Hi tFUnK,
I use a rechargeable NiMH AA 1.2V 2300mAh GP (gpbatteries.com.hk) battery.
It gives me around
one hour of joyride on HIGH mode. I haven't really tried it out on LOW mode so I could tell.
The cool thing: I simply take 2-3 AAs along with me and replace if I need it but I usually only have to replace one time as my night rides are not that long. I was actually wrong when I wrote it produces 22 lumen. On the site they say it will output 220 lumen. Well you don't want to insult 20 lumen by forgetting them, especially if you rely on them during a night ride
About the digital regulation I don't really know - how could one measure such a thing?
Could you please send a link to your flashlights? - I am interested to learn about better/similar products.
Thanks! :-)