Patent ID: 8420271
Filing Date: 2013-04-16
Classification: G01R,H01M,Y02E

Abstract:
1. A method for detecting a low performing cell in a fuel cell stack, said method comprising: measuring the voltage of each fuel cell in the fuel cell stack; determining the minimum cell voltage of the measured voltages; calculating an average cell voltage from the measured voltages; determining a difference between the calculated average cell voltage and the minimum cell voltage; determining whether the difference exceeds a first predetermined voltage threshold; determining whether the minimum cell voltage is less than a second predetermined voltage threshold; incrementing a low performing cell timer if both the difference exceeds the first predetermined voltage threshold and the minimum cell voltage is less than the second predetermined voltage threshold; calculating a ratio between the low performing cell timer and a system run timer; and determining if the ratio exceeds a predetermined percentage to determine whether the fuel cell stack includes a low performing cell.