5Pcs USB Lithium Battery Charger Module With Charging And Protection Features: Input port with micro USB female, can directly use mobile charger for input to the lithium battery, and still retain the input voltage wiring solder joints, can be very convenient. Connect the battery to B + B - insert mobile phone charger to the USB Female then red light is charging and green is full of charged. Specification: Input voltage: 5V Maximum charging current: 1000 mA Charge cut-off voltage: 4.2 V + / - 1% Battery overcharge protection voltage: 2.5 V Battery over-current protection current: 3 A Input interface: Micro USB Dimension: 2.6 x 1.7 cm Package includes: 5 x Charger module board