Short detection in battery cells
First Claim
1. A method, comprising:
- monitoring, by a microprocessor, a plurality of battery cells through circuitry coupled to the plurality of battery cells to monitor at least one of a voltage across at least one of the plurality of battery cells and a current through at least one of the plurality of battery cells;
counting, by the microprocessor, a first number of times a first battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the step of counting comprises determining whether the first battery cell is out of balance with the other battery cells by comparing a relative state of charge of the first battery cell with a relative state of charge of at least one of the other battery cells, wherein the relative state of charge of the first battery cell and the at least one of the other battery cells is determined based, at least in part, on the step of monitoring the plurality of battery cells;
counting, by the microprocessor, a second number of times a second battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the step of counting comprises determining whether the second battery cell is out of balance with the other battery cells by comparing a relative state of charge of the second battery cell with a state of charge of at least one of the other battery cells; and
marking, by the microprocessor, the first battery cell as potentially faulty due to an internal short based, at least in part, on the first count exceeding a first threshold,wherein the first threshold, for marking the first battery cell as potentially faulty due to an internal short is based at least in part on the second count.
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Accused Products
Abstract
Internal shorts and other failures in lithium-ion battery cells may be detected during balancing of the battery cells. A counter may be used to detect when a battery cell is behaving differently than other battery cells by balancing more or less frequently. The counter may increment each time a battery cell is balanced to the other battery cells. A misbehaving battery cell may be flagged, when the counter exceeds a threshold value, for safety checks before an overheating event occurs. This misbehaving battery cell may be faulty due to an internal short. If the faulty battery cell is not corrected by replacement with a different battery cell or corrected by a user resetting the counter, the misbehaving battery cell may be disconnected to prevent the overheating event.
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Citations
24 Claims
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1. A method, comprising:
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monitoring, by a microprocessor, a plurality of battery cells through circuitry coupled to the plurality of battery cells to monitor at least one of a voltage across at least one of the plurality of battery cells and a current through at least one of the plurality of battery cells; counting, by the microprocessor, a first number of times a first battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the step of counting comprises determining whether the first battery cell is out of balance with the other battery cells by comparing a relative state of charge of the first battery cell with a relative state of charge of at least one of the other battery cells, wherein the relative state of charge of the first battery cell and the at least one of the other battery cells is determined based, at least in part, on the step of monitoring the plurality of battery cells; counting, by the microprocessor, a second number of times a second battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the step of counting comprises determining whether the second battery cell is out of balance with the other battery cells by comparing a relative state of charge of the second battery cell with a state of charge of at least one of the other battery cells; and marking, by the microprocessor, the first battery cell as potentially faulty due to an internal short based, at least in part, on the first count exceeding a first threshold, wherein the first threshold, for marking the first battery cell as potentially faulty due to an internal short is based at least in part on the second count. - View Dependent Claims (2, 3, 4, 5, 16, 19, 22)
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6. A computer program product, comprising:
- a non-transitory computer-readable medium comprising;
code to instruct a microprocessor to monitor, through circuitry coupled to a plurality of battery cells, at least one of a voltage across at least one of the plurality of battery cells and a current through at least one of the plurality of battery cells; code to count a first number of times a first battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the code to count the first number of times comprises code to determine whether the first battery cell is out of balance with the other battery cells by comparing a relative state of charge of the first battery cell with a relative state of charge of at least one of the other battery cells, wherein the state of charge of the first battery cell and the at least one of the other battery cells is based, at least in part, on the at least one of a voltage across at least one of a plurality of battery cells and a current through at least one of the plurality of battery cells; code to count a second number of times a second battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the code to count comprises code to determine whether the second battery cell is out of balance with the other battery cells by comparing a relative state of charge of the second battery cell with a relative state of charge of at least one of the other battery cells; and code to mark the first battery cell as potentially faulty due to an internal short based, at least in part, on the first count exceeding a first threshold, wherein the first threshold, for marking the first battery cell as potentially faulty due to an internal short is based at least in part on the second count. - View Dependent Claims (7, 8, 9, 17, 20, 23)
- a non-transitory computer-readable medium comprising;
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10. An apparatus, comprising:
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a plurality of battery cells; circuitry coupled to the plurality of battery cells configured to measure at least one of a current through at least one of the plurality of battery cells and a voltage across at least one of the plurality of battery cells; and a microprocessor coupled to the plurality of battery cells through the circuitry, in which the microprocessor is configured; to monitor at least one of a voltage across at least one of the plurality of battery cells and a current through at least one of the plurality of battery cells; to count a first number of times a first battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the microprocessor is configured to determine whether the first battery cell is out of balance with the other battery cells by comparing a relative state of charge of the first battery cell with a relative state of charge of at least one of the other battery cells, wherein the microprocessor is configured to determine a relative state of charge of the first battery cell and the at least one of the other battery cells based, at least in part, on the monitored at least one of a voltage across at least one of the plurality of battery cells and a current through at least one of the plurality of battery cells; to count a second number of times a second battery cell of the plurality of battery cells is out of balance with other battery cells of the plurality of battery cells, wherein the microprocessor is further configured to determine whether the second battery cell is out of balance with the other battery cells by comparing a relative state of charge of the second battery cell with a relative state of charge of at least one of the other battery cells; and to mark the first battery cell as potentially faulty due to an internal short based, at least in part, on the first count exceeding a first threshold, wherein the first threshold, for marking the first battery cell as potentially faulty due to an internal short is based at least in part on the second count. - View Dependent Claims (11, 12, 13, 14, 15, 18, 21, 24)
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Specification