CR123A thermal shutdown

Interesting...I just observed my first case of thermal shutdown with a Surefire P91 lamp and a 6P+A19. The lamp runs for a couple of minutes then suddenly gets extremely dim, and it's on barely-used cells. I popped all of them out and put them through the DMM, the first two measure 6+ flash amps, the third measures 3 and drops very fast. It also feels *VERY* hot compared to the other two which are just warm.

Once allowed to cool for five minutes, I popped it back into the light and turned everything on, this time I placed the hot cell at the rear of the light so the heat from the lamp wouldn't affect it as much. Lamp relights at full output. 30 seconds later, the lamp dims to the brightness of your average 2D flashlight, I pull out the cells and DMM them again, the same cell is hot and weak. I notice some distortion of the plastic at the front of the cell, similar to what you'd expect from high heat.

Should I discard this cell or put it in a less demanding light? And just out of curiousity, what causes it? Think I got a dud on this one, the rest of the batch is fine. I put a P60 in the 6P, now on the two remaining cells and both are A-OK, as was the first batch of 3 that went through the P91.

Can't wait for my rechargeable 123s.. /ubbthreads/images/graemlins/smile.gif

It reads like that specific 123A cell is not working as it should. If it really is damaged, you shouldn't use it again. Keep it for reference though. 123A cells are powerful and have 'fuses' inside them to help prevent them from exploding under physical or thermal abuse.

Was it a SureFire cell?

Thermal shutdown should not occur using the P91 in the 9P (6P+A19).

I have loads of experience with the 12PM and thermal shutdown. No cell was ever obviously damaged as a result that I recall.

Al

Looks like just minor thermal damage to the jacket but I'll lay off. I believe it's the PTC fuse putting a brake on the cell's output and then resetting as it cools. Think I'll lay off that cell. Don't want to have to rely on the 2mm of Surefire aluminium to protect me against a cell detonating /ubbthreads/images/graemlins/wink.gif even though I am sure it will.

The previous batch of the cells from the same vendor ran thru a P91 without a single hitch, all of them are retiring to the battery eater in peace (1W lantern DD'ed off two nearly-dead CR123s - nearly dead being the keyword to avoid frying the Lux). It isn't a Surefire cell.