Schaeffler has fitted an Audi TT with its 48V hybrid system. The vehicle architecture is based on an electrified rear axle that complements the FWD internal combustion engine. An additional 48V belt-driven starter generator is coupled with the engine. The 48V onboard electric sub-systems use a lithium-ion battery connected via a DC-DC convertor to the 12V onboard electric system, which powers all the different electrical components in the vehicle, from headlights to seat adjusters. The driver can switch between "Eco" and "Sport" driving modes. In Eco mode, the engine is switched off during low-speed driving, traffic, and parking. During braking, the system recuperates energy that is then stored in the lithium-ion battery. It is estimated that 48V hybrid technology could reduce fuel consumption by about 15%.
Significance: Schaeffler introduced the 48-volt electric systems in 2013. Since then, the company has been testing and demonstrating the performance capabilities and efficiency of 48V hybridisation in a range of concepts. Schaeffler has co-developed, along with Ford and Continental, the "Gasoline Technology Car" (GTC) based on a Ford Focus using 48V architecture, and has also developed the "Schaeffler Efficient Future Mobility North America" vehicle, which was showcased at the 2015 Detroit Auto Show. The current range of hybrid vehicles operates at high voltages of approximately 300V, which tend to be costlier than normal internal combustion engine cars in the same range. Schaeffler is attempting to fill the gap between the two with the 48V systems, which provide mild hybrid features to cars at a low cost and with minimal changes to vehicle design. Companies such as Continental, Ricardo, and Bosch are also working to develop 48V mild hybrid systems.
