a *burning* Fenix

[aKindOfBlue]

Hello!
I'm new here, posting from NW Italy.
I'm a led-flashlight-addicted like many other here, for what I can see

I'm writing here hoping to get some useful suggestion to understand what happened to my flashlight.

I have two FENIX flashlights, a PD30, that's always in my pocket, and now a TK40. I use the TK40 mostly for my job, the little one (in my opinion the best) for both job and fun.

Today I've put 8 just-charged eneloop in my TK40, turned it on to test it, and it worked fine.
After a few minutes, time to put it in a bag, I've catched it in my hand and... LET IT FALL TO THE GROUND!
It was hot like hell!!! (it was turned off!)
When I say "hot" I say... I've burned my hand trying to open it immediately to remove batteries, and I still have a burn sign now on my left hand.
I had to use a wool scarf I had near me in order to open the body, and it has been a hard job.
A "puff" of gas came outside the light, and batteries were... litterally frying!
All of them were frying letting out some liquid.

The result is:
-8 new eneloops trashed
-a spoiled TK40 (batteries and heat damaged the battery magazine)
-a big question mark on my head...:thinking:

What the hell happened?

Obviously I will bring it back immediately, as soon as I have time in this week, to the seller, but I still asking myself: have I put batteries in the wrong way?
Is a polarity inversion a possible cause of such a destruction?

Notice that I always am very careful at putting batteries in the right way, and moreover, I've turned it on after replacing batteries... should it have turned on with batteries in the wrong way?

Thanks for your help
:sigh:

 

[John_Galt]

It sounds like a short caused the batteries to leak. Ni-MH batteries do vent, unlike Li-ion batteries, however, the venting does not usually result in flames.

 

[Robin24k]

Can you post some pics of the battery holder and the batteries?

I'm thinking of how any shorting or reversed batteries could be possible...maybe external debris or something broken in the holder?

 

[Gunner12]

Definitely sounds like a short. If you can get pictures, maybe we can figure out what happened.

 

[bigdukesix]

From the 4sevens site on tk40's

Battery Caution: Please double-check the orientation of your eight AA batteries before inserting them into the battery holder. Make sure that all eight AA batteries are properly oriented according to the instructions in the manual: the "negative" ( - ) side of the battery must be toward the small springs in the holder. Inserting the batteries improperly can cause the battery holder to become dangerously hot.

 

[hoongern]

Not sure what may have happened in your case, but even the most careful of people can end up putting in batteries the wrong way.

At least, I used to say I'm very careful with putting in batteries, yet I too managed to put in a battery the wrong way into a charger.

Glad you're ok though. Hope you'll be able to figure out what went wrong. Did you already take out the batteries or leave them in the holder? That would let you know if you put one in the wrong way..

 

[collo]

A handy tip is to use a permanent marker to highlight the positive end of the batteries... makes it easier to see if you got it wrong...

 

[Federal LG]

Sorry about your loss, but that´s why I´m a huge fan of "just 1 battery" lights.

 

[aKindOfBlue]

Thanks for your replies.
It could be only a matter of polarity :sigh:
No other explanation, though I alway pay attention when putting batteries in.

Now I had some time, cleaned the battery magazine (damage to the black paint seems to be the only permanent one) and cleaned with sandpaper the contacts.
It seems to work fine.
:twothumbs

Be careful with polarity with such batteries!

The luck is that the TK40 is a tank. I really don't know if another flashlight would have survived

 

[jorn]

Sorry about your loss, but that´s why I´m a huge fan of "just 1 battery" lights.

+1.
They may not be as bright as a 8x battery light, but my iris will block out light if it gets to bright anyway. (I need to tell myself that all the time or ill end up buying way to many powerful lights)
I never wanted the tk40, worrying something like this may happen to me. One wrong battery and . Murphy's law is usually stalking me. Atleast now i know that murphy dude isn't just only after me

 

[yellow]

8 cells in a 2-strings-of-4-side-by-side setup is simply stupid,
the only real flaw of the TK40.
They should have built it 8 in series.

--> Jetbeam M1X!
"better" in most every respect.

 

[Robin24k]

A handy tip is to use a permanent marker to highlight the positive end of the batteries... makes it easier to see if you got it wrong...

When deciding between Eneloops and Duraloops, I went with the Duraloops mainly because of the "copper top" positive end. I'm sure this isn't the first time Eneloops have been inserted improperly. If lighting isn't good, it's easy to confuse the two ends of the Eneloops.

 

[Apollo Cree]

I'm always concerned about anything battery powered with "fire" in the name or named after mythological beasts that burst into flame periodically.

 

[Alberta-Blue]

I'm always concerned about anything battery powered with "fire" in the name or named after mythological beasts that burst into flame periodically.

HA!!

 

[Stainz]

So, it takes two stacks of four NiMH cells - which are then placed in parallel in the holder? Obviously, they want a lower internal resistance - and greater capacity. Even carefully matched, cells won't age the same - one of the two 4-cell 'batteries' will have a greater EMF than the other - causing it to drain into the lower EMF 'battery'. Poor design, I would think. With the intolerance of NiCds, it would be a real problem. Once again, my one or two CR123a use is vindicated - for me. Sorry for your troubles.

OT - battery related: The instruction manual for my H-F 'Cen Tech' OBDII automotive code reader said nothing about trying to start a car while it was connected. I accidently did that last Wed - fried the regulator circuit and shorted the 9V alkaline memory battery... oops. Killed the fresh battery in seconds - didn't know a 9V alkaline battery could get that hot. $100+ sale priced reader instantly became a toy for my wife's pre-school class. Fortunately, her SRT-4 was fine - and changing the cam sensor the code had indicated fixed it. I probably still saved money - the previous 'Check Engine' light was a minor evaporative emmissions leak - suggested changing the gas cap - which fixed it then.

Stainz

 

[Locoboy5150]

One of the reasons why the TK40 has its unusual battery arrangement is so it can fully operate on all light output modes, including Turbo, with only 4 AA batteries in it.

That flexibility is one of the things that I love most about it.

 

[Joe Talmadge]

A handy tip is to use a permanent marker to highlight the positive end of the batteries... makes it easier to see if you got it wrong...

Good tip! Thanks