A method for identifying the full charging point and the degree of deterioration of lead-acid batteries

The authors propose a new method for quantitatively identifying the full charging point and the degree of deterioration of lead-acid batteries, which are used for power storage equipment and electric vehicles. Discharge according to the hour rate can be also identified. The theory of this method is to recognize the behavior of the active materials generated on the surfaces of electrodes by means of applying rectangular positive (charging)/negative (discharging) current pulses to the battery. Thus the degrees of full charging and deterioration are judged by identifying the ascending/descending inclinations of the battery's voltage waveform. The validity of this method has been verified with different lead-acid batteries through laboratory tests to judge the full charging point and the degree of deterioration. The possibility of utilizing the equipment for commercial use is also under investigation.