JP5272978B2 - Battery device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery device capable of detecting a come-off busbar while restraining a structure being complex and restraining cost hike. <P>SOLUTION: The battery device 20 is provided with a CPU 80. When M is a natural number which shows the number of battery cells or less than that and exceeds the number one, if the CPU 80 detects that a fuse is cut at a time in order from a fuse connected to a positive electrode of a battery cell of the number M toward a side of a fuse connected to a positive electrode of a battery cell of the last number, and also, a fuse is cut at a time in order from a fuse connected to a positive electrode of a battery cell of the number M-1 toward a side of a fuse connected to a negative electrode of a first battery cell, the CPU 80 determines that a busbar connecting between the battery cell of the number M and the battery cell of the number M-1 is coming off. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a technology for detecting a bus bar disconnection of a battery device used in, for example, an electric vehicle.

  An electric vehicle or a hybrid vehicle includes a battery device as a driving source of a motor for traveling the vehicle. The battery device includes a housing and a plurality of battery modules accommodated in the housing. The battery module includes a plurality of battery cells using, for example, one secondary battery as a battery cell. These battery cells are electrically connected in series by a bus bar. The bus bar is fastened and fixed to each battery cell with, for example, a bolt and a nut.

  For example, when the fixing structure for fixing the bus bar to the battery cell is loosened, for example, the nut is loosened, the bus bar may be detached from the battery cell. When the bus bar is detached, it becomes impossible to supply electric power from the battery device to the outside. For this reason, the work which fixes the removed bus bar to a battery cell again is needed.

  However, since the battery module is accommodated in the housing, it is relatively difficult to identify the bus bar that has been removed. For this reason, a technique for identifying a disconnected bus bar has been proposed.

  In this type of technology, a transmitter / receiver capable of transmitting multi-wavelength light while sandwiching an optical fiber provided with a plurality of diffraction gratings between a bus bar and a bolt is used. The transmitter / receiver includes a sensor for detecting multi-wavelength light in the optical fiber and detecting reflected light. The light reflected in the optical fiber varies depending on the state of the internal diffraction grating.

  When the bolt is loosened, the pressure applied to the optical fiber is reduced, and the distance between the diffraction gratings in the optical fiber is shortened. As a result, the reflected light detected by the sensor of the transceiver changes. The transceiver detects the looseness of the bolt from the change in the reflected light and also detects the bus bar that has been removed (see, for example, Patent Document 1).

  However, in the technique disclosed in Patent Document 1, an optical fiber and a transceiver including a sensor are required to detect a disconnected bus bar, so that the structure becomes complex and the cost tends to increase. .

  On the other hand, as a battery device, a structure is proposed in which each battery module includes a battery monitoring device that detects each battery cell. The battery monitoring device includes, for example, a voltage measurement circuit such as an A / D converter, and a CPU that determines the state of each battery cell based on a detection value obtained by the voltage measurement circuit.

  The voltage detection circuit is electrically connected to each battery cell via a fuse, and can measure the voltage of each battery cell. Adjacent fuses in the module are connected by a diode in order to protect the voltage measuring circuit from an excessive reverse voltage generated when the bus bar is removed.

  When the bus bar is disconnected, the load current bypasses the disconnected bus bar and flows through the fuse and the diode, and the fuse is cut (blown), so that the influence of the reverse voltage on the voltage measurement circuit can be reduced.

JP 2008-241421 A

  However, even a battery device having the above-described structure requires a structure using a sensor or the like as disclosed in Patent Document 1 in order to specify a disconnected bus bar. As a result, the cost may be increased.

  An object of the present invention is to provide a battery device capable of specifying a bus bar that has been removed by suppressing the complexity of the structure and suppressing an increase in cost.

  The battery device according to claim 1 is a battery device including at least one battery module. The battery module includes a plurality of battery cells, a bus bar that is provided between each of the battery cells and connects the first to last battery cells in series, and a battery that monitors each of the battery cells. A monitoring device. The battery monitoring device is provided between the voltage measuring unit that measures the voltage of each battery cell, the negative electrode of the first battery cell and the voltage measuring unit, and connects the negative electrode to the voltage measuring unit. A plurality of fuses provided between each positive electrode of each battery cell and the voltage measuring unit, each of which connects the positive electrode to the voltage measuring unit, and a pair connected to both electrodes of the first battery cell. Connected between the connecting portions of the fuse and the voltage measuring portion to connect the connecting portions, and connected to the positive electrodes of the two battery cells arranged in order, the connecting portion of the fuse to the voltage measuring portion And a plurality of diodes that are provided in between to connect the connection units, and a determination unit that determines the state of each battery cell based on the detection result of the voltage measurement unit. The diode provided between the fuses connected to both poles of the first battery cell is provided such that the fuse side connected to the positive electrode is the forward tip side. The diode provided between the fuses connected to the positive electrodes of the two battery cells arranged in order is provided such that the fuse side connected to the positive electrode of the battery cell in the rear is the forward end side in the forward direction. It is done. The determination unit is configured such that when the natural number that is equal to or less than the number indicating the number of the battery cells and exceeds 1 is M, the fuse connected to the battery cells from the Mth to the last is the Mth battery cell. Are sequentially cut from the fuse connected to the positive electrode to the fuse side connected to the positive electrode of the last battery cell, and the first to M−1th battery cells are cut. The fuses to be connected were cut one by one from the fuse connected to the positive electrode of the M-1th battery cell one by one toward the fuse side connected to the negative electrode of the first battery cell. When this is detected, it is determined that the bus bar connecting the Mth battery cell and the M−1th battery cell is disconnected.

  A battery device according to a second aspect is the battery device according to the first aspect, wherein a plurality of the battery modules are provided. By providing inter-module connection bus bars between the battery modules, the first to last battery modules are connected in series in order. The inter-module connection bus bar connects the last battery cell of the battery module in the previous order and the first battery cell of the battery module in the rear order among the two battery modules arranged in order. To do.

