Investigation of contact materials in 42 VDC automotive relay

Automobile makers have revealed plans to increase the voltage of car batteries from 12 V to 42 V in order to use high-power electrical components and improve fuel consumption. It is said that the total power supply to various electrical components of a car can reach to 7-8 kW around 2010. Since, the total power conventional DC 14 V battery can supply is limited to about 2.5 kW, it is considered necessary to increase the voltage of car batteries to DC 42 V. Here in this experiment, using various Ag-based contact materials for relays that were planned to be mounted on real cars at DC 42 V, their durability was tested under conditions which they would be actually used. As a result, it was found that AgZnO contact materials had excellent durability, low contact resistance and high erosion resistance, which coincided with the result obtained from the previously reported simulation test.