Estimation of the capacity of nickel-cadmium batteries by measuring impedance using electrolyte-deficient battery characteristics

This paper describes a method of testing trickle-charged nickel-cadmium (Ni-Cd) batteries. The main causes of deterioration are shown to be short-circuit and electrolyte leakage. In the former case, the batteries are easily tested by measuring the voltage. In the latter case, the authors show that measuring the impedance is an effective way to test the condition of batteries because its logarithm is linearly related to the capacity, and this relationship can be obtained easily and quickly from characteristics of electrolyte-deficient batteries.