  The battery device according to claim 3 is the battery device according to claim 2, wherein the two battery modules arranged in order are connected to the positive electrode of the last battery cell of the previous battery module in order. Between the modules that connect the connecting part of the fuse with the voltage measuring part and the connecting part of the fuse with the voltage measuring part connected to the negative electrode of the first battery cell of the battery module in the rear order. A connection diode; and a battery management unit that is connected to each of the determination units of the plurality of battery modules and monitors each of the battery modules. The inter-module connection diode is provided such that the battery module side in the rear of the two battery modules to which the inter-module connection diode is connected is the forward end side in the forward direction, and the battery management unit is The fuse connected to the battery cell in the last battery module from the Nth battery module, when N is a natural number that is less than or equal to the number indicating the number of the plurality of battery modules and exceeds 1, One by one from the fuse connected to the negative electrode of the first battery cell of the Nth battery module toward the fuse connected to the positive electrode of the last battery cell of the last battery module. Disconnected and the first battery module The fuse connected to the battery cell in the (N−1) th battery module from the fuse connected to the positive electrode of the (N−1) th last battery cell is the first of the first battery module. The inter-module connection bus bar that connects the Nth battery module and the N−1th battery module when it is detected that the fuses are sequentially cut one by one toward the fuse connected to the negative electrode of the battery cell. It is determined that has come off.

  The battery device according to claim 4 is the battery device according to claim 3, wherein the battery module is connected to the inter-module connection diode between two battery modules arranged in order, and the forward direction of the inter-module connection diode is the forward direction. A Zener diode that is reverse to the forward direction is provided.

  In the battery device according to claim 1 of the present application, when one bus bar is removed, the fuses on both sides of the bus bar are sequentially cut one by one. The determination unit can detect the disconnected bus bar without requiring a separate sensor or the like by detecting such a tendency of the fuse to be cut.

  As a result, it is possible to provide a battery device that can identify a disconnected bus bar while suppressing the complexity of the structure and suppressing an increase in cost.

  In the battery device according to claim 2 of the present application, even in a structure including a plurality of battery modules, a battery device capable of specifying a disconnected bus bar is prevented from becoming complicated in structure as in claim 1. At the same time, the increase in cost can be suppressed and provided.

  In the battery device according to claim 3 of the present application, the battery device that can identify the disconnected bus bar, even in the structure including the inter-module connection diode that connects the battery modules, It is possible to provide a structure that suppresses a complicated structure and suppresses an increase in cost. Furthermore, the disconnected module connection bus bar can be detected.

  In the battery device according to claim 4 of the present application, the number of fuses to be cut can be reduced by connecting a Zener diode to the inter-module connection diode.

Schematic which shows an electric vehicle provided with the battery apparatus which concerns on the 1st Embodiment of this invention. Schematic which expands and shows the battery apparatus shown in FIG. Schematic which expands and shows the battery apparatus shown in FIG. Schematic which expands and shows the battery apparatus shown in FIG. 3 is a flowchart showing an example of the operation of the CPU shown in FIG. 1. Schematic which shows the battery apparatus which concerns on the 2nd Embodiment of this invention. 7 is a flowchart showing an example of the operation of the CPU shown in FIG. 7 is a flowchart showing an example of the operation of the BMU shown in FIG. Schematic which shows the battery apparatus which concerns on the 3rd Embodiment of this invention.

  A battery device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram showing an electric vehicle 10 including a battery device 20 of the present invention. The battery device 20 is an example of the battery device of the present invention. The battery device 20 is not limited to being provided in the electric vehicle 10. For example, it may be provided in a hybrid vehicle.

  As shown in FIG. 1, an electric vehicle 10 includes a pair of front wheels 11, a pair of rear wheels 12, a motor 13 that drives the rear wheels 12, a battery device 20 that supplies power to the motor 13, and a display device 100. And. The electric vehicle 10 is, for example, a rear wheel drive, and a motor 13 is connected to the rear wheel 12 via a differential gear 14 and the like. For this reason, when the motor 13 is driven, the rear wheel 12 rotates, and thus the electric vehicle 10 can run.

  The battery device 20 includes a housing 21, a plurality of battery modules accommodated in the housing 21, and a BMU (Buttery Management Unit) 90. In the present embodiment, as an example, first to third battery modules 22, 23, and 24 are provided. Note that the number of battery modules is not limited to three. A plurality of other battery modules may be provided. The first to third battery modules 22 to 24 are examples of battery modules referred to in the present invention.

  The first to third battery modules 22 to 24 are electrically connected in series in order. The first to third battery modules 22 to 24 are sequentially arranged in the direction in which the load current I flows.

  The first to third battery modules 22 to 24 may have the same structure. Therefore, in the present embodiment, the second battery module 23 will be described as a representative. In FIG. 1, the structure of the 2nd battery module 23 is shown concretely, and the structure of the 1st, 3rd battery modules 22 and 24 is abbreviate | omitted and shown with the dashed-two dotted line. In the figure, the first to third battery modules 22 to 24 are arranged in order from right to left.

  The second battery module 23 includes a module housing 30, a plurality of battery cells accommodated in the module housing 30, and a battery monitoring device 31. In the figure, the battery monitoring device 31 is surrounded by a one-dot chain line.

  In the present embodiment, first to fourth battery cells 32, 33, 34, and 35 are provided as an example of the plurality of battery cells. The 1st-4th battery cells 32-35 are the lithium ion batteries which are secondary batteries as an example, Comprising: For example, it is 4V (volt). The first to fourth battery cells 32 to 35 are electrically connected in series with each other in order. In other words, the first to fourth battery cells 32 to 35 are connected in series in the direction in which the load current I flows. Note that the number of the plurality of battery cells is not limited to four. Other plural numbers such as five or six may be used.

  An electrical connection structure of the first to fourth battery cells 32 to 35 will be described. The first battery cell 32 and the second battery cell 33 are electrically connected to each other by a first bus bar 36. The first bus bar 36 is fastened and fixed to the first and second battery cells 32 and 33 by nuts, for example. The first battery cell 32 is the first battery cell referred to in the present invention.

  The second battery cell 33 and the third battery cell 34 are electrically connected to each other by a second bus bar 37. The second bus bar 37 is fastened and fixed to the second and third battery cells 33 and 34 by nuts, for example.

  The third battery cell 34 and the fourth battery cell 35 are electrically connected to each other by a third bus bar 38. The third bus bar 38 is fastened and fixed to the third and fourth battery cells 34 and 35 by nuts, for example.

  The last battery cell referred to in the present invention indicates the battery cell arranged last among a plurality of battery cells connected in series in order. In the present embodiment, the fourth battery cell 35 is the final battery cell referred to in the present invention.

  The battery monitoring device 31 monitors each battery cell. The battery monitoring device 31 includes a voltage measurement circuit 50, a plurality of fuses, a plurality of diodes, and a CPU (Central Processing Unit) 80. The battery monitoring device 31 is an example of a battery monitoring device referred to in the present invention.

  The voltage measurement circuit 50 uses an A / D converter as an example in the present embodiment, and detects a voltage input via a fuse described later. The voltage measurement circuit 50 is an example of a voltage measurement unit referred to in the present invention.

