Year 10 or 11 for my Cygolite Rover II LED headlight. Rated 265 lumens. 4.8 volt ( 4 x 4/3A cells ) NiMH. Fresh charge run time on high is still about 2 hrs. Good enough for my needs. I mainly use it about 6 months of the year, for my short morning commute. I built a spare battery pack out of NiMH AA cells, but I only charged & brought it a few times on evening trips.