Changing the battery of my old Nintendo Game Boy Advance SP, GBA SP, Ebay, Screwdriver, Rechargeable - YouTube
Amazon.com: MPF Products 600mAh OXY-003, GPNT-02 Battery Replacement Kit Compatible with Nintendo Game Boy Micro OXY-001 : Video Games
Rigged an external GameBoy Advance SP battery charger when working on a junk GBA SP that wouldn't charge, using a camera battery charger of the same specs I wasn't using anymore. :