Originally Posted by
2manybikes
cold slows or stops the battery from having full power. If it's cold outside when you get the 44 minutes, that is your real problem. This will happen to all lights to some extent. The best type of batteries to give you the longest run time in the cold are Lithium. Cold batteries get back the run time with no damage.
With my lithium ion lights, I've seen about a 15 - 20% reduction in runtime between summertime temperatures and below freezing temperatures. These are on-bike times. I haven't really tried running lights just in a room to see how long they will run under that condition. What the OP is describing is a > 63% drop in runtime, which is really surprising to me. I looked at the product page the OP linked, and it indicates "Runtimes of the two PID controlled levels (1100Lm and 670Lm) vary greatly with ambient temperature and air circulation." That seems to indicate that the air circulation factor is what is really at work here.