Battery monitoring system and battery pack

Abstract

To ensure the reliability of communication.SOLUTION: A battery monitoring device is applied to a plurality of battery cells installed within a housing 10. The battery monitoring device includes acquisition devices 30 that acquire battery information, and a monitoring device 40 that wirelessly communicates with the acquisition devices 30. The monitoring device 40 includes a master antenna 46, and each acquisition device 30 includes a slave antenna 36. On each of the battery cells, two protrusions 23 having conductive connection portions 24 for electrically connecting the battery cells are formed. Hereinafter, a direction in which the protrusions 23 protrude will be referred to as a protrusion direction Z+. The acquisition device 30 has a substrate extending in directions X and Y intersecting the protrusion direction, and the slave antenna 36 is installed on the substrate. A space is formed between the battery cell and the slave antenna 36.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a battery monitoring system. [Background technology]

[0002] Some battery packs are configured as follows. The battery pack has a metal housing, and within the housing are installed a number of assembled batteries, a number of acquisition devices, and a monitoring device. An acquisition device is installed for each assembled battery, and acquires battery information from the corresponding assembled battery. The monitoring device acquires battery information by wirelessly communicating with each acquisition device.

[0003] The monitoring device and each acquisition device are equipped with antennas for wireless communication. Radio waves emitted from these antennas are reflected by the inner surface of the metal housing, generating a large number of reflected waves. As a result, multiple radio waves may be superimposed on the receiving antenna. Radio wave interference caused by this superposition may cause communication failure, resulting in the failure of wireless communication or a communication interruption.

[0004] The magnitude of communication failure due to radio interference varies depending on the communication frequency. Therefore, when communication is not established or is cut off at a certain communication frequency, wireless communication is performed by changing the communication frequency. The following Patent Document 1 shows such a technology. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 103008 Summary of the Invention [Problem to be solved by the invention]

[0006] According to the above technology, wireless communication can be established by changing the communication frequency. However, it does not prevent communication failure or interruption itself. Therefore, communication failure or interruption may occur frequently, and the communication frequency may have to be changed each time. If communication failure or interruption occurs frequently, the frequency of data updates decreases. Therefore, such a communication system is not suitable for devices that place importance on real-time performance, such as battery packs.

[0007] The inventors have noticed that solving such problems and ensuring the reliability of communication becomes particularly difficult when protrusions having conductive connections that electrically connect the battery cells to each other are formed.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and has as its main object to ensure the reliability of communication when a protrusion having a conductive connection portion that electrically connects battery cells to each other is formed. [Means for solving the problem]

[0009] The first means for solving the above problem is The battery information acquisition device is applied to a plurality of battery cells (22) installed in a housing (10) and includes an acquisition device (30) that acquires battery information including voltage information of the battery cells, and a monitoring device (40) that acquires the battery information by wirelessly communicating with the acquisition device, The monitoring device is provided with a master antenna (46) for the wireless communication, and each of the acquisition devices is provided with a slave antenna (36) for the wireless communication; The above Multiple Battery Cell A given surface In a battery monitoring system, two protrusions (23) having conductive connectors (24) made of a conductor for electrically connecting the battery cells to each other are formed on the battery cell. The direction in which the protrusion protrudes is defined as a protruding direction (Z+), and the acquisition device has a substrate (35) extending in a direction (X, Y) intersecting the protruding direction, the predetermined surface is an end surface of the battery cell in the protruding direction, the child device antenna is mounted on the substrate, A space is formed between the battery cell and the child device antenna.

[0010] According to the above configuration, the direction in which the protrusion protrudes is defined as a protrusion direction (Z+), the acquisition device has a substrate (35) extending in a direction (X, Y) intersecting the protrusion direction, the child device antenna is mounted on the substrate, and a space is formed between the battery cell and the child device antenna. Therefore, when a protrusion having a conductive connection portion that electrically connects battery cells is formed, the reliability of communication can be ensured.

