Features This module can protect the lithium battery from exhaustion during charging or discharging. The module is made of high-quality, reliable and stable electronic components. Provide many functions of over-current, over-voltage, short-circuit protection, over-temperature protection. Suitable for 3.7V or 4.2V lithium battery. Reasonable design, easy to wire and use. Specification: Charging voltage: DC 4.5V-5.5V (DC 5V recommended) Charging current: 0-2.1A Charging standby current: 100uA Full voltage: 4.2V+-1%. Discharge current: 0-2.4A; Discharge standby current: 50uA Discharge efficiency: up to 96% Output voltage: 5V Output current: 0-2.1A; Ambient temperature: -20℃-85℃ Protection function: OCP, OVP, SCP, OTP Wire: GND connect to battery negative VIN connect to positive battery VOUT Connect to Positive Output+ GND Connect to positive output- Package List: 1 x lithium battery charger module. Package List