After several days of monitoring my MacBook Pro battery's health, and reading about many experiences online about the same issue, I have concluded that this is normal behaviour for a new Apple MacBook Pro. A lot of people suggested it takes a month for your new battery to 'settle' and only to be alarmed or consider contacting Apple if the battery health drops below 80%. In my search I also found this handy tip on how to 'calibrate' your battery provided by Apple.

Source: http://www.neuromance.co.za/2010/02/07/apple-macbook-pro-battery-health-queries/

PowerBook G4 (15-inch, double-layer SD) and all models of MacBook or MacBook Pro battery calibration are due to computer using a new battery which has been updated. The use of these computers, follow these steps to calibrate your

Source: http://www.hunt360.org/2010/01/apple-portable-computer-calibration-of-the-computers-battery-for-best-performance/

I concluded my sermon by boasting that my 18-month-old MacBook Pro has been plugged in to AC power most of the time, but since I've calibrated its battery religiously every 30 days or so, it still works almost as well as the day I got

Source: http://shopdella.com/your-battery-needs-a-workout-routine

For more information about battery calibration for other models, consult the apple website. (PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), MacBook Pro (all models), MacBook Pro (17-inch) (all models) and MacBook Air)

Source: http://www.ironpaper.com/current/2010/01/how-to-calibrate-a-macbook-battery/

So give yourself and your MacBook a rest (actually you can continue working – no prob) and calibrate your battery for staying more time wireless. Here you will find the article about how this calibration is done. For aliminium case macbook pro series;. - charge it full - keep the cable plugged for 2-3 hours more - unplug while the computer is on - use the computer until the battery warning appears on the screen - save your work and keep using it (ignore the warning)

Source: http://www.aydincanpolatkan.com/blog/?p=8