BEC systems

BEC systems and voltage regulators for RC model boat building

BEC systems (Battery Eliminator Circuit) ensure a reliable power supply to the receiver, servos and other RC electronics. They step down the higher voltage of the main battery to a stable output voltage suitable for the connected components.

With an external BEC or UBEC, receivers and servos can be powered directly from the model boat’s main battery. This means that an additional receiver battery is not required in many applications. A separate BEC can provide a powerful power supply, particularly for high-torque servos, sail winches or extensive special functions.

In our range, you will find BEC voltage regulators for RC models from Robbe and Hobbywing, as well as adjustable voltage regulators from aero-naut.

Why do you need a BEC in a model boat?

Receivers and servos usually operate at a significantly lower voltage than the propulsion system of an RC boat. If, for example, the model is powered by a multi-cell LiPo battery, this battery voltage must not be connected directly to components that are only designed for lower voltages.

The BEC reduces the battery voltage to a defined output voltage and thus supplies power to, for example:

• RC receivers
• Rudder servos
• Sail winches
• Control modules
• Lighting modules
• Sound modules
• Cameras
• winches and special functions
• other electronic loads

Depending on the BEC used, different output voltages and current ratings can be selected.

External BEC or integrated ESC BEC?

Many electronic speed controllers (ESCs) already have an integrated BEC for powering the receiver. However, when using high-power servos or multiple loads operating simultaneously, its capacity may not be sufficient under certain circumstances.

An external BEC is particularly suitable when a higher current capacity is required, or when the receiver and servos are to be powered independently of the speed controller’s BEC.

Important: If an external BEC and a speed controller with an integrated BEC are used together with the same receiver, the power supplies must not be operated in parallel without the appropriate authorisation. As a rule, the speed controller’s BEC supply must be deactivated.

Robbe RO-BEC+ with 4 A, 6 A and 8 A

The Robbe RO-BEC+ voltage regulators are available in several power ratings and are therefore suitable for RC models of various sizes.

Depending on the model, the output voltage can be set to:

• 6.0 V
• 7.4 V
• 8.4 V

This makes the BEC systems suitable for both classic RC components and modern HV servos.

The models operate as switched-mode BECs and offer high efficiency as well as integrated protection functions against overcurrent and overtemperature.

Depending on the current requirement, variants with 4 A, 6 A or 8 A continuous current are available.

RO-BEC 12A for high current requirements

For applications with particularly high power requirements, a 12 A BEC receiver power supply is also available.

With up to 12 A continuous current and a higher short-term current capacity, it is particularly suitable for larger models or RC systems with several high-power servos and other power consumers.

Here too, the output voltage can be selected to suit the components used.

Hobbywing UBEC for RC models

The Hobbywing UBEC voltage regulators on offer also provide a high-performance external power supply.

The Hobbywing 5A UBEC can be operated with a wide input voltage range and offers selectable output voltages of 5.0 V, 6.0 V or 7.4 V.

For applications requiring higher current, a more powerful 10A UBEC is available. This offers adjustable output voltages of 6.0 V, 7.4 V and 8.4 V, making it suitable for high-power HV servos as well.

BEC for HV servos and high-power sail winches

Modern high-voltage servos are often operated at 7.4 V or 8.4 V. To do this, not only must the servo itself, but also all the connected RC electronics, be rated for the selected voltage.

High-power rudder servos and sail winches in RC sailing boats in particular can draw high currents under load. When selecting the BEC, sufficient reserve capacity should therefore be allowed for.

A BEC that is under-rated can lead to voltage drops under high load. This can cause servos to slow down or, in the worst-case scenario, result in the receiver and electronics temporarily failing.

Adjustable voltage regulators for special functions

In addition to classic BEC systems, this category also includes adjustable voltage regulators for special functions.

These are suitable, for example, for:

• radar motors
• LED lighting
• small electric motors
• additional electronic functions

Thanks to the variable output voltage, it is possible, for example, to adjust the speed of a radar motor to match the prototype or to set a suitable supply voltage for other loads.

Which BEC do I need?

When selecting a suitable BEC voltage regulator, you should pay particular attention to the following technical specifications:

• Input voltage or type of battery used
• Desired output voltage
• Maximum continuous current
• Permissible short-term peak current
• Voltage range of the receiver and servos
• Number and power consumption of the connected loads
• Protection functions
• Dimensions and weight

The current capacity should not be chosen too tightly. If several powerful servos or sail winches are operated simultaneously, a BEC with sufficient power reserve is recommended.

BEC systems for a reliable receiver power supply

Whether it’s a compact voltage regulator for a simple model boat or a high-performance BEC for large functional models, high-voltage servos and sail winches – with a suitably rated power supply, you can ensure a stable voltage for the receiver, servos and special functions.

Discover our selection of BEC systems, UBEC voltage regulators and receiver power supplies for RC model boat building.