Cell discharge voltage monitor circuit for cell capacity grading and method for grading
First Claim
Patent Images
1. A circuit for measuring the capacity of electrochemical cells comprising:
- (a) a constant current power supply for estabilishing a discharge rate for the cell;
(b) a cellholder connected to said supply with negative and positive supply terminals connected to the positive and negative cellholder terminals so as to provide a discharge path for the cell, said discharge path including said constant current power supply;
(c) a switching means connectable in parallel with said holder for abruptly changing from a non-conductive to a conductive state responsive to the voltage of a cell disposed in said holder and providing a by-pass current path around said cell to thereby terminate discharge of a cell in said holder when said cell voltage attains a given value; and
(d) means for indicating the termination of discharge of a cell in said holder.
2 Assignments
0 Petitions
Accused Products
Abstract
A circuit utilized in a cell capacity grading machine for discharging a cell to a predetermined cell voltage which approximates the total discharge of the capacity of the cell. An indicator is provided for automatically indicating the termination of discharge of the cell and for initiating a cell ejection. Cells are capacity graded by ejection from a movable transport at spaced locations, each location corresponding to cells having a predetermined capacity range.
9 Citations
25 Claims
-
1. A circuit for measuring the capacity of electrochemical cells comprising:
-
(a) a constant current power supply for estabilishing a discharge rate for the cell; (b) a cellholder connected to said supply with negative and positive supply terminals connected to the positive and negative cellholder terminals so as to provide a discharge path for the cell, said discharge path including said constant current power supply; (c) a switching means connectable in parallel with said holder for abruptly changing from a non-conductive to a conductive state responsive to the voltage of a cell disposed in said holder and providing a by-pass current path around said cell to thereby terminate discharge of a cell in said holder when said cell voltage attains a given value; and (d) means for indicating the termination of discharge of a cell in said holder. - View Dependent Claims (2, 3, 4, 5, 6, 7, 19)
-
-
8. An apparatus for use in measuring the capacity of a plurality of cells comprising:
-
(a) a constant current power supply for establishing a discharge rate for the cells; (b) a plurality of series connected circuits, each circuit comprising; (i) a cellholder connected to said supply with negative and positive supply terminals connected in circuit with the positive and negative cellholder terminals, respectively so as to provide a discharge path for the cells disposed in each said cellholder. (ii) a switching means connectable in parallel with said holder for changing from a non-conductive to a conductive state responsive to the voltage of a cell disposed in said holder and providing a by-pass current path around said cell to thereby terminate discharge of a cell in said holder while providing a constant current path to the other of said cellholders; and (iii) means for indicating the termination of discharge of a cell in said holder. - View Dependent Claims (9, 10, 11, 12, 13, 14, 20, 21, 22)
-
-
15. A method for capacity grading a cell comprising the step of:
-
(1) loading, at a cell loading station, a plurality of cells in a row of cellholders disposed transversely of a longitudinally movable transport means; (2) initiating the discharge of the cells in said row; (3) detecting the substantially complete discharge of the cells as the cells are moved by said transport means; and (4) ejecting the cells from said cellholders in said row at spaced longitudinal positions of said transport means, said longitudinal position of ejection of a cell being determined by the total discharge time of the cell. - View Dependent Claims (16, 17, 18, 25)
-
-
23. A circuit for the controlled discharge of an electrochemical cell, comprising:
-
(a) a current source; (b) diode means connected in a series path with the current source and the cell to provide a forward discharge current path for the cell, said diode means developing a known voltage drop thereacross during discharge of the cell; (c) electronic switch means connected to provide a by-pass path around said series path for the current from said current source, said switch means having a control electrode; and (d) voltage reference means connected between at least one terminal of said series path and said control electrode for developing a voltage level on said control electrode sufficient to energize said switch means when the voltage of the cell is diminished by discharge to a predetermined value. - View Dependent Claims (24)
-
Specification