Patent ID: 7994755
Filing Date: 2011-08-09
Classification: G01R

Abstract:
1. A method for determining an estimated battery cell module state of a first battery cell module of a battery pack, comprising: measuring at least one of a battery cell module voltage utilizing a voltage sensor, a battery cell module current utilizing a current sensor, and a battery cell module temperature utilizing a temperature sensor, the battery cell module voltage and the battery cell module current and the battery cell module temperature being associated with the first battery cell module of a plurality of battery cell modules in the battery pack; determining the estimated battery cell module state of the first battery cell module at a predetermined time based on an estimated battery pack state associated with the battery pack having the plurality of battery cell modules, and at least one of the battery cell module voltage, the battery cell module current, and the battery cell module temperature, utilizing a computer; and storing a vector corresponding to the estimated battery cell module state in a memory of the computer; wherein determining the estimated battery cell module state includes determining difference value representing a difference between the estimated battery cell module state and the estimated battery pack state based on at least one of the battery cell module voltage, the battery cell module current, and the battery cell module temperature, utilizing the computer, and determining the estimated battery cell module state by adding the estimated battery pack state to the difference value utilizing the computer; wherein determining the difference value representing the difference between the estimated battery cell module state and the estimated battery pack state is performed using one of a linear Kalman filter and a nonlinear Kalman filter; wherein determining the difference value representing the difference between the battery cell module state and the estimated battery pack state is performed less frequently than determining the estimated pack state; wherein the first battery cell module comprises a plurality of electrochemical cells.