  The plurality of fuses allow the voltage measurement circuit 50 to detect the voltages of the first to fourth battery cells 32 to 35 and the positive electrode P of each of the battery cells 32 to 35 and the negative electrode M of the first battery cell 32. Is electrically connected to the voltage measuring circuit 50. In the present embodiment, first to fifth fuses 61 to 65 are used as an example of a plurality of fuses.

  The first fuse 61 electrically connects the negative electrode M of the first battery cell 32 to the voltage measurement circuit 50. Specifically, one end of the first fuse 61 is connected to the negative electrode M of the first battery cell 32, and the other end is connected to the first connection portion 51 of the voltage measurement circuit 50.

  The second fuse 62 electrically connects the positive electrode P of the first battery cell 32 to the voltage measurement circuit 50. Specifically, one end of the second fuse 62 is connected to the positive electrode P of the first battery cell 32, and the other end is connected to the second connection part 52 of the voltage measurement circuit.

  The third fuse 63 electrically connects the positive electrode P of the second battery cell 33 to the voltage measurement circuit 50. Specifically, one end of the third fuse 63 is connected to the positive electrode P of the second battery cell 33, and the other end is connected to the third connection portion 53 of the voltage measurement circuit 50.

  The fourth fuse 64 electrically connects the positive electrode P of the third battery cell 34 to the voltage measurement circuit 50. Specifically, one end of the fourth fuse 64 is connected to the positive electrode P of the third battery cell 34, and the other end is connected to the fourth connection portion 54 of the voltage measurement circuit 50.

  The fifth fuse 65 electrically connects the positive electrode P of the fourth battery cell 35 to the voltage measurement circuit 50. Specifically, one end of the fifth fuse 65 is connected to the positive electrode P of the fourth battery cell 35, and the other end is connected to the fifth connection portion 55 of the voltage measurement circuit 50.

  The plurality of diodes are provided to prevent the voltage measurement circuit 50 from being damaged by a reverse voltage generated when the bus bar is removed due to loosening of the nut or the like. The diode is provided between the connection portion between the fuse connected to the positive and negative electrodes P and M of the first battery cell and the voltage measurement circuit. Further, the diode is provided between the connection portion between the fuse connected to the positive electrode P of two battery cells arranged in sequence and the voltage measurement circuit. In the present embodiment, first to fourth diodes 71 to 74 are provided as an example of a plurality of diodes.

  The first diode 71 is provided between the first and second connection portions 51 and 52, and is connected to the first and second connection portions 51 and 52. The second diode is provided between the second and third connection portions 52 and 53, and is connected to the second and third connection portions 52 and 53. The third diode 73 is provided between the third and fourth connection portions 53 and 54, and is connected to the third and fourth connection portions 53 and 54. The fourth diode 74 is provided between the fourth and fifth connection portions 54 and 55, and is connected to the fourth and fifth connection portions 54 and 55.

  The first diode 71 is arranged such that the second fuse 62 side connected to the positive electrode P of the first battery cell 32 is the forward end side in the forward direction.

  In the second to fourth diodes 72 to 74, the fuse side connecting the positive electrode P of the battery cell in the rear order and the voltage measurement circuit 50 among the fuses connected to the third to fifth connection parts 53 to 55 is forward. It is arrange | positioned so that it may become the front end side. In addition, as above-mentioned that the order said here is back, the 1st-4th battery cells 32-35 are located in order, and show a back side relatively along this order.

  Specifically, the second diode 72 is arranged such that the third connection portion 53 is the forward end. The third diode 73 is arranged such that the fourth connection portion 54 is the forward end. The fourth diode 74 is arranged such that the fifth connection portion 55 is the forward end.

  The protection operation for the voltage measurement circuit 50 by the first to fourth diodes 71 to 74 and the first to fifth fuses 61 to 65 will be described.

  FIG. 2 is an enlarged schematic diagram showing the battery device 20 shown in FIG. FIG. 2 shows a state at the moment when the second bus bar 37 comes off as an example. Here, the term “disconnected” means that the bus bar connecting the two battery cells arranged in sequence is disconnected from at least one of these two bus bars, and the electrical connection between them is cut off.

  In a state where the second bus bar 37 is not detached, in the third and fourth connection portions 53 and 54, the fourth connection portion 54 is at a higher potential than the third connection portion 53. However, when the second bus bar 37 is detached, an excessive reverse voltage is generated in which the third connection portion 53 is at a high potential with respect to the fourth connection portion 54.

  For this reason, as shown by arrows in the figure, the flow of the load current I is indicated by an arrow, so that the load current I bypasses the second bus bar 37 that has been disconnected, and the third and fourth fuses 63 and 64 and the third diode. 73. Since the load current I flows in this manner, the load current does not flow into the voltage measurement circuit 50, so that the failure of the voltage measurement circuit 50 is suppressed.

  Further, when the load current I flows through the third and fourth fuses 63 and 64, the third and fourth fuses 63 and 64 are blown (an example of cutting) by the load current I. FIG. 3 shows a state where the third and fourth fuses 63 and 64 are melted. As shown in FIG. 3, when the third and fourth fuses 63 and 64 are blown, the load current I is supplied to the second and fifth fuses 62 and 64 disposed on both sides of the third and fourth fuses 63 and 64, respectively. 65 and the second to fourth diodes 72 to 74. Thereafter, the second and fifth fuses 62 and 65 are blown.

  The first to fifth fuses 61 to 65 are blown against a large current (load current I) due to a reverse voltage, but are not blown when the first to third bus bars 36 to 38 are not detached.

  FIG. 4 shows a state in which the second and fifth fuses 62 and 65 are blown. When the second and fifth fuses 62 and 65 are melted, the current path through which the load current I flows in the battery device 20 is broken.

  When the load current I flows as described above, even if any of the bus bars is disconnected, the load current I does not flow to the voltage measurement circuit 50 and the flow of the load current I itself stops. This suppresses the voltage measurement circuit 50 from being damaged.

  When a fuse is cut due to one of the bus bars coming off, the fuse in the battery module is cut along one trend as described above. This tendency will be described.

  When one of the bus bars is removed from the battery module, the fuse connected to the last battery cell from the battery cell in the rear order among the two battery cells connected to the removed bus bar is the battery in the rear order. The fuses connected to the cells are cut one by one in order from the fuse connected to the last battery cell. In this case, the battery cell whose order is later is the Mth battery cell according to the present invention, and the battery cell whose order is earlier is the M-1th battery cell according to the present invention.

  Further, of the two battery cells arranged in the above order from the fuse connected to the first battery cell, the fuse connected to the battery cell in the previous order is 1 from the fuse connected in order to the previous battery cell. One by one is cut in order toward the fuse connected to the second battery cell.

