JP6656834B2 - Battery pack - Google Patents

Description

  The present invention relates to a battery pack having a fuse for interrupting current in an abnormal state of the battery.

  A battery pack is provided with a fuse that detects an abnormal state of the battery and cuts off current, thereby improving safety. In order to realize this, a battery pack in which a fuse 93 is connected in series with a battery 91 has been developed as shown in FIG. (See Patent Document 1)

  The above-described battery pack is an abnormality detection circuit that detects an abnormal state of the unit cell 91 and controls a blow switch 94 that blows the fuse 93. The abnormality detection circuit detects an abnormal state of the battery pack and turns on the blow switch 94 to blow the fuse 93. In the battery pack of FIG. 5, a resistance heating element 95 that heats and blows the fuse 93 is arranged near the fuse 93, that is, in a state of being thermally coupled to the fuse 93. The fusing switch 94 is connected to an intermediate connection point 96 of the resistance heating element 95 and an earth line 97. When the blow switch 94 is turned on, a current flows from the battery pack 92 to the resistance heating element 95, and the resistance heating element 95 generates heat by Joule heat to blow the fuse 93. When an excessive current flows through the battery pack 92, the fuse 93 is self-heated by Joule heat and blows.

JP-A-2002-204525

  In the battery pack of FIG. 5, the fuse is blown in an abnormal state of the battery pack to ensure high safety. However, in the battery pack having this structure, the fuse may be blown by mistake during the assembly process. This is because, in the assembling process, the abnormality detection circuit erroneously determines that the assembled battery is in an abnormal state depending on the order in which the circuits are connected. The abnormality detection circuit operates normally when connection of all connection terminals is completed, but normal operation is not guaranteed when some connection terminals are connected. For example, as shown in FIG. 6, in the circuit configuration in which the abnormality detection circuit 80 detects the voltage of each of the cells 91 constituting the battery pack 92 and determines the abnormal state of the cells 91, , The correct voltage of the unit cells 91 cannot be detected in the order of connection. In FIG. 6, when the voltage detection lines 85 connected to the battery pack 92 are connected in the order of A, B, C, and D, the voltage detection circuit 81 normalizes the voltages of the cells B1, B2, and B3. Can be detected. The voltage detection circuit 81 detects the voltage at the point B as the voltage of the cell B1, detects the voltage difference between the point C and the voltage at the point B as the voltage of the cell B2, and detects the voltage difference between the points D and C as the element. This is because it can be detected as the voltage of the battery B3. However, in the assembly process, if point D is connected to voltage detection circuit 81 without connecting B and C after connection at point A, the voltage divided by input resistor 82 is applied to voltage detection circuit 81. Is entered. When the input side of the buffer amplifier 83 is connected to the unit cell 91, the input resistor 82 does not use a high-precision resistor because an error in electric resistance does not cause a voltage detection error of the unit cell 91. Therefore, when the voltage divided by the input resistor 82 is input to the buffer amplifier 83 and detected as the voltage of the unit cell 91, the unbalance of the electric resistance of the input resistor 82 is detected as the voltage of the unit cell 91, The unit cell 91 may be erroneously determined to be an abnormal voltage. This adverse effect can be solved by specifying the order in which the voltage detection lines 85 are connected. However, the voltage detection lines 85 are connected by a connector or connected in a state where components are set in a fixed position in an assembly process. It is always difficult to connect in a fixed order. Therefore, in the assembling process, the abnormality detection circuit 80 may erroneously determine that the assembled battery 92 is in an abnormal state and blow the fuse 93.

  The present invention has been developed to solve this drawback. An important object of the present invention is to provide a battery pack capable of reliably preventing a fuse from being erroneously blown during an assembling process, while having an extremely simple circuit configuration.

