Abstract: A battery pack monitoring system comprises first and second wirings connected to each battery cell, an RC filter formed of a resistor and a capacitor, and a discharging switch provided between two second wirings in a voltage monitoring device. The first and second wirings and the discharging switch are also connected to both ends of an inter-group group wire. In the second wiring of each battery cell, a discharging resistor is provided not to cause discharging of the charge in the capacitor. In the second wiring connected to a low voltage side for the inter-group wiring, a current limiting resistor having a higher resistance value than the discharging resistor is provided. A substitute discharging switch and a discharging resistor are provided so that the substitute discharging switch is turned on upon a voltage drop generated when current flows through the current limiting resistor.

Abstract: A battery monitoring device for monitoring an assembled battery having multiple battery cells includes: a range specifying unit that specifies a detection range; a voltage detection unit that detects a voltage of each battery cell in the detection range, includes an A/D converter for inputting a voltage corresponding to the voltage of each battery cell and a digital filter for inputting a digital signal output from the A/D converter and functioning as a low pass filter, and outputs an output signal of the digital filter as a detection signal representing a detection result of the voltage of each battery cell; and a characteristic setting unit that sets a characteristic of the digital filter.

Abstract: A battery management device is configured to set a limited measurement range that limits a range for measuring a voltage of each of a plurality of batteries for a vehicle. The battery management device is configured to measure the voltage of each of the plurality of batteries within the limited measurement range.

Abstract: A correction current output circuit comprises a first voltage dividing circuit for generating a voltage in which an output voltage from a bandgap reference voltage circuit is divided in multiple stages, first and second correction circuits connected between a power supply and a ground, and a second voltage dividing circuit for dividing the above voltage in multiple stages in a path in which a positive temperature characteristic voltage is generated with the band gap reference voltage circuit. Current output terminals of a the second transistor of the first correction circuit and a first transistor of the second correction circuit are connected to a common connection point, and a current for correcting the temperature characteristic of a reference voltage generation circuit is output from the common connection point.

Abstract: An assembled battery monitoring system includes: a voltage monitoring apparatus; discharging resistance elements and RC filters that are correspondingly coupled between battery cells of an assembled battery and the voltage monitoring apparatus; and discharging switches disposed in the voltage monitoring apparatus correspondingly to the battery cells. The voltage monitoring apparatus has at least three connection terminals for each of the battery cells. Two of the connection terminals are used to monitor a voltage of a corresponding battery cell through an output terminal of a corresponding RC filter, and at least one of a remainder of the connection terminals is used to form a discharging path of the corresponding battery cell when a corresponding discharging switch is turned on. Each discharging resistance element is disposed on the discharging path at a position that prohibits discharging of charges stored in a capacitor of the corresponding RC filter.

Abstract: A battery pack monitoring system comprises first and second wirings connected to each battery cell, an RC filter formed of a resistor and a capacitor, and a discharging switch provided between two second wirings in a voltage monitoring device. The first and second wirings and the discharging switch are also connected to both ends of an inter-group group wire. In the second wiring of each battery cell, a discharging resistor is provided not to cause discharging of the charge in the capacitor. In the second wiring connected to a low voltage side for the inter-group wiring, a current limiting resistor having a higher resistance value than the discharging resistor is provided. A substitute discharging switch and a discharging resistor are provided so that the substitute discharging switch is turned on upon a voltage drop generated when current flows through the current limiting resistor.

Abstract: In an assembled battery monitoring system, a voltage monitoring apparatus monitors voltages of battery cells of an assembled battery. Discharging resistance elements and RC filters are correspondingly coupled between the battery cells and the voltage monitoring apparatus. Discharging switches are disposed inside of the voltage monitoring apparatus correspondingly to the battery cells. The discharging resistance elements are each disposed on a discharging path at a position that prohibits discharging of charges stored in a capacitor of the corresponding RC filter. A fault diagnosis device simultaneously turns on two discharging switches, which are apart from each other across at least two discharging switches, and determines that any of the discharging switches between the two discharging switches simultaneously turned on has a fault, when a terminal voltage of any of the battery cells that are located between the two discharging switches simultaneously turned on changes over a predetermined voltage.

