XCSOURCE 5 pcs 1A 5V Micro USB TP4056 Lithium Battery Power Charger Board Module TE420 Input Voltage: 4.5~5.5V Full charging voltage: 4.2V This module is used for single-cell lithium or lithium multi-section parallel, charging ports can take power from USB. It can be used for voltage 3.6 3.7V, etc. 18650, polymer and other lithium battery charge and discharge protection. MINI USB input terminal with a female, can be directly input to do with the phone charger rechargeable lithium battery, and still retains the input voltage wiring pads, can be very convenient DIY.