With the new rebel Minimag on high mode, you should expect to see similar runtime with the old Lux III version, except with a long tail of low light moon mode after a little more than three and a half hours from the new rebel version, the old version just cuts out with no moon mode and you're left in the dark. On low mode, expect close to 20 hours of runtime with alkalines (80 mA) and even more with good rechargeable NiMH's / low self discharge types.. I'm pretty happy with my new Rebel Minimag, the LED doesn't come lose and pop off after a 6 foot drop onto concrete, like the first generation (there are two gen's of Lux III MM's) Lux III Minimag would, and after around 7 minutes of continuous use on high mode, I can feel the area near the head of the light getting hot, so heatsinking has definitely been improved! If you're going to get a 2AA Minimag LED, definitely get the new rebel version if you can. It uses a Rebel 90 for Godsakes!!! I would estimate the total output to be right around 55 lumens, a bit brighter than the Rayovac 1 Watt 2AA (reflector version), with a little more throw on spot focus. I also like how the MM led's start out on a nice flood focus with no donut hole in the middle..