OSTENT 850mAh Rechargeable Lithium-ion Battery + Tool Pack Kit Compatible for Nintendo GBA SP Rechargeable Lithium, 100% brand-new and high quality 850 mAh 3.7V Rechargeable Battery for GBA SP Never run out of power while you are about to upgrade the winning point Money-saving and environment-protective by using the rechargeable battery Please charge the battery for 12 hours when using for the first time