A system and method for monitoring fuel cells in a fuel cell group. The system includes a sensor circuit, such as a voltage sensor circuit, that monitors a condition of the fuel cells. If the sensor circuit detects a low performing cell, then it sends a signal to a tone generator that generates a frequency signal that switches a load into and out of the cell group. A voltage sensor detects the voltage of the cell group including the frequency signal, and sends the detected voltage signal to a tone decoder that decodes the frequency signal to determine that the fuel cells are low performing.