In a support document, Apple states that outdated products cannot be repaired for hardware, "without exception." This means that any 15-inch MacBook Pro with Retina display from mid-2012 that requires a new battery or any other repair will no longer be available at an official Apple Store.
Your only alternative will be to follow one of iFixit's home repair guides or inquire at independent stores, although many do not install Apple-authorized parts.
When unveiling the MacBook Pro with Retina display at WWDC 2012, Phil Schiller said it was "a breakthrough in engineering screens", stating that "there has never been such an attractive laptop."
In addition to being the first MacBook Pro with Retina display, the 2012 model had a much thinner design than its predecessors thanks to the elimination of the Ethernet port and optical drive for CD / DVD. It also included two Thunderbolt and USB-A ports, an HDMI port, and an SD card slot.
