I see a lot of praise and recommendation towards these little batteries, but I can’t seem to find them at any of the normal vendors. I see listings at a few stores, but I haven’t heard them mentioned here.
If you're looking for more serious power, AW IMR14500 is the only way to go! With a Qlite installed, stock at 3.04A potential, the Efest delivered 2.60A while the AW gave 2.99A. So my Efest's are backup to the hotter AW. :)
I just checked a sk68 with a cheapo trustfire, 2/$5 shipped as I recall, 1.79 volts, but it was also visible dim when I turned on the light. I just needed to remember which lights have Lion and which NimH.