LOPURS 4500mah Replacement Mobile Phone Battery & Cover Back Door for Blackberry Z10 (Stl100-2, Stl100-3) Battery Specs. Capacity: 4500mAh . Battery type: Lithium Ion, Voltage: 3.8V Li-ion High Quality Replacement Mobile Phone Battery & Cover Back Door It is recommended to fully drain and fully charge the battery especially during the first 3 charging and discharging cycles, doing so may greatly improve the overall life of the battery