US 6,208,147 B1 · Method of and apparatus for measuring battery capacity by impedance spectrum analysis

Abstract

Provided with a method of measuring battery capacity by impedance spectrum analysis, which is to measure a characteristic impedance spectrum of primary and secondary batteries and determine the battery capacity the method including the steps of: (1) measuring the characteristic impedance spectrum of a battery in a predetermined frequency region; (2) determining a parameter from the measured impedance spectrum; (3) monitoring in advance the correlation between the determined parameter and the battery capacity measured by a real-time discharge technique; and (4) determining the battery capacity from the characteristic impedance spectrum of a battery having an unknown capacity based on the monitored correlation.

Claims11

Dependent claims

A method of measuring battery capacity by measurement and analysis of impedance spectrum, which is to measure a characteristic impedance spectrum of primary and secondary batteries and determine the battery capacity the method comprising the steps of:

(1) measuring the characteristic impedance spectrum of a battery in a predetermined frequency region;
(2) determining one or more parameter from the measured impedance spectrum;
(3) monitoring in advance the correlation between the determined model parameter and the battery capacity measured by a real-time discharge technique;
and
(4) determining the battery capacity from the characteristic impedance spectrum of a battery having an unknown capacity based on the monitored correlation.

2 more elements

An apparatus for measuring battery capacity by impedance spectrum analysis, the apparatus comprising:

a battery connector unit having a battery connected thereto;
a measurement unit for applying an input current corresponding to a digital input signal composed of a superposition of predefined finite multiple frequencies to both terminals of the battery via the battery connector unit, and converting input current and output voltage applied to both terminals of the battery into a digital signal continuously;
and
a central control unit for storing the digital signal output from the measurement unit, converting the digital signal to a complex digital impedance expressed by a function of frequency by performing a Fourier transform, and fitting the complex impedance to a predefined model parameter or a plural of model parameters.

1 more element

Dependencies are inferred from the claim text.

Method of and apparatus for measuring battery capacity by impedance spectrum analysis

Life of this patent

Method of and apparatus for measuring battery capacity by impedance spectrum analysis

Life of this patent

Abstract

Claims11