Originally Posted by znomit

Alkalines tend to drop slowly through the entire runtime, whereas NiMH are reasonably constant voltage over most of their life, they drop quickly at the start and end.
Depending on the led driver the battery voltage may not matter so much.

I tested two cateye ld600s and the AAA alkalines outlasted the NiMH ... yes I was surprised.

Regardless AAs have around 2.5x the runtime, I'm a little disappointed these new lights all rock AAAs.

Oh, and if anyone has seen a 1W red led being driven at 1W they'll agree all of these blinkies are feeble. 30 hr runtime off 2AAAs? 1/10W