This is a TP4056 Based 1A max LiPo (Lithium Polymer) Battery Charger Module with Micro USB port based input option inbuilt. The TP4056 is a complete constant-current/constant-voltage linear charger for single cell lithium-ion batteries. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The TP4056 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached.