A connector assembly for voltage monitoring of bus bars electrically connecting adjacent battery cells of a battery module includes a connector having a plurality of terminals configured to be mated with a control module connector associated with the battery module. A multi-wire planar cable extends from the connector. The multi-wire planar cable has a plurality of wires terminated to corresponding terminals and a common jacket for the plurality of wires. The jacket has grooves between adjacent wires for controlled separation of the wires and surrounding jacket portions at a sensor end of the multi-wire planar cable to define separated planar cable segments. The separated planar cable segments are routed to different areas for termination to different voltage sensors associated with corresponding bus bars.