Each HDCKU battery for iPad Air comes with a built-in IC chip that prevents Over-Charging, Over-Discharging, Over-Heating and Short-Circuiting.Battery Replacement Kit Compatible with Apple iPad Air/5 A1474, A1475, A1476, supports all versions Wi-Fi and Cellular (NOT Compatible with any iPad Air 2,Part Number :A1566 A1567)Grade A cells ensure longer battery life (500+ cycles) and high-speed, efficient charging.High quality replacement battery 8827mAh, 3.73 V, 32.9Wh.Best replacement for the original battery with comparable standby and talk time32.9Whr Extra High Capacity, extra-long standby times.HDCKU battery for Ipad air is sent out with little to no power, so please charge it for about 4 - 6 hours before using.Please double check to make sure the battery matches your iPad Air model.It’s better to use the OEM cable and charger to charge it.