Nintendo Game Boy Advance SP Battery Replacement - iFixit Repair Guide
Amazon.com: GBA SP Battery Replacement, Pickle Power 900mAh Rechargeable Lithium-ion Battery with Tool Kit Compatible With Nintendo Gameboy Advance SP Battery : Video Games
Amazon.com: Gameboy Advance SP Battery Pack, 850mAh Replacement Rechargeable Lithium-ion Battery + Tool Pack Kit Compatible with Nintendo GBA SP : Video Games