Abstract
A new battery pack for the new TOYOTA PRIUS has been developed. The new battery has a rectangular module with six cells linked in series. Due to the simple structure which places the rectangular modules side by side, and other parts in battery pack also being made more compact, an approx.60% decrease in the battery pack volume and 30% decrease in weight have been realized. Also, improvements in the electrode configuration and materials used in the battery have improved battery performance.