  Further, in the plurality of battery cells arranged in order, the fuses positioned in a symmetrical order with the removed bus bar as a boundary are cut at the same time (concept including substantially the same time). The fuses located in a symmetrical order here are fuses connected to the positive electrodes P of the same number of battery cells counted from the disconnected bus bar.

  For example, when the second bus bar 37 that connects the second battery cell 33 and the third battery cell 34 is disconnected, the combination of fuses in the symmetric order with respect to the second bus bar 37 is one. A combination of the third and fourth fuses 63 and 64 connected to the positive electrodes P of the second and third battery cells 33 and 34 as the second battery cell and the first and fourth batteries as the second battery cell The second and fifth fuses 62 and 65 are connected to the positive electrode P of the cells 32 and 33.

  Since the first battery cell 32 has a fuse connected to each of the positive and negative electrodes P and M, even if the fuse is located in the same order with a certain bus bar as a boundary, the first battery cell 32 If it is included, it is not a fuse connected to the positive electrode of the same number of battery cells counted from the one bus bar.

  This point will be described. When the first bus bar 36 is disconnected, the positive polarity P of the first and second battery cells 32 and 33, which are the first battery cells, can be used as a combination of the fuses in the symmetrical order with respect to the first bus bar 36. A combination of the second and third fuses 62, 63 connected to the fourth fuse 64, a fourth fuse 64 connected to the positive electrode P of the third battery cell 34 which is the second battery cell, and the first first This is a first fuse 61 connected to the negative electrode M of one battery cell 32. Thus, the number of battery cells counted from the bus bar is shifted.

  The voltage measurement circuit 50 detects a voltage value input through the first to fifth fuses 61 to 65.

  Next, the description returns to the configuration of the battery device 20. The CPU 80 is connected to the voltage measurement circuit 50 and determines the states of the first to fourth battery cells 32 to 35 based on the detection result of the voltage measurement circuit 50. The CPU 80 is an example of a determination unit referred to in the present invention. As an example of the operation of the CPU 80, the potential difference between the first and second fuses 61 and 62 (the voltage of the first battery cell 32) detected by the voltage measurement circuit 50 is compared with the voltage of another battery cell. Then, the state of the first battery cell 32 is determined. This operation is the same for other battery cells. Note that the determination operation of the CPU 80 is not limited to this, and the state of each battery cell may be determined from other information.

  The first and third battery modules 22 and 24 have the same structure as the second battery module 23 as described above.

  Next, connection between modules will be described. The first battery module 22 and the second battery module 23 are connected to each other, and the second battery module 23 and the third battery module 24 are connected to each other.

  Specifically, the first battery cell 32 that is the first of the second battery modules 23 is connected to the fourth battery cell 35 that is the last of the first battery modules 22 for the first inter-module connection. The bus bars 40 are electrically connected to each other. The fourth battery cell 35 which is the final version of the second battery module 23 is connected to the first battery cell 32 which is the first of the third battery module 24 by the second inter-module connection bus bar 41. Electrically connected.

  The first and second inter-module connection bus bars 40 and 41 are examples of the inter-module connection bus bar referred to in the present invention. By connecting the battery modules in series with each other, all the battery cells in the battery device 20 are connected in series.

  The BMU 90 is connected to each CPU 80 of the first to third battery modules 22 to 24 and monitors each battery module 22 to 24. As an example of monitoring, the BMU 90 detects the remaining amount of power of the battery device 20 and displays the remaining amount of power of the battery device 20 on a fuel gauge (not shown) provided in an instrument panel (not shown). . Further, based on the remaining amount of power of the battery device 20, a calculation is made of how much the motor 13 can output.

  For example, when any bus bar in the battery device 20 is removed, the display device 100 can display the removed bus bar. Specifically, the display device 100 is connected to the BMU 90, and the BMU 90 displays on the display device 100 a bus bar that has been removed based on information from each CPU 80.

  The operator can identify the disconnected bus bar by checking the display device 100. Therefore, the operator can efficiently work to fix the removed bus bar to the battery cell again. The display device 100 is an example of a means for notifying the operator of the bus bar that has been removed. For this reason, the means (device) used for notifying the operator of the removed bus bar is not limited to the display device 100.

  Next, the operation of the battery device 20 will be described.

  In the first to third battery modules 22 to 24, each CPU 80 grasps the voltage value of the first to fourth battery cells 32 to 35 based on the detection value of the voltage measurement circuit 50, and the first to fourth battery modules 22 to 24. The state of the battery cells 32 to 35 is determined. And the state of each battery cell is transmitted to BMU90. The BMU 90 detects the remaining amount of power of the entire battery device 20 from the state of the first to third battery modules 22 to 24 transmitted from each CPU 80, and detects how much the motor 13 can output.

  Next, as an example of the operation when any of the bus bars is removed, the operation of the battery device 20 when the second bus bar 37 of the second battery module 23 is removed will be described. In the present embodiment, the third and fourth battery cells 34 and 35 connected to each other by the second bus bar 37 are the M, M−1th battery cells. FIG. 5 is a flowchart showing an example of the operation of the CPU 80. The operation of the CPU 80 of the second battery module 23 will be described with reference to FIG.

  As shown in FIG. 5, the CPU 80 detects whether any of the first to third bus bars 36 to 38 is disconnected based on the detection result transmitted from the voltage measurement circuit 50. Specifically, the disconnected bus bar is detected by detecting the cut fuse and determining the tendency of the fuse to be cut. Note that the flowchart shown in FIG. 5 is a part of the operation of the CPU 80 and is periodically performed.

  As shown in step ST1, the CPU 80 determines whether or not there is a blown fuse among the first to fifth fuses 61 to 65. If there is a fuse for which no voltage is input to the voltage measurement circuit 50 among the first to fifth fuses 61 to 65, the CPU 80 determines that this fuse is blown.

  In this embodiment, first, as shown in FIG. 2, since the load current I passes through the third and fourth fuses 63 and 64, the third and fourth fuses 63 and 64 are cut. No voltage is input to the voltage measurement circuit 50 through the fuses 63 and 64. The CPU 80 determines that the third and fourth fuses 63 and 64 are cut. Then, the process proceeds to step ST2.

  In step ST2, the CPU 80 determines whether or not the blown fuse detected in step ST1 is a pair of fuses connected to the positive electrodes P of two battery cells arranged in order. In the present embodiment, the third and fourth fuses 63 and 64 are fused at the same time (concept including substantially the same time).

