Battery pack diagnostic method and battery pack diagnostic apparatus

摘要

A battery pack diagnostic apparatus that performs diagnosis on a plurality of cells constituting a battery pack measures the current flowing through the battery pack and starts a cell voltage measurement at the terminals of each cell when the absolute value of the measured current flowing through the battery pack has sustained a level equal to or lower than a predetermined value over a specific length of time. By detecting a faulty cell based upon the measured cell voltage value at individual cells thus obtained, a cell failure occurring while the battery pack is used in a normal state such as while the vehicle is in a running state can be detected reliably.