4 charging channels can charge the battery separately.4 slots can be adjusted according to different battery lengths. The charger will display the status of each rechargeable battery when charging, and automatically stop charging when complete, with multiple safety protections. Rechargeable battery charger support USB charging. Capable of charging 1-4 Pcs different battery simultaneously. Automatically detects battery power status and selects the appropriate voltage and charge mode. Perfect protection function:under voltage protection,over voltage protection,over current protection,over temperature protection,short circuit protection,anti-reverse battery protection, Zero Volume Battery Repair and excellent heat dissipation design. Package Included: 1pcs USB Battery Charger(4-Slot), Only Charger. Package Included: 1pcs USB Battery Charger(4-Slot）