Bosch has said it will supply stop-start systems to BMW for series production from March. The technology will be fitted as standard on the 1 Series from then, as part of BMW’s EfficientDynamics collection of technologies, that also includes regenerative braking..


Volkmar Denner, member of the Bosch board of management, said that key to the Bosch stop-start system is a specially adapted starter, which it calls the Smart Starter Motor.


The company already produces the battery sensor that is needed to detect the battery’s current state of charge and to communicate this information via the energy management system. “Bosch has drawn on its combined competence in drive trains, energy management, and starter technology to develop this system and its control function,” said Denner.  There is no need for any further adjustments to the drive train or the engine. This gives the system its excellent cost-benefit ratio, and makes it so attractive compared with alternative systems.


The number of engine starts the starter has to make – its service life, in other words – has been significantly increased for this application. In addition, the starter’s improved-performance electric motor, and a low-noise, stronger pinion-engaging mechanism ensure that the engine starts reliably, quickly, and quietly. Despite the increased number of functions, the starter is compact, and can be integrated into the vehicle just as easily and quickly as other starters. 


The ECE15 measuring cycle, the urban component of the New European Driving Cycle (NEDC), calls for twelve 15 second stops over a distance of seven kilometers. During such a journey, the Bosch system reduces fuel consumption and CO2 emissions by as much as eight percent, depending on the vehicle. If the stops last longer, the actual saving of CO2 emissions and fuel can be significantly higher.