I did a calibration once on day one, but now my battery has depleted it's total capacity from the origianl 5450 mah to 5320 mah (From 100% to 97%)! What is happening, should I do another calibration or do I have a defective battery? The info above is both consistent under the OSX info (About this this Mac) and Coconut Battery. If the battery needs replacing, is it done in-store or am I supposed ship it? Any suggestion is appreciated.