Abstract: A correction current output circuit comprises a first voltage dividing circuit for generating a voltage in which an output voltage from a bandgap reference voltage circuit is divided in multiple stages, first and second correction circuits connected between a power supply and a ground, and a second voltage dividing circuit for dividing the above voltage in multiple stages in a path in which a positive temperature characteristic voltage is generated with the band gap reference voltage circuit. Current output terminals of a the second transistor of the first correction circuit and a first transistor of the second correction circuit are connected to a common connection point, and a current for correcting the temperature characteristic of a reference voltage generation circuit is output from the common connection point.

Abstract: A route switching circuit includes: a pair of normal detection routes that output voltages of a positive side connection point and a negative side connection point, which are different from each other, in multiple batteries for constituting an assembled battery; and a pair of diagnosis detection routes that output the voltages of the positive side connection point and the negative side connection point, and confirm a connection state of the normal detection routes by using the normal detection routes, which output at least one of a voltage of a positive side battery connected to a positive side from the positive side connection point and a voltage of a negative side battery connected to a negative side from the negative side connection point.

Abstract: In an assembled battery monitoring system, a voltage monitoring apparatus monitors voltages of battery cells of an assembled battery. Discharging resistance elements and RC filters are correspondingly coupled between the battery cells and the voltage monitoring apparatus. Discharging switches are disposed inside of the voltage monitoring apparatus correspondingly to the battery cells. The discharging resistance elements are each disposed on a discharging path at a position that prohibits discharging of charges stored in a capacitor of the corresponding RC filter. A fault diagnosis device simultaneously turns on two discharging switches, which are apart from each other across at least two discharging switches, and determines that any of the discharging switches between the two discharging switches simultaneously turned on has a fault, when a terminal voltage of any of the battery cells that are located between the two discharging switches simultaneously turned on changes over a predetermined voltage.

Abstract: A voltage detecting device detects a differential voltage between two input nodes having a non-zero common mode voltage. A differential voltage detecting circuit 5 detects the differential voltage by sampling each voltage of the input nodes and outputs a detection voltage indicating a detection result. A leak canceling circuit generates a compensating current, which flows in opposition to a leak current flowing out from the input nodes in correspondence to an operation of the differential voltage detecting circuit. An operation control part controls the leak canceling circuit to perform or stop a canceling operation. A failure diagnosing part performs a failure diagnosis about the leak canceling circuit based on a first detection value and a second detection value of the detection voltages, which are detected during periods when the leak canceling circuit performs and stops the canceling operation.

Abstract: An assembled battery monitoring system includes: a voltage monitoring apparatus; discharging resistance elements and RC filters that are correspondingly coupled between battery cells of an assembled battery and the voltage monitoring apparatus; and discharging switches disposed in the voltage monitoring apparatus correspondingly to the battery cells. The voltage monitoring apparatus has at least three connection terminals for each of the battery cells. Two of the connection terminals are used to monitor a voltage of a corresponding battery cell through an output terminal of a corresponding RC filter, and at least one of a remainder of the connection terminals is used to form a discharging path of the corresponding battery cell when a corresponding discharging switch is turned on. Each discharging resistance element is disposed on the discharging path at a position that prohibits discharging of charges stored in a capacitor of the corresponding RC filter.

Abstract: A voltage detecting device detects a differential voltage between two input nodes having a non-zero common mode voltage. A differential voltage detecting circuit 5 detects the differential voltage by sampling each voltage of the input nodes and outputs a detection voltage indicating a detection result. A leak canceling circuit generates a compensating current, which flows in opposition to a leak current flowing out from the input nodes in correspondence to an operation of the differential voltage detecting circuit. An operation control part controls the leak canceling circuit to perform or stop a canceling operation. A failure diagnosing part performs a failure diagnosis about the leak canceling circuit based on a first detection value and a second detection value of the detection voltages, which are detected during periods when the leak canceling circuit performs and stops the canceling operation.

Abstract: A route switching circuit includes: a pair of normal detection routes that output voltages of a positive side connection point and a negative side connection point, which are different from each other, in multiple batteries for constituting an assembled battery; and a pair of diagnosis detection routes that output the voltages of the positive side connection point and the negative side connection point, and confirm a connection state of the normal detection routes by using the normal detection routes, which output at least one of a voltage of a positive side battery connected to a positive side from the positive side connection point and a voltage of a negative side battery connected to a negative side from the negative side connection point.