  Since the third and fourth fuses 63 and 64 are fuses connected to the positive electrodes P of the second and third battery cells 34 and 35, which are two battery cells arranged in order, the CPU 80 has two It is detected that the fuse connected to the positive electrode P of the battery cell is blown. Then, the process proceeds to step ST3.

  In addition, when the fuse connected to the positive electrode P of two battery cells arranged in order is not blown, the process proceeds to step ST4. If the fuses connected to the positive electrodes P of two battery cells arranged in sequence are not cut at the same time (concept including almost the same time), for example, if only one fuse is cut, the fuse is cut off due to the bus bar being disconnected Instead, it is determined that the fuse has blown due to a failure in the voltage measurement circuit 50.

  After step ST3, the blown fuse is specified. First, in step ST3, it is determined whether or not the second and third fuses 62 and 63 are cut. In the present embodiment, first, since the third and fourth fuses 63 and 64 are cut, the process proceeds to step ST5.

  In step ST5, it is determined whether or not the third and fourth fuses 63 and 64 are cut at the same time (concept including substantially the same time). In the present embodiment, since the third and fourth fuses 63 and 64 are fused at the same time (a concept including substantially the same time), the process proceeds to step ST6.

  In step ST6, it is next determined whether or not the second and fifth fuses 62 and 65 are blown. In the present embodiment, as shown in FIG. 3, after the third and fourth fuses 63 and 64 are cut, the load current I flows through the second and fifth fuses 62 and 65. For this reason, as shown in FIG. 4, following the 3rd and 4th fuses 63 and 64, the 2nd and 5th fuses 62 and 65 are blown out simultaneously (concept including substantially simultaneous).

  In the present embodiment, as described above, the second and fifth fuses 62 and 65 are cut simultaneously (concept including substantially the same) following the third and fourth fuses 63 and 64. It is detected that the fuses 62 and 65 of 2 and 5 are cut. Then, the process proceeds to step ST7.

  In step ST <b> 7, the CPU 80 determines that the second bus bar 37 has been removed from the determination result, and transmits the determination result to the BMU 90. Based on the result transmitted from the CPU 80, the BMU 90 displays on the display device 100 that the second bus bar 37 of the second battery module 23 has been removed.

  Thus, when a certain bus bar is disconnected, the fuse connected to the last battery cell from the fuse connected to the battery cell in the order of the two battery cells connected to the disconnected bus bar is: The fuses connected to the rear battery cell are cut one by one from the fuse connected to the last battery cell.

  Further, the fuse connected to the battery cell in the previous order among the two battery cells arranged in sequence from the fuse connected to the first battery cell is the fuse connected to the positive electrode P of the previous battery cell. To the fuse connected to the first battery cell, one by one in order.

  Further, in the plurality of battery cells arranged in order, the fuses connected to the battery cells positioned in a symmetrical order with the removed bus bar as a boundary are disconnected at the same time (concept including substantially the same time).

  The CPU 80 identifies the bus bar that has been disconnected by detecting the tendency of the fuse to be cut as described above.

  In the present embodiment, the case where the second bus bar 37 is removed has been described, but the same applies to other bus bars.

  For example, when the first bus bar 36 is disconnected, the load current I first passes through the second and third fuses 62 and 63, so that the second and third fuses 62 and 63 are simultaneously (concept including substantially the same). Disconnected. Therefore, the CPU 80 proceeds from step ST3 to step ST8.

  In step ST <b> 8, the CPU 80 determines whether the first and fourth fuses 61 and 64 are blown after the second and third fuses 62 and 63. When the second and third fuses are cut, the load current I then flows through the first and fourth fuses 61 and 64. Therefore, the first and fourth fuses 61 and 64 are then cut.

  When the first bus bar 36 is disconnected, the CPU 80 detects the disconnection of the first and fourth fuses 61 and 64 following the disconnection of the second and third fuses 62 and 63, and then step ST9. Proceed to

  In step ST9, the CPU 80 determines that the first bus bar 36 has been disconnected, and transmits the determination result to the BMU 90. Based on the transmission result from the CPU 80, the BMU 90 displays on the display device 100 that the first bus bar 36 of the second battery module 23 has been removed.

  For example, when the third bus bar 38 is disconnected, the load current I first flows through the fourth and fifth fuses 64 and 65. For this reason, first, the fourth and fifth fuses 64 and 65 are cut. Therefore, the CPU 80 detects that the fourth and fifth fuses 64 and 65 have been cut. Then, the process proceeds from step ST10 to step ST11.

  In step ST11, the CPU 80 determines whether another fuse is blown after the fourth and fifth fuses 64 and 65. In the present embodiment, the fifth fuse 65 is arranged at the end of the current path 300 through which the load current I flows in the battery module. Therefore, when the fifth fuse 65 is cut, the flow of the load current I Stops. For this reason, when the third bus bar 38 is removed, the fuses other than the fourth and fifth fuses 64 and 65 are not blown.

  When the third bus bar 38 is cut, the CPU 80 detects that other fuses are not cut. Then, the process proceeds to step ST12.

  In step ST12, the CPU 80 determines that the third bus bar 38 has been disconnected, and transmits the determination result to the BMU 90. The BMU 90 displays on the display device 100 that the third bus bar 38 of the second battery module 23 has been removed based on the transmission result from the CPU 80.

  If it is determined in step ST6 that the next blown fuse is not the second and fifth fuses 62 and 65, the disconnection of the third and fourth fuses 63 and 64 is not caused by the disconnection of the bus bar. The process proceeds to step ST4.

  Similarly, in step ST8, when it is detected that the next blown fuse is not the first or fourth fuse 61 or 64, the second or third fuse 62 or 63 is cut off because the bus bar is disconnected. Since it is not a cause, it progresses to step ST4.

  Similarly, if it is detected in step ST11 that any of the fuses has been cut, the process proceeds to step ST4.

  In the CPU 80 of the first and third battery modules 22 and 24 in which neither bus bar is detached, the process proceeds from step ST1 to the end.

As described above, the CPU 80 can identify the disconnected bus bar without requiring a separate sensor or device by detecting the tendency of the fuse to be cut when the bus bar is disconnected. For this reason, the battery device 20 can detect a bus bar that has been removed by suppressing the complexity of the structure and suppressing an increase in cost.

  Next, a battery device according to a second embodiment of the present invention will be described with reference to FIGS. In addition, the structure which has a function similar to 1st Embodiment attaches | subjects the same code | symbol as 1st Embodiment, and abbreviate | omits description. In the present embodiment, a fourth battery module 25 is further provided, and the battery modules are connected by an inter-module connection diode. Other structures may be the same as those in the first embodiment. The different structure will be described.

