Method for estimating battery degradation

摘要

A method for estimating battery degradation is provided. In this method, a remaining capacity is obtained by looking up a device characteristic table according to a steady open circuit voltage of a battery. Besides, a constant current is provided to charge the battery, and when a terminal voltage of the battery reaches to a charging preset voltage, a constant voltage is provided to charge the battery. The transition point information at the transition from a constant current mode to a constant voltage mode, which includes a transition point estimated open circuit voltage, a transition point voltage, a transition point current and a transition point battery temperature, is analyzed based on voltage, current, temperature and capacity information measured during the charging process. A battery degradation index is calculated from the transition point information.

主权项

1. A method for estimating battery degradation, adapted to a battery management system and comprising:
charging a battery with a constant current/constant voltage mixed charging procedure through the battery management system, wherein the battery is charged in a constant current mode when a terminal voltage of the battery has not reached a charging preset voltage, and the battery is charged in a constant voltage mode when the terminal voltage of the battery has reached the charging preset voltage; before the constant current/constant voltage mixed charging procedure is performed, obtaining a remaining capacity by looking up a device characteristic table according to a steady open circuit voltage of the battery; after the constant current/constant voltage mixed charging procedure starts, accumulating a charged capacity of the battery obtained in the constant current mode; obtaining a transition point capacity by adding the remaining capacity and the charged capacity; and obtaining the transition point estimated open circuit voltage by looking up the device characteristic table again according to the transition point capacity; and calculating a degradation index of the battery based on a transition point voltage, the transition point estimated open circuit voltage, a transition point current, and a transition point battery temperature at a transition from the constant current mode to the constant voltage mode during the constant current/constant voltage mixed charging procedure.