Two terminal nicad battery charger with battery voltage and temperature sensing
First Claim
1. In a method of charging a battery of a two-terminal battery pack through the corresponding two charging terminals of said battery pack by supplying charging voltage to said two charging terminals from a charging circuit, said charging circuit having terminals connectable to said two charging terminals, respectively, to supply said charging voltage, providing said charging circuit with an electrical battery temperature measuring means in association with said two charging terminals, measuring battery temperature, and separating said two charging terminals from said charging circuit terminals after said battery is charged to a desired level, the improvement comprising:
- effectively electrically removing said battery from said charging terminals while electrically measuring battery temperature through said two charging terminals by said electrical measuring means.
1 Assignment
0 Petitions
Accused Products
Abstract
Method and apparatus is disclosed for measuring battery temperature and battery voltage during battery charging. The system is designed to charge a battery using two charging terminals and sensing battery voltage and temperature through the charging terminals. In measuring the temperature of the battery, the battery is electrically isolated from the sensing circuit during a portion of the charging cycle where the charging voltage is less than the battery voltage. Should the temperature of the battery, as measured, increase to a predetermined upper limit, the charging cycle is switched to a trickle charge on the battery. The battery voltage is measured at the instant when charging voltage exceeds the battery voltage to give a true indication of the recharged potential of the battery. When the sensed battery voltage is at the desired level, charging is switched to trickle charge. The system provides battery temperature and voltage sensing by the use of two terminal battery construction which is superior to the existing three and four terminal battery charging constructions.
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Citations
54 Claims
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1. In a method of charging a battery of a two-terminal battery pack through the corresponding two charging terminals of said battery pack by supplying charging voltage to said two charging terminals from a charging circuit, said charging circuit having terminals connectable to said two charging terminals, respectively, to supply said charging voltage, providing said charging circuit with an electrical battery temperature measuring means in association with said two charging terminals, measuring battery temperature, and separating said two charging terminals from said charging circuit terminals after said battery is charged to a desired level, the improvement comprising:
effectively electrically removing said battery from said charging terminals while electrically measuring battery temperature through said two charging terminals by said electrical measuring means. - View Dependent Claims (2, 3, 4, 5)
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6. In a method of charging a battery of a two-terminal battery pack through the corresponding two charging terminals of said battery pack by supplying charging voltage to said two charging terminals from a charging circuit, said charging circuit having terminals connectable to said two charging terminals, respectively, to supply said charging voltage, measuring battery temperature using an electrical battery temperature measuring means in association with said two charging terminals, and separating said two charging terminals from said charging circuit terminals after said battery is charged to a desired level, the improvement comprising:
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providing said battery pack in an enclosure with said two charging terminals exterior of said enclosure for separate electrical contact with said two charging circuit terminals; providing said temperature measuring means to include means for sensing battery temperature; providing said sensing means within said battery enclosure adjacent to said battery, said sensing means being electrically coupled to said two charging terminals; and effectively electrically removing said battery from said charging terminals while electrically measuring battery temperature through said two charging terminals by said sensing means. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14)
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15. In a method of charging a battery of a two-terminal battery pack through the corresponding two charging terminals of said battery pack by supplying charging voltage to said two charging terminals from a charging circuit, said charging circuit having terminals connectable to said two charging terminals, respectively, to supply said charging voltage, providing said charging circuit with an electrical battery temperature measuring means in association with said two charging terminals, measuring battery temperature, and separating said two charging terminals from said charging circuit terminals after said battery is charged, the improvement comprising:
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effectively electrically removing said battery from said charging terminals while electrically measuring battery temperature through said charging terminals by said electrical measuring means; intermittently changing said charging voltage applied to said charging terminals to a potential less than the battery potential to cause a falling off and a subsequent rise in said charging voltage; preventing discharge of said battery through said charging terminals by discharge prevention means; and detecting said charging voltage while current commences to flow or is about to cease flowing through said discharge prevention means to determine the voltage of said battery. - View Dependent Claims (16, 17, 18)
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19. In a method for detecting battery temperature of a two charging terminal battery pack during a charging cycle for said battery and switching to a trickle charging cycle for said battery when a predetermined temperature for said battery is detected, connecting said two charging terminals to two corresponding terminals of a charging circuit, and disconnecting said battery from said charging circuit terminals after said battery is charged to a desired level, providing electrical means responsive to change in battery temperature, said electrical means changing a detectable electrical characteristic thereof in response to increase in battery temperature, said electrical means being associated with said two charging terminals, the improvement comprising:
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intermittently applying a detecting voltage to said battery charging terminals which is less than the instaneous battery voltage; preventing discharge of said battery through said charging terminals during the application of said detecting voltage to said charging terminals, said detecting voltage being applied to said electrical means independent of said battery; detecting a change in said electrical characteristic when said detecting voltage is applied to said electrical means where a detected change in said electrical characteristic is in response to a change in said batery temperature; and switching to said trickle charging cycle in response to detecting a predetermined upper limit for battery temperature. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. In an apparatus for charging battery of a two terminal battery pack through its corresponding two charging terminals by connecting said two terminals with two corresponding terminals of a battery charging circuit of said apparatus, said charging circuitry having means for supplying a charging voltage to said two charging terminals, electrical means for measuring battery temperature which are associated with said two charging terminals, respectively, said battery temperature meauring means inclluding means for sensing battery temperature, said sensing means being adjacent said battery and electrically connected to said two charging terminals during battery charging, said charging terminals being separable from said two charging circuit terminals, the improvement comprising:
means for effectively electrically removing said battery from said charging terminals while said measuring means measures battery temperature by applying a voltage on said sensing means via said two charging terminals. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A rechargeable battery pack having a battery, two charging terminals and a thermistor in parallel with said battery, said thermistor being responsive to change in battery temperature, and said thermistor associated with said two charging terminals, the improvement comprising:
a diode in series with said battery and in parallel with said thermistor for preventing discharge of said battery through said two charging terminals, said battery comprising a plurality of cells connected in series and contained in an enclosure, said two charging terminals being exterior of said enclosure, said thermistor being within said enclosure adjacent one or more of said cells. - View Dependent Claims (54)
Specification