  FIG. 6 is a schematic diagram showing the battery device 20 of the present embodiment. The battery device 20 is mounted on the electric vehicle 10 as in the first embodiment. In the present embodiment, as an example, the battery device 20 includes a fourth battery module 25 in addition to the first to third battery modules 22 to 24. The structure of the fourth battery module 25 may be the same as the structure of the first to third battery modules 22 to 24.

As shown in FIG. 6, the fourth battery module 25 includes a third battery module 24.
Are electrically connected in series. Specifically, the fourth battery cell 35 that is the last battery cell of the third battery module 24 and the first battery cell 32 that is the first battery cell of the fourth battery module 25 are: The third inter-module connection bus bar 42 is electrically connected in series. The third inter-module connection bus bar 42 is an example of the inter-module connection bus bar referred to in the present invention.

  In the first to fourth battery modules 22 to 25 connected in series in order, an inter-module connection diode is provided between two battery modules arranged in order.

  This point will be specifically described. In the two battery modules arranged in order, the connection part between the fuse and the voltage measuring circuit 50 connected to the positive electrode P of the last battery cell in the battery module in the previous order, and 1 in the battery module in the rear order. The inter-module connection diode is electrically connected to the junction between the fuse connected to the negative electrode M of the second battery cell and the voltage measurement circuit. The inter-module connection diode is provided such that the battery module side in the rear order is the front end side in the forward direction.

  In the present embodiment, the first inter-module connection diode 111 is electrically connected directly to the fifth connection portion 55 of the first battery module 22 and the first connection portion 51 of the second battery module 23. Has been. The second inter-module connection diode 112 is electrically connected to the fifth connection portion 55 of the second battery module 23 and the first connection portion 51 of the third battery module 24. The third inter-module connection diode 113 is electrically connected to the fifth connection portion 55 of the third battery module 24 and the first connection portion 51 of the fourth battery module 25.

  In the present embodiment, when the inter-module connection bus bar that connects the battery modules is disconnected, the disconnected inter-module connection bus bar can be specified. This point will be described.

  First, the operation of the battery device 20 will be described. 7 and 8 are flowcharts illustrating an example of the operation of the battery device 20. FIG. 7 shows an example of the operation of each CPU 80. FIG. 8 shows an example of the operation of the BMU 90. The operation of specifying the removed bus bar when any of the bus bars in each battery module is removed is the same as in the first embodiment.

  Next, the operation when the inter-module connection bus bar is removed will be described by taking as an example the case where the second inter-module connection bus bar 41 is removed. In the present embodiment, the second and third battery modules 23 and 24 connected by the second inter-module connection bus bar 41 are the N, N-1th battery modules referred to in the present invention.

  First, the tendency of the fuse of the battery device 20 to be cut when the second inter-module connection bus bar 41 is removed will be described.

  When the second inter-module connection bus bar 41 is disconnected, the load current I bypasses the second inter-module connection bus bar 41 and flows through the fuses and diodes on both sides of the second inter-module connection bus bar 41. . As a result, the fuses located in the target order with respect to the second inter-module connection bus bar 41 are the fifth fuse 65 of the second battery module 23 and the first fuse 61 of the third battery module 24. Are cut one by one at the same time (concept including substantially simultaneous).

  The fuse is cut at least either a fuse connected to the negative electrode M of the first battery cell of the first battery module or a fuse connected to the positive electrode P of the last battery cell of the last battery module. Continue until one is cut.

  When the second inter-module connection bus bar 41 is removed as in the present embodiment, the second fuse 62 of the first battery module 22 and the fifth fuse 65 of the fourth battery module 25 are: Since the fuses are located in a symmetrical order with respect to the second inter-module connection bus bar 41, the fuses continue to be cut until the pair of fuses are cut at the same time (concept including substantially the same time). When the pair of fuses are cut, the flow of the load current I is stopped.

  As another example, when the first inter-module connection bus bar 40 is disconnected, the load current does not flow when the first fuse 61 of the first battery module 22 is cut. For this reason, when the first inter-module connection bus bar 40 is cut, the cutting of the fuse continues until the first fuse 61 of the first battery module 22 is cut.

  The BMU 90 determines that the inter-module connection bus bar has been removed when the following two conditions are satisfied. The first condition is that when the battery cells connected to the cut fuses in each battery module are arranged in the order in which the fuses are cut, the order of the battery cells is in the order in which they are arranged in series. Or, it is the reverse of the order in series. In other words, it is cut toward the fifth fuse 65 in the order of first, second, third, fourth and fifth, or it is cut into the first fuse 61 in the order of fifth, fourth, third, second and first. It is a case where it cuts toward.

  Note that the fifth fuse 65 of the fourth battery module 25 and the second fuse 62 of the first battery module 22 are simultaneously (like the case where the second inter-module connection bus bar 41 is cut) ( In the case where the first fuse 61 of the first battery module 22 is cut, the first fuse 61 of the first battery module 22 is not cut.

  The second condition is that there are combinations in which the order of the fuses to be cut is opposite to each other in the two battery modules arranged in order. In other words, the fuses are cut in the first to fifth order in one battery module, and the fuses are cut in the fifth to first order in the other battery module. When these two conditions are satisfied, it is determined that the inter-module connection bus bar that connects the combinations in which the order of connection to the blown fuses in the two battery modules arranged in the above order is reversed has been removed. In the first battery module 22, the first fuse 61 may not be cut as described above.

  Next, the operation of the CPU 80 will be specifically described with reference to FIG. As shown in FIG. 7, in this embodiment, steps ST20 to ST23 are added as the operation of the CPU 80. Step ST20 is provided between steps ST1 and ST2.

  First, the operation of the CPU 80 in the first battery module 22 will be described. In the first battery module 22, in step ST20, the first fuse 61 connected to the negative electrode M of the first battery cell or the positive electrode P of the fourth battery cell 35 which is the final battery cell is connected. It is determined whether or not the fifth fuse 65 is cut. In the present embodiment, since the fifth fuse 65 is first cut when the second inter-module connection bus bar 41 is removed, the CPU 80 detects that the fifth fuse 65 has been cut. Then, the process proceeds to step ST21.

  In step ST21, the CPU 80 determines whether or not the fuse connected to the positive electrode P of the battery cell arranged in order with respect to the battery cell to which the previously cut fuse is connected has been cut next. In the present embodiment, since the fourth fuse 64, the third fuse 63, and the second fuse 62 are successively cut following the fifth fuse 65, the process proceeds to step ST22.

