Amazon.com: iFixit A1398 A1618 Battery for MacBook Pro 15" Retina (Mid 2015) - Repair Kit : Electronics
Surprise! iFixit says you can't do much to fix or upgrade the 2015 MacBook | Ars Technica
Amazon.com: iFixit Battery Compatible with MacBook Pro 15" Retina (Mid 2018/2019) - Repair Kit : Electronics
Just installed battery #3 in my mid-2015 MacBook Pro. Also applied fresh thermal paste and removed the dust. Here's to many more years of use! : r/ macbookpro
Amazon.com: iFixit Compatible with Battery MacBook Pro 15" Retina (Mid 2015) : Electronics
How To: Replace 13 inch MacBook Pro 2015 Battery - YouTube
How To: Replace the Battery in a Macbook Pro 13" Unibody - YouTube