Degradation degree computing method and unit for battery
AssigneeYazaki Corporation
InventorYouichi Arai
Life of this patent
Estimating the term…
Abstract
A base resistance of the battery is obtained by cyclically measuring a discharge current and a voltage between a pair of terminals of the battery, while a rush current is flowing in an electric load electrically connected to the pair of the terminals. The rush current monotonically decreases from a peak to a constant value after the rush current monotonically increases from zero to the peak. A concentration polarization resistance and an activation polarization resistance of the battery are also obtained from the discharge current and the terminal voltage. A degradation degree of the battery is obtained by multiplying the degradation degrees of the base resistance and the polarization resistances together.
Claims4
A degradation degree computing method for a battery for supplying an electrical power to a load, the method comprising the steps of:
- a first step for obtaining a base resistance of the battery by cyclically measuring a discharge current and a voltage between a pair of terminals of the battery while a rush current is flowing in an electric load electrically connected to the pair of terminals, the rush current monotonically decreasing from a peak to a constant value after the rush current monotonically increases from zero to the peak,
- a second step for obtaining at least one of a concentration polarization resistance and an activation polarization resistance of the battery from the discharge current and the terminal voltage that are measured in the first step,
- a third step for obtaining a degradation degree of the base resistance which is a ratio of the base resistance obtained by the first step to an original base resistance of the battery,
- a fourth step for obtaining a polarization resistance degradation degree which is a ratio of one of the concentration polarization resistance and the activation polarization resistance to an original polarization resistance, and
- a fifth step for obtaining a degradation degree of the battery by multiplying the base resistance degradation degree and the polarization resistance degradation degree together.
A degradation degree computing unit of a battery for supplying an electrical power to a load, the unit comprising:
- a measuring means for measuring a discharge current and a voltage between a pair of terminals of the battery while a rush current is flowing in an electric load electrically connected to the pair of terminals, the rush current monotonically decreasing from a peak to a constant value after the rush current monotonically increases from zero to the peak,
- a base resistance computing means for obtaining a base resistance of the battery from the discharge current and the voltage that are measured by the measuring means,
- a polarization resistance computing means for obtaining at least one of a concentration polarization resistance and an activation polarization resistance of the battery from the discharge current and the terminal voltage that are measured by the measuring means,
- a base resistance degradation degree computing means for obtaining a degradation degree of the base resistance which is a ratio of the base resistance obtained by the base resistance computing means to an original base resistance of the battery,
- a polarization resistance degradation degree computing means for obtaining a polarization resistance degradation degree which is a ratio of one of the concentration polarization resistance and the activation polarization resistance to an original polarization resistance, and
- a battery degradation degree computing means for obtaining a degradation degree of the battery by multiplying the base resistance degradation degree and the polarization resistance degradation degree together.
Dependencies are inferred from the claim text.