  The battery pack of the present invention includes an assembled battery 2 in which a plurality of unit cells 1 are connected in series, positive and negative output terminals 9 connected to the output side of the assembled battery 2, an output terminal 9 and the assembled battery 2. A fuse 3 that is connected between the fuses 1 and blows out when the cell 1 is abnormal and cuts off the current of the battery pack 2; an abnormality detection circuit 4 that detects an abnormal state of the cell 1 and outputs an abnormality signal; A fusing circuit 5 that is controlled by the detection circuit 4 to blow the fuse 3 in an abnormal state of the unit cell 1; The fusing circuit 5 includes an operation check circuit 6 for checking a normal connection state of the battery pack. The operation check circuit 6 checks a normal connection state, and outputs an abnormality signal from the abnormality detection circuit 4. In this state, the blowing circuit 5 blows the fuse 3.

Further , an output switch 7 connected between the output terminal 9 and the battery pack 2 and a control circuit 8 for controlling the output switch 7 to be turned on and off are provided. The control circuit 8 switches the output switch 7 to the on state. , you output a voltage of the output terminal 9 two sets battery 2. The fusing circuit 5 includes a fusing switch 11 and a sub-switch 12 that constitutes an operation check circuit 6 connected in series with the fusing switch 11. The sub-switch 12 is connected between the output switch 7 and the output terminal 9. As a switch that can be switched on by the voltage of the output voltage detection point 10, the sub-switch 12 is switched on by the voltage of the output voltage detection point 10, and when the sub-switch 12 is on, the abnormality detection circuit 4 by detecting the abnormal conditions, it blows the fuse 3 by switching the blown switch 11 to the oN state.

The battery pack according to the present invention includes a fusing circuit 5 including a fusing switch 11 and a sub-switch 12 constituting an operation check circuit 6 connected in series with the fusing switch 11. The sub-switch 12 is turned on by the current of the battery pack 2, and the abnormality detection circuit 4 detects the abnormal state of the unit cell 1 when the sub-switch 12 is on. detecting and, it blows the fuse 3 by switching the blown switch 11 to the oN state.

The battery pack of the present invention includes an output switch 7 connected between the output terminal 9 and the battery pack 2, and a control circuit 8 for turning the output switch 7 on and off. It is switched on, you output a voltage of the output terminal 9 two sets battery 2. The fusing circuit 5 includes a fusing switch 11 and an AND circuit 14 connected to the input side of the fusing switch 11. The fusing circuit 6 includes an operation check circuit 6 that detects an output voltage between the output switch 7 and the output terminal 9. As a circuit for detecting the voltage of 10 and outputting an ON signal to the AND circuit 14, both the operation check circuit 6 and the abnormality detection circuit 4 input the ON signal to the AND circuit 14 and switch the fusing switch 11 to the ON state. It blows the fuse 3 Te.

In the battery pack of the present invention, the fusing circuit 5 includes a fusing switch 11 and an AND circuit 14 connected to the input side of the fusing switch 11. The operation check circuit 6 detects the current of the battery pack 2. Then, as a circuit for outputting an ON signal to the AND circuit 14, both the operation check circuit 6 and the abnormality detection circuit 4 input an ON signal to the AND circuit 14, switch the blowing switch 11 to the ON state, and blow the fuse 3. you.

  In the battery pack of the present invention, the output switch 7 is used as a charge / discharge switch for controlling the charge / discharge current of the battery pack 2, and the control circuit 8 detects overcharge and overdischarge of the battery pack 2, and controls the charge / discharge switch. Circuit.

  In the battery pack of the present invention, the abnormality detection circuit 4 may include a voltage detection circuit 20 that detects a voltage of each unit cell 1 constituting the assembled battery 2 and detects an abnormal state of the unit cell 1. it can.

  The battery pack of the present invention has a feature that the fuse can be reliably prevented from being erroneously blown in the assembling process while having an extremely simple circuit configuration. That is, the battery pack of the present invention is controlled by the abnormality detection circuit, and the blowing circuit for blowing the fuse in an abnormal state of the unit cell has an operation check circuit for checking a normal connection state of the pack battery. This is because the fusing circuit blows the fuse in a state where the operation check circuit checks the normal connection state and outputs an abnormal signal from the abnormality detection circuit.

