I have a Quark Tactical 123 and I was wondring if I could use RCR123's in it. Would it make some levels brighter/unuseable? How would runtime be in comparison to primary CR123's?
To summarize what you're looking for from the above linked thread: The single 123 quark doesn't get brighter on RCR123s vs CR123s. Runtime will be shorter on RCR123s as they have less capacity than primary CR123s.
...and the QAA can handle a 3.7v 14500 instead of a AA because...
...it's the SAME HEAD as the Q123. There seamed to be some confusion about that in a couple other threads. In fact I've NEVER used a AA in my QAA. ONLY 14500.