A charging module usable with a conductive bus having a center rail disposed intermediate a first conductive rail and a second conductive rail. The charging module has a base on which is disposed a centered electrical contact and a first plurality of electrical contacts. The centered electrical contact is arranged on the base such that the centered electrical contact will engage with the center rail when the housing is placed into a use position on the conductive bus. The first plurality of electrical contacts are arranged on the base along a perimeter of a first circle that is generally centered on the centered electrical contact such that at least one of the first plurality of electrical contacts will engage with the first conductive rail and at least one different one of the first plurality of electrical contacts will engage with the second conductive rail when the housing is placed into the use position on the conductive bus in any rotational orientation of the housing relative to the conductive bus over a full 360 degrees.