1 is a circuit diagram of a battery pack according to one embodiment of the present invention. It is a circuit diagram of a battery pack according to another embodiment of the present invention. It is a circuit diagram of a battery pack according to another embodiment of the present invention. It is a circuit diagram of a battery pack according to another embodiment of the present invention. It is a circuit diagram of a conventional battery pack. FIG. 3 is a circuit diagram illustrating an example of an abnormality detection circuit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below illustrate a battery pack for embodying the technical idea of the present invention, and the present invention does not specify the battery pack as follows. Furthermore, this specification does not in any way specify the members indicated in the claims as members of the examples.

  The battery pack shown in the circuit diagrams of FIGS. 1 to 4 is connected between an assembled battery 2 in which a plurality of unit cells 1 are connected in series, and an assembled battery 2 and an output terminal 9, and A fuse 3 that is blown when an abnormality occurs and interrupts the current of the battery pack 2; an abnormality detection circuit 4 that detects an abnormal state of the unit cell 1; and a fuse that is controlled by the abnormality detection circuit 4 and detects an abnormal state of the unit cell 1. And a fusing circuit 5 for fusing 3. The fusing circuit 5 includes an operation check circuit 6 for checking a normal connection state of the battery pack. The operation check circuit 6 checks a normal connection state, and outputs an abnormality signal from the abnormality detection circuit 4. In this state, the fusing circuit 5 blows the fuse 3.

  1 to 4, the output switch 7 is connected between the output terminal 9 and the battery pack 2, and the output switch 7 is controlled on and off by the control circuit 8. In these battery packs, the fusing circuit 5 includes a fusing switch 11.

  1 and 2 includes a sub-switch 12 in which the operation check circuit 6 is connected in series with the fusing switch 11. In the battery pack of FIG. 1, the operation check circuit 6 is a sub-switch 12 composed of an FET, and the voltage of the output voltage detection point 10 is input to the gate of the FET. When the battery pack is normally assembled and the voltage of the output terminal 9 is output to the output voltage detection point 10, the operation check circuit 6 inputs this output voltage as an ON signal to the gate of the FET, The switch 12 is turned on. This pack battery can prevent the fuse 3 from being blown by mistake during the assembly process, while having the simplest circuit configuration. This is because the operation check circuit 6 can be constituted by one FET.

  In the battery pack of FIG. 2, the operation check circuit 6 detects the current flowing through the battery pack 2 and checks that the battery is connected normally. Therefore, the operation check circuit 6 for the battery pack includes a sub-switch 12 connected in series with the fusing switch 11 and a current detection circuit 13 that detects the current of the battery pack 2 and switches the sub-switch 12 to the ON state. Prepare. When the battery pack 2 is assembled normally, that is, normally connected, and connected to the main device, a current flows through the battery pack 2. Therefore, this current is detected, and it is determined that the battery pack 2 has been normally assembled. The circuit 6 switches the sub-switch 12 to the ON state. Even if the abnormality detection circuit 4 outputs an abnormality signal and the fusing switch 11 is turned on in a state where the fuse 3 is not normally connected, the fuse 3 is blown because the sub-switch 12 is off in a state where the connection is not normally performed. It will not be done. Therefore, even if the abnormality detection circuit 4 outputs an abnormality signal to the fusing circuit 5 in the assembling process, the fuse 3 is not blown. The battery pack determines whether or not a normal voltage is output to the output terminal 9 and does not switch the sub-switch 12 to the ON state. Fusing of the fuse 3 can be prevented.

  The fusing circuit 5 of the battery pack of FIG. 3 includes a fusing switch 11 and an AND circuit 14 connected to the input side of the fusing switch 11. The operation check circuit 6 is a circuit that outputs the voltage at the output voltage detection point 10 between the output switch 7 and the output terminal 9 to the AND circuit 14 as an ON signal. In this battery pack, both the operation check circuit 6 and the abnormality detection circuit 4 input an ON signal to the AND circuit 14 and switch the blowing switch 11 to the ON state to blow the fuse 3. In this battery pack, the output switch 7 is turned on in a normal connection state, and the voltage at the output voltage detection point 10 becomes the voltage at the output terminal 9. Therefore, since the circuit for inputting the voltage of the output voltage detection point 10 to the AND circuit 14 can be used as the operation check circuit 6, the operation check circuit 6 can have a very simple circuit configuration.

