Method of detecting and resolving memory effect
First Claim
1. A method for detecting a memory effect comprising the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery.
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Accused Products
Abstract
A method of detecting and resolving a memory effect capable of detecting the memory effect with ease and with high precision and resolving even when the vehicle is in motion is provided. A current in a secondary battery is detected, a variation ΔSOC in a residual battery capacity for a predetermined time period is calculated according to at least current integration by multiplying the detected current by a predetermined charge efficiency (S302), a temperature of the secondary battery is detected and a variation ΔV in a no-load voltage for the predetermined time period is calculated based on the detected current, and an internal resistance corresponding to the detected temperature and the SOC is calculated (S303). A ratio k of the variation in the no-load voltage to the variation in the residual battery capacity is calculated (S304). If the ratio exceeds a predetermined threshold value kst, then the battery is judged to have a memory effect (S307), and the usage range of the SOC is extended for a predetermined time period (S308) or the correction of the SOC using voltages is prohibited for a predetermined time period(S309).
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Citations
22 Claims
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1. A method for detecting a memory effect comprising the steps of:
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detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery. - View Dependent Claims (2, 3)
wherein the predetermined charge efficiency is determined based on the detected temperature and the residual battery capacity obtained by the current operation. -
3. The method for detecting a memory effect according to claim 1,
wherein the predetermined threshold value is determined based on a level of memory effect intended to be judged.
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4. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, setting a control range of the residual battery capacity broader than a normal usage range.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
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5. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, prohibiting correction of a residual battery capacity obtained by the operation based on a voltage variation for a predetermined time period.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
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6. A method for detecting a memory effect comprising the steps of:
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detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery. - View Dependent Claims (7, 8)
wherein the predetermined charge efficiency is determined based on the detected temperature and the residual battery capacity obtained by the current operation. -
8. The method for detecting a memory effect according to claim 6,
wherein the predetermined threshold value is determined based on a level of memory effect intended to be judged.
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9. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, setting a control range of the residual battery capacity broader than a normal usage range.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
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10. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
performing an operation on a variation in a residual battery capacity for a predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency;
detecting a temperature of the secondary battery;
calculating a variation in a no-load voltage for the predetermined time period, based on the detected current and an internal resistance corresponding to the detected temperature and the residual battery capacity obtained by the operation;
calculating a ratio of the variation in the no-load voltage to the variation in the residual battery capacity; and
if the ratio of the variation in the no-load voltage to the variation in the residual battery capacity is not less than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, prohibiting correction of a residual battery capacity obtained by the operation based on a voltage variation for a predetermined time period.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
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11. A method for detecting a memory effect comprising the steps of:
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detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery. - View Dependent Claims (12, 13, 14)
wherein a temperature of the secondary battery is detected, and the predetermined charge efficiency is determined based on the detected temperature and the residual battery capacity obtained by the current operation. -
13. The method for detecting a memory effect according to claim 11,
wherein the calculation of the no-load voltage is carried out when a deviation of the output voltage corresponding to the detected current within predetermined ranges in a charge direction and a discharge direction is within a predetermined variance range. -
14. The method for detecting a memory effect according to claim 11,
wherein the predetermined threshold value is determined based on a level of memory effect intended to be judged.
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15. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, calculating an area formed by a variation curve of the no-load voltage versus a residual battery capacity in a normal usage range, and based on a difference between the area and an area formed by a variation curve of the no-load voltage versus a residual battery capacity in the normal usage range when a memory effect does not occur, setting a control range of the residual battery capacity broader than the normal usage range.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
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16. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, calculating an area formed by a variation curve of the no-load voltage versus a residual battery capacity in a normal usage range, and based on a difference between the area and an area formed by a variation curve of the no-load voltage versus a residual battery capacity in the normal usage range when a memory effect does not occur, prohibiting correction of a residual battery capacity obtained by the operation based on a voltage variation for a predetermined time period.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery;
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17. A method for detecting a memory effect comprising the steps of:
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detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery. - View Dependent Claims (18, 19, 20)
wherein a temperature of the secondary battery is detected, and the predetermined charge efficiency is determined based on the detected temperature and the residual battery capacity obtained by the current operation. -
19. The method for detecting a memory effect according to claim 17,
wherein the calculation of the no-load voltage is carried out when a deviation of the output voltage corresponding to the detected current within predetermined ranges in a charge direction and a discharge direction is within a predetermined variance range. -
20. The method for detecting a memory effect according to claim 17,
wherein the predetermined threshold value is determined based on a level of memory effect intended to be judged.
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21. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, calculating an area formed by a variation curve of the no-load voltage versus a residual battery capacity in a normal usage range, and based on a difference between the area and an area formed by a variation curve of the no-load voltage versus a residual battery capacity in the normal usage range when a memory effect does not occur, setting a control range of the residual battery capacity broader than the normal usage range.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charge state;
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22. A method for resolving a memory effect detected by a memory effect detecting method that includes the steps of:
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charged state;
detecting an output voltage from the secondary battery while associating the output voltage with the detected current;
calculating a no-load voltage at the detected current being zero, based on a variation in the output voltage with respect to the detected current for a predetermined time period;
performing an operation on a residual battery capacity for the predetermined time period according to at least current integration by multiplying the detected current by a predetermined charge efficiency, based on the calculated no-load voltage;
calculating a correlation coefficient between the no-load voltage and the residual battery capacity obtained by the operation in a predetermined variation range; and
if the correlation coefficient is not more than a predetermined threshold value, judging as a memory effect occurring in the secondary battery,the method for resolving a memory effect comprising;
if the battery is judged to have a memory effect according to the memory effect detecting method, calculating an area formed by a variation curve of the no-load voltage versus to a residual battery capacity in a normal usage range, and based on a difference between the area and an area formed by a variation curve of the no-load voltage versus a residual battery capacity in the normal usage range when a memory effect does not occur, prohibiting correction of a residual battery capacity obtained by the operation based on a voltage variation for a predetermined time period.
- detecting a current flowing through a secondary battery configured by combining a plurality of single cells into an assembled battery and used in a middle charged state;
Specification