CHARGER & STORAGE BOX: The charger box independently charges 1-8 AA Li-ion batteries (1.5V) simultaneously with 350mA fast-charging current per slot; the box design integrates storage and charging, saving a lot of space,very portable. Note: Only compatible for Keeppower AA batteries SMART PROTECTION: Features MCU-controlled trickle charging and intelligent ΔV/-ΔV cutoff to prevent over-voltage, over-charging, and over-heating. Automatically detects and rejects non-rechargeable, short-circuit, or defective batteries for optimal safety LED INDICATOR LIGHT: Flashes green to indicate charging,steady light indicate fully charged. Steady red light indicates temperature too high; Flashing red light indicates battery cannot be charged or not compatible LONG CYCLE LIFE: With no memory effect and a very low self-discharge rate, our double A rechargeable lithium batteries have more than 1600 rechargeable cycles, which can save you a lot of money 3 HOURS FAST CHARGE: 3 hours quick charge for 1-8 aa lithium batteries.Type-C charging port is suitable for all kinds of interface input, you could use a laptop, car charger,power bank,adapters to charge the batteries, which makes the charging more flexible BATTERY COMPATIBILITY: Revolutionary technology makes batteries larger in capacity, longer lasting,ideal for high power products such as Xbox, remote control, toys, digital camera, solar light, flashlight, Gamepad, VR Grip, Doorbell, Door Lock, Microphone, Radio, Alarm Clock, Scale, Blood Pressure Monitor, etc.. Introducing the Keeppower AA battery charging system - a sophisticated solution for your rechargeable battery needs. This compact charging box accommodates 1-8 AA Li-ion batteries (1.5V) simultaneously, delivering a swift 350mA charging current per slot. The intelligent charging system features MCU-controlled protection against overcharging, overheating, and over-voltage, while the smart ΔV/-ΔV cutoff ensures optimal battery care. The USB-C charging port provides convenient power input, while the system automatically detects and rejects non-rechargeable, short-circuited, or defective batteries for safety. A standout feature is its ability to revive completely drained (0V) batteries through activation mode. The kit includes four 1.5V 3600mWh AA Li-ion batteries and a sleek storage box that doubles as the charger. The charger accepts 5.0V-3.0A input and provides 5V output, making it compatible with standard USB power sources. Perfect for photographers, electronic device users, and anyone seeking a reliable, high-capacity battery solution.