Patent ID: 8228036
Filing Date: 2012-07-24
Classification: H01M,H02J,Y02E

Abstract:
1. A battery pack comprising: a housing; a first group of cells positioned within the housing, wherein the first group of cells includes at least two series-connected cells; a second group of cells positioned within the housing, wherein the second group of cells includes at least two series-connected cells; a third group of cells positioned within the housing, wherein the third group of cells includes at least two series-connected cells, wherein the first group of cells, the second group of cells, and the third group of cells are connected in series; and two tap connections to connect the first group of cells, the second group of cells, and the third group of cells to a detection circuit to provide respective voltages across the first, second, and third groups of cells to the detection circuit, the detection circuit including a microprocessor programmed to calculate at least one voltage ratio between the first group of cells and the second group of cells, at least one voltage ratio between the second group of cells and the third group of cells, and at least one voltage ratio between the third group of cells and the first group of cells, wherein the microprocessor is programmed to compare the at least one voltage ratio between the first group of cells and the second group of cells to a predetermined voltage ratio, compare the at least one voltage ratio between the second group of cells and the third group of cells to the predetermined voltage ratio, and compare the at least one voltage ratio between the third group of cells and the first group of cells to the predetermined voltage ratio, and wherein the microprocessor is programmed to determine at least one of an over-voltage condition and an under-voltage condition of a cell in the first, second or third group of cells based on the comparisons.