  In step ST <b> 22, the CPU 80 determines whether or not the fuses that have been cut first are continuously cut one by one up to the fuse at the opposite end of the current path 300 through which the load current flows in the battery module. As described above, in the first battery module 22, the first fuse 61 may not be cut. The current path 300 referred to here is constituted by a battery cell, a fuse, a diode, or the like, and is a path through which the load current I flows.

  In the present embodiment, since the second inter-module connection bus bar 41 is disconnected, the CPU 80 continuously disconnects the fifth fuse 65 from the fifth fuse 65 toward the second fuse 62. It is detected that the fuse 65 to the second fuse 62 are successively cut one by one. Then, the process proceeds to step ST23.

  In step ST <b> 23, the CPU 80 transmits information to the BMU 90 that the fuses are continuously blown one by one from the fifth fuse 65 to the second fuse 62.

  Next, the second battery module 23 will be described. In the second battery module 23, as in the first battery module 22, the fifth fuse 65 is first cut, and then the fuses are successively inserted one by one in the order of 4, 3, 2, and 1. Disconnected. The CPU 80 of the second battery module 23 performs the same operation as the CPU 80 of the first battery module 22.

  Next, the operation of the third battery module 24 will be described. Within the third battery module 24, the first fuse 61 to the fifth fuse 65 are successively cut one by one in order. For this reason, in step ST23, the CPU 80 of the third battery module 24 transmits to the BMU 90 information that the first fuse 61 to the fifth fuse 65 have been successively blown one by one.

  Next, the operation of the fourth battery module 25 will be described. The CPU 80 of the fourth battery module 25 performs the same operation as the CPU 80 of the third battery module 24.

  In each CPU 80, when it is determined in step ST21 that the fuses connected to the battery cells arranged in order are not cut, the process proceeds from step ST21 to step ST4. In step ST22, when the fuses arranged at the other end of the current path 300 are not continuously cut (except for the first battery module 22), the process proceeds to step ST4.

  FIG. 8 is a flowchart showing a part of the operation of the BMU 90. As shown in FIG. 8, in step ST <b> 31, the BMU 90 determines whether fuse cutting information has been received from each CPU 80.

  As shown in FIG. 7, when the second inter-module connection bus bar 41 is removed, information that the first to fifth fuses 61 to 65 of the second to fourth battery modules 23 to 25 are disconnected, and Since the information that the second to fifth fuses 62 to 65 of the first battery module 22 have been cut is transmitted to the BMU 90, the process proceeds to step ST32.

  In step ST <b> 32, the BMU 90 determines from which CPU 80 the information specifying the removed bus bar is transmitted. When any of the bus bars in the battery module is disconnected, the CPU in the battery module identifies the bus bar that has been disconnected, and transmits information on the disconnected bus bar to the BMU 90 (the above operation will be described in the first embodiment).

  However, when the inter-module connection bus bar is disconnected, each CPU 80 cannot identify which bus bar is disconnected. For this reason, in step ST32, the BMU 90 has not received the information specifying the bus bar that has been removed. Therefore, the process proceeds to step ST33.

  In step ST33, when the cut fuses are arranged in the cut order, it is determined whether or not the battery cells to which the fuses are connected are arranged in order. As described above, when the inter-module connection bus bar is removed, when the battery cells to which the cut fuses are connected are arranged in the order in which the fuses have been cut, the battery cells are in order from the first to the last. Or in order from the last to the first.

  Since the BMU 90 has received information from the CPUs 80 of the first to fourth battery modules 22 to 25 that the fuse cutting tendency in each battery module is the above-described tendency, the process proceeds to step ST34.

  In step ST <b> 34, the BMU 90 determines that the inter-module connection bus bar that connects the combination battery modules in which the order in which the fuses are cut in the adjacent battery modules is reversed is removed.

  In the present embodiment, in the second and third battery modules 23 and 24, the fuse cutting order is reversed. For this reason, the BMU 90 determines that the second inter-module connection bus bar 41 is disconnected. Then, the process proceeds to step ST35.

  In step ST35, the BMU 90 displays on the display device 100 that the second inter-module connection bus bar 41 is disconnected in order to notify that the second inter-module connection bus bar 41 has been disconnected.

  When any bus bar in the battery module is removed, the BMU 90 receives information on the removed bus bar from the CPU. For this reason, when the information of the bus bar that has already been removed is received from the CPU 80, the process proceeds from step ST32 to step ST35.

  Further, in step ST33, the arrangement of the battery cells when the battery cells connected to the cut fuses are arranged in the order of cutting the fuses is not in the order when the plurality of battery cells are connected in series, and If it is not the reverse of the above order, the process proceeds to step ST36, where it is determined that the fuse is blown due to a failure in the voltage measurement circuit.

  In the present embodiment, in addition to the effects of the first embodiment, even when the inter-module connection bus bar that connects the battery modules is removed, the removed bus bar can be identified.

  In the present embodiment, since the case where the second inter-module connection bus bar 41 is removed has been described as an example, all the first to fifth fuses 61 to 65 of the second to fourth battery modules 23 to 25 are continuously provided. The 2nd-5th fuse 62-65 of the 1st battery module 22 was cut | disconnected continuously.

  However, for example, when the first inter-module connection bus bar 40 is removed, the cutting of the fuse in the battery device 20 stops when the first fuse 61 of the first battery module 22 is cut. At this time, the fifth fuse 65 of the second battery module 23 is continuously cut, and the first to fifth fuses 61 to 65 in the third and fourth battery modules 24 and 25 are not cut.

  For this reason, when the BMU 90 specifies that the inter-module connection bus bar is removed, the fuse in any of the battery modules may not be cut as described above. Even in this case, the BMU 90 determines that the inter-module connection bus bar is disconnected between the battery modules when the order of cutting the internal fuses between the adjacent battery modules is opposite to each other.

  Next, a battery device according to a third embodiment of the present invention will be described with reference to FIG. In addition, the structure which has the same function as 2nd Embodiment attaches | subjects the code | symbol same as 2nd Embodiment, and abbreviate | omits description. In this embodiment, the structure of the inter-module connection diode is different from that of the second embodiment. Furthermore, a Zener diode is provided. Other structures may be the same as in the second embodiment. The different structure will be described.

  FIG. 9 is a schematic view showing the battery device 20 of the present embodiment. As shown in FIG. 9, in this embodiment, a Zener diode is used as the inter-module connection diode, and one Zener diode whose forward direction is opposite to the inter-module connection diode is provided.

  Specifically, Zener diodes are used as the first to third inter-module connection diodes 111 to 113. Further, Zener diodes 121 are provided in the inter-module connection diodes 111 to 113 so that the forward directions are opposite to each other.

