Patent ID: 9588184
Date: 2017-03-07
CPC Classifications: B60L,G01R,H01M,Y02E,Y02T

Claim:
1. A method of managing a state of charge of a battery having a plurality of battery cells in a hybrid electric power system comprising a fuel cell, the method comprising: calculating an individual state of charge for each battery cell; calculating an average state of charge for the battery cells; defining a minimum average state of charge threshold; defining a maximum average state of charge threshold; calculating an overall state of charge for the battery such that when the average state of charge is below the minimum threshold, the overall state of charge is calculated based on the state of charge of a subset of battery cells having the lowest state of charge relative to the other battery cells, and when the average state of charge is above the maximum threshold, the overall state of charge is calculated based on the state of charge of a subset of battery cells having the highest state of charge relative to the other battery cells; preventing battery cell discharge if the average state of charge is below the minimum threshold and the overall state of charge is at or below a level at which the subset of battery cells having the lowest state of charge would overdischarge if discharged; and preventing battery cell charge if the average state of charge is above the maximum threshold and the overall state of charge is at or above a level at which the subset of battery cells having the highest state of charge would overcharge if charged.