One of the stores I work at sells those, although I don't own one myself. The specs claim you should expect up to 2 hours on high with a new battery. If the unit is new just contact the company for a warranty claim. If its over a year old and out of warranty - could simply be the battery, which is a user replaceable 2,300 mAh Li-Ion unit. Swapping in a new one should solve the issue.