Method and apparatus for detecting cell deterioration in an electrochemical cell or battery
First Claim
1. Apparatus for determining a physical property of an electrochemical cell or battery comprising:
- immittance measuring circuitry coupled to said cell or battery with a pair of current-carrying contacts and a separate pair of voltage-sensing contacts and adapted to apply time-varying electrical excitation to said cell or battery with said pair of current-carrying contacts, to sense time-varying electrical response to said excitation with said pair of voltage-sensing contacts, and to utilize said excitation and said response to measure components of complex immittance at n discrete frequencies, where n is a finite integer equal to or greater than two but less than a maximum value;
computation circuitry responsive to said complex immittance components and adapted to evaluate elements of a 2n-element equivalent circuit model from said measured complex immittance components at said n discrete frequencies;
whereas said immittance measuring circuitry is further adapted to utilize said excitation and said response to measure components of complex immittance at m additional discrete frequencies where m is a finite integer equal to or greater than one but less than a maximum value, wherein said computation circuitry is not adapted to evaluate elements of the 2n-element equivalent circuit model from said measured complex immittance components at said m discrete frequencies; and
,whereas said computation circuitry is further adapted to calculate complex immittance components of said 2n-element equivalent circuit model at said m additional discrete frequencies, and adapted to mathematically compare said calculated immittance components with said measured immittance components at said m additional discrete frequencies to obtain comparison results, said comparison results being related to said physical property.
0 Assignments
0 Petitions
Accused Products
Abstract
A testing device contains measuring circuitry adapted to apply time-varying electrical excitation to a cell or battery, to sense a time-varying electrical response, and to thus determine components of complex immittance at n+m discrete frequencies, where n is an integer equal to or greater than two and m is an integer equal to or greater than one. Computation circuitry utilizes measured complex immittance components at the n discrete frequencies to evaluate the elements of a 2n-element equivalent circuit model. It then calculates the complex immittance of this model at the m discrete frequencies and mathematically compares components of the calculated immittances with components of the measured immittances at the m discrete frequencies. The results of this comparison establish the degree of cell deterioration without regard to the battery'"'"'s manufacturer, group size, or its electrical ratings.
885 Citations
26 Claims
-
1. Apparatus for determining a physical property of an electrochemical cell or battery comprising:
-
immittance measuring circuitry coupled to said cell or battery with a pair of current-carrying contacts and a separate pair of voltage-sensing contacts and adapted to apply time-varying electrical excitation to said cell or battery with said pair of current-carrying contacts, to sense time-varying electrical response to said excitation with said pair of voltage-sensing contacts, and to utilize said excitation and said response to measure components of complex immittance at n discrete frequencies, where n is a finite integer equal to or greater than two but less than a maximum value; computation circuitry responsive to said complex immittance components and adapted to evaluate elements of a 2n-element equivalent circuit model from said measured complex immittance components at said n discrete frequencies; whereas said immittance measuring circuitry is further adapted to utilize said excitation and said response to measure components of complex immittance at m additional discrete frequencies where m is a finite integer equal to or greater than one but less than a maximum value, wherein said computation circuitry is not adapted to evaluate elements of the 2n-element equivalent circuit model from said measured complex immittance components at said m discrete frequencies; and
,whereas said computation circuitry is further adapted to calculate complex immittance components of said 2n-element equivalent circuit model at said m additional discrete frequencies, and adapted to mathematically compare said calculated immittance components with said measured immittance components at said m additional discrete frequencies to obtain comparison results, said comparison results being related to said physical property. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A method for determining a physical property of an electrochemical cell or battery comprising the steps of:
-
coupling immittance measuring circuitry to said cell or battery with a pair of current-carrying contacts and a separate pair of voltage-sensing contacts; using said immittance measuring circuitry to measure complex immittance of said cell or battery at n discrete frequencies where n is a finite integer equal to or greater than two but less than a maximum value; using computation circuitry to evaluate elements of a 2n-element equivalent circuit model from said complex immittance at said n discrete frequencies; using said immittance measuring circuitry to measure complex immittance of said cell or battery at m additional discrete frequencies where m is a finite integer equal to or greater than one but less than a maximum value, wherein said computation circuitry is not adapted to evaluate elements of said 2n-element equivalent circuit model from said complex immittance at said m discrete frequencies; using said computation circuitry to calculate complex immittance of said 2n-element equivalent circuit model at said m additional discrete frequencies; using said computation circuitry to mathematically compare components of said calculated and said measured complex immittances at said m additional discrete frequencies; and
,determining said physical property from the results of said comparison. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
-
16. Apparatus for evaluating a degree of cell deterioration in an electrochemical cell or battery comprising:
-
immittance measuring circuitry coupled to said cell or battery with separate pairs of current carrying and voltage-sensing contacts and adapted to apply time-varying electrical excitation to said cell or battery and to sense a time-varying response, said excitation and response containing frequency components at n discrete frequencies where n is a finite integer equal to or greater than two but less than a maximum value and further adapted to measure complex immittance values at each of said n discrete frequencies; computation circuitry responsive to said measured complex immittance values of said cell or battery at said n discrete frequencies and adapted to evaluate element values of a 2n-element equivalent circuit model of said cell or battery from said measured immittance values at said n discrete frequencies; whereas said excitation and said response contain frequency components at m additional discrete frequencies, where m is a finite integer equal to or greater than one but less than a maximum value, and said immittance measuring circuitry is adapted to measure immittance components at each of said m additional discrete frequencies, wherein said computation circuitry is not adapted to evaluate element values of said 2n-element equivalent circuit model of said cell or battery from said measured immittance values at said m discrete frequencies; and
,whereas said computation circuitry is further adapted to calculate complex immittance components of said 2n-element equivalent circuit model at said m additional discrete frequencies, and adapted to mathematically compare said calculated immittance components with said measured immittance components at said m additional discrete frequencies to obtain comparison results, said comparison results being related to said degree of cell deterioration. - View Dependent Claims (17, 18, 19, 20, 21)
-
-
22. A method for determining a degree of cell deterioration of an electrochemical cell or battery comprising the steps of:
-
coupling immittance measuring circuitry to said cell or battery with a pair of current-carrying contacts and a separate pair of voltage-sensing contacts; using said immittance measuring circuitry to measure complex immittance of said cell or battery at n discrete frequencies where n is a finite integer equal to or greater than two but less than a maximum value; using computation circuitry to evaluate elements of a 2n-element equivalent circuit model from said measured complex immittance at said n discrete frequencies; using said immittance measuring circuitry to measure complex immittance of said cell or battery at m additional discrete frequencies where m is a finite integer equal to or greater than one but less than a maximum value, wherein said computation circuitry is not adapted to evaluate elements of said 2n-element equivalent circuit model from said measured complex immittance at said m discrete frequencies; using said computation circuitry to calculate complex immittance of said 2n-element equivalent circuit model at said m additional discrete frequencies; using said computation circuitry to mathematically compare components of said calculated complex immittance at said m additional discrete frequencies with said measured complex immittance at said m additional discrete frequencies to obtain a comparison result; and
,determining said degree of cell deterioration from said comparison result. - View Dependent Claims (23, 24, 25, 26)
-
Specification