Macbook pro 13 Inch battery A1713 & A2171 Battery Specification- Voltage: 11.41V. Capacity: 66.2Wh / 5800mAh, Battery Type: Li-ion. Higher capacity than original battery (4781mAh/54.5Wh)--Longer Operating Time Newest 4.0 upgraded OEM Battery for Apple macbook pro- Japan High Performance Electric Core. Cobalt Proportion: >98%. Upgrade chip. Up to 1500+ recharge cycles over the life of the battery. Overcharger and Discharger Circuit Protection, Ensure fast charges and low power consumption