[0011] The battery pack of [Configuration 1] has a housing, a battery pack, an acquisition device, and a monitoring device. A plurality of the battery packs are installed in the housing, and each battery pack has a plurality of battery cells. The acquisition device is installed for each battery pack, and acquires battery information including voltage information of each of the battery cells from the battery pack corresponding to the acquisition device. The monitoring device acquires the battery information by wirelessly communicating with the acquisition device.

[0012] The monitoring device includes a master antenna for the wireless communication. Each of the acquisition devices includes a slave antenna for the wireless communication. Each of the assembled batteries is formed with a protrusion having a conductive connection part made of a conductor that electrically connects the battery cells to each other.

[0013] In the following, the direction in which the protrusion protrudes is referred to as the protruding direction. Within the housing, at least a portion of each of the child device antennas is disposed in the protruding direction further from the end of each of the conductive connecting parts in the protruding direction. Then, the unreflected direct waves of the radio waves transmitted from the parent device antenna reach and are received by each of the child device antennas without being blocked by the conductive connecting parts, and the unreflected direct waves of the radio waves transmitted from each of the child device antennas reach and are received by the parent device antenna without being blocked by the conductive connecting parts.

[0014] Characteristic configurations of the present disclosure will be described below. In [Configuration 1], each child device antenna is intentionally placed in an area protruding from the end of each conductive connection part in the housing, which tends to be narrow due to space and other factors. This realizes a structure in which direct waves from the parent device antenna reach each child device antenna without being blocked by the conductive connection part, and each child device antenna can receive from the parent device antenna a direct wave with stronger propagation strength than a reflected wave. In addition, a structure in which direct waves from each child device antenna reach the parent device antenna without being blocked by the conductive connection part is realized, and the parent device antenna can receive from each child device antenna a direct wave with stronger propagation strength than a reflected wave. As a result, it is possible to ensure communication reliability compared to a case in which each antenna can only receive reflected waves from the other antenna. [Configuration 2] The battery pack according to configuration 1, wherein the conductive connection portion has an electrode terminal (25, 26) of each of the battery cells and a bus bar (27) that electrically connects the electrode terminals of adjacent battery cells, and the end of the conductive connection portion in the protruding direction is the end of the bus bar in the protruding direction. [Configuration 3] The battery pack according to configuration 1, wherein the conductive connection portion has an electrode terminal (25, 26) of each of the battery cells and a bus bar (27) that electrically connects the electrode terminals of adjacent battery cells, and an end of the conductive connection portion in the protruding direction is an end of the electrode terminal in the protruding direction. [Configuration 4] the acquisition device has a substrate (35) extending in a direction (X, Y) intersecting the protruding direction, and a distance (G1) in the protruding direction between the substrate and an inner surface of the housing is larger than a distance (G2) in the protruding direction between an end of the conductive connection part in the protruding direction and the substrate; The battery pack according to any one of configurations 1 to 3, wherein the child device antenna is disposed on a surface of the board on the protruding direction side. [Configuration 5] the acquisition device has a substrate (35) extending in a direction (X, Y) intersecting the protruding direction, and a distance (G2) in the protruding direction between an end of the conductive connection portion in the protruding direction and the substrate is larger than a distance (G1) in the protruding direction between the substrate and an inner surface of the housing; The battery pack according to any one of configurations 1 to 3, wherein the child device antenna is disposed on a surface of the board on a side opposite to the protruding direction (Z-). [Configuration 6] 6. The battery pack according to any one of configurations 1 to 5, wherein the housing has a shielding portion made of a conductive material, and the parent unit antenna and each of the child unit antennas are surrounded by the shielding portion. [Configuration 7] The battery pack of any one of configurations 1 to 6, wherein the plurality of assembled batteries are arranged side by side in a first direction (X) perpendicular to the protruding direction, and each of the assembled batteries has the plurality of battery cells arranged side by side in a second direction (Y) perpendicular to both the protruding direction and the first direction, and each of the protrusions is a ridge extending in the second direction. [Configuration 8] The battery pack according to any one of configurations 1 to 7, wherein each of the acquisition devices has a case (33) made of a non-conductive material, the child unit antenna being installed inside the case and attached to the protrusion. [Configuration 9] 9. The battery pack according to claim 8, wherein a portion of the case is disposed between the protrusions and in a direction opposite to the protruding direction (Z-) from an end of the conductive connection portion in the protruding direction. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a battery pack according to a first embodiment; [Diagram 2] A plan view showing the battery pack [Diagram 3] Front cross-sectional view showing the battery pack [Figure 4] FIG. 11 is a front cross-sectional view showing wireless communication between a comparative example and the present embodiment. [Diagram 5] FIG. 11 is a front cross-sectional view showing a battery pack according to a second embodiment; [Figure 6] FIG. 13 is a front cross-sectional view showing a battery pack according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Next, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment, and can be appropriately modified and implemented without departing from the spirit of the invention.

