Battery monitoring device and battery monitoring circuit

Abstract

To provide a battery monitoring device that can reduce influence of noise.SOLUTION: A battery monitoring device 70 is connected to a plurality of battery cells. The battery monitoring device 70 comprises: a battery monitoring IC 40 for monitoring a plurality of battery cells; and a circuit board 50 that connects a battery monitoring IC with the battery cells. The battery monitoring circuit includes: a plurality of first ADCs 41 that are connected to a positive electrode terminal and a negative electrode terminal of each battery cell and output an electric signal for complex impedance measurement of each battery cell; and a plurality of second ADCs 42 that are connected to the positive electrode terminal and the negative electrode terminal of each battery cell and output an electric signal for state detection of each battery cell. The circuit board 50 includes: the first ADCs; and a plurality of terminal pairs connected to object cells as battery cells corresponding to the first ADC, respectively. The terminal pairs are individually provided for the first ADCs.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to a battery monitoring device and a battery monitoring circuit. [Background technology]

[0002] As disclosed in Patent Document 1, there is a battery monitoring device that monitors a battery having a plurality of battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-95746 A Summary of the Invention [Problem to be solved by the invention]

[0004] A battery monitoring device may have a configuration in which two conversion circuits for converting analog signals into digital signals are connected to each battery cell. The conversion circuits are connected to the positive and negative terminals of the battery cell via wiring. One of the two conversion circuits outputs an electrical signal for measuring the complex impedance of the battery cell.

[0005] In such a configuration, the battery monitoring device may be connected to the battery cells by common wiring in the conversion circuits corresponding to adjacent battery cells. In this case, it is difficult to use differential pair wiring. Therefore, the battery monitoring device may output an electrical signal for complex impedance measurement that is affected by noise.

[0006] One disclosed object is to provide a battery monitoring device and a battery monitoring circuit that can reduce the effects of noise. [Means for solving the problem]

[0007] The battery monitoring device disclosed herein is A battery monitoring device connected to a plurality of battery cells (11 to 18), The battery monitoring circuit (40) monitors a plurality of battery cells, and a circuit board (50) connects the battery monitoring circuit and the battery cells, The battery monitoring circuit is a plurality of first conversion circuits (41) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for measuring the complex impedance of each battery cell; a plurality of second conversion circuits (42) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for detecting the state of each battery cell; A first conversion circuit and a second conversion circuit are connected in pair to each battery cell; The circuit board is a plurality of terminal pairs (60a) connected to a first conversion circuit and a target cell which is a battery cell corresponding to the first conversion circuit; The terminal pair is characterized in that it is provided individually for the first conversion circuit.

[0008] In this way, the battery monitoring device includes a plurality of first conversion circuits that output a battery voltage for complex impedance measurement of each battery cell. A terminal pair connected to each first conversion circuit and a target cell is provided individually for each first conversion circuit. This makes it easy to connect the battery monitoring device to the plurality of battery cells with differential pair wiring. Therefore, the battery monitoring device can output a battery voltage for state detection from the second conversion circuit, and output a battery voltage for complex impedance measurement with reduced effects of noise from the first conversion circuit.

[0009] The battery monitoring circuit disclosed herein also includes: A battery monitoring circuit connected to a plurality of battery cells (11-18) via a circuit board (50) and monitoring the battery cells, a plurality of first conversion circuits (41) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for measuring the complex impedance of each battery cell; a plurality of second conversion circuits (42) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for detecting the state of each battery cell; a circuit terminal pair (40a) connected to each of the first conversion circuits and a target cell which is a battery cell corresponding to each of the first conversion circuits; A first conversion circuit and a second conversion circuit are connected in pair to each battery cell; The circuit terminal pairs are characterized in that they are individually provided for each of the first conversion circuits.

[0010] In this way, the battery monitoring circuit includes a plurality of first conversion circuits that output a battery voltage for measuring the complex impedance of each battery cell. A circuit terminal pair connected to each first conversion circuit and the target cell is provided individually for each first conversion circuit. This makes it easy to connect the battery monitoring circuit to the plurality of battery cells with differential pair wiring. Therefore, the battery monitoring circuit can output a battery voltage for state detection from the second conversion circuit, and output a battery voltage for complex impedance measurement with reduced noise effects from the first conversion circuit.

