To surely eliminate, as defective, an abnormal product which does not reveal an abnormality until a certain period later after the assembling.
A battery is assembled, and thereafter, 1-5% of the electric capacity of this battery is temporarily discharged. This battery is then aged, and at a point of time when a prescribed inspection period (for example, within three weeks) passed from the temporary discharge, whether the open circuit voltage of the battery is within a prescribed standard voltage range or not is judged, and whether the close circuit voltage of the battery is a prescribed standard voltage or more is also judged. Thus, an abnormal product by moisture inclusion can be judged by the close circuit voltage inspection, and abnormal products other than it can be judged by the open circuit voltage inspection.
IZUMI AKIHIDE
ISHIGURO YASUHIRO
SUZUKI MASAAKI
