New to the forum here, but I've been reading some posts for a while, and have a few questions about my new light. Maybe all you knowledgeabke folks here can help me out. Anyway, I was inspired a while back to pick up the Olight M20, to replace my Fenix P2D. I'm currently using 2 CR123 primaries in it. Am I not taking advantage of this light's full potential by not using RCR123s? I think the consensus is RCR's provide more power, and therefore better output? And would I be better off with RCR123's or with a 18650? Which will maximize output, runtime? And can someone please explain all this regulated business? Does the M20 run regulated on some battery types, but not others? And what's the deal with "protected" batteries? They're safer, better, my flashlight won't explode when using them, or what? Sorry for the barrage of questions, but I've been reading some threads on these subjects here and there, and it's still a bit murky. Thanks!