DAOKI 5PCS TP4056 Micro USB 5V 1A 18650 Lithium Battery Charger Board with Over Charge Discharge Protection (Pack of 5) Input Voltage: 4.5~5.5V Full charging voltage: 4.15V 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.