Originally Posted by
Brian Sorrell
There are three power settings plus "turbo". On the dimmest setting, they are reported to last for about 10 hours. On the brightest non-turbo setting, they seem to last me a few hours (total time, that is. My trips in the dark are usually just across town or to visit friends.) Turbo is recommended for only short periods of time and I suspect that'll burn them out pretty quickly.
If by "burn them out" you mean Turbo will harm the light, then no it won't. In a normal bicycle-riding scenario, or even walking or just working in open air, you can run Turbo non-stop on an L2D Premium Q5. If you stick it in your pocket and leave it running on Turbo for an hour, yeah,
then you might have an overheating problem
As for runtime, here's a runtime chart on Turbo, and from the graph, you can definitely see why you should use NiMH rechargeables instead of alkaline AA:
On the dimmest setting, an L2D Q5 will run over 50 hours on one NiMH AA, not 10.