[0017] [First embodiment] 1 is a perspective view showing a battery pack 101 of the first embodiment. The battery pack 101 is mounted on a vehicle or the like. The battery pack 101 has a metal housing 10, and a plurality of assembled batteries 20, a plurality of acquisition devices 30, and a monitoring device 40 that are installed in the housing 10. The acquisition devices 30 and the monitoring device 40 configure a battery monitoring system that monitors each assembled battery 20.

[0018] In the following, three mutually orthogonal directions are referred to as the "left-right direction X," the "front-back direction Y," and the "up-down direction Z" in accordance with the drawings. However, the battery pack 101 can be installed in any direction, for example, by setting the "up-down direction Z" as described below to be left-right or front-back, or by setting the "left-right direction X" as described below to be front-back.

[0019] The multiple battery packs 20 are arranged side by side in the left-right direction X. Each battery pack 20 has multiple battery cells 22 lined up in the front-rear direction Y. A ridge-like protrusion 23 that protrudes upward Z+ from the top surface of the battery pack 20 and extends in the front-rear direction Y is formed on the left and right ends of the top surface of each battery pack 20. Specifically, each protrusion 23 is a ridge that extends from the top surface of the front end battery cell 22 to the top surface of the rear end battery cell 22.

[0020] An acquisition device 30 is installed for each assembled battery 20. Each acquisition device 30 is installed between the left and right protrusions 23 of the assembled battery 20 corresponding to it. Each acquisition device 30 acquires battery information, which is information related to the assembled battery 20, from the assembled battery 20 corresponding to it. The battery information includes, for example, voltage information and temperature information of each of the multiple battery cells 22 in the assembled battery 20, and information on the current flowing through the assembled battery 20.

[0021] In this embodiment, the monitoring device 40 is attached to the left side surface of the leftmost battery pack 20. The monitoring device 40 wirelessly communicates with each acquisition device 30. Through this wireless communication, the monitoring device 40 transmits acquisition commands to the acquisition devices 30 to acquire battery information, receives battery information from each acquisition device 30, and transmits equalization commands to the acquisition devices 30 to equalize the voltages of each battery cell 22.

[0022] The housing 10 is made of a conductor such as metal, etc. Therefore, the entire housing 10 constitutes a shielding portion that reflects radio waves.

[0023] 2 is a plan view showing the battery pack 101. Each protrusion 23 has a protrusion base 28 made of a non-conductor and a conductive connection part 24 made of a conductor that electrically connects the battery cells 22 to each other. The conductive connection part 24 has electrode terminals 25, 26 of each battery cell 22 and a bus bar 27. The bus bar 27 electrically connects the electrode terminals 25, 26 of the battery cells 22 that are adjacent in the front-rear direction Y to each other. The protrusion base 28 is made of resin or the like and is installed in a manner that covers the conductive connection part 24.

