How about the lithium battery charging module circuit based on TP4056?

　　TP4056 is a complete single-cell lithium-ion battery with constant current/constant voltage linear charger. The SOP8 package with a heat sink on the bottom and a small number of external components make the TP4056 an ideal choice for portable applications. TP4056 can work with USB power supply and adapter power supply.

　　TP4056 is a complete single-cell lithium-ion battery with constant current/constant voltage linear charger. The SOP8 package with a heat sink on the bottom and a small number of external components make the TP4056 an ideal choice for portable applications. TP4056 can work with USB power supply and adapter power supply.

　　TP4056 Features

　　Programmable charging current up to 1000mA does not require MOSFETs, sense resistors or isolation diodes for single-cell lithium-ion batteries, complete linear chargers in SOP package constant current/constant voltage operation, and can be achieved without the risk of overheating Thermal regulation function to maximize charging rate

　　4.2V preset charging voltage with an accuracy of ±1.5%

　　Charging current monitor output for battery power detection

　　Automatically recharge

　　Charging status dual output, no battery and fault status display

　　C/10 charging termination

　　The power supply current in standby mode is 55uA

　　2.9V trickle charging device version soft start limits the inrush current

　　The battery temperature monitoring function adopts 8-pin SOP-PP package.

　　TP4056 pin and function

　　TEMP (pin 1:): battery temperature detection input terminal, battery temperature detection input terminal, battery temperature detection input terminal. Connect the TEMP pin to the output terminal of the battery's NTC sensor. If the voltage of the TEMP pin is less than 45% of the input voltage or greater than 80% of the input voltage, it means that the battery temperature is too low or too high, and charging is suspended.

　　If TEMP is directly connected to GND, the battery temperature detection function is cancelled, and other charging functions are normal.

　　PROG (pin 2): constant current charging current setting and charging current monitoring terminal current monitoring terminal. Connect an external resistor from the PROG pin to the ground terminal to program the charging current. During the pre-charging phase, the voltage of this pin is modulated at 0.1V; during the constant current charging phase, the voltage of this pin is fixed at 1V. In all modes of the charging state, measuring the voltage of this pin can estimate the charging current according to the following formula:

　　GND (Pin 3:): Power ground.

　　Vcc (pin 4): Input voltage positive input terminal Input voltage positive input terminal. . The voltage of this pin is the working power supply of the internal circuit. When the voltage difference between Vcc and BAT pin is less than 30mV, the TP4056 will enter a low-power shutdown mode, and the current at the BAT pin is less than 2uA.

　　BAT (pin 5): battery connection terminal battery connection terminal battery connection terminal. Connect the positive terminal of the battery to this pin. When the chip is disabled or in sleep mode, the leakage current of the BAT pin is less than 2uA. The BAT pin provides charging current and a 4.2V limit voltage to the battery. Pulled to low level by the internal switch, indicating that the charging is complete.

　　(Pin 7) Open-drain output charge status indicator indicator end. When the charger is charging the battery, the pin is in a high-impedance state.

　　CE (pin 8) chip enable input terminal chip enable input terminal. A high input level will make the TP4056 in a normal working state; a low input level will make the TP4056 in a state of being forbidden to charge. The CE pin can be driven by TTL level or CMOS level.