Pondering how much light I got for different battery types, I resorted to manufacturers published figures - for a given output, in lumens, how long would a light provide illumination, relative to its weight.

Bottom line - lithium ion batteries are considerably more efficient than AA, providing almost three times longer light.

I compared a Zebralight H53, with rechargeable batteries against a Zabralight H600, equipped with 18650 battery @3000mAh.

H53 provided 4.2 hours at 106 lumens, weighing 2.8 oz.

H600 provided 13.6 hours at 126 lumens weighing 3.3 oz.

I assume roughly comparable results at different lumen outputs.

I have both models and I like them equally - sturdy and dependable, but I can hike all night with the 600 - not the case with the 53.

Comments welcome...