Life-saving explosions: Bosch technology for electric cars

Bosch has developed an innovative safety system that uses controlled mini explosions to disconnect the battery of electric cars in the event of an accident.

The popularisation of electric cars poses new challenges for manufacturers. Today, the electric cars launched onto the market meet all the necessary safety requirements. They also pass standardised crash tests with flying colours, such as those carried out by Euro NCAP, where electric cars such as the Renault ZOE easily achieve five stars.

However, many users still express concern about driving an electric car in the event of being involved in an accident. How do manufacturers ensure that the high-voltage current supplied by the battery does not leak through the metal bodywork of a hybrid or electric car in the event of a rollover or collision, with the damage that this causes to the entire electrical system?

Controlled micro explosions to deactivate the EV battery

Bosch, one of the most important automotive component manufacturers, supplies the technology required for this type of vehicle. One of its most interesting developments is that of the semiconductors responsible for deactivating the vehicle’s electronic circuits in the event of an accident, in a fraction of a second. This not only keeps the occupants safe, but also allows rescue teams to work immediately without the risk of electric shock.

What the system developed by Bosch does is disconnect the battery of a hybrid or electric car in the event of an accident, by means of a fuse that is triggered by a small pyrotechnic charge, in a similar way to an airbag. This eliminates the possible risk of fire or electric shock. These “pyrotechnic fuses” use the vehicle’s sensors, which detect an impact, to activate the car’s other safety systems.

The semiconductor device developed by Bosch to activate the pyrotechnic fuse measures just 10×10 mm and weighs a few grams. The micro explosions it produces insert a wedge into the high-voltage cable linking the battery and the power electronics, thereby cutting off the flow of current.

Bosch uses the CG912 IC microchip, a development of Bosch’s original design for activating airbags, which has already fully demonstrated its effectiveness. This chip, the size of a fingernail, contains millions of transistors, and is responsible for activating the vehicle’s various safety functions in the event of an accident.