Kia has revealed its all-new mild hybrid powertrain at the Geneva Motor Show. The powertrain – part of a future technologies exhibit on Kia’s show stand – is designed to simultaneously reduce emissions and improve engine performance in Kia’s next-generation models. Interestingly, the technology will be made available for both petrol and diesel models in Kia’s model line-up.
Developed by Kia’s European R&D centre in Russelsheim, Germany, the new hybrid system employs a 48 volt lead-carbon battery, which powers a small electric motor to increase the engine’s power output and cut exhaust emissions. The development team behind the mild hybrid powertrain selected lead-carbon batteries over lithium-ion equivalents as they require no active cooling, are more easily recyclable at the end of the vehicle’s life and can function much more efficiently in sub-zero temperatures.
Kia’s mild hybrid system will enable a car to be driven in an electric-only mode at low speeds and when cruising, while the battery is recharged under deceleration at all speeds. In heavy traffic and on urban roads, the powertrain will also feature a zero-emission stop-start system. Using a belt-driven starter generator – replacing the conventional alternator – the engine is able to restart with almost no noise or vibration.
The battery also supplies energy to an electric supercharger, which increases torque and power at low engine speeds. Engineers behind the development of the powertrain see the electric supercharger supporting a larger conventional turbocharger, which would seamlessly take over to provide greater power and torque as engine speeds rise. The new hybrid system could also be fitted without the electric supercharger for a simpler powertrain layout in smaller models.
In applying the technology to production cars, Kia engineers are targeting reductions in CO2 emissions of up to 15 per cent, while the electric supercharger is designed to deliver power increases of 15 to 20 per cent depending on its application.
The new powertrain would also allow vehicle development engineers to reduce the size of a vehicle’s existing battery and starter motor.