I restiored a rev A i recently bought to resell and basically last night on full charge with brightness at like half, all I did was surf the web and facebook and stuff. this thing BARELY lasted 2 hours 45 mins. I have a brand new rev B under my bed I have yet to open cause of making 100% sure I like it which I do but dang NOT if the battery life is THIS bad...how can they advertise 4.5 hours n its like HALF of that....I mean as many of you may recall i was considering keeping a sony Vaio TT over this AIR and i KNOW for a fact the vaio TT battery lasts well over 5 hours FOR SURE...id give up a little screen size but thats about it... HELPPPPP this is UNBELIEVABLE