I recently ordered another 2xCR123/18650 light and think I want to begin using rechargeable 18650’s rather than buying so many CR123’s. I began researching and there are TONS of batteries and options out there. Do I want protected or non-protected cells? USB charger or AC smart charger? What brands are best? Seems like Amazon has pulled a lot of these in recent months based on all the dead links I’ve found and some other forum comments. I believe I need a button type, not flat. I believe I want the highest mah rating possible. If it matters, I have Surefire, Fenix, and Nitecore lights. What do you guys use?