[0011] The aspects disclosed in this specification adopt different technical means to achieve their respective objectives. The claims and the parenthetical symbols described in this section are illustrative of the corresponding relationship with the embodiments described below, and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the following detailed description and the attached drawings. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a schematic configuration of a battery device in a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 is a cross-sectional view taken along line III-III in FIG. [Figure 4]FIG. 2 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 2 is a cross-sectional view taken along line VV in FIG. 1. [Figure 6] 1 is a diagram showing a schematic configuration of a battery monitoring device and a flexible substrate in a first embodiment. [Figure 7] 13 is a diagram showing a schematic configuration of a battery device according to a second embodiment. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 8 is a cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 8 is a cross-sectional view taken along line XX in FIG. [Figure 11] 13 is a diagram showing a schematic configuration of a battery device according to a third embodiment. [Figure 12] 12 is a cross-sectional view taken along line XII-XII in FIG. 11. [Figure 13] 13 is a cross-sectional view taken along line XIII-XIII in FIG. 11. [Figure 14] 14 is a cross-sectional view taken along line XIV-XIV in FIG. 11. [Figure 15] 13 is a diagram showing a schematic configuration of a battery device according to a fourth embodiment. [Figure 16] 16 is a cross-sectional view taken along line XVI-XVI in FIG. 11. [Figure 17] FIG. 12 is a cross-sectional view taken along line XVII-XVII in FIG. [Figure 18] FIG. 13 is a cross-sectional view taken along line XVIII-XVIII in FIG. [Figure 19] 13 is a diagram showing a schematic configuration of a battery monitoring device and a flexible substrate in a fifth embodiment. [Figure 20] 13 is a diagram showing a schematic configuration of a battery monitoring device and a flexible substrate in a sixth embodiment. [Figure 21] 13 is a diagram showing a schematic configuration of a flexible substrate in a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other parts of the configuration may be applied by referring to the other embodiment described previously.

[0014] <Battery device> The battery device of this embodiment will be described with reference to Figs. 1 to 6. As shown in Fig. 1, the battery device mainly includes a battery pack 10, a flexible substrate 30, and a battery monitoring device 70. The battery device is configured to be mountable on a moving object, for example. The moving object may be, for example, a vehicle, an aircraft, a ship, a construction machine, or an agricultural machine. The battery device may also be called a battery system. In this embodiment, as an example, a battery device including a battery pack 10 including a plurality of battery cells 11 to 18 is used. However, it is sufficient for the battery device to include a plurality of battery cells 11 to 18. In other words, the plurality of battery cells 11 to 18 do not have to be divided into units called battery packs 10.

[0015] In the assembled battery 10, a plurality of battery cells 11-18 are arranged side by side. In the assembled battery 10, a plurality of battery cells 11-18 are connected in series. A flexible substrate 30 is connected to each of the battery cells 11-18. The flexible substrate 30 is also connected to a battery monitoring device 70. The assembled battery 10 is connected to the battery monitoring device 70 via the flexible substrate 30. In the battery device, each of the battery cells 11-18 is monitored by the battery monitoring device 70. In the present embodiment, as an example, one assembled battery 10 and one battery monitoring device 70 corresponding to the assembled battery 10 are adopted. However, the present disclosure is not limited thereto. The battery device may include a plurality of assembled batteries 10 and a plurality of battery monitoring devices 70 corresponding to each assembled battery 10. In addition, the battery device may include a plurality of assembled batteries 10 and a battery monitoring device 70 provided in common to the plurality of assembled batteries 10. Furthermore, the battery device may include a microcomputer connected to the battery monitoring device 70. In this case, the flexible substrate 30 may be provided in common to the multiple battery packs 10 and the multiple battery monitoring devices 70. The flexible substrate 30 may also be provided in common to the multiple battery packs 10 and one battery monitoring device 70.

[0016] <Battery pack> For example, lithium ion secondary batteries, nickel hydride secondary batteries, etc. can be used for each of the battery cells 11 to 18. In the present embodiment, as an example, the battery pack 10 includes eight battery cells 11 to 18. However, the battery pack 10 may include any number of battery cells.

[0017] As shown in FIG. 1, each of the battery cells 11-18 has positive terminals 11p-18p and negative terminals 11n-18n at both ends in the longitudinal direction. More specifically, the first battery cell 11 has a first positive terminal 11p and a first negative terminal 11n. The second battery cell 12 has a second positive terminal 12p and a second negative terminal 12n. The third battery cell 13 has a third positive terminal 13p and a third negative terminal 13n. The fourth battery cell 14 has a fourth positive terminal 14p and a fourth negative terminal 14n. The fifth battery cell 15 has a fifth positive terminal 15p and a fifth negative terminal 15n. The sixth battery cell 16 has a sixth positive terminal 16p and a sixth negative terminal 16n. The seventh battery cell 17 has a seventh positive terminal 17p and a seventh negative terminal 17n. The eighth battery cell 18 has an eighth positive terminal 18p and an eighth negative terminal 18n.

