4 in 1 Charge/Discharger/Lithium Battery Protection/Battery Indicator Module _x000D_ _x000D_ _x000D_ Specification: _x000D_ Charge voltage: DC 4.5V-5.2V (recommend DC 5V) _x000D_ Charging current: 0-2.1A _x000D_ Charge quiescent current: 100uA _x000D_ Full charge voltage: 4.2V1% _x000D_ Discharge current: 0-3.5A _x000D_ Discharge quiescent current: 50uA _x000D_ Discharge conversion efficiency: Max 96% _x000D_ Output voltage: 5V _x000D_ Output current: 0-2.1A _x000D_ Operating temperature: -20~85 _x000D_ Size: 26.7*18.1*5.7mm _x000D_ Weight: 1.9g _x000D_ _x000D_ Comes with battery protection functions, do not need battery protection board: _x000D_ Overcurrent protection(OCP) _x000D_ Overvoltage protection(OVP) _x000D_ Short circuit protection(SCP) _x000D_ Over temperature protection(OTP) _x000D_ _x000D_ Pin description: _x000D_ VIN: Charging port + _x000D_ GND: Charging port - _x000D_ BAT: Battery port + _x000D_ GND: Battery port - _x000D_ GND: Output port - _x000D_ VOUT: Output port + _x000D_ KEY: Output trigger port(Low pulse trigger) _x000D_ _x000D_ How to use: _x000D_ 1. In discharge mode(In the charging mode, the KEY function is invalid), trigger the KEY once - turn on the output; Continuously trigger KEY twice - turn off the output. _x000D_ 2. When connecting the load for the first time, it will automatically turn on the output. If the load is less than 50mA, the output will be turned off after 30 seconds; If the load is more than 50mA, it will continuously turn on the output.