What Is the Difference Between ESCs With and Without BEC? How to Tell the Difference

When choosing an ESC (Electronic Speed Controller), you may come across two types: ESCs with BEC and ESCs without BEC.

The main difference is whether the ESC can directly provide power to the receiver and other low-voltage electronic devices.

What Is a BEC?

BEC stands for Battery Eliminator Circuit.

Simply put, a BEC is a voltage regulator built into the ESC. It reduces the higher voltage from the main battery to the lower voltage required by the receiver, typically 5V, allowing the ESC to power the receiver.

For example:

24V Battery → ESC Built-in BEC → 5V → Receiver

With a built-in BEC, there is no need to add a separate power supply module for the receiver.

What Is the Difference Between ESCs With and Without BEC?

ESCs With BEC

Examples include Feather 30A and Feather 100A.

These ESCs have a built-in BEC. They can control the motor while also supplying power to the receiver.

One way to identify them is by checking the wire connected to the receiver.

The receiver connection wire usually has three wires:

• Power (+)

• Ground (−)

• Signal

The power wire supplies low-voltage power to the receiver, so the receiver can be powered directly through the ESC.

ESCs Without BEC

Examples include Feather 45A and Feather 80A.

These ESCs do not have a built-in BEC. They are designed to control the motor but cannot directly provide power to the receiver.

The receiver connection wire usually has two wires:

• Ground (−)

• Signal

Since there is no power wire, the ESC cannot supply power to the receiver.

How to Tell If an ESC Has a BEC

One of the easiest ways is to check the receiver connection wire.

3 wires → Usually indicates an ESC with BEC

2 wires → Usually indicates an ESC without BEC

For example:

However, in actual use, it is always recommended to check the ESC's product specifications for confirmation, as wire and connector designs may vary between different models.

What If the ESC Does Not Have a BEC?

If you are using an ESC without a BEC, there is no need to worry.

You can simply add a separate BEC or suitable power supply module to provide the required low-voltage power to the receiver.

For example:

Battery → ESC → Motor

At the same time:

Battery → External BEC → Receiver

This allows the system to work normally even when the ESC itself does not have a built-in BEC.

Summary

In simple terms:

ESC with BEC:
Controls the motor and can also power the receiver, making the wiring simpler.

ESC without BEC:
Controls the motor only and requires an additional BEC or power supply module to power the receiver.

Therefore, when choosing an ESC, don't just look at the maximum current, voltage, and motor type. You should also check whether the ESC has a BEC and whether its BEC output voltage and maximum output current meet the requirements of your control system.