Formula E Circuit Brings EVs to the Race Track

Cutting-edge race car developments could find their way into consumer EVs.

(Source: Formula E.)

(Source: Formula E.)

Some of the most advanced developments in electric vehicle (EV) technology take place not in the lab, but on the racetrack. Specifically, the Formula E racing series. And these innovations will undoubtedly have a significant impact on the EVs you’ll find on your commute to work.

Now in its eighth season, Formula E is a championship racing league that features high-performance racing EVs made by some of the biggest car companies in the world. Not only does it feature high-speed action, but it is paving the way for the electric cars of the future. Similar to Formula One, Formula E consists of teams of two drivers who pilot race cars—except these are fully electric.

Each team uses a standard layout—for the most part. The chassis, battery, bodywork, tires and major auxiliary parts such as suspension are the same. The current Gen2 vehicle has a chassis mostly designed by Italian race car manufacturer Dallara, a McLaren/Atieva battery and Michelin tires.

(Source: Formula E.)

(Source: Formula E.)

Where they differ—and where innovation can bring a competitive edge—is in the powertrain. Each team must develop its own powertrain cluster that includes the motor-generator unit (MGU), inverters and gearbox. There are currently 10 registered manufacturers developing the powertrain: Audi, BMW, DS, Jaguar, Porsche, Penske Autosport, Mahindra, Nissan and NIO.

The MGU is smaller and lighter than a conventional combustion engine. It also has an added benefit of acting as a generator, creating electrical energy when braking that can be stored in the battery.

The Formula E car has such a powerful torque output that it removes the need for a multi-ratio gearbox. In fact, the motor is capable of producing full torque at zero revolutions per minute (RPM), while combustion engines only achieve full torque at a much higher RPM. No team uses a multi-ratio gearbox and the vehicles can operate on only one gear throughout the race.

The inverter is a device that switches the electric current from the motor’s AC to the battery’s DC; it essentially takes the place of the conventional fuel injection or ignition. When the race car accelerates, the battery provides energy through the inverter to power the motor, channeling the power through a reduction gearbox and differential to spin the rear wheels. When the driver brakes, the inverter switches and the motor generates electric current that creates a drag on the drivetrain to help slow the rear wheels. The electricity created under braking gets directed into the battery, increasing its available charge and extending the vehicle’s range.

And then there’s the battery itself, mounted in the middle of the car. It’s called the Rechargeable Energy Storage System (RESS), or the ‘Traction’ battery. Each Formula E battery contains over 5,000 cells, each the size of a AA battery, made by Sony subsidiary Murata. The cells are packed tightly into a series of modules inside a carbon casing developed by McLaren Applied Technologies. Rows of cells are offset from each other, with cooling plates placed between the rows to regulate the temperature of the cell bodies. The modules themselves are surrounded by cooling pipes and manifolds with electric bus bars that connect them into a single 800 volt DC output.

The battery has an electronic management system that monitors each cell’s voltage, state of charge and temperature. If a cell’s temperature gets too high, the system will warn the electronic control unit to restrict the power flow until it cools again. If that doesn’t work, the ECU will cut the motor as a last safety measure.

A notable concern with the battery is that it remains live, even after the vehicle crashes. This creates a risk of electric shock. That’s why the casing is made from strong carbon fiber with Xylon anti-intrusion panels on the outside and layers of glass fiber insulation on the inside. The cooling medium is a dielectric oil-based fluid that is unable to conduct electricity should it spill due to a breach of the outer casing. Naturally, the structure has been crash-tested. 

The cells inside each module are connected in series as well as in parallel, and the modules themselves are also interconnected—resulting in a battery that can produce 800 volts (that’s double the voltage a Tesla battery can produce) with 54 kilowatt hours of storage capacity.

This allows the race car to complete the full 45-minute race without recharging—a big step forward from the early Formula E seasons where drivers had to swap cars mid-race. However, the battery is heavy, coming in at over 880 pounds.

Still, with 250 kilowatts of power (equivalent to 335 braking horsepower), the Gen2 race car will go from zero to 62 mph in 2.8 seconds and reach a top speed of about 174 mph. The vehicle is 203 inches long, 69.6 inches wide and 41 inches high, with a maximum ride height of 2.95 inches off the ground.

It’s clear the race cars of Formula E are at the forefront of EV technology development. But that’s not all that Formula E is doing to advance sustainability. In fact, in 2020 the Furmula E World Championship became the first global sport to be certified with a net zero carbon footprint.

Since EVs run cleaner and quieter than combustion automobiles, Formula E races can run in busy city centers, bringing events closer to fans; this is in contrast to the loud and exhaust-filled conventional motorsport events that need to be held further away. Formula E events also use a one-day format to minimize disruption to the host urban centers. In addition, many operational and logistical practices are sustainable; for example, all the vehicles and equipment are transported by sea between events to avoid air transport emissions. In addition, the series brings its own power generators to charge the cars with clean, renewable Glycerine fuel.

On a broader level, the technological breakthroughs made by carmakers on the Formula E circuit could trickle down to the consumer products they offer. For example, the battery capacity of a Nissan Leaf today is almost three times that of the 2015 version of the vehicle. Mercedes has stated that its 2021 EQS will have a 435-mile range and a 31 minute charge time on a DC fast charger. Formula E participants are also electrifying their lines and their EVs improve with every iteration. The technologies these companies develop for their EV race cars, and the solutions to EV problems they resolve on the race track, have the potential to accelerate the efficiency, range and capabilities of consumer electric vehicles.

Formula E is already working on its next-gen racer, the Gen3, which is anticipated to debut in Spring 2022. It will feature both front and rear powertrains, and claims to be the world’s most efficient racing car that will recoup 40 per cent of the energy it uses in a race. It will be lighter and smaller than the Gen2.

Read more about cutting-edge high performance electric vehicles at Battista Electric Hypercar Completes Speed and Handling Tests.