  The fusing circuit 5 of the battery pack shown in FIG. 4 includes a fusing switch 11 and an AND circuit 14 connected to the input side of the fusing switch 11. The operation check circuit 6 detects the current of the battery pack 2, This is a circuit that outputs an ON signal to the AND circuit 14. In this battery pack, both the operation check circuit 6 and the abnormality detection circuit 4 input an ON signal to the AND circuit 14 and switch the blowing switch 11 to the ON state to blow the fuse 3. When the assembly of the battery pack is completed and a normal connection state is established, and the battery is connected to the main device and a current flows through the battery pack 2, the operation check circuit 6 outputs an ON signal to the AND circuit 14. In the battery pack assembling process, when the normal connection is not completed, no load current flows through the battery pack 2, and the operation check circuit 6 does not output an ON signal to the AND circuit 14 in this state. Therefore, this battery pack is also in a normal connection state after assembly is completed, and only when the abnormality detection circuit 4 outputs an abnormality signal to the AND circuit 14, the fusing switch 11 is switched to the ON state and the fuse is switched to the ON state. Fuse 3

  The assembled battery 2 of the battery pack shown in FIGS. 1 to 4 has two or more unit cells 1 connected in series. The unit cell 1 is a lithium ion battery. The battery pack in which the unit cell 1 is a lithium ion battery is characterized in that it is light and small and can have a large charge / discharge capacity. However, the present invention does not specify a unit cell as a lithium ion secondary battery, and can use any rechargeable battery. An assembled battery 2 in which a plurality of unit cells 1 are connected in series is charged and discharged by passing the same current to the unit cells 1 connected in series, but the electrical characteristics of each unit cell 1 are not necessarily completely. not the same. Therefore, the remaining capacity and voltage of each unit cell 1 become unbalanced as charging and discharging are repeated. The unbalance of the unit cells 1 is set to overcharge or overdischarge a specific unit cell 1. Overdischarging and overcharging of the unit cell 1 increase the deterioration of the unit cell 1 and shorten the life. In order to reduce the deterioration of each unit cell 1, the voltage of the unit cell 1 is detected, and the charging / discharging current is controlled. That is, in a state where the battery pack 2 is charged, any one of the cells 1 is overcharged, or when the voltage becomes higher than the set voltage, the charging is stopped. When the battery is over-discharged or the voltage becomes lower than the set voltage, the discharge is stopped to charge and discharge while protecting each unit cell 1.

  The fuse 3 is connected between the output terminal 9 and the battery pack 2 to protect the battery pack 2 from excessive current. In the battery packs of FIGS. 1 to 4, the resistance heating element 15 is arranged in a thermally coupled state close to the fuse 3. The resistance heating element 15 is connected in parallel with the fuse 3, and connects the intermediate connection point 16 to the fusing circuit 5. The resistance heating element 15 is energized by the battery pack 2 in the on state of the fusing circuit 5 to generate heat and blow the fuse 3. Although not shown, the fusing circuit can be directly connected to the fuse without using a resistance heating element and can be blown. There is no need for the circuit to blow a fuse by directly blowing a blow current, and the fuse can be blown by energizing the resistance heating element, so that the fuse can be blown by reducing the current of the blow circuit. In addition, when the battery pack is in an abnormal state, the fusing circuit is switched to the ON state, and the fuse is blown to improve the safety of the battery pack.

