I have an aluminum unibody macbook bought 2/08. I've been having some battery issues: 1) Even when plugged in for a whole day, it never seems fully charged. It always shows a percentage in the 90's instead of 100%. 2) The battery drains several times faster than it used to just a month ago. 3) It shuts down without warning around 40% charge, according to what my computer says. Does this sound familiar? I googled and read that maybe I should reset the PRAM or something. Should I just take it in? I have Applecare.