Amazon.com: Temark New A1382 Battery for MacBook Pro 15 inch A1286 (only for Early 2011, Late 2011, Mid 2012), fit MC721LL/A MC723LL/A 661-5844 020-7134-A : Electronics
Apple again replacing 2012-2013 MacBook Pro batteries | Cult of Mac
How To Test A MacBook Battery To See If It Needs Replacing And Replace It - Macworld UK