Method, arrangement and computer program product for determining an end-of-life state of a battery
First Claim
1. A method for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the method comprising:
- during a discharge of the battery, measuring, by a measuring circuit, a first discharge voltage value provided by the battery at a first point of time;
during the discharge, measuring, by the measuring circuit, a second discharge voltage value provided by the battery at a second point of time T2;
computing, by a processing circuit, a predicted backup time that the battery can support, based on the first and second discharge voltage values and the first and second points of time;
during the discharge, measuring, by the measuring circuit, a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time;
computing, by the processing circuit, an average discharge current from the plurality of discharge current values;
calculating, by the processing circuit, a discharged capacity by multiplying the average discharge current by a difference between the second and first points in time;
calculating, by the processing circuit, an actual capacity of the battery before the discharge, based on the initial capacity and the average discharge current;
calculating, by the processing circuit, a remaining capacity after discharge according to a difference between the actual capacity and the discharged capacity;
calculating, by the processing circuit, an expected backup time (Texpected) that the battery can support, according to Texpected=(T2+(Cremain/Iaverage))*k, wherein Cremain is the remaining capacity, laverage is the average discharge current, and k is an aging factor indicating the age of the battery;
comparing , by the processing circuit, the predicted backup time and the expected backup time; and
if the expected backup time is less than or equal to the predicted backup time, determining that the battery is in an EOL state.
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Accused Products
Abstract
Techniques for determining an end-of-life state of a battery. During a discharge a first discharge voltage value U1(T1) provided by the battery at a first point of time T1and a second discharge voltage value U2 (T2) provided by the battery at a second point of time T2 are measured. A predicted backup time Tpredicted is computed based on the measured values and the first and second points in time. Furthermore, during the discharge, a plurality of discharge current values at a plurality of points of time on or between the first point of time T1 and the second point of time T2 are measured, and an average discharge current, Iaverage, is computed. An expected backup time Texpected is then computed based on the initial capacity of the battery and Iaverage. If Texpected is less than or equal to Tpredicted then the EOL state of the battery is determined.
7 Citations
12 Claims
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1. A method for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the method comprising:
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during a discharge of the battery, measuring, by a measuring circuit, a first discharge voltage value provided by the battery at a first point of time; during the discharge, measuring, by the measuring circuit, a second discharge voltage value provided by the battery at a second point of time T2; computing, by a processing circuit, a predicted backup time that the battery can support, based on the first and second discharge voltage values and the first and second points of time; during the discharge, measuring, by the measuring circuit, a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time; computing, by the processing circuit, an average discharge current from the plurality of discharge current values; calculating, by the processing circuit, a discharged capacity by multiplying the average discharge current by a difference between the second and first points in time; calculating, by the processing circuit, an actual capacity of the battery before the discharge, based on the initial capacity and the average discharge current; calculating, by the processing circuit, a remaining capacity after discharge according to a difference between the actual capacity and the discharged capacity; calculating, by the processing circuit, an expected backup time (Texpected) that the battery can support, according to Texpected=(T2+(Cremain/Iaverage))*k, wherein Cremain is the remaining capacity, laverage is the average discharge current, and k is an aging factor indicating the age of the battery; comparing , by the processing circuit, the predicted backup time and the expected backup time; and if the expected backup time is less than or equal to the predicted backup time, determining that the battery is in an EOL state. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An arrangement for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the arrangement comprising:
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a measuring circuit configured to measure a first discharge voltage value provided by the battery at a first point of time and a second discharge voltage value provided by the battery at a second point of time T2; and a processing circuit configured to compute a predicted backup time that the battery can support, based on the first and second discharge voltage values and the first and second points in time; wherein the measuring part is further configured to measure a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time; and wherein the processing circuit is further configured to; compute an average discharge current from the plurality of discharge current values; calculate a discharged capacity by multiplying the average discharge current by a difference between the second and first points in time; calculate an actual capacity of the battery before the discharge, based on the initial capacity and the average discharge current; calculate a remaining capacity after discharge according to a difference between the actual capacity and the discharged capacity; calculating an expected backup time (Texpectected) that the battery can support, according to Texpected=(T2+(Cremain/Iaverage))*k, wherein Cremain is the remaining capacity, Iaverage is the average discharge current, and k is an aging factor indicating the age of the battery; compare the predicted backup time and the expected backup time; and if the expected backup time is less than or equal to the predicted backup time, determine that the battery is in an EOL state. - View Dependent Claims (8, 9, 10)
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11. A non-transitory computer readable medium storing a computer program for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the computer program comprising computer program segments that, when executed by a computer, cause the computer to:
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compute, by a processing circuit, a predicted backup time that the battery can support, based on measured values of a first discharge voltage, by a measuring circuit, provided by the battery at a first point of time and a second discharge voltage, by a measuring circuit, provided by the battery at a second point of time T2; during the discharge, measuring, by the measuring circuit, a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time; compute, by the processing circuit, an average discharge current from a plurality of measured discharge current values; calculate, by the processing circuit, a discharged capacity by multiplying the average discharge current by a difference between the second and first points in time; calculate, by the processing circuit, an actual capacity of the battery before the discharge, based on the initial capacity and the average discharge current; calculate, by the processing circuit, a remaining capacity after discharge according to a difference between the actual capacity and the discharged capacity; calculating, by the processing circuit, an expected backup time (Texpected) that the battery can support, according to Texpected=(T2+(Cremain/Iaverage))*k, wherein Cremain is the remaining capacity, Iaverage is the average discharge current, and k is an aging factor indicating the age of the battery; comparing, by the processing circuit, the expected backup time and the predicted backup time; and
,if the expected backup time is less than or equal to the predicted backup time, determine the EOL state of the battery. - View Dependent Claims (12)
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Specification