Following the opening race of the Formula E season in Ad Diriyah, Saudi Arabia, ABB has unveiled the powertrain behind the Gen2 racer. The second-generation fully electric car is designed to offer more power and to eliminate the need for mid-race vehicle swaps.
Thanks to major gains in battery capacity, cars this season can – for the first time – drive from start to finish on a single charge, with greater peak performance available throughout the race. As Frank Muehlon, head of ABB’s global electric vehicle charging infrastructure, confirmed, “The greatest gains we will see this year are in battery technology: with just 20% more weight the battery delivers 95% more energy. That really is testament to the power of e-mobility.”
Reflecting the rapid advances in electric vehicle technology being made globally, the Gen2 car features comprehensive performance and safety upgrades over its predecessor. Battery energy storage is increased to 5kWh – nearly double last season’s 28kWh batteries – and voltage has been increased to 900V, from 700V. As a result, the mid-race pit stop to swap cars is eliminated. During the race, energy recovered while braking charges the battery.
Tires for Season 5 have also changed. Michelin re-engineered the treaded all-weather design for lighter weight and lower rolling resistance, as well as faster warm-up. Each car is permitted two sets of tires per event.
The Gen2’s brakes get an electronic brake-by-wire system at the rear, replacing the previous hydraulic system. This improves the operation of the regenerative braking system.
A new carbon fiber and aluminum honeycomb chassis structure from Dallara of Italy is used by all 11 of the two-car teams. The Gen2 bodywork borrows design elements from endurance racing cars – this means the front tires are now enclosed to reduce wind drag.
For 2018, the electric motors are allowed a 250kW limit, up from a previous maximum of 200kW. That translates to a top speed of 280km/h (174mph), compared with 225km/h (140mph) last season. The electric motors also serve as generators under braking.
The bodywork of the Gen2 car has been redesigned, managing airflow to minimize wind drag and add grip-enhancing downforce at racing speed. Rear wings are now integrated with the fenders; last season’s standalone wing is gone.
Building on the long experience of chassis builder Dallara, the Gen2 cars are fitted with suspension arms constructed of carbon fiber, shaped to minimize wind resistance and robust enough to withstand the uneven surfaces of city-center racecourses.
Cooling radiators mounted at the exit of the air ducts in the bodywork provide critical cooling for the battery and drivetrain. Maintaining optimum temperatures of the electrical components is vital for maximum output and efficiency.
