Mikroe Charger 3 Click is a standalone battery charger with thermal regulation that features the NanJing Top Power ASIC Corp TP4056. The TP4056 is a complete constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. The charge voltage of the TP4056 is specified at 4.2V with the charge current programmable via an onboard digital potentiometer, automatically terminating the charge cycle when the charging current drops to 1/10th the programmed value. It also features current monitoring, under-voltage lockout, automatic recharge, and two LEDs to indicate charge termination and the presence of an input voltage.