Delphi's Battery Disconnect Safety Device on Mercedes
Mercedes-Benz is among the first automakers to include Delphi Corporation's Battery Disconnect Safety Device (BDSD) on multiple new car lines. Several Mercedes-Benz models incorporate Delphi's BDSD, including all C-Class sport coupes and luxury sedans and the M-Class sport utility vehicles.
Delphi's 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.
Although Delphi's BDSD disconnects power from the vehicle battery to unfused cables, it does not cut power to safety functions such as door locks, hazard lights, interior lighting and automatic emergency call systems. Delphi's BDSD is mounted near the battery, in most cases using only two bolts. This makes replacement of a deployed BDSD quick and easy. Because it is comprised of a small number of parts, all enclosed in high-strength fiber-reinforced plastic, and because electrostatic discharge protection is built in, it is unlikely that an installer could trigger deployment of the pyrotechnic device. Even if activation were to occur during installation, the risk of injury is very low because all action takes place inside the reinforced plastic housing.
