My ED2 Defender (CR123A lithium battery's) and just to be on the fair side, Ive had the same problem with another brand of flashlight. If I screw the cap on all the way the battery life is only a couple of weeks.
The only way I can get good battery life is to keep the cap on with only about 2 threads which means every time I need to use my light I have to screw the cap back on.
The only way I can get good battery life is to keep the cap on with only about 2 threads which means every time I need to use my light I have to screw the cap back on.