Battery diagnostic device, battery diagnostic method, and battery diagnostic system

Abstract

A battery diagnostic device, a battery diagnostic method, and a battery diagnostic system are provided. The battery diagnostic device according to the present invention includes a data acquisition unit that acquires battery information indicating a history of changes over time in the terminal voltage and charging current of a battery for each charging cycle performed a reference number of times according to a constant current (CC)-constant voltage (CV) charging protocol for a battery in a BOL (beginning of life) state, and a control unit that calculates an initial CC capacity ratio for each charging cycle performed a reference number of times based on the battery information. The control unit is configured to determine a representative initial CC capacity ratio based on the initial CC capacity ratio for each charging cycle, and compare the representative initial CC capacity ratio with a predetermined representative reference CC capacity ratio to diagnose whether the battery has a sign of accelerated deterioration.