How to Use TP4056 - USB-C 5V 1A 18650: Examples, Pinouts, and Specs

The TP4056 is a lithium battery charger module specifically designed for charging 18650 lithium-ion batteries. It features a USB-C input for convenient power delivery and provides a constant current of 1A and a constant voltage of 4.2V, ensuring safe and efficient charging. This module is widely used in DIY electronics projects, portable power banks, and battery-powered devices.

• Charging 18650 lithium-ion batteries in DIY projects
• Power banks and portable chargers
• Battery-powered IoT devices
• Solar-powered battery charging systems
• Backup power supplies for embedded systems

The TP4056 module is compact and efficient, with the following key specifications:

The TP4056 module has several pins and connectors for input, output, and monitoring:

1. Connect the Power Source:
   Plug a USB-C cable into the module's USB-C input. Ensure the power source provides a stable 5V supply.

2. Connect the Battery:

   • Connect the positive terminal of the 18650 battery to the BAT+ pin.
   • Connect the negative terminal of the battery to the BAT- pin.
     Ensure proper polarity to avoid damage to the module or battery.

3. Optional Output Connection:
   If you want to power an external device while charging the battery, connect the device to the OUT+ and OUT- pins.

4. Monitor Charging Status:

   • The red LED (CHRG) will light up during charging.
   • The blue LED (STDBY) will light up when the battery is fully charged or no battery is connected.

• Battery Protection: Use a protected 18650 battery or add a separate protection circuit to prevent overcharging, over-discharging, and short circuits.
• Heat Management: The module may heat up during operation. Ensure proper ventilation or add a heatsink if necessary.
• Adjusting Charging Current: The default charging current is 1A. To adjust it, replace the onboard resistor (Rprog) with a different value. Refer to the TP4056 datasheet for resistor values corresponding to desired currents.
• Avoid Reverse Polarity: Always double-check connections to avoid damaging the module or battery.

The TP4056 can be used to charge a battery that powers an Arduino UNO. Below is an example of monitoring the battery voltage using the Arduino:

// Example code to monitor battery voltage using Arduino UNO
const int batteryPin = A0; // Analog pin connected to BAT+ via a voltage divider
const float voltageDividerRatio = 2.0; // Adjust based on your resistor values
const float referenceVoltage = 5.0; // Arduino's reference voltage (5V for UNO)

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(batteryPin, INPUT); // Set battery pin as input
}

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

Note: Use a voltage divider circuit to step down the battery voltage to a safe range for the Arduino's analog input (0-5V).

1. Module Overheating:

   • Cause: High charging current or insufficient ventilation.
   • Solution: Reduce the charging current by replacing the Rprog resistor or improve ventilation.

2. Battery Not Charging:

   • Cause: Incorrect connections or damaged battery.
   • Solution: Verify the polarity of the battery connections and check the battery's health.

3. LEDs Not Lighting Up:

   • Cause: No power input or faulty module.
   • Solution: Ensure the USB-C cable is properly connected and the power source is functional.

4. Output Voltage Too Low:

   • Cause: Battery is deeply discharged or damaged.
   • Solution: Allow the battery to charge for some time. If the issue persists, replace the battery.

Q1: Can I use the TP4056 to charge batteries other than 18650?
A1: Yes, the TP4056 can charge other lithium-ion or lithium-polymer batteries with a nominal voltage of 3.7V and a full charge voltage of 4.2V. Ensure the battery's capacity and charging current are compatible.

Q2: Can I power a device directly from the TP4056 while charging the battery?
A2: Yes, but ensure the device's current draw does not exceed the module's output capacity. For high-power devices, use a separate power management circuit.

Q3: How do I adjust the charging current?
A3: Replace the onboard Rprog resistor with a different value. Refer to the TP4056 datasheet for the resistor-to-current mapping.

Q4: Is the TP4056 safe for unattended charging?
A4: While the TP4056 has built-in safety features, it is recommended to use a protected battery and monitor the charging process for added safety.