Amazon.com: SLE-TECH A1321 Battery for Apple MacBook Pro 15" inch A1286 (Only for Mid 2009, Early/Late 2010), fits MC118LL/A MC373LL/A MB986LL/A Series Notebook : Electronics
Determine battery cycle count for Mac laptops - Apple Support
Batteries for MacBook Pro 15" Unibody 2009 - 2010 Models
How Long Does Your MacBook Pro Battery Last? | OSXDaily