CAPACITY ESTIMATING METHOD FOR LITHIUM ION BATTERY, METHOD AND APPARATUS FOR JUDGING DETERIORATION AND LITHIUM ION BATTERY PACK

摘要

PROBLEM TO BE SOLVED: To provide a simple method for estimating the capacity of a lithium ion battery, a simple method and an apparatus for judging the deterioration of the lithium ion battery, and a lithium ion battery pack provided with a means which estimates the capacity of the battery and gives warning of the deterioration of the battery as occasion demands. SOLUTION: A capacity estimating method for a lithium ion battery finds a time interval (t) from the point of time when a charging voltage in the course of constant-current(CC) charging by a charging current Ic reaches a preset voltage Vs, up to the point of time when a charging condition is switched from the constant current(CC) charging over to constant voltage (CV) charging, when the lithium ion battery is charged by a constant-current constant-voltage system; and calculates an estimated capacity C of the lithium ion battery using the time internal (t). A method and an apparatus are provided for judging the deterioration of the lithium ion battery by the method. A lithium ion battery pack provided with a means for executing the capacity estimating method is formed.