A method and apparatus for detecting a bad cell in a storage battery (12) having a plurality of cells are provided. Input circuitry (54) electrically couples to first and second terminals (22, 24) of the storage battery (12). Voltage measuring circuitry (70) coupled to the input circuitry provides a voltage output related to a voltage potential between the first and second terminals (22, 24) of the storage battery (12). Conductance measuring circuitry (50, 56, 70) coupled to the input circuitry (54) provides a conductance output related to conductance of the storage battery (12). Voltage and conductance comparison circuitry (56) compares the measured voltage and conductance to references and provides outputs. Output circuitry (56) provides a bad cell output based upon the results of the comparisons.