  The abnormality detection circuit 4 detects an abnormal state of the unit cells 1 constituting the assembled battery 2, and outputs an ON signal abnormality signal to the fusing circuit 5 in an abnormal state. The abnormality detection circuit 4 of FIGS. 1 to 4 includes a voltage detection circuit 20 that detects the voltage of each unit cell 1 in order to detect an abnormal state of the battery pack 2. The voltage detection circuit 20 in these figures includes a buffer amplifier 21 for inputting the voltage of each unit cell 1, and the input side of the buffer amplifier 21 is connected to the plus side of the unit cell 1. Further, an input resistor 22 is connected to the input side of the buffer amplifier 21. The input resistor 22 is a resistor having a large electric resistance, for example, a resistor of 1 MΩ or more. The output side of the buffer amplifier 21 is connected to the arithmetic circuit 23. The arithmetic circuit 23 detects the voltage of each unit cell 1 and compares the detected voltage with a preset voltage stored in advance to determine an abnormal state of the unit cell 1. In FIGS. 1 and 2, one abnormality detection circuit 4 is provided for three unit cells 1, but the number of abnormality detection circuits also depends on the number of unit cells 1 connected in series. May increase. For example, when the number of unit cells 1 connected in series is six, the abnormality detection circuit 4 is provided in each of three unit cells 1 (that is, two abnormality detection circuits 4 are provided), and any abnormality detection is performed. When the circuit 4 determines that the unit cell 1 is in an abnormal state, the fusing switch 11 may be turned on.

  The arithmetic circuit 23 detects the voltage of the unit cell 1 from the voltage difference between the voltages input from the respective buffer amplifiers 21. The arithmetic circuit 23 in FIGS. 1 and 2 detects the voltages of the three sets of unit cells 1 from the voltage difference between the points D and C, the potential difference between the points C and B, and the voltage difference between the points B and A. . The arithmetic circuit 23 compares the detected voltage with the set voltage to determine whether or not the state is abnormal. The set voltage is a voltage value at which the unit cell 1 becomes abnormal. Therefore, when the detected voltage is higher or lower than the set voltage, the arithmetic circuit 23 determines that the unit cell 1 is in an abnormal state, and outputs an ON signal for switching the fusing circuit 5 to the ON state.

  The fusing circuit 5 of FIGS. 1 and 2 has a fusing switch 11 and a sub-switch 12 connected in series. The fusing switch 11 and the sub-switch 12 are semiconductor switching elements such as FETs and transistors, and the fusing switch 11 is switched on by an ON signal of an abnormal signal input from the abnormality detecting circuit 4. The sub-switch 12 is switched to an ON state by an ON signal input from the operation check circuit 6.

  1 and 2, the source and the drain of the FET of the fusing switch 11 are connected between the resistance heating element 15 and the ground line 17, and the gate on the input side is connected to the abnormality detection circuit 4. I have. When an ON signal is input to the gate from the abnormality detection circuit 4, the fusing switch 11 is turned on to energize the resistance heating element 15, and the resistance heating element 15 heats and fuses the fuse 3. The fusing switch 11 is kept in the off state in a normal use state in which the on state is not input to the gate, and does not energize the resistance heating element 15.

  The output switch 7 is connected to the battery pack 2 side from an output voltage detection point 10 to which the sub-switch 12 is connected to detect the voltage of the output terminal 9. 1 and 3 are connected between the output voltage detection point 10 and the fuse 3. However, the output switch can be connected between the fuse and the battery pack.

  The output switch 7 is turned on and off to prevent overcharging of the battery pack 2 being charged and overdischarging of the battery pack 2 being discharged, and uses a semiconductor switching element such as an FET or a transistor. Is done. The output switch 7 is a charge / discharge switch for controlling the charge / discharge current of the battery pack 2. The charge switch switches off the charge current to prevent the battery pack 2 from being overcharged. A semiconductor switch such as a transistor or a FET is used as a discharge switch for preventing overdischarge.

  The output switch 7 shown in FIGS. 1 to 4 has two sets of FETs connected in series, one of which is a discharge switch 25 and the other is a charge switch 26. The discharge switch 25 is turned off when the battery pack 2 stops discharging, and the charge switch 26 is turned off when the charging of the battery pack 2 is stopped. Each FET is connected in parallel with a diode 27 that conducts in the opposite direction in the off state. Therefore, even when the discharge switch 25 is in the off state, that is, in the state where the remaining capacity becomes the minimum capacity and the charging is stopped, the charging current can flow, and the remaining capacity becomes the maximum capacity and the charging switch 26 is turned off to perform charging. In this state, a discharge current can flow.

