MacBook Pro 13" Unibody Early 2011 Battery Replacement - iFixit Repair Guide
Amazon.com: A1494 A1618 Battery Only for (Mid 2015, Mid 2014, Late 2013) A1398 MacBook Pro - Replacement Battery for 15-inch MacBook Pro A1398 - [Upgraded A1494/A1618 Universal Version] : Electronics
Amazon.com: A1618 A1494 A1398 Battery for MacBook Pro Battery 15 inch Retina Mid 2015 Mid 2014 Late 2013, Fit for MacBookPro 11,2 11,3 11,4 11,5 2013 2014 2015 MacBook pro 11.26V/95Wh : Electronics
Amazon.com: 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
Amazon.com: A1618 A1494 A1398 Battery for MacBook Pro Battery 15 inch Retina Mid 2015 Mid 2014 Late 2013, Fit for MacBookPro 11,2 11,3 11,4 11,5 2013 2014 2015 MacBook pro 11.26V/95Wh : Electronics
NewerTech® : Batteries : NuPower® Battery for MacBook Pro 13" Retina late 2013 to early 2015 Models