How to Use TP4056: Examples, Pinouts, and Specs

The TP4056 is a lithium battery charger IC designed to provide a constant current/constant voltage (CC/CV) charging profile for single-cell lithium-ion batteries. It is widely used in battery-powered devices due to its compact size, high efficiency, and integrated safety features. The TP4056 simplifies the charging process by offering built-in thermal regulation, over-voltage protection, and an easy-to-use interface for monitoring charging status.

• Charging single-cell lithium-ion or lithium-polymer batteries
• Power banks and portable chargers
• Wearable devices and IoT gadgets
• DIY electronics projects
• Battery management systems

The TP4056 is a highly versatile IC with the following key specifications:

The TP4056 IC typically comes in an 8-pin SOP package. Below is the pinout and description:

1. Power Supply: Connect a 5V DC power source (e.g., USB) to the VCC pin. Ensure the input voltage is within the 4.0V-8.0V range.
2. Battery Connection: Connect the positive terminal of the lithium-ion battery to the BAT pin and the negative terminal to GND.
3. Programming Charging Current: Use a resistor (Rprog) between the PROG pin and GND to set the charging current. The formula is: [ I_{CHARGE} = \frac{1000}{R_{PROG}} ] For example, a 1.2kΩ resistor sets the charging current to approximately 833mA.
4. Status LEDs: Connect LEDs to the STAT1 and STAT2 pins for visual charging status:
   • STAT1 ON, STAT2 OFF: Charging in progress.
   • STAT1 OFF, STAT2 ON: Charging complete.
   • Both OFF: No battery connected or standby mode.
5. Thermal Regulation: The TP4056 automatically reduces the charging current if the IC temperature exceeds safe limits.

• Battery Safety: Always use a single-cell lithium-ion battery with a built-in protection circuit to prevent overcharging or deep discharge.
• Heat Dissipation: Ensure proper heat dissipation by using a PCB with adequate thermal pads or copper areas.
• Input Voltage: Avoid exceeding the maximum input voltage of 8.0V to prevent damage to the IC.
• Thermistor: For enhanced safety, connect an NTC thermistor to the TEMP pin to monitor battery temperature.

The TP4056 can be used alongside an Arduino UNO to monitor battery voltage. Below is an example code snippet:

// Example: Monitor battery voltage using Arduino UNO
const int batteryPin = A0; // Analog pin connected to battery via voltage divider
float voltageDividerRatio = 2.0; // Adjust based on your resistor values

void setup() {
  Serial.begin(9600); // Initialize serial communication
}

void loop() {
  int rawValue = analogRead(batteryPin); // Read analog value
  float batteryVoltage = (rawValue * 5.0 / 1023.0) * voltageDividerRatio;
  
  // Print battery voltage to the Serial Monitor
  Serial.print("Battery Voltage: ");
  Serial.print(batteryVoltage);
  Serial.println(" V");
  
  delay(1000); // Wait for 1 second before next reading
}

Note: Use a voltage divider to scale down the battery voltage to within the Arduino's 0-5V ADC range.

1. No Charging Current

   • Cause: Incorrect Rprog resistor value or damaged IC.
   • Solution: Verify the Rprog resistor value and ensure it matches the desired charging current. Check for proper connections.

2. Overheating

   • Cause: Insufficient heat dissipation or high ambient temperature.
   • Solution: Improve PCB thermal design or reduce the charging current.

3. LEDs Not Working

   • Cause: Incorrect LED connections or damaged LEDs.
   • Solution: Verify LED polarity and connections to STAT1/STAT2 pins.

4. Battery Not Charging

   • Cause: Faulty battery or incorrect wiring.
   • Solution: Test the battery with a multimeter and ensure proper connections to the BAT and GND pins.

• Can I use the TP4056 to charge multiple batteries in series?

  • No, the TP4056 is designed for single-cell lithium-ion batteries only.

• What happens if the input voltage exceeds 8.0V?

  • The IC may be permanently damaged. Always ensure the input voltage is within the specified range.

• Can I disable charging temporarily?

  • Yes, pull the CE pin high to disable charging.

• Is the TP4056 suitable for fast charging?

  • The maximum charging current is 1A, which is sufficient for most single-cell batteries but may not qualify as "fast charging" for larger batteries.

By following this documentation, you can effectively integrate the TP4056 into your projects and ensure safe and efficient battery charging.