My Arc LS popped today

Has anyone experienced your Arc LS popping when unscrewing it?

Today while waiting for staff members in the conference room, I decided to take out my Arc LSH to do my routine cleaning of the threads and battery check. Upon loosening the Kroll switch, once the O-ring cleared the body, I got a noticable pop. Not loud, but enough to know that the pressure inside the light, was greater than outside the light. Plus you could smell the lithium battery very strong. (Whatta good smell /ubbthreads/images/graemlins/grin.gif)

No big deal, no damage, just curious. Plus I see that I'll need a new battery in about 2 weeks. I date the batteries when I install them with a Sharpie, and tend to use one up about every six weeks. Just my little way to gauge my usage patterns.

--Chris

My Educated Guess:

When you screwed the battery compartment into the head, as soon as the O-ring engaged you started building up pressure inside with each turn since it was now air tight. Removing the Kroll released the pressure at a faster rate than unscrewing the body because of the volume difference of the parts. (Screwing in the battery compartment compresses more air than would screwing in the Kroll.) Hence the pop.

Doh! My mistake. I meant the whole tail end, not just the Kroll switch. There goes my technical writing skills right out the window.

I had used it the previous night periodically for an hour, so maybe the battery gased a bit. Surefire exp. 2/2013

--Chris

OK, how's this?

When you put it together was it cool? If you then put it in your warm pocket the air inside would have expanded, allowing it to pop when unscrewed due to the now higher pressure inside. As to why it popped instead of just hissing, I don't know.

>When you put it together was it cool?

Yep.

I could buy that, but I generally take it apart and clean the threads (usually during boring conference calls) at least once a week, and have never had this happen. Strange. /ubbthreads/images/graemlins/icon3.gif

Like I said, probably from using it doing car work last night and the battery gassed a bit. Just goes to show the waterproofness of this light.

its most probably the battery....pressure fluctuations from the usual temperature variations most people experience shouldn't be enough to create enough pressure to cause a pop...this is from my experience so YMMV /ubbthreads/images/graemlins/wink.gif

and i do find the smell emitted by lithium batteries quite pleasant too! /ubbthreads/images/graemlins/grin.gif

I would replace the 123-cell immediately.

You scared me for a second... From the subject I thought the LS had stopped working.

There are several causes of popping as mentioned by fellow CPF'ers. Another reason to add to the list is the 123 cells have a pressure vent that may hold the pressure until the ambient drops below a certain level then unload the internal pressure all at once.

Peter

It's actually startin' to sound like a leakin' 123...

[ QUOTE ]
Gransee said:
You scared me for a second... From the subject I thought the LS had stopped working.

[/ QUOTE ]
That's what I thought too - that the LED itself "popped" and the flashlight no longer worked. /ubbthreads/images/graemlins/icon15.gif

Sounds like the battery vented to me, though I've never had an Arc-LS or any other flashlight make a popping noise when I opened it.

Somewhere on another forum a long time ago, somebody posted a chemical formula for that "sickly sweet" odor that comes from lithium CR123 and AA batteries that are heavily used. I think I likened the smell to that of "rotten honey" that Captain Kirk smelled whenever that "creature" from Omicron Theta (?) was nearby. /ubbthreads/images/graemlins/grin.gif

My LSH-P has "popped" before, and the battery was perfectly fine, although, it was at the end of its charge.

On two occasions, i had accidentally left my ARC LS on for a long period of time. Once was when i was sleeping; i guess i must have rolled over the switch and activated it. I awoke with a hot (but not burning) sensation on my rib cage...it must have been on for at lease an hour or so. The second time, the light must have activated in my pockets on my way to class. 30-40 minutes later, i had a hot sensation in my pants...and it wasn't comfy.

Both occasions happened on the same battery, and it died a few days later when i actually had to use it. There was about 15 minutes of light left before it fell into moon mode. The battery had been in the ARC LS for a good 2-3 months without a change or inspection and the compartment was never opened during that period. When i finally opened it to change the battery, i heard a "pop" as soon as the oring became seperated from the battery compartment. It wasn't at all loud or even a cause to get worried about. I just assumed that some preasure was built up during that time.

As far as i know, the times that i encountered that "pop", the batteries were totally fine, were not leaking, or even emitted a strong lithium odor. The batteries were just dead or dying.

I'm assuming that the increased pressure in the battery (from use) had probably nearly equalized with the pressure within the Arc battery compartment (compartment pressure increasing in small jumps as the battery vented to equalize presure over time).

I'll additionally assume that the "pop" might be the battery venting it's overpressure through it's relief valve due to the reduced pressure when the compartment is bled to ambient pressure.

(Hopefully that explanation makes some sort of sense. The reason I think it might be the battery's relief valve is I believe the pressure relief around the compartment O-ring might be too slow to register as a "pop" when it is opened.)

/ubbthreads/images/graemlins/popcorn.gif

what i can infer from all the above accounts, is that the seals on the arc LS are so tight, that not even gases can seep through which i believe is a good indication of how waterproof they are /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/thumbsup.gif

Thanks for the responses folks! /ubbthreads/images/graemlins/thumbsup.gif

Peter - I thought the title would scare some folks after I posted, but figured it would get more views. /ubbthreads/images/graemlins/grin.gif

LEDagent - Same scenario. I had used my Arc LS the previous night a good bit (~ 1 hour), haven't unscrewed it in about 3 weeks and I've probably got around 15 minutes before moon-mode kicks in.

Tomas - Makes perfect sense.

chamenos/PG - Maybe Arc can market it's waterproofing by saying "positive pressure battery chamber" He he. /ubbthreads/images/graemlins/grin.gif

i have the utmost confidence in my arc LS when it comes to water-resistance /ubbthreads/images/graemlins/wink.gif