Audi will launch a 48-volt electrical system on its future cars, as opposed to the 12-volt standard that is used on virtually every production car today. The impetus for going to a higher voltage system is that, according to Audi, current 12-volt systems are nearly overloaded with all the electronics on a modern car.
"It enables us to make more energy available. That paves the way for new technologies with which we can make our cars more sporty, more efficient, and more convenient to use," Audi board member for technical development Professor Dr. Ulrich Hackenberg said in a statement.
In future Audi cars, the 48-volt electrical system will use a lithium-ion battery and a new, more energy efficient alternator that can also serve as the starter motor. A special converter provides 12-volt power for certain elements of the car's electrical system; the car will retain a 12-volt battery, too, for certain functions. Audi says that the new alternator design helps recover as much as 10 kw of energy during deceleration, which is claimed to help save a modest amount of fuel in real-world use.
The big impact of the 48-volt electric system is that Audi will use the added power for electric turbochargers. Because they do not depend on engine speed, like traditional turbochargers or turbochargers, the electric units can spool up sooner and reduce lag. Last year, European bureau chief Georg Kacher reported that Audi plans to introduce a 3.0-liter twin-turbo diesel V-6 engine with a third, electrically operated turbocharger. The company previously showed concept cars in Europe with that engine arrangement, including the RS5 TDI concept pictured above, and it is now likely to come to production cars. No firm timeline has been announced, however.
Audi also says that a 48-volt electrical system could allow for "dynamic chassis control" and promises to demonstrate such technologies soon. That likely concerns some sort of active suspension that needs significant amounts of electrical energy to operate.