Im trying to find batteries that will fit this flashlight otheer than the cr17345(123 3v) like a li-ion, my nitecore srt7 uses two cr123a batteries or one 18650 which is what I use in it. Im trying to figure out if there is a better battery that will replace the cr17345 like the 18650 replaces the cr123a's in my nitecore.... Thanks, zack