Mercedes-Benz is using Delphi’s Battery Disconnect Safety Device (BDSD) on C-Class sport coupes and luxury sedans and M-Class sport utility vehicles. The BDSD prevents short circuiting that could occur following some collisions.

Mark Sabau, global product business unit director at Delphi Electrical Centers, said the BDSD severs the connection between the battery and the starter and alternator in less than 1 millisecond after an electrical signal from the airbag control unit triggers the pyrotechnic safety switch. “Fuses may protect other cables, but high variation in currents that flow through this cable while cranking the engine prohibits their use here, he noted.

Delphi's BDSD disconnects power from the vehicle battery to unfused cables but does not cut power to safety functions such as door locks, hazard lights, interior lighting and automatic emergency call systems. The device is mounted near the battery and typically requires only two bolts, thus facilitating replacement of deployed units.