TP4056 is a small charger module for li-ion battery, very often used in combination with 3.7V 18650 battery, Esp8266/Esp32 chips and solar panels.
It includes overcurrent protection and auto cutoff charging circuit to preserve battery life. Two onboard LEDs reports the operational status: one LED indicate charge in progress and another one LED indicates fully charged battery. Max output current is 1A, input voltage il 4.5 V-5.5 V.
wiring diagram