Method and apparatus for estimating the service life of a battery
First Claim
1. An apparatus adapted to estimate the service life of a battery comprising:
- a temperature measurement circuit adapted to measure a temperature of an operating environment of the battery and to output a signal representative of a temperature range in which the operating environment temperature resides; and
a controller coupled to the temperature measurement circuit and adapted to estimate the service life of the battery based on the signal output by the temperature measurement circuit.
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Accused Products
Abstract
An apparatus is provided for estimating the service life of a battery. The apparatus includes a temperature measurement circuit that measures a temperature of an operating environment of the battery and outputs a signal representative of the temperature of the operating environment. A controller coupled to the temperature measurement circuit receives the temperature signal therefrom and estimates the service life of the battery based on the temperature signal. Preferably, the temperature measurement circuit outputs a signal representative of a temperature range in which the measured operating environment temperature resides and the controller estimates the service life of the battery based on the temperature range signal output by the temperature measurement circuit. A method and a computer program product also are provided for similarly estimating the service life of a battery.
39 Citations
20 Claims
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1. An apparatus adapted to estimate the service life of a battery comprising:
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a temperature measurement circuit adapted to measure a temperature of an operating environment of the battery and to output a signal representative of a temperature range in which the operating environment temperature resides; and
a controller coupled to the temperature measurement circuit and adapted to estimate the service life of the battery based on the signal output by the temperature measurement circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
a thermistor having a resistance that varies with temperature, the resistance of the thermistor providing a measure of the temperature of the operating environment of the battery; and
an encoder circuit coupled to the thermistor and adapted to generate at least one bit representative of the temperature range in which the operating environment temperature of the battery resides based on the resistance of the thermistor.
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3. The apparatus of claim 2 further comprising:
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a first voltage divider circuit coupled to the thermistor and adapted to generate a temperature-sensitive voltage signal based on the resistance of the thermistor; and
a second voltage divider circuit coupled to the encoder circuit, the second voltage divider circuit adapted to generate at least one reference voltage; and
wherein the encoder circuit comprises a comparator circuit adapted to;
compare the temperature-sensitive voltage signal to the at least one reference voltage;
generate a first voltage level if the temperature-sensitive voltage signal is greater than the at least one reference voltage; and
generate a second voltage level if the temperature-sensitive voltage signal is less than the at least one reference voltage.
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4. The apparatus of claim 3 wherein the second resistive divider is adapted to generate a plurality of reference voltages and wherein the comparator circuit includes a plurality of comparators, each comparator adapted to:
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compare the temperature-sensitive voltage signal to a different one of the plurality of reference voltages;
generate a first voltage level if the temperature-sensitive voltage signal is greater than the different one of the reference voltages; and
generate a second voltage level if the temperature-sensitive voltage signal is less than the different one of the reference voltages.
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5. The apparatus of claim 4 wherein the encoder circuit further comprises circuitry coupled to the plurality of comparators and adapted to encode the voltage levels generated by the plurality of comparators into a plurality of bits indicative of the temperature range in which the operating environment temperature resides.
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6. The apparatus of claim 1 wherein the controller comprises:
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a plurality of counter means, each counter means having a count and a temperature range associated therewith, each counter means for counting a time the battery is operated within the temperature range associated with the counter means; and
estimation means for estimating the service life of the battery based on the count of each counter means.
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7. The apparatus of claim 6 wherein the estimation means comprises means for estimating the service life of the battery based on the count of each counter means and a pro-rate factor for each counter means that depends on the temperature range associated with the counter means.
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8. The apparatus of claim 7 wherein the plurality of counter means comprise:
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a first counter means having a temperature range of less than about 28°
C. associated therewith;
a second counter means having a temperature range of between about 280°
C. and about 32°
C. associated therewith;
a third counter means having a temperature range of between about 32°
C. and about 36°
C. associated therewith; and
a fourth counter means having a temperature range of greater than about 36°
C. associated therewith.
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9. The apparatus of claim 8 wherein:
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the pro-rate factor for the first counter means is about 1.0;
the pro-rate factor for the second counter means is about 1.22;
the pro-rate factor for the third counter means is about 1.5; and
the pro-rate factor for the fourth counter means is about 1.83.
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10. The apparatus of claim 1 wherein the controller comprises means for periodically estimating the service life of the battery.
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11. The apparatus of claim 10 wherein the controller comprises means for estimating the service life of the battery about every 5 minutes.
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12. The apparatus of claim 1 wherein the controller comprises means for generating an alarm if a maximum service life of the battery is exceeded.
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13. A method of estimating the service life of a battery comprising:
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measuring a temperature of an operating environment of the battery;
outputting a signal representative of a temperature range in which the operating environment temperature resides; and
estimating the service life of the battery based on the signal representative of the temperature range in which the operating environment temperature resides. - View Dependent Claims (14, 15, 16, 17)
determining a time the battery is operated within each of a plurality of temperature ranges; and
estimating the service life of the battery based on the time the battery is operated within each of the plurality of temperature ranges.
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16. The method of claim 15 wherein estimating the service life of the battery comprises estimating the service life of the battery based on the time the battery is operated within each of the plurality of temperature ranges and based on a pro-rate factor for each temperature range.
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17. The method of claim 13 further comprising generating an alarm if a maximum service life of the battery is exceeded.
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18. An apparatus for estimating the service life of a battery comprising:
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temperature measurement means for measuring a temperature of an operating environment of a battery and for outputting a signal representative of a temperature range in which the temperature resides; and
estimating means coupled to the temperature measurement means, the estimating means for estimating the service life of the battery based on the signal output by the temperature measurement means.
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19. An apparatus adapted to estimate the service life of a battery comprising:
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a temperature measurement circuit adapted to measure a temperature of an operating environment of the battery and to output a signal representative of a temperature range in which the operating environment temperature resides; and
a controller coupled to the temperature measurement circuit and adapted to receive the signal output by the temperature measurement circuit and to estimate the service life of the battery based on the signal output by the temperature measurement circuit, wherein the controller comprises;
a plurality of counter means, each counter means having a count and a temperature range associated therewith, each counter means for counting a time the battery is operated within the temperature range associated with the counter means; and
estimation means for estimating the service life of the battery based on the count of each counter means and a pro-rate factor for each counter means that depends on the temperature range associated with the counter means.
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20. An apparatus adapted to estimate the service life of a battery comprising:
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a temperature measurement circuit adapted to measure a temperature of an operating environment of the battery and to output a signal representative of a temperature range in which the operating environment temperature resides; and
a controller coupled to the temperature measurement circuit and adapted to receive the signal output by the temperature measurement circuit and to estimate the service life of the battery based on the signal output by the temperature measurement circuit, wherein the controller comprises;
a plurality of counter means, each counter means having a count and a temperature range associated therewith, each counter means for counting a time the battery is operated within the temperature range associated with the counter means; and
estimation means for estimating the service life of the battery based on the count of each counter means and a pro-rate factor for each counter means that depends on the temperature range associated with the counter means;
wherein the plurality of counter means comprise;
a first counter means having a temperature range of less than about 28°
C. associated therewith and a pro-rate factor of about 1.0;
a second counter means having a temperature range of between about 28°
C. and about 32°
C. associated therewith and a pro-rate factor of about 1.22;
a third counter means having a temperature range of between about 32°
C. and about 36°
C. associated therewith and a pro-rate factor of about 1.5; and
a fourth counter means having a temperature range of greater than about 36°
C. associated therewith and a pro-rate factor of about 1.83.
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Specification