Waterproof Torches and h gas buildup.

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
:confused: Hi all. I'm sure that this subject has been discussed numerous times, but it would be great if someone in the know could add to my meagre knowledge of same.
As i understand it, all batteries or cells produce hydrogen gas [ herein, h ] as a byproduct of use or storage to a greater or lesser extent. OK, not normally an issue in normal day to day use, but whatabout in sealed torches, like high end professional and tactical ones, that we're all very fond of?!
eg; Could a 2xAA cell IPX8 rated LED torch produce enough h in an hour of use to create an explosive situation from switch contact arcing ?
Is there a standard that requires switches to be isolated from battery chambers in IPX8 or higher rated torches ?
Does Li-ion chemistry create a similar scenario?
Is this all just hot air, or a valid point?
It all may be irrelevant, but i would be interested to know?
Lots of thanks for your thoughts. :thumbsup:
 

u238

Newly Enlightened
Joined
Dec 1, 2009
Messages
37
This is an interesting question, that I don't know the answer to. But, I imagine that the h2 buildup during normal operating conditions would be minute.
 

Gunner12

Flashaholic
Joined
Dec 18, 2006
Messages
10,063
Location
Bay Area, CA
There are pictures of NiMh batteries that have released gas a bit. Since these lights have rubber tailcaps, the tailcap balloons out. If the batteries release gas though, that means something is happening that shouldn't like, overdischarging.

Also, you need oxygen for any combustion. There's isn't much room for air in the flashlight after you add the batteries. I'd bet it takes quite a lot of pressure to make one of the flashlights fail from pressure (presuming no rubber tailcap to act as pressure valve).

It is a valid point in my opinion, but not much to be worried about.
 
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