The charger has its own LED indicator that shows the charging status. The LED indicator lights up permanently red during charging, while the LED lights up green when the battery is fully charged or in standby mode. The three charger can charge one or two or three batteries at the same time, whose model corresponds to the included battery. Dual port charger has 5V 2.1A micro and Type-C input. The Type-C input allows you to conveniently use your own Type-C charging cable. You can conveniently connect the included micro USB charging cable via the micro input. Built-in intelligent chip automatically detects output voltage and adjusts voltage to protect the charger. Two batteries are the same size as the original battery, which fits well with the sports camera. The included micro USB charging cable can connect the charger to laptop, power supply, car charger and power bank to charge these batteries. Comfortable and effective. Specifications: - Three-way charger: model: BC-AB1 Input: 5V 2.1A Output: 4.35V 700mA * 3 Power supply: micro USB/type C. Charger size: 7 x 5.5 x 2.15 cm Weight of the charger: 33 g. - Rechargeable lithium-ion battery * 2: compatible device: action camera. Voltage:3.85V Capacity:1300mAh Power:5.0Wh Battery Weight(1pc):31g ------------------------------- Package Size:10.6*8*4.6cm Package Weight:155g Package Includes:1 x BC-AB1 Charger 2 x Li-ion Batteries1 x Micro USB Charging Cable Warning: the charger does not support the simultaneous use of two charging ports.