearted admonishment to not mess around with this one. We both got a chuckle out of it as I promised not to.

It arrived last week, and all is well. Malkoff w/primaries are in the C2, and will remain that way. The 6P trembles with fear. :devil:
 
What happens when you short IMR16340

Why do people insist on using titles that are meaningless to the search engine. This thread will be lost forever after a month, and people will complain search doesn't work. :thinking:

suggested title:
"What happens when you short AW IMR16340?"
 
Re: What happens when you short IMR16340

Why do people insist on using titles that are meaningless to the search engine. This thread will be lost forever after a month, and people will complain search doesn't work.
I've just done a search, and this is the only thread on CPF with the unarguably memorable word "dingo" in the title. Far from being lost forever after a month, it will therefore be uniquely easy to find in future.
 
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