Bought one of these UV LED flashlights for an experiment, but the battery holder got stuck with AA NIMH cells. Upon prying loose and retrieving from the other side of the room, the battery holder wasn't usable. Anyway, wired in a USB cord and it ran pretty well at 5V and 580mA. Then all of a sudden my battery pack for it started dying quickly. Went back to check it and it was drawing 1.3A at 5V now. So went and bought a 5V 2A power supply.