Apparatus and switching method for improving cycle-life and capacity of a battery pack
First Claim
1. A device, comprising:
- a plurality of battery cells selectively coupled in parallel;
at least one switch responsive to a control signal for selectively decoupling at least a select cell among the plurality of battery cells; and
a charging system for supplying a source voltage and a source current to the plurality of battery cells, wherein the charging system is programmed to;
determine a capacity for each of the plurality of battery cells;
determine a desired cutoff current for a select one of the plurality of battery cells having the smallest capacity;
determine an optimal source cutoff current according to the capacity of the select one of the plurality of battery cells;
adjust the source current according to the optimal source cutoff current; and
upon the source current reaching the optimal source cutoff current, provide the control signal to control the operation of the at least one switch.
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Accused Products
Abstract
A charging system (108) supplies a source voltage (Vco, FIG. 5) and a source current (Ico, FIG. 5) to a plurality of battery cells (110). The charging system operates according to a method (200) including the steps of determining (202) a capacity for each of the plurality of battery cells (120 and 130), determining (204) a desired cutoff current (Ico1, FIG. 5) for a select one of the plurality of battery cells (120) having the smallest capacity, determining (206) an optimal source cutoff current according to the capacity of the select one of the plurality of battery cells, adjusting (208) the source current according to the optimal source cutoff current, and upon the source current reaching the optimal source cutoff current, switching out the select one of the plurality of battery cells to allow continued charging of another cell until it is fully charged.
26 Citations
20 Claims
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1. A device, comprising:
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a plurality of battery cells selectively coupled in parallel;
at least one switch responsive to a control signal for selectively decoupling at least a select cell among the plurality of battery cells; and
a charging system for supplying a source voltage and a source current to the plurality of battery cells, wherein the charging system is programmed to;
determine a capacity for each of the plurality of battery cells;
determine a desired cutoff current for a select one of the plurality of battery cells having the smallest capacity;
determine an optimal source cutoff current according to the capacity of the select one of the plurality of battery cells;
adjust the source current according to the optimal source cutoff current; and
upon the source current reaching the optimal source cutoff current, provide the control signal to control the operation of the at least one switch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A battery pack having a plurality of battery cells that works in conjunction with a charging system that supplies a source voltage and a source current and determines a capacity for each of the plurality of battery cells, a desired cutoff current for a select one of the plurality of battery cells having the smallest capacity, and an optimal source cutoff current according to the capacity of the select one of the plurality of battery cells, the battery pack comprising:
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the plurality of battery cells selectively coupled in parallel;
at least one switch responsive to a control signal for selectively decoupling at least the select one among the plurality of battery cells; and
wherein the plurality of battery cells receive an adjusted source current based on the optimal source cutoff current and the at least one switch is controlled to selectively decouple upon the source current reaching the optimal source cutoff current. - View Dependent Claims (11, 12, 13)
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15. In a charging system supplying a source voltage and a source current to a plurality of battery cells, a method comprising the steps of:
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determining a capacity for each of the plurality of battery cells;
determining a desired cutoff current for a select one of the plurality of battery cells having the smallest capacity;
determining an optimal source cutoff current according to the capacity of the select one of the plurality of battery cells;
adjusting the source current according to the optimal source cutoff current; and
upon the source current reaching the optimal source cutoff current, disconnecting at least the select one of the plurality of battery cells while continuing to apply the source current to a remaining set of cells among the plurality of battery cells. - View Dependent Claims (14, 16, 17, 18, 19, 20)
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Specification