Patent ID: 7429849
Filing Date: 2008-09-30
Classification: G01R

Abstract:
1. A method of confirming a battery charge amount and degradation state, comprising: a first step of measuring or calculating at a plurality of battery temperatures a cycle test battery in respect of battery internal and outside surface temperatures and one selected from battery open voltage, current and voltage during discharge, and current and voltage during charging at prescribed time intervals substantially until an end of life of the cycle test battery; a second step of using measured or calculated values to generate a determination table showing relationships between charge amounts and degradation states at said prescribed time intervals; a third step of measuring or calculating a subject battery in respect of said battery internal and outside surface temperatures and said one selected from battery open voltage, current and voltage during discharge, and current and voltage during charging; and a fourth step of comparing determination table values with said battery internal and outside surface temperatures and at least one measured or calculated value of the subject battery to make a primary confirmation of a present subject battery charge amount and degradation state in accordance with a determination table location of matching values and to make an overall confirmation of results of the primary confirmation based on an appearance ratio of said determination table location, thereby estimating said present subject battery charge amount and degradation state, wherein the first step comprises any one of (i) a calculation of a direct current resistance BZ of the cycle test battery from a formula: BZ=(B