[0024] More specifically, with respect to each assembled battery 20, each battery cell 22 has a positive electrode terminal 25 and a negative electrode terminal 26 as the above-mentioned electrode terminals 25, 26. For example, the frontmost battery cell 22 is installed with the negative electrode terminal 26 on the left side and the positive electrode terminal 25 on the right side. The second battery cell 22 from the front is installed with the positive electrode terminal 25 on the left side and the negative electrode terminal 26 on the right side, opposite to the frontmost battery cell 22. The third battery cell 22 from the front is installed with the negative electrode terminal 26 on the left side and the positive electrode terminal 25 on the right side, similar to the frontmost battery cell 22.

[0025] In this way, each battery cell 22 aligned in the front-rear direction Y is installed with the positions of the positive electrode terminal 25 and the negative electrode terminal 26 reversed in the left-right direction X with respect to the preceding battery cell 22. The negative electrode terminal 26 of each battery cell 22 other than the rearmost battery cell 22 is electrically connected to the positive electrode terminal 25 of the succeeding battery cell 22 by a bus bar 27. In this way, the multiple battery cells 22 are electrically connected in series. The positive electrode terminal 25 of the frontmost battery cell 22 is connected to a predetermined positive electrode wiring 15, and the negative electrode terminal 26 of the rearmost battery cell 22 is connected to a predetermined negative electrode wiring 16.

[0026] Fig. 3(a) is a cross-sectional view taken along line IIIa-IIIa in Fig. 2. Fig. 3(b) is an enlarged view of the battery pack 20 at the left end in Fig. 3(a) and its periphery. The bus bar 27 is installed so as to cover the negative electrode terminal 26 and the positive electrode terminal 25 which are electrically connected thereto. Therefore, the upper end of the bus bar 27 constitutes the upper end 24z of the conductive connection portion 24. The protrusion base 28 is installed so as to cover the bus bar 27 from above.

[0027] Each acquisition device 30 has a case 33 made of a non-conductive material such as resin, and a board 35 provided inside the case 33. A child device antenna 36 for wireless communication with the monitoring device 40 is mounted on the board 35. A left attachment part 31 that protrudes leftward is provided on the left side surface of each case 33, and a right attachment part 32 that protrudes rightward is provided on the right side surface of each case 33.

[0028] The left attachment portion 31 is secured to the left protrusion 23 of the battery pack 20 with a screw or the like, and the right attachment portion 32 is secured to the right protrusion 23 of the battery pack 20 with a screw or the like. As a result, each case 33 is attached to the left and right protrusions 23 of the corresponding battery pack 20 in a manner spanning the space between the left and right protrusions 23. Therefore, the position of each child device antenna 36 in the left-right direction X is between the left and right protrusions 23 of the battery pack 20 corresponding to that child device antenna 36. The positions of each child device antenna 36 in the front-rear direction Y may be the same or may be shifted from each other in the front-rear direction Y.

[0029] The lower part of each case 33 is disposed between the protrusions 23 at a position Z- below the upper end 24z of the conductive connection part 24. On the other hand, the upper part of each case 33 and the substrate 35 are disposed at a position Z+ above the upper end 24z of the conductive connection part 24.

[0030] Hereinafter, the distance in the vertical direction Z between the upper surface of the substrate 35 and the ceiling surface of the housing 10 is referred to as the "first distance G1," and the distance in the vertical direction Z between the upper end 24z of the conductive connection portion 24 and the lower surface of the substrate 35 is referred to as the second distance G2. In this embodiment, the first distance G1 on the upper side is larger than the second distance G2 on the lower side. Then, on the upper surface of each substrate 35, the child device antenna 36 is installed in a manner that protrudes upward Z+ from the upper surface of the substrate 35. Therefore, each acquisition device 30 has the child device antenna 36 above the upper end 24z of the conductive connection portion 24.

[0031] The monitoring device 40 also includes a board 45 at approximately the same height as the boards 35 of the acquisition devices 30. A parent unit antenna 46 for wireless communication with each acquisition device 30 is installed on the upper surface of the board 45 so as to protrude upward Z+ from the upper surface of the board 45. Therefore, the monitoring device 40 includes the parent unit antenna 46 at Z+ above the upper end 24z of the conductive connection portion 24.

