I read about battery capacity versus " # of cycles ". What exactly constitutes a " cycle "? Do you have to run the batter down to a certain level and then charge it to count as a 'cycle'? Is running the laptop with battery in and AC adapter on the best way to insure a long life? You know, run the laptop on battery power when it is needed, and not just because you can. I used to think I knew about this, but after reading several threads/posts I have to wonder!