  In the present embodiment, by connecting the Zener diode 121 to the inter-module connection diodes 111 to 113, all the fuses in the battery device 20 are cut even if any bus bar is removed. Can be suppressed.

  This point will be specifically described. For example, when the second inter-module connection bus bar 41 is disconnected, the fuses of the target order are continuously cut in order from the second inter-module connection bus bar 41 (in the second embodiment). Description). At this time, the output voltage of the battery device 20 decreases by the voltage of the battery cell that is out of the current path 300 through which the load current I flows.

  For this reason, when the output voltage of the battery device 20 is lower than the Zener voltage of the Zener diode 121, the load current I does not flow through the Zener diode 121. As a result, the cutting of the fuse is stopped.

  By setting each zener voltage to a predetermined value, the number of fuses to be cut can be suppressed even when any bus bar is disconnected.

  In the present embodiment, in addition to the effects of the second embodiment, the number of fuses to be cut can be suppressed.

  In this embodiment, a Zener diode is used for each inter-module connection diode, and a Zener diode is connected to each inter-module connection diode so that the forward direction is reversed. However, it is not limited to this. Each module connecting diode may not be a Zener diode, but may be a diode used in the first and second embodiments.

  In the first to third embodiments, the plurality of battery cells included in the battery device 20 are divided into a plurality of battery modules (three or four) as an example. However, the battery device 20 is not limited to a structure including a battery module.

  For example, even when the battery device 20 includes a plurality of battery cells, the plurality of battery cells may be electrically connected in series without being divided into a plurality of battery modules. In other words, this is a structure in which the battery device includes one battery module. Even with this structure, a detached bus bar can be detected.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, you may delete some components from all the components shown by embodiment mentioned above. Furthermore, you may combine the component covering different embodiment suitably.

  DESCRIPTION OF SYMBOLS 20 ... Battery device, 22 ... 1st battery module, 23 ... 2nd battery module, 24 ... 3rd battery module, 25 ... 4th battery module, 31 ... Battery monitoring apparatus, 32 ... 1st battery cell 33 ... second battery cell 34 ... third battery cell 35 ... fourth battery cell 36 ... first bus bar 37 ... second bus bar 38 ... third bus bar 40 ... first Bus bar for inter-module connection, 41 ... second bus bar for inter-module connection, 42 ... third bus bus for inter-module connection, 50 ... voltage measurement circuit (voltage measurement unit), 61 ... first fuse, 62 ... first 2 fuses 63 ... third fuse 64 64 fourth fuse 65 ... fifth fuse 71 71 first diode 72 72 second diode 73 73 third die , 74 ... fourth diode, 80 ... CPU (determination unit), 90 ... BMU (battery management unit), 111 ... first inter-module connection diode, 112 ... second inter-module connection diode, 113 ... Third module connecting diode, 121... Zener diode.

Claims (4)

A battery device comprising at least one battery module,
The battery module is
Multiple battery cells;
A bus bar that is provided between each of the battery cells and connects the battery cells from the first to the last one in series,
A battery monitoring device for monitoring each of the battery cells,
The battery monitoring device includes:
A voltage measuring unit for measuring the voltage of each battery cell;
Provided between the negative electrode of the first battery cell and the voltage measuring unit to connect the negative electrode to the voltage measuring unit, and provided between each of the positive electrode of each battery cell and the voltage measuring unit, and A plurality of fuses connecting each of the positive electrodes to the voltage measurement unit;
A pair of fuses connected to both poles of the first battery cell are connected between the connection portions of the fuses with the voltage measuring section to connect the connection portions, and to the positive electrodes of the two battery cells arranged in order. A plurality of diodes provided between the connecting portions of the fuse to be connected to the voltage measuring portion and connecting the connecting portions;
A determination unit that determines the state of each battery cell based on the detection result of the voltage measurement unit, and
The diode provided between the fuses connected to both poles of the first battery cell is provided such that the fuse side connected to the positive electrode is the forward tip side,
The diode provided between the fuses connected to the positive electrodes of the two battery cells arranged in order is provided such that the fuse side connected to the positive electrode of the battery cell in the rear is the forward end side in the forward direction. And
The determination unit is configured such that when the natural number that is equal to or less than the number indicating the number of the battery cells and exceeds 1 is M, the fuse connected to the battery cells from the Mth to the last is the Mth battery cell. Are sequentially cut from the fuse connected to the positive electrode to the fuse side connected to the positive electrode of the last battery cell, and the first to M−1th battery cells are cut. The fuses to be connected were cut one by one from the fuse connected to the positive electrode of the M-1th battery cell one by one toward the fuse side connected to the negative electrode of the first battery cell. And detecting that the bus bar connecting the Mth battery cell and the M-1th battery cell is disconnected. Equipment. A plurality of the battery modules are provided,
By providing an inter-module connection bus bar between the battery modules, the battery modules from the first to the last are connected in series in order,
The inter-module connection bus bar connects the last battery cell of the battery module in the previous order and the first battery cell of the battery module in the rear order among the two battery modules arranged in order. The battery device according to claim 1, wherein: In the two battery modules arranged in order, the connection part to the voltage measuring part of the fuse connected to the positive electrode of the last battery cell of the battery module in the previous order, and the battery module in the rear order An inter-module connection diode that connects a connection portion of the fuse connected to the negative electrode of the first battery cell to the voltage measurement portion;
A battery management unit connected to each determination unit of the plurality of battery modules and monitoring each battery module; and
The inter-module connection diode is provided so that the battery module side in the rear of the two battery modules connected by the inter-module connection diode is the front end side in the forward direction.
The battery management unit is connected to the battery cell in the last battery module from the Nth battery module, where N is a natural number that is equal to or less than the number indicating the number of the plurality of battery modules and exceeds 1. The fuse to be connected from the fuse connected to the negative electrode of the first battery cell of the Nth battery module to the fuse connected to the positive electrode of the last battery cell of the last battery module. And the fuse connected to the battery cell in the (N−1) th battery module from the first battery module is connected to the N−1th last battery cell. 1 of the first battery module from the fuse connected to the positive electrode The inter-module connection that connects the Nth battery module and the N−1th battery module when it is detected that the fuses are sequentially cut one by one toward the fuse connected to the negative electrode of the battery cell of the eye. The battery device according to claim 2, wherein it is determined that the bus bar is disconnected. A zener diode connected between the two battery modules arranged in order and connected to the inter-module connection diode and having a forward direction opposite to a forward direction of the inter-module connection diode. Item 4. The battery device according to Item 3.

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