[0032] According to this embodiment, the following effects can be obtained: In the following, radio waves that have never been reflected since being transmitted from the antennas 36, 46 are referred to as "direct waves," and radio waves that have been reflected at least once since being transmitted from the antennas 36, 46 are referred to as "reflected waves."

[0033] 4(a) is a front cross-sectional view showing a comparative example in which the position of each child device antenna 36 is shifted downward Z- from the state of this embodiment, and the entirety of each child device antenna 36 is disposed Z- below the upper end 24z of the conductive connection part 24. Note that the position of each child device antenna 36 in the left-right direction X and the front-back direction Y in this comparative example is the same as in this embodiment.

[0034] When the entirety of each child device antenna 36 is located Z- below the upper end 24z of the conductive connection portion 24 as in this comparative example, the direct wave Rd from the parent device antenna 46 is blocked by the conductive connection portion 24 and does not reach each child device antenna 36, ​​and only the reflected wave Ri reaches and is received by each child device antenna 36. Conversely, the direct wave from each child device antenna 36 is also blocked by the conductive connection portion 24 and does not reach the parent device antenna 46, and only the reflected wave reaches and is received by the parent device antenna 46.

[0035] In this embodiment, as shown in Fig. 4(b), the parent unit antenna 46 and each child unit antenna 36 are intentionally arranged in a region Z+ above the upper ends 24z of each conductive connection portion 24 in the housing 10, which tends to be narrow due to space constraints, etc. Note that in Fig. 4 and other figures, the upper portion of the battery pack 20 and the like are exaggeratedly shown large for ease of viewing, but the actual region Z+ above the upper ends 24z of each conductive connection portion 24 in the housing 10 is much smaller than that shown in Fig. 4 and other figures.

[0036] Due to the above arrangement of the antennas 46, 36, the direct wave Rd from the parent antenna 46 reaches each child antenna 36 without being blocked by any conductor, including the conductive connection 24. Therefore, each child antenna 36 can receive the direct wave Rd from the parent antenna 46, which has a stronger propagation strength than the reflected wave Ri. Conversely, the direct wave from each child antenna 36 also reaches the parent antenna 46 without being blocked by any conductor, including the conductive connection 24. Therefore, the parent antenna 46 can also receive the direct wave from each child antenna 36, ​​which has a stronger propagation strength than the reflected wave. As a result, the reliability of communication can be ensured compared to a case in which each antenna 36, ​​46 can only receive a reflected wave from the other antenna 46, 36.

[0037] 3(b), in this embodiment, the first interval G1 on the upper side is larger than the second interval G2 on the lower side. Each child device antenna 36 is installed on the upper surface of the substrate 35. Therefore, the first interval G1, which is the relatively larger of the first interval G1 and the second interval G2, can be effectively utilized to ensure a space for installing the child device antenna 36.

[0038] In addition, in this embodiment, the housing 10 is a conductor such as metal, and the entire housing 10 constitutes a shielding portion that reflects radio waves, so that the parent unit antenna 46 and each child unit antenna 36 are surrounded by the shielding portion. Therefore, radio waves from outside the housing 10 are unlikely to reach the parent unit antenna 46 and each child unit antenna 36. Therefore, radio wave interference with those external radio waves is unlikely to occur. This also ensures the reliability of communication. Conversely, radio waves transmitted by the parent unit antenna 46 and each child unit antenna 36 are unlikely to leak outside the housing 10. Therefore, it is possible to suppress adverse effects on other communication devices outside the battery pack 101.

[0039] In this embodiment, the multiple battery packs 20 are arranged side by side in the left-right direction X. Each protrusion 23 is a ridge extending in the front-rear direction Y perpendicular to the left-right direction X. Therefore, the protrusions 23 extending in the front-rear direction Y would normally tend to block direct waves between the parent unit antenna 46 and each child unit antenna 36. Therefore, in this embodiment, the above-mentioned effect of allowing direct waves to reach the other antennas 36, 46 can be more significantly obtained.

