How to Use BEC module : Examples, Pinouts, and Specs

A BEC (Battery Eliminator Circuit) module is an electronic device designed to provide a stable, regulated voltage output from a higher voltage input source. It is commonly used in remote-controlled (RC) vehicles, drones, and other electronic systems to power components such as servos, receivers, and flight controllers without requiring a separate battery. By stepping down the voltage from the main power source (e.g., LiPo battery), the BEC module ensures that sensitive electronics receive a consistent and safe voltage level.

• Powering RC vehicle receivers and servos
• Supplying voltage to flight controllers in drones
• Providing regulated power to LEDs or other low-voltage components
• Eliminating the need for multiple batteries in electronic systems

Below are the typical technical specifications for a standard BEC module. Note that actual values may vary depending on the specific model.

The BEC module typically has three main connections: input, output, and ground. Below is a table describing the pin configuration.

Some BEC modules may also include a jumper or switch to select the output voltage (e.g., 5V or 6V).

1. Connect the Input Voltage:

   • Connect the VIN (+) pin to the positive terminal of your battery or power source.
   • Connect the GND pin to the negative terminal of your battery or power source.

2. Connect the Output Voltage:

   • Connect the VOUT (+) pin to the positive terminal of the device you want to power (e.g., receiver, servo, or flight controller).
   • Connect the GND pin to the ground terminal of the device.

3. Voltage Selection (if applicable):

   • If your BEC module has a voltage selection jumper or switch, set it to the desired output voltage (e.g., 5V or 6V) before powering the module.

4. Power On:

   • Once all connections are secure, power on the system. The BEC module will regulate the input voltage and provide a stable output to your connected devices.

• Check Voltage Ratings: Ensure that the input voltage is within the specified range of the BEC module. Exceeding the maximum input voltage can damage the module.
• Avoid Overloading: Do not exceed the maximum output current rating of the BEC module. Overloading can cause overheating or failure.
• Heat Dissipation: If the BEC module becomes warm during operation, ensure proper ventilation or consider adding a heatsink to improve heat dissipation.
• Polarity: Double-check the polarity of all connections to avoid damaging the module or connected devices.
• Noise Filtering: For sensitive applications, consider adding a capacitor on the output to further reduce voltage ripple.

A BEC module can be used to power an Arduino UNO from a higher voltage source, such as a 3S LiPo battery (11.1V). Below is an example connection and code.

• Connect the VIN (+) pin of the BEC module to the positive terminal of the LiPo battery.
• Connect the GND pin of the BEC module to the negative terminal of the LiPo battery.
• Connect the VOUT (+) pin of the BEC module to the 5V pin of the Arduino UNO.
• Connect the GND pin of the BEC module to the GND pin of the Arduino UNO.

// Example code to blink an LED connected to pin 13 of the Arduino UNO
// Ensure the Arduino is powered via the BEC module (5V output)

void setup() {
  pinMode(13, OUTPUT); // Set pin 13 as an output
}

void loop() {
  digitalWrite(13, HIGH); // Turn the LED on
  delay(1000);            // Wait for 1 second
  digitalWrite(13, LOW);  // Turn the LED off
  delay(1000);            // Wait for 1 second
}

1. BEC Module Not Powering the Load:

   • Cause: Incorrect wiring or polarity.
   • Solution: Double-check all connections and ensure the input and output polarities are correct.

2. Overheating:

   • Cause: Exceeding the maximum current rating or poor ventilation.
   • Solution: Reduce the load current or improve airflow around the module. Consider using a heatsink.

3. Voltage Output is Unstable:

   • Cause: Input voltage is too low or noisy.
   • Solution: Ensure the input voltage is within the specified range. Add a capacitor to the input or output for additional filtering.

4. No Output Voltage:

   • Cause: Faulty module or blown internal components.
   • Solution: Test the module with a multimeter. Replace the module if it is damaged.

Q: Can I use a BEC module with a 4S LiPo battery?
A: Yes, as long as the input voltage of the BEC module supports the voltage range of the 4S LiPo battery (typically ~14.8V).

Q: Can I power multiple devices with a single BEC module?
A: Yes, but ensure the total current draw of all devices does not exceed the maximum output current rating of the BEC module.

Q: Is it safe to use a BEC module with sensitive electronics?
A: Yes, most BEC modules provide a stable and low-ripple output voltage, making them suitable for sensitive electronics. However, adding a capacitor for additional filtering is recommended in critical applications.

Q: How do I select the correct BEC module for my application?
A: Consider the input voltage range, output voltage, and maximum output current required for your application. Choose a module that meets or exceeds these requirements.