LV ELECTRICAL SYSTEMS

In the high-speed, high-stakes world of motorsport, every component of a race car plays a critical role in performance. While much of the attention is focused on powertrain, aerodynamics, vehicle dynamics and tire strategy. Low voltage (LV) electrical systems go under the radar as the unsung heroes that power essential functions within the vehicle. From powering the car’s ignition system to controlling lights, sensors, and data acquisition tools, these systems may operate at relatively low voltages, but their importance is immense.

In this article, we will dive into the crucial low voltage electrical systems in race cars, exploring their components, roles, and how they contribute to the overall performance, safety, and strategy during a race.

What are Low Voltage Electrical Systems?

In the context of motorsport, low voltage electrical systems typically operate at voltages between 12V to 48V. These systems power the car’s auxiliary functions, supporting the high-performance systems such as the engine, gearbox, and transmission but at a lower voltage range. While high-voltage systems handle critical power delivery to the motor or hybrid powertrains, low voltage systems are responsible for less energy-intensive tasks that still require precision and reliability.

Key functions of low voltage systems include powering sensors, controlling lights and displays, and providing electrical power to the car’s communication systems and cockpit displays. These systems often rely on the car’s 12V battery, though hybrid race cars or vehicles with additional power requirements may use separate low-voltage power units for different systems.

Key Components of Low Voltage Electrical Systems in Race Cars

12V Battery:

The 12V battery is the backbone of most low voltage electrical systems in traditional race cars, providing power for various subsystems and backup functions. In hybrid or electric race cars (like Formula E), the 12V battery still serves the purpose of powering non-high-voltage systems, but additional high-capacity batteries power the electric motors.

The 12V Battery Typically Powers:

  • The Engine Control Unit (ECU) and related sensors.
  • The Dashboard Displays – Driver communication systems.
  • Lighting Systems – Including headlights and signal indicators.
  • Cooling Fans – Powers the car’s electronics and cockpit.
  • Data Acquisition Systems – Collects and transmit telemetry.

Motorsport batteries are designed to be lightweight and powerful, capable of delivering a high burst of power during the race while withstanding extreme temperatures and vibrations.

Sensors & Actuators:

Race cars are fitted with an array of sensors that monitor virtually every aspect of vehicle performance, from tire temperature and pressure to engine temperature and exhaust gases. These sensors feed critical data to the ECU and other monitoring systems, which helps the driver and the pit crew optimise strategy.

Examples Of LV Sensors:

  • Accelerometers (Above) – Accelerometers are used to measure a vehicles movement on an X,Y and Z axis. These sensors are used to by trackside engineers to optimise vehicle setup by accessing a vehicle in different states. Some of these include pitch under braking, roll in the corners, (taken as lateral acceleration) and heave/bump.
  • Tire Pressure Sensors (TPS) – These sensors monitor the pressure and temperature of each tire, providing real-time data that helps teams decide when to pit for tire changes or adjust tire pressures to match track conditions.
  • Temperature Sensors – Monitoring engine and fluid temperatures is crucial for preventing overheating and maintaining optimal performance. These sensors, powered by the 12V system, send data to the ECU to adjust cooling systems or make engine performance tweaks.
  • Suspension Sensors – Advanced suspension systems in motorsport are equipped with sensors that monitor the forces acting on the vehicle. These sensors provide feedback to the ECU. Suspension sensors can also be used to give a better understand of aerodynamic performance.

These sensors are connected to actuators, which adjust settings or control systems, such as adjusting the car’s suspension stiffness or controlling the brake balance based on sensor readings.

Displays & Data Loggers:

Inside the cockpit, race car drivers are bombarded with a constant stream of information, displayed through dashboard displays. These displays, powered by low-voltage electrical systems, provide the driver with key metrics like lap times, fuel levels, tire data, and engine health. In some cases, the display can also show warnings or alerts when sensors detect critical issues (e.g., engine overheating or low tire pressure).

Data acquisition systems work in tandem with the sensors, collecting real-time performance data from the car. Low-voltage systems are responsible for:

  • Displaying real-time metrics to the driver.
  • Recording telemetry data for post-race analysis and live pit-to-car communication.
  • Adjusting performance settings based on input from the driver or race engineer.

In high-tech racing series like Formula 1, the data systems are incredibly advanced, transmitting hundreds of data points per second back to the pit crew, where it can be analysed to adjust strategy or car setup.

Lighting and Communication Systems:

While lighting systems on a race car may seem like a small component, they play a critical role in visibility and communication. From headlights to signal lights, low-voltage systems control the lighting systems on a race car, which helps both the driver and their team stay aware of conditions on the track.

  • Headlights and Brake Lights – In endurance racing, the 12V system is responsible for controlling the headlights and brake lights, which are vital for visibility, especially in low-light conditions or during night races.
  • Signal Lights – These include turn signals and pit light indicators, which allow the driver to communicate with their team and other competitors on the track.
  • Radio and Communication Systems – A race car’s communication system allows the driver to stay in contact with the pit crew throughout the race. This two-way communication system operates on low voltage, sending and receiving signals to share data, instructions, and feedback.

Cooling and Auxiliary Systems:

Race cars generate enormous amounts of heat, and many of their components—especially the engine, electronics, and driver cockpit—require effective cooling systems to maintain optimal temperatures. Low voltage systems are often tasked with controlling these cooling fans and coolant pumps, ensuring that both the car’s engine and the electronics remain within a safe operating temperature range.

  • Electronic Cooling Systems – Motorsport teams often use fans to cool sensitive electronics, such as the ECU, data acquisition systems, and hybrid powertrain components. These systems are powered by the low voltage electrical system.
  • Cockpit Cooling – In endurance racing or during extreme conditions, the driver’s cockpit may be equipped with cooling systems, such as air conditioning or fans, to help keep the driver comfortable. These systems are critical in long races where heat exhaustion could impact performance.

The Role of LV Systems in Hybrid & Electric Racing:

In hybrid or electric racing, low voltage systems are even more crucial. While high-voltage systems (often 400V or higher) manage the electric motor and regenerative braking systems, the low voltage system still manages essential functions such as driver interfaces, telemetry, and even the energy management system.

  • Formula E – The car’s 12V systems power not only basic functions like lights and communications but also provide backup power to the Battery Management System (BMS), which monitors the energy flow and isolation resistance values from the HV battery.
  • Formula 1 – The hybrid systems on F1 cars rely on their LV systems to manage the Energy Recovery System (ERS), collect data from sensors, and adjust performance settings in real-time.

While low voltage electrical systems in race cars might not get the same attention as engines or aerodynamics, they are critical to a car’s performance, safety, and reliability. These systems ensure that the car runs smoothly, efficiently, and safely, handling everything from sensors and telemetry to cockpit displays and communication systems. As motorsport continues to evolve, especially with the rise of hybrid and electric technologies, the role of low voltage systems will only become more important.

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