Amazon.com: Fosmon 2200mAh Rechargeable Battery Pack Compatible with Xbox Series X/S, Xbox One/One X/One S Elite Controllers - 1 Pack, Recharge C-10777 Battery Charger (Not Included) : Video Games
Lithium Ion Cylindrical Battery - 3.7v 2200mAh : ID 1781 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Fosmon Dual 2 MAX Charger Compatible with Xbox Series X/S (2020), Xbox One/One X/One S Elite Controllers, High Speed Docking Charging with High Capacity 2X 2200mAh Rechargeable Battery Packs - White -