MacBook Pro 13" Unibody (Mid 2009-Mid 2012) Battery - iFixit
You can finally replace the battery in your MacBook Pro with Retina by yourself if you've got the nerve | iMore
Buy New A1322 A1278 Built-in Battery Replacement for Apple MacBook Pro 13 inch Mid 2012 2010 2009 Early & Late 2011 661-5229 661-5557 020-6547-A 020-6765-A 6-Cell High Performance[11.1V 66.6Wh 6000MAH] Online in Poland. B08Y5GPHTT