SC600Fd is good considering the size and what it can output with it. Still, I’m looking for more and here is some things I would like to improve:
1. Lots of lumens without stepping down. Thermal regulator would be good because cold winter (–10C, –20C, –30C) can help with cooling.
2. More throw, but at least same smooth flood
3. More runtime and 4 x 18650 is not a problem
4. Better CRI (especially red), better tint (closer to white than cream white), closer to 4000K than 5000K.
5. No PWM or something which could be disturbing in subconscious level. I don’t notice anything with SC600Fd, but improvement doesn’t hurt.
6. Smooth stepping down. SC600Fd flickers when stepping down