The X40/X41 won't get 7 hours unless you have an Ultra Low Voltage CPU. IBM says you get 10 hours with 8 cell battery and extended life battery (62Wh + 27Wh = 89Wh). So i got a LV 1.5GHz, but i don't think that the consumption increases that much with a non-LV. My X40 1.5GHz LV needs with disabled ...