Re: 7.2V, 850mAh for a luxeon five in a two AA mag
If you put a full 5W into 2AA minimag, you will be running the emitter very very hot, which will cut the already short 500h life spam for a Lux-V even shorter. It will be much better to use a Lux-III with a buck regulator---you can get almost the same amount of light with a much longer life spam.