Hi, I'm considering buying the Quark AA2 "X" (w/ the XM-L). Just curious if there's a cool-off period necessary when running the flashlight at Max output (280 lumens), i.e. 10 minutes on 1 minute off, or if it's safe (for the flashlight and the batteries) to have it on for as long as the batteries last? I plan on using eneloops but might also use alkalines on a rare occasion.