Hi Gents. This Surefire L4 was in my wife's cars glovebox for the last 2.5 years. I just took it out to change the batteries and noticed the light was real dull and blue. I changed the batts, and same deal. I always use Titaniaum CR123 batts. I exchanged my work L4 head ( which has been used for 3 years, almost daily and no problems ) and it worked fine on that body/batteries. I just mailed it back to Surefire for warranty. They were very helpful and were going to pay for the return shipping. Thanks for the heads up on the LIFETIME warranty. I will update you about the repairs in hopefully a few weeks
AC