[0018] The bus bars 21 to 29 are connected to the terminals 11p to 18p, 11n to 18n. The first bus bar 21 is connected to the first negative terminal 11n. The second bus bar 22 is connected to the first positive terminal 11p and the second negative terminal 12n. The third bus bar 23 is connected to the second positive terminal 12p and the third negative terminal 13n. The fourth bus bar 24 is connected to the third positive terminal 13p and the fourth negative terminal 14n. The fifth bus bar 25 is connected to the fourth positive terminal 14p and the fifth negative terminal 15n. The sixth bus bar 26 is connected to the fifth positive terminal 15p and the sixth negative terminal 16n. The seventh bus bar 27 is connected to the sixth positive terminal 16p and the seventh negative terminal 17n. The eighth bus bar 28 is connected to the seventh positive terminal 17p and the eighth negative terminal 18n. The ninth bus bar 29 is connected to the eighth positive terminal 18p. In this manner, the multiple battery cells 11-18 are connected in series via the bus bars 22-28.

[0019] <Flexible circuit board> The flexible substrate 30 will be described with reference to Figures 1 to 5. In Figure 1, for ease of understanding, upper layer wiring 31 is indicated by solid lines and lower layer wiring 32 is indicated by dotted lines. Similarly, vias 33 are indicated by cross marks (cross lines).

[0020] The flexible substrate 30 is connected to the positive electrode terminals 11p-18p and negative electrode terminals 11n-18 of the multiple battery cells 11-18. The flexible substrate 30 is a substrate for connecting the battery monitoring device 70 and the assembled battery 10. The flexible substrate 30 corresponds to a wiring substrate. In this embodiment, a flexible substrate is used as an example of the wiring substrate. However, a rigid substrate can also be used as the wiring substrate. Note that the flexible substrate 30 only needs to be connected to the multiple battery cells 11-18, and does not have to correspond to the unit of the assembled battery 10.

[0021] 2 to 5, flexible substrate 30 includes electrically insulating base material 34 and wiring 3 provided on base material 34. Wiring 3 includes upper layer wiring 31 and lower layer wiring 32 laminated via base material 34, and vias 33 that electrically connect upper layer wiring 31 and lower layer wiring 32 of different layers. Wiring 3 is covered by base material 34 with its ends exposed. The ends of wiring 3 are connection portions with bus bars 21 to 29 and circuit board 50.

[0022] The vias 33 are mainly made of a conductive material such as copper or silver, etc. The vias 33 connect the upper layer wiring 31 and the lower layer wiring 32. The vias 33 correspond to an interlayer connection member.

[0023] The upper layer wiring 31 and the lower layer wiring 32 are mainly composed of conductive materials such as aluminum and copper. The upper layer wiring 31 and the lower layer wiring 32 are formed by patterning a conductive thin film. The upper layer wiring 31 and the lower layer wiring 32 are laminated in the thickness direction of the base material 34. The upper layer wiring 31 and the lower layer wiring 32 correspond to pattern wiring. The upper layer wiring 31 and the lower layer wiring 32 can also be called layer wiring.

[0024] 1 and other figures, the wiring 3 has a plurality of wiring portions 301-309 individually connected to the bus bars 21-29. Each of the wiring portions 301-309 is composed of an upper layer wiring 31, a via 33, and a lower layer wiring 32. Each of the wiring portions 301-309 has one end connected to the bus bars 21-29 and the other end connected to the circuit board 50.

[0025] Specifically, the first wiring portion 301 is connected to the first bus bar 21. The second wiring portion 302 is connected to the second bus bar 22. The third wiring portion 303 is connected to the third bus bar 23. The fourth wiring portion 304 is connected to the fourth bus bar 24. The fifth wiring portion 305 is connected to the fifth bus bar 25. The sixth wiring portion 306 is connected to the sixth bus bar 26. The seventh wiring portion 307 is connected to the seventh bus bar 27. The eighth wiring portion 308 is connected to the eighth bus bar 28. The ninth wiring portion 309 is connected to the ninth bus bar 29.

[0026] Each of the wiring portions 301-309 has a configuration in which a portion thereof connected to each of the bus bars 21-29 is exposed from the base material 34. Similarly, each of the wiring portions 301-309 has a configuration in which a portion thereof connected to the circuit board 50 is exposed from the base material 34. The portion connected to the circuit board 50 is a part of the connector portion 60.

