A battery cell monitoring system and method of operating the system are provided. The system includes a plurality sense lines and a plurality of cell sense units that each include an active semiconductor device are electrically coupled to the sense lines for transferring a device current characteristic of a bias voltage based on an input device voltage applied thereto. A cell sense reader unit includes a voltage generator for outputting the input voltage to the cell sense units in an alternating fashion across each of the sense lines. The cell sense reader unit includes a current measuring device for sampling the device current output from the active semiconductor device as the input device voltage is alternated. The cell sense reader unit calculates the bias voltage and determines a cell voltage of each of a plurality of battery cells each connected to one of the cell sense units.