I normally have my battery in percentage. When i change it to time left (96%), it fluctuate from 1:40 to 2:06 -> 1:20 -> 1:58,... But shouldn't battery be 5hr (3 hr to be reality)? I have my slingbox, Firefox, skype, yahoo messenger running. Brightness is on level 9 (max at level 16). I have the new SR MBP. Is there something wrong?