Analysis of surface roughness and contact pressure at copper connector using nickel and silver plating for EV battery

Abstract

This paper will discuss the influence of surface roughness and material copper plating on the connectors to reduce contact resistance until steady state due to contact pressure. The experiment using three samples: copper connector without plating, copper connector with nickel plating and copper connector with silver plating. Increasing contact pressure and surface roughness at each connector was measured to find out the effect on the value of contact resistance. Measurement of contact resistance of connector perform with 4-wire method, and the amount of current supplied between 2 A, 4 A, and 6 A. The measurement was using Surface Roughness Tester to find out the surface roughness of the contact area of each sample. Then morphology of contact surface was monitored with magnification up to 1000 times. The results show that connector with nickel plating having lower contact pressure followed by connector with silver plating and copper connector without plating. The contact resistance is not only influenced by the resistivity of the contact material, but also influenced by morphology and roughness.