I apologize if this has been answered earlier, but I could not find useful info with search. I own a MBP 13", unibody, late 2009 model. Its battery is stated at 7 hrs (although I never had such, in normal use, normally between 4-4.5 hrs). Anyway, the new MPB 13", currently available, has its battery stated at "up to 10 hrs". I wonder if the latter, newer battery fits in my (older model) MBP. The form factor is the same, I don't know whether pins or something are different.