  The control circuit 8 is a safety protection circuit that switches the output switch 7 to the ON state when the battery pack can be used normally. The control circuit 8 includes a detection unit 31 that detects the voltage, current, temperature, and the like of the unit cell 1, a control unit 32 that controls the output switch 7 to be on / off based on the battery information detected by the detection unit 31, A communication unit 33 for transmitting battery information; The detection unit 31 detects a voltage of the current detection resistor 30 connected in series with the battery pack 2 to detect a charge / discharge current.

  The control unit 32 determines the state of the unit cell 1 based on the voltage and temperature of the unit cell 1 detected by the detection unit 31, and turns on the output switch 7 in a state where the battery pack 2 can be normally charged and discharged. The output switch 7 is turned off when the battery pack 2 cannot be used normally. For example, the control unit 32 compares the detected values of the unit cell 1 such as the voltage and temperature detected by the detecting unit 31 and the remaining capacity calculated from the detected current and voltage with a preset setting range. When the value exceeds the set range, the output switch 7 is turned off. The control unit 32 communicates the battery information detected by the detection unit 31 to the main unit via the communication unit 33.

  The control unit 32 that detects the current of the battery pack 2 can be used together with the operation check circuit 6. The control unit 32 detects the current of the battery pack 2 and switches the sub-switch 12 to the ON state in a state where the current is detected (see the dashed line in FIG. 2), or inputs an ON signal to the AND circuit 14 (FIG. 4). In this battery pack, since the control unit 32 is used in combination with the operation check circuit 6, there is no need to provide the operation check circuit 6 as a dedicated circuit, and the circuit configuration can be simplified.

  The battery pack in which the charge switch 26 and the discharge switch 25 connected in series are controlled to be turned on and off by the control circuit 8 has a voltage of the charged unit cell 1 higher than the maximum voltage, or has a remaining capacity of the maximum capacity. If it becomes higher, the charging switch 26 is turned off to interrupt the charging current. When the voltage of the unit cell 1 is lower than the minimum voltage or the remaining capacity is lower than the minimum capacity, the discharge switch 25 is turned off to interrupt the discharge current. When the temperature of the unit cell 1 is higher than the maximum temperature or lower than the minimum temperature, the charge switch 26 and the discharge switch 25 are turned off to stop charging and discharging.

  In the battery packs of FIGS. 3 and 4, an AND circuit 14 is connected to the input side of the fusing switch 11. The AND circuit 14 receives the ON signal of the abnormality detection circuit 4 and the ON signal input from the operation check circuit 6, and switches the fusing switch 11 of the fusing circuit 5 to the ON state. In this battery pack, the fusing switch 11 is turned on to blow the fuse 3 in a state where the ON signal is input from both the abnormality detection circuit 4 and the operation confirmation circuit 6 to the AND circuit 14. Even if the abnormality detection circuit 4 outputs an ON signal, this battery pack is in a state where the ON signal from the operation check circuit 6, that is, the voltage at the output voltage detection point 10 does not rise to the output voltage, or Is not flowing, the fusing switch 11 is not switched to the ON signal. This is because the AND circuit 14 can switch the fusing switch 11 to the ON state only when the ON signal is input to both terminals.

  1 to 4, even if the abnormality detection circuit 4 determines that the voltage of the unit cell 1 is in an abnormal state and outputs an ON signal in the assembling process, the operation confirmation circuit 6 outputs the ON signal. Unless the fuse is output, the fuse 3 is not blown. 1 and FIG. 3, the operation check circuit 6 does not output an ON signal when the voltage at the output voltage detection point 10 does not rise to the output voltage, and the battery packs of FIGS. This is because the operation check circuit 6 does not output an ON signal when no current flows through the battery 2. Therefore, even if the abnormality detection circuit 4 erroneously determines that the assembled battery 2 is in an abnormal state in the assembling process, the fuse 3 is not blown without the operation confirmation circuit 6 outputting an ON signal. When the assembly of the battery pack is completed and the connection state is normal, the operation check circuit 6 outputs an ON signal and switches the sub-switch 12 to the ON state, or outputs an ON signal to the AND circuit 14 to 3 is in a state of being melted. Therefore, in this state, if the abnormality detection circuit 4 determines that the state is abnormal and outputs an ON signal, the fuse 3 is blown. However, the fuse 3 is not blown in a state where a normal connection state is not achieved.