[0040] In this embodiment, the case 33 of each acquisition device 30 is made of a non-conductive material and does not block radio waves. The child device antenna 36 is installed inside the case 33, and the case 33 is attached to the protrusion 23. This allows the child device antenna 36 to be easily positioned in a position where it can communicate with the parent device antenna 46 by direct waves.

[0041] In addition, the lower part of the case 33 is disposed Z- below the upper ends 24z of the conductive connecting parts 24 between the protruding parts 23. Therefore, the spaces between the protruding parts 23 can be effectively utilized.

[0042] [Second embodiment] Next, a second embodiment will be described. In the following embodiments, the same reference numerals will be used for the same or corresponding members as those in the previous embodiments. However, the battery pack itself will be used with a different reference numeral for each embodiment. This embodiment will be described based on the first embodiment, focusing on the differences from the first embodiment.

[0043] 5 is a front cross-sectional view showing a battery pack 102 of the second embodiment. Each protrusion 23 is installed in such a manner that the positive terminal 25 and the negative terminal 26 penetrate the bus bar 27 in the up-down direction Z. Therefore, in this embodiment, the upper ends of the positive terminal 25 and the negative terminal 26 form the upper end 24z of the conductive connection part 24. The parent unit antenna 46 and the child unit antenna 36 are disposed above the upper end 24z of the conductive connection part 24 (Z+).

[0044] According to this embodiment, even in a mode in which the upper ends of the positive electrode terminal 25 and the negative electrode terminal 26 form the upper end 24z of the conductive connecting portion 24, the same effects as those of the first embodiment can be obtained.

[0045] [Third embodiment] Next, a third embodiment will be described. The third embodiment will be described based on the first embodiment, focusing on the differences from the first embodiment.

[0046] 6 is a front cross-sectional view showing a battery pack 103 of the third embodiment. In this embodiment, the substrate 35 is disposed in an upper Z+ position than in the first embodiment, and the lower second gap G2 is larger than the upper first gap G1. In each acquisition device 30, the child device antenna 36 is disposed on the lower surface of the substrate 35 so as to protrude downward from the lower surface to the Z- position.

[0047] In this embodiment, the second interval G2 on the lower side is larger than the first interval G1 on the upper side. Each child device antenna 36 is installed on the lower surface of the substrate 35. Therefore, the second interval G2, which is relatively larger among the first interval G1 and the second interval G2, can be effectively utilized to ensure a space for installing the child device antenna 36.

[0048] [Other embodiments] The above-described embodiment can be modified as follows. For example, in each figure, the entirety of each antenna 46, 36 is disposed at Z+ above the upper end of the protrusion 23. Alternatively, at least a part of each antenna 46, 36 may be disposed at Z- below the upper end of the protrusion 23 and Z+ above the upper end 24z of the conductive connection part 24. Even if the antenna is disposed at Z- below the upper end of the protrusion 23, radio waves can pass through if the antenna is disposed at Z+ above the upper end 24z of the conductive connection part 24. Therefore, according to the above embodiment, the area below Z- below the upper end of the protrusion 23 and above Z+ above the upper end 24z of the conductive connection part 24 can be effectively utilized.

[0049] Also, for example, in each embodiment, the entirety of each antenna 46, 36 is disposed at Z+ above the upper end 24z of the conductive connection portion 24. Alternatively, a part of each antenna 46, 36 may be disposed at Z- below the upper end 24z of the conductive connection portion 24 within the limit within which the antennas 46, 36 can communicate with each other by direct waves. In other words, only a part of each antenna 46, 36 may be disposed at Z+ above the upper end 24z of the conductive connection portion 24 so as to be able to communicate with the other antenna 36, ​​46 by direct waves.

[0050] Also, for example, in each embodiment, at least a portion (upper end) of the parent device antenna 46 is disposed above the upper ends 24z of the conductive connection parts 24. Alternatively, the upper end of the parent device antenna 46 may be disposed below the upper ends 24z of the conductive connection parts 24 within a range where the parent device antenna 46 and each child device antenna 36 can communicate with each other by direct waves.

