How to Use 3S 12.6V 2A 18650 Lithium Battery Charger Module Type C: Examples, Pinouts, and Specs

The 3S 12.6V 2A 18650 Lithium Battery Charger Module is a compact and efficient charging solution designed for charging three 18650 lithium-ion batteries connected in series. It provides a maximum output voltage of 12.6V and a charging current of up to 2A. The module features a Type C USB interface, making it compatible with modern power sources such as USB-C adapters, power banks, and laptops.

• Powering portable electronic devices
• DIY battery packs for robotics and IoT projects
• Backup power systems
• Battery maintenance and charging for 3S lithium-ion configurations

Below are the key technical details of the 3S 12.6V 2A 18650 Lithium Battery Charger Module:

The module has the following key connections:

1. Connect the Battery Pack:
   • Connect the positive terminal of the 3S battery pack to the B+ pin.
   • Connect the negative terminal of the 3S battery pack to the B- pin.
2. Connect the Load (Optional):
   • If you want to power a load while charging, connect the load's positive terminal to P+ and the negative terminal to P-.
3. Power the Module:
   • Use a USB-C cable to connect the module to a 5V power source, such as a USB adapter or power bank.
4. Monitor Charging:
   • The LED indicator will show the charging status:
     • Red LED: Charging in progress.
     • Green LED: Charging complete.

• Ensure the battery pack is properly balanced and configured in a 3S arrangement before connecting to the module.
• Use a high-quality USB-C power source capable of delivering at least 2A for optimal performance.
• Avoid short-circuiting the B+ and B- terminals, as this may damage the module or the battery pack.
• Do not exceed the module's maximum input voltage of 5V to prevent damage.
• Ensure adequate ventilation during charging to prevent overheating.

If you are using the module to power an Arduino UNO, connect the P+ and P- terminals to the Arduino's VIN and GND pins, respectively. Below is an example code snippet to monitor the battery voltage using the Arduino's analog input:

// Define the analog pin connected to the battery voltage divider
const int batteryPin = A0;

// Define the voltage divider ratio (adjust based on your resistor values)
const float voltageDividerRatio = 3.0; 

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

void loop() {
  int rawValue = analogRead(batteryPin); // Read the analog value
  float batteryVoltage = (rawValue * 5.0 / 1023.0) * 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 (0-5V) for the Arduino's analog input.

1. Module Not Charging the Battery

   • Cause: Incorrect battery connection or damaged battery pack.
   • Solution: Verify the battery pack is properly connected to the B+ and B- terminals. Check the battery pack for damage or imbalance.

2. LED Indicator Not Turning On

   • Cause: Insufficient input power or faulty USB-C cable.
   • Solution: Ensure the power source provides at least 2A. Try using a different USB-C cable or power adapter.

3. Overheating During Charging

   • Cause: Poor ventilation or excessive ambient temperature.
   • Solution: Place the module in a well-ventilated area and avoid charging in high-temperature environments.

4. Load Not Receiving Power

   • Cause: Improper connection to P+ and P- terminals.
   • Solution: Double-check the load connections and ensure the battery pack is charged.

• Can I use this module to charge a single 18650 battery?

  • No, this module is specifically designed for 3S (three cells in series) configurations. Using it with a single cell may damage the battery or the module.

• What happens if I connect a power source with more than 5V?

  • The module may be damaged if the input voltage exceeds 5V. Always use a 5V power source.

• Can I use this module to charge other types of batteries?

  • This module is designed for lithium-ion batteries only. Do not use it with other battery chemistries, such as NiMH or lead-acid.

• Is it safe to leave the battery connected after charging is complete?

  • Yes, the module includes overcharge protection, but it is recommended to disconnect the battery if not in use for extended periods.