I have had this macbook for over 2 years and recently my charger went out, so i bought a new one (60 watt) and now it wont charge it. I have taken out the battery and held the power button for 5 seconds put the battery back in and then plugged it in, and that charges it. But when i take the charger back out it wont charge it at all, so the only way i can charge the battery is if i repeat the steps all over again. Can someone help me out? Do i need a new battery? What's the...