[0051] Also, for example, in each embodiment, the substrate 35 of each acquisition device 30 is disposed at Z+ above the upper end 24z of the conductive connection portion 24. Alternatively, the substrate 35 of each acquisition device 30 may be disposed at Z- below the upper end 24z of the conductive connection portion 24, and only the upper portion of each child device antenna 36 may be disposed at Z+ above the upper end 24z of the conductive connection portion 24. Note that even in this case, the first interval G1 is greater than the second interval G2.

[0052] 3 to 5, each child device antenna 36 protrudes directly upward from the upper surface of substrate 35, but instead, each child device antenna 36 may protrude obliquely upward from the upper surface of substrate 35. Also, for example, in FIG. 6, each child device antenna 36 protrudes directly downward from the lower surface of substrate 35, but instead, each child device antenna 36 may protrude obliquely downward from the lower surface of substrate 35.

[0053] Also, for example, in each drawing, the parent unit antenna 46 protrudes directly upward from the upper surface of the substrate 45, but instead, the parent unit antenna 46 may protrude diagonally upward from the upper surface of the substrate 45. Also, for example, the substrate 45 of the monitoring device 40 may be disposed above Z+ from the state of each embodiment, and the parent unit antenna 46 may protrude directly downward or diagonally downward from the lower surface of the substrate 45.

[0054] Also, for example, in each embodiment, the child device antenna 36 is provided inside the case 33, but instead, the child device antenna 36 may be provided on the outer surface of the case 33, the upper surface of the protrusion 23, or the like. Also, for example, in each embodiment, each protrusion 23 is a protrusion extending from the upper surface of the front-end battery cell 22 to the upper surface of the rear-end battery cell 22, but instead, each protrusion 23 may be a protrusion extending intermittently in the front-rear direction Y by being interrupted between each bus bar 27.

[0055] Also, for example, in each embodiment, the entire housing 10 is a conductor, but only a part of its outer surface, etc., may be a shielding portion made of a conductor. Also, for example, in each embodiment, each assembled battery 20 has a plurality of battery cells 22 in one row in the front-rear direction Y, but the battery cells 22 may be divided into two or more rows. Also, for example, in each embodiment, the monitoring device 40 is installed on the left side surface of the leftmost assembled battery 20, but it may be installed on the right side surface of the rightmost assembled battery 20, the front or rear surface of the assembled battery 20 in the middle of the left and right, the inner surface of the housing 10, etc. [Explanation of symbols]

[0056] 10...housing, 22...battery cell, 23...projection portion, 24...conductive connection portion, 30...acquisition device, 35...board, 36...child unit antenna, 40...monitoring device, 46...parent unit antenna, Z+...upward.

Claims

1. The battery information acquisition device (30) is applied to a plurality of battery cells (22) installed in a housing (10) and acquires battery information including voltage information of the battery cells, and a monitoring device (40) that acquires the battery information by wirelessly communicating with the acquisition device, The monitoring device is provided with a master antenna (46) for the wireless communication, and each of the acquisition devices is provided with a slave antenna (36) for the wireless communication; In the battery monitoring system, two protrusions (23) having conductive connecting parts (24) made of a conductor that electrically connect the battery cells to each other are formed on predetermined surfaces of the plurality of battery cells, The direction in which the protrusion protrudes is defined as a protruding direction (Z+), and the acquisition device has a substrate (35) extending in a direction (X, Y) intersecting the protruding direction, the predetermined surface is an end surface of the battery cell in the protruding direction, the child device antenna is mounted on the substrate, A battery monitoring system, wherein a space is formed between the battery cell and the child device antenna.

2. The battery monitoring system according to claim 1 , wherein the child device antenna and the substrate are disposed in the protruding direction further from an end of the conductive connection portion in the protruding direction.

3. The battery monitoring system according to claim 1 , wherein the slave antenna is disposed on a surface of the substrate opposite to a surface facing the battery cell.

