hi there, i just want to ask, how long can a macbook pro battery last? when i let it sleep but i took off the ac adaptor.. because, i let my macbook pro sleep on friday at around 5:30pm, it only uses battery power during sleep, but, when i came home on monday evening at around 7pm, my macbook pro is already shut down. i didn't know if the battery just drained, or my battery life is shorter than it should be because, i know that sleeping consumes just little power... is there something wrong with my macbook pro or battery? thanks...