Battery pack manager
First Claim
1. A battery pack manager for a plurality of unit cells of secondary battery connected in series, comprising:
- a cell equalizer, associated with said unit cells, that equalizes cell voltages developed by the unit cells;
an overcharge/overdischarge detector, associated with said unit cells, that detects an overcharge and an overdischarge of said unit cells; and
an inhibit circuit that prevents said cell equalizer from discharging said unit cells when said overcharge/overdischarge detector is operating.
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Accused Products
Abstract
In a battery pack manager that manages series-connected rechargeable unit cells, a cell equalizer equalizes the cell voltages by individually discharging the unit cells according to deviations from reference voltages. An overcharge/overdischarge detector detects an overcharge and an overdischarge state of each unit cell. An inhibit circuit prevents the cell equalizer from discharging the unit cells when the overcharge/overdischarge detector is activated to reduce the cell voltage variability, which would otherwise occur as a result of interference from the overcharge/overdischarge detector, so that the overcharge/overdischarge states of all unit cells can be determined with precision. Connecting lines of the unit cells are monitored to detect a line-cut. The inhibit circuit further inhibits the cell equalizer when the connecting lines are being monitored to reduce the cell voltage variability, which would otherwise occur as a result of interference from the line-cut detection, so that false line-cut detection is avoided.
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Citations
21 Claims
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1. A battery pack manager for a plurality of unit cells of secondary battery connected in series, comprising:
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a cell equalizer, associated with said unit cells, that equalizes cell voltages developed by the unit cells;
an overcharge/overdischarge detector, associated with said unit cells, that detects an overcharge and an overdischarge of said unit cells; and
an inhibit circuit that prevents said cell equalizer from discharging said unit cells when said overcharge/overdischarge detector is operating. - View Dependent Claims (3, 5)
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2. A battery pack manager for a plurality of unit cells of secondary battery connected in series, comprising:
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a cell equalizer, associated with said unit cells, that equalizes cell voltages developed by the unit cells;
a line monitor, associated with said unit cells, that monitors connecting lines that connect said unit cells to said cell equalizer;
an overcharge/overdischarge detector, associated with said unit cells, that detects an overcharge and an overdischarge of said unit cells; and
an inhibit circuit that prevents said cell equalizer from discharging said unit cells when said line monitor is monitoring said connecting lines. - View Dependent Claims (4, 6)
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7. A battery pack manager for a plurality of unit cells of secondary battery connected in series, comprising:
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a cell equalizer, connected to said unit cells via a plurality of connecting lines, that equalizes cell voltages developed by the unit cells;
an overcharge/overdischarge detector, connected to said unit cells via said plurality of connecting lines, that makes a decision on whether said unit cells are overcharged or overdischarged;
a line-cut detector that detects a line-cut on said plurality of connecting lines; and
an inhibit circuit that inhibits decision output of said overcharge/overdischarge detector when a line-cut is detected by said line-cut detector on one of said connecting lines.
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8. A battery pack manager for a plurality of unit cells of secondary battery connected in series, comprising:
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a cell equalizer, connected to said unit cells via a plurality of connecting lines, that equalizes cell voltages developed by the unit cells;
an overcharge/overdischarge detector, connected to said unit cells via said connecting lines, that makes a decision on whether said unit cells are overcharged or overdischarged;
a line-cut detector that detects a line-cut on said connecting lines; and
an inhibit circuit that inhibits discharge operation of said cell equalizer when a line-cut is detected by said line-cut detector on one of said connecting lines.
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- 9. A battery pack manager for a plurality of rechargeable unit cells connected in series, wherein said unit cells are divided into a plurality of battery-pack modules, comprising a battery-pack controller, connected to said battery-pack modules via a pair of battery-pack connecting lines and a plurality of module-connecting lines, that successively detects a voltage value of each of said battery-pack modules, determines that a line-cut has occurred on one of said battery-pack connecting lines if a single zero-voltage value is detected and determines that a line-cut has occurred on one of said module-connecting lines if two zero-voltage values are detected in succession.
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16. A method of detecting a line-cut on a plurality of connecting lines connecting a plurality of series-connected rechargeable unit cells to control circuitry, wherein said unit cells are divided into a plurality of battery-pack modules, comprising the steps of:
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a) successively detecting a voltage value of each of said battery-pack modules; and
b) determining that a line-cut has occurred on one of said battery-pack connecting lines if a single zero-voltage value is detected or that a line-cut has occurred on one of said module-connecting lines if two zero-voltage values are detected in succession. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification