CONTROL VALVE TYPE LEAD-ACID STORAGE BATTERY

PROBLEM TO BE SOLVED: To provide a control valve type lead-acid storage battery excellent in cycle life property. SOLUTION: The control valve type lead-acid storage battery is formed by housing necessary number of laminated cathode plates, anode plates, and separators in a battery case with a prescribed group pressure D, and injecting electrolytic solution therein. The repeated restoration ratio R of the separator is not less than 20%, and a ratio of group pressure W after injecting the electrolyte solution to the group pressure D ((W/D)×100%)is not less than 50%. Here, the repeated restoration ratio R is obtained by measuring the thickness t20of the separator of liquid-absorbed state in a state of burdening a load of 20 kPa, next, burdening loads of 1 kPa and 50 kPa alternately by 10 times, measuring the thickness t1and t10at 10th of burdening of 1 kPa and 50 kPa, dividing the difference t1-t50by t20, and multiplying the above value by 100, namely, R=[(t1-t50)/t20]×100. COPYRIGHT: (C)2007,JPO&INPIT