Patent ID: 8502541
Filing Date: 2013-08-06
Classification: G01R,H01M,Y02E

Abstract:
1. A method of evaluating battery packs comprising: measuring a cell open voltage for each battery cell group in a section of battery cells; measuring a voltage under charge, or a voltage under load, or both, at a predetermined time interval for each battery cell group in the section of battery cells; determining a magnitude of the difference between the open cell voltage and the voltage under charge, or the voltage under load, or both, for each battery cell group in the section of battery cells by subtracting the voltage under charge from the cell open voltage, or subtracting the voltage under load from the cell open voltage, or both; and determining a maximum difference between the open cell voltage and the voltage under charge, or the voltage under load, or both; determining a minimum difference between the open cell voltage and the voltage under charge, or the voltage under load, or both; determining a range by subtracting the minimum difference from the maximum difference; and determining if the range exceeds a predetermined level.