Dear all, I just got an 2013 MBA 11'' with i7 and 8g ram. When fully charged, it is showing that I have 6:42 hours left. Is this normal? or is there any problem with my setting? I only opened a few webpages. It is claimed that the i5 model could last 9+ hours. Does an i7 necessarily cause such a dramatic reduction in battery life? Can anyone using the same model share some experience? Thanks very much!