*Staring at my M3 nerviously*
Why?
You keep it locked out right?
The batteries are only a few months old even if they are partially used?
SureFire gets its SF123A from the only CR123A manufacturer in the USA. If the assumption is that no external factors influenced this event and therefore the safety of the batteries is in question then the same question must be made of all USA-manufactured CR123A batteries.
Given that Chinese CR123A are well known and documented as being dangerous and not suitable for high output / multi-battery flashlights, the result is a question of where to get 'safe' CR123A batteries if you make the assumption that all USA-manufactured CR123A batteries are no longer safe based on this event.
But this assumes there were no unavoidable extenuating factors that contributed to the batteries in the classic old-school 9Z 'exploding'.
I suspect this event could easily have been avoided.
The most important thing I notice is that that 9Z does not have a LockOut TailCap (called a Z41) that was introduced to the SureFire range when SureFire changed the 9Z to the Z3.
Being able to disable a high output, multi-cell flashlight is vital in helping to prevent damage from unintentional activation. Damage to the now discontinued Lexan polycarbonate window being the most normal occurrence.
The flashlight would not have acted this way unless it was activated, even only slightly, especially in a confined space like a pouch or clothing where the heat building up could not escape. This can't happen in disabled flashlights, even when the batteries are damp and whole mix of discharge states as the electrical circuit is not complete and the compromised batteries are not being stressed.
If the batteries were stored or the flashlight opened in wet / high humidity conditions, and/or if the batteries were subject to crushing or vibrations then this can compromise them and significantly contribute to 'explosion' events.
If the batteries were partially used I understand that compromises their shelf-life. If partially used batteries are stored in the flashlight for a long time then they could become unmatched as they degrade at different rates which is a contributing factor in 'explosion' events.
American-made CR123A batteries remain the only source of the safest possible CR123A batteries.
Do not mix old and new batteries.
Do not mix new and used batteries.
Do not mix different brands of batteries (even if they are technically exactly the same this is like mixing different age batteries).
Disable the flashlight when it is not in use. Check that it actually disabled for transportation/storage and even carry when immediate use is not required/anticipated.
If immediate use is required/anticipated ensure that you will notice as soon as the flashlight is activated accidentally.
Store spare batteries in a dry, cool place where they can not be crushed, short-circuited, get mixed up or subjected to intense vibrations.
Do not store partially used batteries in devices.
Replace or use up batteries that have been stored in devices every year or so. Avoid storing batteries in devices.
Take especial care when using high output lamps options and/or multiple-cell flashlights.
If in any doubt use up the batteries in single-celled flashlights.
I'm certain that SureFire will want to examine the flashlight, the bits and pieces of battery and the remain batteries from that box.
Al