[0027] As described above, the second bus bar 22 to the eighth bus bar 28 are connected to the terminals of two adjacent battery cells. Therefore, the second wiring portion 302 to the eighth wiring portion 308 are provided in common to the two adjacent battery cells. The second wiring portion 302 to the eighth wiring portion 308 correspond to a common wiring.

[0028] Therefore, the second wiring portion 302 to the eighth wiring portion 308 are connected to the positive electrode terminal of one of the two battery cells 11 to 18, and are connected to the negative electrode terminal of the other battery cell. Furthermore, each of the second wiring portion 302 to the eighth wiring portion 308 is branched into a positive electrode wiring portion and a negative electrode wiring portion. In other words, each of the second wiring portion 302 to the eighth wiring portion 308 includes a positive electrode wiring portion and a negative electrode wiring portion. The positive electrode wiring portions 302p to 309p are also referred to as positive electrode wiring portions 3p. On the other hand, the negative electrode wiring portions 301n to 308n are also referred to as negative electrode wiring portions 3n.

[0029] Specifically, the second wiring portion 302 branches into a second positive wiring portion 302p and a second negative wiring portion 302n. The second positive wiring portion 302p is a portion that functions as a wiring connected to the first positive terminal 11p. The second negative wiring portion 302n is a portion that functions as a wiring connected to the second negative terminal 12n.

[0030] The third wiring portion 303 branches into a third positive wiring portion 303p and a third negative wiring portion 303n. The third positive wiring portion 303p functions as a wiring connected to the second positive terminal 12p. The third negative wiring portion 303n functions as a wiring connected to the third negative terminal 13n.

[0031] The fourth wiring portion 304 branches into a fourth positive wiring portion 304p and a fourth negative wiring portion 304n. The fourth positive wiring portion 304p functions as a wiring connected to the third positive terminal 13p. The fourth negative wiring portion 304n functions as a wiring connected to the fourth negative terminal 14n.

[0032] The fifth wiring portion 305 branches into a fifth positive wiring portion 305p and a fifth negative wiring portion 305n. The fifth positive wiring portion 305p functions as a wiring connected to the fourth positive terminal 14p. The fifth negative wiring portion 305n functions as a wiring connected to the fifth negative terminal 15n.

[0033] The sixth wiring portion 306 branches into a sixth positive wiring portion 306p and a sixth negative wiring portion 306n. The sixth positive wiring portion 306p functions as a wiring connected to the fifth positive terminal 15p. The sixth negative wiring portion 306n functions as a wiring connected to the sixth negative terminal 16n.

[0034] The seventh wiring portion 307 branches into a seventh positive wiring portion 307p and a seventh negative wiring portion 307n. The seventh positive wiring portion 307p functions as a wiring connected to the sixth positive terminal 16p. The seventh negative wiring portion 307n functions as a wiring connected to the seventh negative terminal 17n.

[0035] The eighth wiring portion 308 branches into an eighth positive wiring portion 308p and an eighth negative wiring portion 308n. The eighth positive wiring portion 308p functions as a wiring connected to the seventh positive terminal 17p. The eighth negative wiring portion 308n functions as a wiring connected to the eighth negative terminal 18n.

[0036] The first wiring portion 301 is connected to only the first negative electrode terminal 11n of one first battery cell 11 among the multiple terminals 11p-18p, 11n-18n. Therefore, the first wiring portion 301 is also referred to as a first negative electrode wiring portion 301n. Similarly, the ninth wiring portion 309 is connected to only the eighth positive electrode terminal 18p of one eighth battery cell 18 among the multiple terminals 11n-18n, 11p-18p. The ninth wiring portion 309 is also referred to as a ninth positive electrode wiring portion 309p.

[0037] Furthermore, as shown in Figs. 2 and 4, the positive wiring portion 3p and the negative wiring portion 3n are configured as differential pair wiring. That is, the flexible substrate 30 includes a plurality of differential pair wirings, that is, positive wiring portions 302p-309p connected to the positive terminals 11p-18p of the respective battery cells 11-18 and negative wiring portions 301n-308n connected to the negative terminals 11n-18n of the respective battery cells 11-18. The flexible substrate 30 has a plurality of differential pair wirings corresponding to the respective battery cells 11-18. Each differential pair wiring is provided with a positive wiring portion and a negative wiring portion running in parallel. The differential pair wiring corresponds to a pair wiring portion. The differential pair wiring is a wiring in which two wirings are arranged in parallel, and electronic signals of the same magnitude but opposite polarity are transmitted to each wiring.

