MUNICH, Germany -- BMW AG and DaimlerChrysler AG have dropped plans to put 42-volt on-board electrical networks in their cars.
DaimlerChrysler was the first large automaker to put a stop to the project. BMW also has backed other plans for 42-volt technology.
Stephan Wolfsried, who is responsible for electrical engineering at the Mercedes Car Group, said: "Both engineering risks and costs for all the new components are incalculable. The 42-volt system no longer exists for us."
Besides, 42 volts would not be compatible with hybrid powertrains. The electric motor of the Toyota Prius, for example, works with a maximum of 500 volts.
Boosting operating voltage had seemed to be a logical solution to meeting increasing electrical demands in vehicles.
An electrical output of about 3 kilowatts is needed in today's cars. In the future the figure will be 8 kilowatts to cope with new electric steering systems, brakes and climatic controls.
Unexpected obstacles killed the 42-volt system.
Each electrical component from an interior light to the ABS sensor would need to be redesigned for 42 volts. A light would need an individual transformer, which would be expensive.
Another problem is that all plug and socket connections need to meet significantly higher standards. An electric arc, for example, could give off a hundred times as much energy through a loose contact than before.
The auto industry went through an expensive transformation 40 years ago when changing from 6 volts to 12 volts.