I went on vacation for 1 month and when I came back my mac wouldn't charge! In the corner it would say "Not Charging" and and the battery lights do not turn on when I press the button on the battery itself. The mac only works when I have it plugged in. Anyone else had this problem? Do I need a new battery? It's a 13" white macbook... about 2.5 years old. It has the Intel processor but not the Core2Duo.