Pre Charge: This lithium battery charge module supports pre charge. When the battery voltage is below 2.8V, the battery will be precharged at 180mA. High Safety: When the charging current reaches the final floating charging voltage and drops to 100mA, the charging cycle will terminate automatically. When the battery voltage drops below 4.1V, the charging cycle begins again. Automatic Close: This battery charger board supports auto close. If the load is less than 50MA, automatically close the output. Easy Control: This charge integrated module can be easily controlled. Trigger the KEY port once to turn on power indicator and open 5V output. Continuously trigger the KEY port twice to turn off power indicator and close 5V output. Type C Input: This charge discharge module adopts Type C input, which ensures high accuracy in charging voltage.