How to Use TP4056: Examples, Pinouts, and Specs

The TP4056 is a lithium-ion battery charger IC designed for single-cell lithium-ion batteries. It provides a constant current/constant voltage (CC/CV) charging profile, ensuring safe and efficient charging. The IC is equipped with built-in thermal regulation, over-voltage protection, and automatic charge termination, making it a reliable choice for battery-powered applications. Its compact design and simple interface make it ideal for portable electronics, power banks, and DIY projects.

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

1. Power Supply: Connect a DC power source (4.0V to 8.0V) to the VCC pin. Ensure the power source can supply sufficient current for the charging process.
2. Battery Connection: Connect the positive terminal of the lithium-ion battery to the BAT pin and the negative terminal to GND.
3. Set Charging Current: Use a resistor between the PROG pin and GND to set the charging current. The formula to calculate the resistor value is: [ I_{CHG} = \frac{1200}{R_{PROG}} ] where ( I_{CHG} ) is the charging current in mA and ( R_{PROG} ) is the resistor value in kΩ.
4. Status Indicators: Connect LEDs to the STAT1 and STAT2 pins with appropriate current-limiting resistors to monitor the charging status:
   • STAT1 ON, STAT2 OFF: Charging in progress.
   • STAT1 OFF, STAT2 ON: Charging complete.
   • Both OFF: No battery connected or charging disabled.
5. Thermal Protection: Optionally, connect an NTC thermistor to the TEMP pin for temperature monitoring. If unused, connect the TEMP pin to GND.

• Ensure the input voltage does not exceed 8.0V to avoid damaging the IC.
• Use a heat sink or proper ventilation if charging at high currents to prevent overheating.
• Always verify the battery's specifications to ensure compatibility with the TP4056.
• Avoid reverse polarity connections to prevent damage to the IC and battery.

The TP4056 can be used with an Arduino UNO to monitor the charging status. Below is an example code to read the status pins:

// Define the status pins connected to TP4056
const int stat1Pin = 2; // STAT1 pin connected to Arduino digital pin 2
const int stat2Pin = 3; // STAT2 pin connected to Arduino digital pin 3

void setup() {
  pinMode(stat1Pin, INPUT); // Set STAT1 pin as input
  pinMode(stat2Pin, INPUT); // Set STAT2 pin as input
  Serial.begin(9600);       // Initialize serial communication
}

void loop() {
  int stat1 = digitalRead(stat1Pin); // Read STAT1 pin
  int stat2 = digitalRead(stat2Pin); // Read STAT2 pin

  if (stat1 == LOW && stat2 == HIGH) {
    Serial.println("Charging in progress...");
  } else if (stat1 == HIGH && stat2 == LOW) {
    Serial.println("Charging complete.");
  } else {
    Serial.println("No battery connected or charging disabled.");
  }

  delay(1000); // Wait for 1 second before checking again
}

1. Problem: The battery is not charging.

   • Solution: Verify the input voltage is within the 4.0V to 8.0V range. Check the connections to the BAT and GND pins. Ensure the CE pin is pulled low to enable charging.

2. Problem: The IC overheats during charging.

   • Solution: Reduce the charging current by increasing the R_PROG resistor value. Ensure proper ventilation or use a heat sink.

3. Problem: Status LEDs are not working.

   • Solution: Check the connections to the STAT1 and STAT2 pins. Verify the LEDs and resistors are functioning correctly.

4. Problem: Charging stops prematurely.

   • Solution: Ensure the battery is not faulty or fully charged. Check the TEMP pin connection if using a thermistor.

• Can I use the TP4056 to charge multiple batteries in series? No, the TP4056 is designed for single-cell lithium-ion batteries only. Charging multiple cells in series requires a specialized battery management system (BMS).

• What happens if the input voltage exceeds 8.0V? Exceeding 8.0V can damage the IC. Always use a regulated power supply within the specified range.

• Can I adjust the charging voltage? No, the charging voltage is fixed at 4.2V ± 1% and cannot be adjusted.

• Is the TP4056 suitable for fast charging? The maximum charging current is 1A, which is suitable for most single-cell lithium-ion batteries. For faster charging, consider ICs designed for higher currents.