If you're building a drone, RC car, or robotics project, chances are you're already using an ESC (Electronic Speed Controller). What many don’t realize is that most ESCs come with a built-in BEC (Battery Eliminator Circuit), which can be used as a reliable 5V power supply for your Arduino.

In this guide, you'll learn exactly how to power an Arduino Uno using an ESC BEC — including a real photo demonstration and wiring instructions.

Why Use an ESC BEC to Power Arduino?

ESCs with built-in BECs output a regulated 5V, which is perfect for directly powering your Arduino through the 5V pin. This is useful in RC projects where you already use a LiPo battery for motors, so you don’t need a separate power source for the microcontroller.

Components You’ll Need

  • ESC with 5V BEC output (e.g., 30A ESC)
  • 11.1V 3S LiPo Battery (e.g., 2200mAh)
  • Arduino Uno or compatible board
  • Breadboard and jumper wires (optional)
  • (Optional) LED for testing

Wiring Instructions

  1. Connect your LiPo battery to the ESC’s main power input.
  2. The BEC wires (usually red, black, and white) are connected to:
    • Red wire → Arduino 5V pin
    • Black wire → Arduino GND
    • White wire (signal) is unused if you’re only using the ESC to power Arduino.
  3. When the LiPo is connected, the ESC provides a stable 5V through the BEC.
  4. Your Arduino powers up automatically — no USB or extra battery required.

Do not power your Arduino from 2 sources at the same time! For example don't connect your Arduino with your laptop and at the same time power it with the ESC BEC 5V. That would damage your components.

Important Notes

  • Only connect to the 5V pin — do not use VIN, as it expects 7–12V.
  • Make sure your ESC has a built-in BEC — some don't.
  • Always disconnect the LiPo battery when not in use to avoid over-discharge.
  • Handle LiPo batteries with care — they are powerful but require safe usage.

Benefits of ESC BEC Power

  • Efficient use of one battery for both motors and microcontroller
  • Cleaner wiring for mobile robots and drones
  • No need for external voltage regulators or USB power

Use Cases

  • RC Drones and Quadcopters
  • RC Boats and Cars
  • Battery-powered Arduino Robots

Alternatives to ESC BEC Power

  • USB Cable (from laptop or power bank)
  • 9V or 12V Battery via VIN
  • 5V Regulator Modules
  • 18650 Battery Pack via VIN (see our guide)

Conclusion

Powering Arduino with an ESC BEC is a smart and efficient choice for RC enthusiasts and robot builders. It saves space, simplifies wiring, and leverages the existing LiPo power system.