Has anyone conducted testing of RMR battery life in extreme cold temps? I believe the runtime Trijicon provides is rated for 70F. If your RMR is exposed to 0F what kind of drain can you expect on the battery?

As the RMR battery drains at what point is its brightness significantly reduced?

Been running an RMR on a duty pistol for 3.5 years in Minnesota as a street cop.  This includes hours spent outside continuously in winter conditions and sub-zero winter temps.  The cold has minimal effect on the overall battery life.  I had one battery run for 2.5 years on an RM06 before the gun had to be taken out of service and I had to get a new pistol and optic.  The most recent gun has an RM07 on top, and that battery ran 7 months before crapping out.  Both saw winters in patrol and tactical functions.  The big difference in battery life is likely related to the fact that I was dialing the illumination a lot more proactively with the newer RM07, as during the summer months I was cranking up the illumination in the afternoons (I work a mid-shift from 4pm-2am).  In the winter, if I opt to run the dot on manual mode, I don’t have to run the illumination as high since it gets dark so early.

When the battery starts to die, the reticle starts to dim.  My last one pretty much just dimmed and died in less than 2 days.  First time I’ve had a battery die on duty for an RMR (I’ve tested other optics too).  I was amazed how fast it crapped out, and I’m not sure it wasn’t a bad battery, though it was a Duracell so I tend to think it wasn’t.  I’m running another test with the RM07 before I move to a different optic, so I can get an accurate test confirmation.