yea, tarig is right..... there are SoOoOo many factors to length of the battery, (screen size, screen brightness, bluetooth, airport, applications running, processors running, temperature, ect.) but just using safari (via airport) with the screen on half bright i get 2 hrs, well at least thats what the little calculator says, but once i get to about 12% it suddenly jumpes to 0%; so 2 hrs might more be like 1hr and 40 min