Air pressure build-up in AAA

Recently I've been doing a lot of air travel and of course my AAA went with me. I noticed that after I went on the plane, my ARC AAA built up air pressure in its tube. When I tried to release the screw, it went 'pop'. This happened to me twice now and it actually quite difficult to release it. I had both my arc AAA and AA with me in the cabin but my AA seems to be fine. I wonder if anyone has noticed the same problem? How can you alleviate it as it makes unscrewing the head to switch it on quite hard.
Cheers
Tone

did it happen before or after the plane took off? it could be due to the atmospheric pressure outside the arc AAA dropping. either that or the battery is venting gasses. the only way around that is to open up the battery compartment every once in a while to release the gas.

Well I didn't use it on the plane but try to use it after the plane landed when I noticed the problem.

Thanks for your suggestion about open up the battery compartment. I'll try that next time.

Try opening the arc, and thereby releasing the pressure, when you're mid-flight. This will stop pressure build up.

I've had CMG Infinities "pop" open in my pocket.
VERY startling.

I had pressure building up my AAA twice. No flights or changes of altitude. The first time I could barely get the head unscrewed it was so tight from the pressure. The "pop" was pretty intense when it finally opened. The battery must have outgased somehow. It was a Duracell Ultra, by the way.
Samething thing second time around with a fresh battery but less intense.

I had something happen in a Infinity happen when I went from high altitued in PA to low (nearly sea level) altitude here in Texas. Hard to turn and made a definite pop, spraying a bit of grease on my hand as well. I kinda freaked out, thinking it was acid untill I realized that the battery was intact.
It's just the pressure making friction between the head and barrel threads.

-Jason

Has anyone taken the ARC4 to altitude and inspected it for this? Does altitude interfere with the switch operation?

To cure this problem, I'd think you'd need to sacrifice "waterproofness". Any vent to allow pressure equalization might permit water entry. An occasional 'pop' is worth the price in simplicity, IMHO.

I had the same phenomenon however I was not on a plane.
I simply left it in the car for a few days. I was able to
repeat the phenomenon. Sometimes i even feel significant resistance to my screwing in the head to turn on the light!

My theory is this. It seems like the o-rings
seal air from coming out better than in. So at night when it's cool, air inside is low pressure, so it pulls in air. Then i the day time and it heats up, pressure builds up inside.

what do you think of my theory?

david

[ QUOTE ]
PhotonBoy said:
To cure this problem, I'd think you'd need to sacrifice "waterproofness". Any vent to allow pressure equalization might permit water entry. An occasional 'pop' is worth the price in simplicity, IMHO.

[/ QUOTE ]

Gore makes a cloth that will not pass water molecules, that can be put over the hole. There is also a ceramic that will do the same thing, and is more durable. Neither will pass straight water. I know the ceramic is good to a certain depth too.

In theory that might be possible, but I don't think the cooling of the air would cause enough of a pressure differential to suck air in. And the temperature difference would have to be extreme to cause that kind of pressure buildup. I dunno, never tested it, so you might be on to something. I think the batteries must be some outgassing to cause that much of a pressure buildup, maybe outgassing due to the low pressure in the airplane cabin, or outgassing because of the heat of the car.

I think the problem is definitely pressure buildup, but you don't have to sacrifice waterproofness to fix it. All you need is a self energizing seal, which allows a seal from one direction only. Check the tailcap seal of a Mini Maglite (only the minimag has it) to see what I'm talking about. I wonder if this is the reason they made this change a long time ago? Hmm...maybe they're not as dumb as they seem /ubbthreads/images/graemlins/tongue.gif

My AAA was left on and the cell outgassed to the point is was very hard to remove the head. Now that I know what happened I'll just push the head and body together real hard while unscrewing them.