SECONDARY BATTERY SYSTEM

摘要

PROBLEM TO BE SOLVED: To reduce the cost of a secondary battery system for estimating the degradation of a cell.SOLUTION: A secondary battery system 20 is a system for determining the degradation of a cell 102 which includes an electrode body 70. The secondary battery system 20 comprises: a surface pressure sensor 24 for measuring one of a surface pressure value PC at a central part C of the electrode body 70 and a surface pressure value PL at a left end part L of the electrode body; and an electronic control unit (ECU) 300 which determines the degradation of the cell 102 on the basis of the surface pressure values PC and PL. Based on a pressure of the entire electrode body 70 (a total surface pressure value PT), which is determined by a temperature TB of the cell 102 and a state of charge (SOC) of the cell 102, and the pressure measured by the surface pressure sensor 24, the ECU 300 estimates the other one of the surface pressure values PC and PL. Then, the ECU 300 determines the degradation of the cell 102 by comparing the surface pressure value PC with the surface pressure value PL.