i started playing with mine out of the box for about 30 or so.. maybe 45, and the meter went down about 1/5th. so 3hrs of continuous usage? ill have to check the specs and see what others have to say. thats not too bad. i used the visor on 2 AAA nimh batteries everyday and it seemed to last at least 2 weeks. each day's usage was at least 5min total id say. given the power and color, im satisfied. i just hope it doesnt deteriorate much over time