Amazon.com: New Laptop Replacement Battery for A1278 A1322 [MacBook Pro 13 inch] - (Mid 2009, Mid 2010, Early 2011, Late 2011, Mid 2012), fit MB990LL/A MC724LL/A - [Li-Polymer 6-Cell 66.6Wh 11.1V] : Electronics
Amazon.com: A1382 Battery for MacBook Pro 15 inch A1286 Early 2011 Late 2011 Mid 2012 New Replacement Laptop Battery (7200mAh 10.95V/78.84Wh 25 Months Warranty) : Electronics
MacBook Pro 15" Unibody Early 2011 Battery Replacement - iFixit Repair Guide
Amazon.com: A1322 Battery,Runpower Replacement Battery for MacBook Pro 13 inch A1278 Battery(Mid 2009 Mid 2010 Early 2011 Late 2011 Mid 2012) : Electronics
Amazon.com: iFixit Battery Compatible with MacBook Pro 15" Unibody (Early 2011-Mid 2012) - Repair Kit : Electronics
MacBook Pro 15" Unibody Early 2011 Battery Replacement - iFixit Repair Guide
Amazon.com: iProPower A1382 Battery for MacBook Pro A1286 15" inch Laptop [Only for Early 2011, Late 2011, Mid 2012 Version] High Capacity 7200mAh 10.95V/77.5Wh Replacement Battery : Electronics
Amazon.com: iFixit Battery Compatible with MacBook Pro 15" Unibody (Early 2011-Mid 2012) - Repair Kit : Electronics
Replacing the Battery in a MacBook Pro Unibody (2009-2012) in 5 Minutes! - YouTube
MacBook Pro 13" Unibody Early 2011 Battery Replacement - iFixit Repair Guide
MacBook Pro 17" Unibody Battery Replacement - iFixit Repair Guide
MacBook Pro 15" Unibody Early 2011 RAM Replacement - iFixit Repair Guide
MacBook Pro 15" Unibody Early 2011 Battery Replacement - iFixit Repair Guide