Charger apparatus capable of determining deterioration of second battery
First Claim
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1. A charger, comprising:
- an output circuit unit configured to output a charging current to a secondary battery;
a voltage detection unit configured to detect a voltage of the secondary battery; and
a control unit configured to control the output circuit unit to carry out charging operations each of which includes a constant current charging and a constant voltage charging sequentially performed in that order,wherein, during the constant current charging, a level of the charging current is decreased stepwisely by plural current conversions and, during the constant voltage charging, the charging current flows at a constant voltage, andwherein the control unit determines whether or not the secondary battery has deteriorated depending on a result of comparing an index value and a predetermined threshold associated with a deteriorated secondary battery, the index value being obtained by using voltage drop values of the secondary battery that occur by two or more of the current conversions.
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Abstract
A charger includes an output circuit unit to output a charging current to a secondary battery, a voltage detection unit to detect a voltage of the secondary battery, and a control unit to control the output circuit unit, whereby constant current charging and constant voltage charging are performed. The control unit decreases a constant current value of the charging current by stages during the constant current charging and determines that the secondary battery has deteriorated by using a first voltage drop value of the secondary battery occurring upon first conversion and a second voltage drop value of the secondary battery occurring upon second conversion.
23 Citations
16 Claims
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1. A charger, comprising:
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an output circuit unit configured to output a charging current to a secondary battery; a voltage detection unit configured to detect a voltage of the secondary battery; and a control unit configured to control the output circuit unit to carry out charging operations each of which includes a constant current charging and a constant voltage charging sequentially performed in that order, wherein, during the constant current charging, a level of the charging current is decreased stepwisely by plural current conversions and, during the constant voltage charging, the charging current flows at a constant voltage, and wherein the control unit determines whether or not the secondary battery has deteriorated depending on a result of comparing an index value and a predetermined threshold associated with a deteriorated secondary battery, the index value being obtained by using voltage drop values of the secondary battery that occur by two or more of the current conversions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A charger, comprising:
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an output circuit unit configured to output a charging current to a secondary battery; a voltage detection unit configured to detect a voltage of the secondary battery; and a control unit configured to control the output circuit unit to carry out charging operations each of which includes a constant current charging and a constant voltage charging sequentially performed in that order, wherein, during the constant current charging, a level of the charging current is decreased stepwisely by plural current conversions and, during the constant voltage charging, the charging current flows at a constant voltage, and wherein the control unit determines that the secondary battery has deteriorated if a voltage drop value of the secondary battery, which is detected by the voltage detection unit upon one of the current conversions, is equal to or greater than a predetermined threshold associated with a deteriorated secondary battery wherein a memory device is provided in a battery pack including the secondary battery, and wherein the control unit stores, in the memory device, the voltage drop value corresponding to said one of the current conversions in an initial phase in which the number of charging times of the secondary battery is equal to or smaller than a a predetermined number of charging times of the secondary battery and excludes a deviation between the voltage drop value in the initial phase and a reference voltage value thereof when determining whether or not the secondary battery has deteriorated. - View Dependent Claims (15, 16)
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Specification