4. The battery monitoring system of claim 1 , wherein the slave antenna is installed on a surface of the substrate facing the battery cell and is positioned in the protruding direction further than the protruding end of the conductive connection portion in the protruding direction.

5. The battery monitoring system according to any one of claims 1 to 4, wherein the slave antenna is disposed between the two protrusions in a direction intersecting the protruding direction.

6. The battery monitoring system according to any one of claims 1 to 5, wherein the acquisition device is attached so as to straddle the space between the two protrusions.

7. The battery monitoring system according to any one of claims 1 to 6, wherein a lower portion of the acquisition device is disposed in a space between the two protrusions.

8. The battery monitoring system according to any one of claims 1 to 7, wherein the slave antenna is positioned closer to the center than the end of the battery cell in the longitudinal direction of the battery cell in a direction intersecting the protruding direction.

9. The battery monitoring system according to any one of claims 1 to 8, wherein the slave antenna and the substrate are provided on a member that connects the two protrusions.

10. A battery monitoring system as described in any one of claims 1 to 9, wherein the parent unit antenna and the child unit antenna are arranged in a direction perpendicular to the protrusion direction.

11. Each of the acquisition devices has a case from which a mounting portion (31, 32) to be attached to the protrusion protrudes, The battery monitoring system according to any one of claims 1 to 10, wherein at least a portion of each of the slave device antennas is disposed in the protruding direction beyond the mounting portion.

12. A battery pack including the housing (10), a plurality of assembled batteries (20) installed in the housing, each of the assembled batteries having a plurality of battery cells, and the battery monitoring system according to any one of claims 1 to 11, the acquisition device is provided for each of the assembled batteries, and acquires the battery information from the assembled battery corresponding to the acquisition device; Within the housing, at least a portion of each of the child device antennas is positioned in the protruding direction further than an end (24z) of each of the conductive connection portions in the protruding direction.

13. 13. The battery pack of claim 12, wherein an unreflected direct wave (Rd) of the radio waves transmitted from the parent unit antenna reaches and is received by each of the child unit antennas without being blocked by the conductive connection portion, and an unreflected direct wave of the radio waves transmitted from each of the child unit antennas reaches and is received by the parent unit antenna without being blocked by the conductive connection portion.

14. 14. The battery pack according to claim 12, wherein the conductive connection portion has an electrode terminal (25, 26) of each of the battery cells and a bus bar (27) that electrically connects the electrode terminals of adjacent battery cells, and an end of the conductive connection portion in the protruding direction is an end of the bus bar in the protruding direction.

15. 14. The battery pack according to claim 12, wherein the conductive connection portion has an electrode terminal (25, 26) of each of the battery cells and a bus bar (27) that electrically connects the electrode terminals of adjacent battery cells, and an end of the conductive connection portion in the protruding direction is an end of the electrode terminal in the protruding direction.

16. 16. The battery pack according to claim 12, wherein the housing has a shielding portion made of a conductive material, and the parent unit antenna and each of the child unit antennas are surrounded by the shielding portion.

17. The battery pack according to any one of claims 12 to 16, wherein the plurality of assembled batteries are arranged side by side in a first direction (X) perpendicular to the protruding direction, and each of the assembled batteries has the plurality of battery cells arranged in a second direction (Y) perpendicular to both the protruding direction and the first direction, and each of the protrusions is a ridge extending in the second direction.

18. A battery pack as described in any one of claims 12 to 17, wherein each of the acquisition devices has a case (33) made of a non-conductive material, the case having the child unit antenna installed inside and attached to the protrusion.

19. 19. The battery pack according to claim 18, wherein the part of the case is disposed between the protruding portions in a direction opposite to the protruding direction (Z-) from an end of the conductive connection portion in the protruding direction.

20. The monitoring device is attached to a side surface of the battery pack, The battery pack according to any one of claims 12 to 19, wherein the acquisition device is attached to an upper surface of the assembled battery via the protrusion.

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