Bosch celebrates 100 years of starter motors

A century ago, in March 1914, Bosch presented its first electric starter motor for automobiles, marking a giant leap forward in automotive electrification and making driving safer and more comfortable.

While the earliest starter motors weighed almost 10kg and delivered just 0.6 kilowatts of power, the starter motors in Bosch’s product portfolio weigh between 1.9 and 17kg and cover a power range of 0.8 to 9.2 kilowatts, demonstrating just how far starter motor technology has advanced.
“The starter motor is typical of the products Bosch launched in the early days of motorisation. All of them were designed to eliminate shortcomings in function, operation, and safety,” says Ulrich Kirschner, president of the Bosch Starter Motors and Generators division. It was Gottlob Honold, Bosch’s chief engineer, who had the idea of using an electric motor to start the engine. Other manufacturers had already attempted to do the same; while the results of their efforts worked relatively well, they were still unsuitable for everyday use and series production.

No more cranking

Electric starter motors were a great relief for motorists of the day. It took a lot of effort to start a heavy, large-volume engine and with manual starting there was always a risk that the crank handle might slip or suddenly kick back – possibly causing serious injury. This at a time when many people were still suspicious of the recently introduced automobile. Owners – predominantly wealthy individuals who were becoming keen on driving their automobiles themselves rather than being chauffeured – demanded a more convenient alternative. The new electric starter motor could be operated safely and reliably, first by means of a foot pedal and soon after at the touch of a button.
Initially, most of the demand for electric starter motors came from North America. This was reason enough for Robert Bosch to ramp up starter motor production at the company’s plant in Plainfield, New Jersey in 1914. Initially, sales of the new device remained modest; by 1927 Bosch had sold approximately 11,000 units. Then the starter motor gradually became more widely accepted, and nearly 550,000 were sold by 1933. But still it took decades for the crank handle to disappear completely from the world’s roads.

Starter motors save fuel
Series production of starter motors specifically tailored for use in start-stop systems began in 2007. To save fuel, this function stops the engine when the vehicle is at a standstill. As soon as the driver presses the gas pedal, the engine starts again – quickly, quietly, and automatically.

In order to achieve further reductions in fuel consumption and CO₂ emissions, Bosch says its engineers are working on gradually extending the scope of engine shutoff. In what is known as coasting mode, the engine will initially be shut off whenever the vehicle is coasting to a stop. Later, the coasting function will be extended to stop the engine even while on the open road, whenever the driver’s foot is no longer on the gas pedal.
Today, the component major offers a broad spectrum of robust, reliable starter motors for petrol and diesel engines – for passenger cars and commercial vehicles, supporting both 12 and 24 volt vehicle electrical systems. In addition to ease of integration, these starter motors are lightweight, compact, and powerful, reducing fuel consumption and emissions.

At present, Bosch manufactures more than 12 million starter motors every year, and these are installed in at least one in every five newly manufactured vehicles worldwide.