  The above-described battery pack determines the normal connection state by detecting the voltage rise at the output voltage detection point 10 and the current of the battery pack 2. According to the present invention, the operation check circuit 6 determines that the connection state is normal. The elements are not specified as the voltage of the output voltage detection point 10 and the current of the battery pack 2, but all elements that can determine a normal connection state, for example, each unit cell 1 in a state where the battery pack is connected to the main device. The normal connection state can be determined by detecting a voltage change of the battery cell 1 or detecting a temperature change of each unit cell 1 in a state where the unit cell 1 is used by being connected to the main device. When the battery pack is connected to the main unit and used, the voltage and temperature of each battery cell 1 change. However, when each battery cell 1 is not connected properly, the battery cell 1 detected by the abnormality detection circuit 4 is used. Is changed as the voltage dividing ratio of the input resistor 22, and when the cells 1 are normally connected, the voltage of each cell 1 detected by the abnormality detection circuit 4 is always constant. The reason is that the voltage fluctuates due to the imbalance of the electrical characteristics of the unit cell 1. Further, the temperature change of each unit cell 1 in a state where the battery pack is assembled and connected to the main device to discharge the battery pack 2 is higher than that in the case where the current is not passed through the battery pack 2, so that the operation check circuit is provided. 6 can detect whether the battery is in a normal connection state by detecting the battery temperature.

  INDUSTRIAL APPLICABILITY The battery pack of the present invention can prevent a fuse from being blown due to a malfunction in an assembling process, and can improve the yield.

REFERENCE SIGNS LIST 1 unit cell 2 assembled battery 3 fuse 4 abnormality detection circuit 5 blowout circuit 6 operation check circuit 7 output switch 8 control circuit 9 output terminal 10 output voltage detection point 11 blowout switch 12 sub Switch 13 Current detection circuit 14 AND circuit 15 Resistance heating element 16 Intermediate connection point 17 Ground line 20 Voltage detection circuit 21 Buffer amplifier 22 Input resistance 23 Operation circuit 25 Discharge switch 26 Charge switch 27 ... Diode 30 ... Current detection resistor 31 ... Detection unit 32 ... Control unit 33 ... Communication unit 80 ... Abnormality determination circuit 81 ... Voltage detection circuit 82 ... Input resistance 83 ... Buffer amplifier 85 ... Voltage detection line 91 ... Battery 92 ... Battery pack 93 ... Fuse 94 ... Blow-off switch 95 ... Resistance heating element 96 ... Intermediate connection point 97 ... Earth line

Claims (6)

