Something WEIRD happened today: Flashlight Pressurized!

Hudson456

Newly Enlightened
Joined
Jan 23, 2016
Messages
150
Using my Streamlight ProTac 2AA today and noticed that the switch felt weird. Looked down and saw this!


Disassembled using safety goggles and gloves. Heard and felt a large depressurization, o-ring bulged outward. Upon examination: no battery explosion, no leaking, no nothing. Batteries were the black XX high capacity eneloops.


What gives????


9m7PYtg.jpg
 

archimedes

Flashaholic
Joined
Nov 12, 2010
Messages
15,780
Location
CONUS, top left
Offgassing.

Likely way overdischarged ... perhaps parasitic drain ???

Or, could you have mixed a nearly full battery with a nearly empty one ?
 
Last edited:

jon_slider

Flashlight Enthusiast
Joined
Mar 31, 2015
Messages
5,110
black XX high capacity eneloops.
this link mentions venting as a result of over discharging:
Discharge Termination
To prevent the potential for irreversible harm to the battery caused by battery reversal in discharge, removal ofthe load from the battery prior to total discharge is highly recommended. ...At the point both electrodes are reversed, substantial hydrogen gas evolution occurs, which mayresult in battery venting as well as irreversible damage.
 

Hudson456

Newly Enlightened
Joined
Jan 23, 2016
Messages
150
Offgassing.

Likely way overdischarged ... perhaps parasitic drain ???

Or, could you have mixed a nearly full battery with a nearly empty one ?




If the batteries were discharged why did the light still work? Usually the modes on the Protac will go all wonky when the battery is low, but I was in the middle of using it and it was just fine!


Should I really just throw away these expensive batteries or try to charge them again? The really look just fine!
 

jon_slider

Flashlight Enthusiast
Joined
Mar 31, 2015
Messages
5,110
If the batteries were discharged why did the light still work? Usually the modes on the Protac will go all wonky when the battery is low, but I was in the middle of using it and it was just fine!


Should I really just throw away these expensive batteries or try to charge them again? The really look just fine!

have you tried measuring their voltage on a meter?
do they seem normal?
my guess is at least one of them is not holding a charge

have you repeatedly run the batteries down until they are no longer working? THAT could be the error of your ways.
if it was me, I would take a voltage reading and see if one of them is much lower than the other

then, IF you're able to charge in a fireproof location, such as inside your oven (oven off!)
you could recharge, check if they get hot, and check if they take a full charge
next you could put the same batteries that already malfunctioned back in your light, and see if they malfunction again

but, the take away lesson is that Eneloops do NOT like being discharged until they are dead. And it IS possible at least one of your batteries is damaged from over discharging, repeatedly..

let us know what your voltage tests tell you
 

archimedes

Flashaholic
Joined
Nov 12, 2010
Messages
15,780
Location
CONUS, top left
They may not necessarily "look" different after severe offgassing, but (at the least) capacity is likely to be significantly impaired
 

marinemaster

Flashlight Enthusiast
Joined
Mar 1, 2003
Messages
1,238
Location
Atlanta, GA
That typically happens in two battery format. One battery format somewhat safer. My 1xAAA definitely makes a loud popping noise when I unscrew it after long .
Btw the Streamlight Propoly series I have they all have a small hole vent.
 
Last edited:

INFRNL

Flashlight Enthusiast
Joined
Feb 7, 2012
Messages
2,971
Location
Bottom Of Pikes Peak
that seems like plenty good voltage for aa. I did a runtime test today on a light and ending voltage before resting was around 0.8v, each one was slightly different in voltage. tested single and double aa using eneloop pro's

Theoretically, going off voltage alone, i don't see an issue with your AA's.

If it were me and I tend to do silly things, I would make a safety area( make sure nothing can get damaged besides aa's and charger) and charge the cells back up using the cheapest charger you have (just in case, ie eneloop charger)
 

jon_slider

Flashlight Enthusiast
Joined
Mar 31, 2015
Messages
5,110
Are they fried?
not
I don't think you have a problem until they go below 0.8v

when the problem happened, had you been running the light on HIGH for a while? Thats the only in use scenario I can speculate would cause high drain rate and venting.

you turned up a good article about venting challenges for eneloops in sealed lights.
if it was me, I would charge the batteries up, and use them. I don't see a problem specifically with the batteries.
I would look instead for whether you are able to duplicate the venting event, and if so, try to avoid whatever behavior triggers it.

Nothing you have said so far suggests a catastrophic failure. However, Im a total newbie, Connor seems to have a lot more technical expertise, so, try to respect his concerns, and consider asking him to help you figure out which cell is bad. My bet though is that if you use a different set of batteries, in the same way that created the venting event, then they will vent again.

Did you for example, run the light on high for extended time, such that it was getting hot?
 

Hudson456

Newly Enlightened
Joined
Jan 23, 2016
Messages
150
not
I don't think you have a problem until they go below 0.8v

when the problem happened, had you been running the light on HIGH for a while? Thats the only in use scenario I can speculate would cause high drain rate and venting.

you turned up a good article about venting challenges for eneloops in sealed lights.
if it was me, I would charge the batteries up, and use them. I don't see a problem specifically with the batteries.
I would look instead for whether you are able to duplicate the venting event, and if so, try to avoid whatever behavior triggers it.

Nothing you have said so far suggests a catastrophic failure. However, Im a total newbie, Connor seems to have a lot more technical expertise, so, try to respect his concerns, and consider asking him to help you figure out which cell is bad. My bet though is that if you use a different set of batteries, in the same way that created the venting event, then they will vent again.

Did you for example, run the light on high for extended time, such that it was getting hot?


I WAS using the light on high (not that this older Protac has a super bright high mode), for about 10 minutes straight. But I've done that in the past plenty of times and never had this happen.

As a quick fix, I was thinking about just removing the O-Ring in the light, allowing whatever wants to vent to vent, as waterproofness is not needed in my application.
 

jon_slider

Flashlight Enthusiast
Joined
Mar 31, 2015
Messages
5,110
I was thinking about just removing the O-Ring in the light, allowing whatever wants to vent to vent, as waterproofness is not needed in my application.

that sounds reasonable to me

otoh, the gas that vents is hydrogen, it is flammable
maybe it would be better to know when you go into venting mode, by monitoring the tailcap
I was concerned that your approach to open the light with goggles and gloves, did not address safety concerns around inhaling vent gases, or having them ignite..

you may find that venting only happens when the battery goes below 1.2v
that might account for your prior use of High mode without venting, on fully charged cells, not sure

so far nothing you have posted is a huge red flag that would make me throw those batteries out
instead I would try to figure out if the venting was a one time thing, precipitated by a long run on high, that brought the batteries down below 1.2

again, not an expert, just my opinions
I do use eneloops, and I have run them down below 1.2 before. But the light I use has no rubber tailcap to bulge, its a twisty, and has O rings. IF the battery ever vented, Ive had no way of knowing that.

if I was you, and I had a "problem light", I would consider releasing the tailcap once in a while, especially after running on high. I would be more inclined to replace the light, than the batteries.

I still think your idea of removing the Oring is a valid option.
 
Top