Device and method for estimating remaining battery capacity
First Claim
1. A remaining battery capacity estimating device for estimating a remaining battery capacity from inter-terminal voltage of a battery and current passed through the battery, comprising:
- a current measuring unit that measures the current;
a voltage measuring unit that measures the inter-terminal voltage;
a first remaining capacity storage that stores a first remaining battery capacity as a remaining battery capacity correlated with open-circuit voltage of the battery;
a second remaining capacity storage that stores a second remaining battery capacity produced by subtracting the first remaining battery capacity from the remaining battery capacity that increases and decreases by the current;
a current calculator that calculates remaining capacity difference current between the first remaining battery capacity and the second remaining battery capacity;
a first remaining capacity estimator that estimates the first remaining battery capacity on the basis of a value obtained by removing the remaining capacity difference current from the current and the inter-terminal voltage and has the estimate stored in the first remaining capacity storage;
a second remaining capacity calculator that calculates the second remaining battery capacity by adding up the remaining capacity difference current and has the result stored in the second remaining capacity storage; and
an adder that obtains the remaining battery capacity by adding the first remaining battery capacity and the second remaining battery capacity,wherein the remaining capacity difference current of the current calculator being, when the battery is charged, a current value that allows the second remaining battery capacity to be smaller than the first remaining battery capacity by a quantity corresponding to a first potential difference as a potential difference during battery charging, andthe remaining capacity difference current of the current calculator being, when the battery is discharged, a current value that allows the first remaining battery capacity to be smaller than the second remaining battery capacity by a quantity corresponding to a second potential difference as a potential difference during battery discharging.
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Accused Products
Abstract
This invention is concerning a device including a current calculator that calculates remaining capacity difference current on the basis of a first remaining battery capacity reflected on open-circuit voltage of a battery and a second remaining battery capacity not reflected on the open-circuit voltage, a first remaining capacity estimator that estimates the first remaining battery capacity on the basis of a value produced by removing the remaining capacity difference current from the current value of the battery and the inter-terminal voltage of the battery, a second remaining capacity calculator that calculates the second remaining battery capacity by adding up the remaining capacity difference current, and an adder that obtains a remaining battery capacity of the battery by adding the estimate of the first remaining battery capacity and the calculation value of the second remaining battery capacity. The current calculator calculates the remaining capacity difference current so that the first remaining battery capacity and the second remaining battery capacity have a prescribed potential difference.
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Citations
11 Claims
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1. A remaining battery capacity estimating device for estimating a remaining battery capacity from inter-terminal voltage of a battery and current passed through the battery, comprising:
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a current measuring unit that measures the current; a voltage measuring unit that measures the inter-terminal voltage; a first remaining capacity storage that stores a first remaining battery capacity as a remaining battery capacity correlated with open-circuit voltage of the battery; a second remaining capacity storage that stores a second remaining battery capacity produced by subtracting the first remaining battery capacity from the remaining battery capacity that increases and decreases by the current; a current calculator that calculates remaining capacity difference current between the first remaining battery capacity and the second remaining battery capacity; a first remaining capacity estimator that estimates the first remaining battery capacity on the basis of a value obtained by removing the remaining capacity difference current from the current and the inter-terminal voltage and has the estimate stored in the first remaining capacity storage; a second remaining capacity calculator that calculates the second remaining battery capacity by adding up the remaining capacity difference current and has the result stored in the second remaining capacity storage; and an adder that obtains the remaining battery capacity by adding the first remaining battery capacity and the second remaining battery capacity, wherein the remaining capacity difference current of the current calculator being, when the battery is charged, a current value that allows the second remaining battery capacity to be smaller than the first remaining battery capacity by a quantity corresponding to a first potential difference as a potential difference during battery charging, and the remaining capacity difference current of the current calculator being, when the battery is discharged, a current value that allows the first remaining battery capacity to be smaller than the second remaining battery capacity by a quantity corresponding to a second potential difference as a potential difference during battery discharging. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for estimating a remaining battery capacity from inter-terminal voltage of a battery and current passed through the battery, comprising:
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a current calculating step of calculating remaining capacity difference current between a first remaining battery capacity and a second remaining battery capacity, the first remaining battery capacity being a remaining battery capacity correlated with open-circuit voltage of the battery, the second remaining battery capacity being obtained by subtracting the first remaining battery capacity from the remaining battery capacity that increases and decreases by the current measured by a current measuring unit; a first remaining capacity estimating step of estimating the first remaining battery capacity on the basis of a value obtained by removing the remaining capacity difference current from the current and the inter-terminal voltage and having the estimate stored in a first remaining capacity storage; a second remaining capacity calculating step of calculating the second remaining battery capacity by adding up the remaining capacity difference current and having the result stored in a second remaining capacity storage; and an addition step of obtaining the remaining battery capacity by adding the first remaining battery capacity and the second remaining battery capacity, wherein the remaining capacity difference current calculated in the current calculating step being, when the battery is charged, a current value that allows the second remaining battery capacity to be smaller than the first remaining battery capacity by a quantity corresponding to a first potential difference as a potential difference during battery changing, and, when the battery is discharged, a current value that allows the first remaining battery capacity to be smaller than the second remaining battery capacity by a quantity corresponding to a second potential difference as a potential difference during battery discharging.
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Specification