An assembled battery in which a plurality of unit cells are connected in series;
Positive and negative output terminals connected to the output side of the battery pack,
A fuse that is connected between the output terminal and the assembled battery and that is blown when the unit cell is abnormal and cuts off the current of the assembled battery;
An abnormality detection circuit that detects an abnormal state of the unit cell and outputs an abnormality signal;
A fusing circuit controlled by the abnormality detection circuit to blow the fuse in an abnormal state of the unit cell,
The fusing circuit includes an operation check circuit for checking a normal connection state of the battery pack,
The operation check circuit checks a normal connection state, and the blowing circuit blows the fuse in a state where an abnormal signal is output from the abnormal detection circuit,
An output switch connected between the output terminal and the battery pack;
A control circuit that controls the output switch to be on / off,
Wherein the control circuit switches the output switch to the ON state, Ri greens so as to output a voltage of the battery pack to said output terminal,
The fusing circuit includes a fusing switch and a sub-switch that constitutes the operation check circuit connected in series with the fusing switch,
A switch in which the sub-switch is turned on by a voltage at an output voltage detection point between the output switch and the output terminal;
The sub-switch is turned on at the voltage at the output voltage detection point, and in the on-state of the sub-switch, the abnormality detection circuit detects an abnormal state of the unit cell and turns the fusing switch on. A battery pack that is switched to blow the fuse. An assembled battery in which a plurality of unit cells are connected in series;
Positive and negative output terminals connected to the output side of the battery pack,
A fuse that is connected between the output terminal and the assembled battery and that is blown when the unit cell is abnormal and cuts off the current of the assembled battery;
An abnormality detection circuit that detects an abnormal state of the unit cell and outputs an abnormality signal;
A fusing circuit controlled by the abnormality detection circuit to blow the fuse in an abnormal state of the unit cell,
The fusing circuit includes an operation check circuit for checking a normal connection state of the battery pack,
The operation check circuit checks a normal connection state, and the blowing circuit blows the fuse in a state where an abnormal signal is output from the abnormal detection circuit,
The fusing circuit includes a fusing switch and a sub-switch that constitutes the operation check circuit connected in series with the fusing switch,
The sub-switch is a switch that detects the current of the battery pack and is turned on,
The sub-switch is turned on by the current of the battery pack, and in the on-state of the sub-switch, the abnormality detection circuit detects an abnormal state of the unit cell, and switches the fusing switch to the on state. A battery pack configured to blow the fuse. An assembled battery in which a plurality of unit cells are connected in series;
Positive and negative output terminals connected to the output side of the battery pack,
A fuse that is connected between the output terminal and the assembled battery and that is blown when the unit cell is abnormal and cuts off the current of the assembled battery;
An abnormality detection circuit that detects an abnormal state of the unit cell and outputs an abnormality signal;
A fusing circuit controlled by the abnormality detection circuit to blow the fuse in an abnormal state of the unit cell,
The fusing circuit includes an operation check circuit for checking a normal connection state of the battery pack,
The operation check circuit checks a normal connection state, and the blowing circuit blows the fuse in a state where an abnormal signal is output from the abnormal detection circuit,
An output switch connected between the output terminal and the battery pack;
A control circuit that controls the output switch to be on / off,
The control circuit switches the output switch to the ON state, and outputs the voltage of the battery pack to the output terminal ,
The fusing circuit includes a fusing switch, and an AND circuit connected to an input side of the fusing switch,
The operation check circuit is a circuit that detects a voltage at an output voltage detection point between the output switch and the output terminal and outputs an ON signal to the AND circuit.
A battery pack wherein both the operation check circuit and the abnormality detection circuit input an ON signal to the AND circuit, and switch the blowing switch to an ON state to blow the fuse. An assembled battery in which a plurality of unit cells are connected in series;
Positive and negative output terminals connected to the output side of the battery pack,
A fuse that is connected between the output terminal and the assembled battery and that is blown when the unit cell is abnormal and cuts off the current of the assembled battery;
An abnormality detection circuit that detects an abnormal state of the unit cell and outputs an abnormality signal;
A fusing circuit controlled by the abnormality detection circuit to blow the fuse in an abnormal state of the unit cell,
The fusing circuit includes an operation check circuit for checking a normal connection state of the battery pack,
The operation check circuit checks a normal connection state, and the blowing circuit blows the fuse in a state where an abnormal signal is output from the abnormal detection circuit,
The fusing circuit includes a fusing switch, and an AND circuit connected to an input side of the fusing switch,
The operation check circuit detects a current of the battery pack, and outputs an ON signal to the AND circuit.
A battery pack wherein both the operation check circuit and the abnormality detection circuit input an ON signal to the AND circuit, and switch the blowing switch to an ON state to blow the fuse. The battery pack according to claim 1 or 3 ,
The output switch is a charge / discharge switch that controls the charge / discharge current of the battery pack,
A battery pack wherein the control circuit detects overcharge and overdischarge of the battery pack and controls the charge / discharge switch. The battery pack according to any one of claims 1 to 5 ,
A battery pack comprising a voltage detection circuit, wherein the abnormality detection circuit detects a voltage of each unit cell constituting the assembled battery to detect an abnormal state of the unit cell.

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