[0038] Specifically, the flexible substrate 30 includes, as differential pair wirings, a first negative electrode wiring portion 301n and a second positive electrode wiring portion 302p, a second negative electrode wiring portion 302n and a third positive electrode wiring portion 303p, a third negative electrode wiring portion 303n and a fourth positive electrode wiring portion 304p, and a fourth negative electrode wiring portion 304n and a fifth positive electrode wiring portion 305p. Further, the flexible substrate 30 includes, as differential pair wirings, a fifth negative electrode wiring portion 305n and a sixth positive electrode wiring portion 306p, a sixth negative electrode wiring portion 306n and a seventh positive electrode wiring portion 307p, a seventh negative electrode wiring portion 307n and an eighth positive electrode wiring portion 308p, and an eighth negative electrode wiring portion 308n and a ninth positive electrode wiring portion 309p.

[0039] For example, the first negative electrode wiring portion 301n and the second positive electrode wiring portion 302p can be said to be differential pair wirings for the first battery cell 11. Also, the second negative electrode wiring portion 302n and the third positive electrode wiring portion 303p can be said to be differential pair wirings for the second battery cell 12. Note that each of the second wiring portion 302 to the eighth wiring portion 308 can also be said to be branched into a positive electrode wiring portion and a negative electrode wiring portion of different differential pair wirings. Further, the positive electrode wiring portions 302p to 309p and the negative electrode wiring portions 301n to 308n can also be said to be parts of the respective differential pair wirings. That is, it can be said that a differential pair wiring is formed by a part of the first negative electrode wiring portion 301n and a part of the second positive electrode wiring portion 302p.

[0040] Also, as shown in FIG. 4, in the differential pair wiring, the positive electrode wiring portions 302p to 309p and the negative electrode wiring portions 301n to 308n are provided in different layers via the base material 34. In the present embodiment, as an example, an example in which the positive electrode wiring portions 302p to 309p are constituted by the upper layer wiring 31 and the negative electrode wiring portions 301n to 308n are constituted by the lower layer wiring 32 is adopted. However, the present disclosure is not limited thereto.

[0041] Furthermore, as shown in FIG. 4, in the thickness direction of the base material 34, the positive electrode wiring portions 302p to 309p and the negative electrode wiring portions 301n to 308n of each differential pair wiring are arranged to face each other. That is, the positive electrode wiring portion and the negative electrode wiring portion constituting the differential pair wiring face each other in the thickness direction of the base material 34 and are provided so as to run parallel. For example, the first negative electrode wiring portion 301n connected to the first battery cell 11 and the second positive electrode wiring portion 302p are arranged to face each other in the thickness direction of the base material 34 and are provided so as to run parallel.

[0042] However, the present disclosure is not limited to this. The positive electrode wiring portion and the negative electrode wiring portion constituting the differential pair wiring may run parallel in the same layer. That is, the positive electrode wiring portion and the negative electrode wiring portion constituting the differential pair wiring may be provided in parallel in the same layer.

[0043] Each differential pair wiring is connected to each terminal pair 60a of the circuit board 50. The terminal pair 60a is a pair of two terminals of the circuit board 50. Therefore, the circuit board 50 has a plurality of terminal pairs 60a. The plurality of terminal pairs 60a are included in the connector portion 60. Each terminal pair 60a is individually connected to each first ADC 41. The circuit board 50 and the first ADC 41 will be described later.

[0044] As shown in FIGS. 1, 3, and 5, the flexible substrate 30 has a portion where the pattern wirings in the same layer cross each other. In the present embodiment, the lower layer wiring 32 crosses. Therefore, the flexible substrate 30 is provided with a relief wiring portion 35 for avoiding the crossing lower layer wiring 32. The relief wiring portion 35 includes a via 33 and an upper layer wiring 31.

[0045] In the present embodiment, the wiring 3 through which the electrical signal for measuring the complex impedance of the battery cells 11 to 18 and the electrical signal for detecting the states of the battery cells 11 to 18 flow is adopted. However, the flexible substrate 30 may be provided with wiring 3 other than the above.

[0046] <Battery monitoring device> With reference to FIGS. 1 and 6, the battery monitoring device 70 will be described. In FIG. 6, mainly, the portions corresponding to some of the battery cells 10m-1, 10m, and 10m+1 are illustrated. Note that the battery cell 10m-1 and the battery cell 10m+1 are battery cells adjacent to the battery cell 10m.

[0047] As shown in FIG. 6, the battery monitoring device 70 is connected to a plurality of battery cells 11 to 18. The battery monitoring device 70 includes a battery monitoring IC 40 that monitors the plurality of battery cells 11 to 18, and a circuit board 50 that connects the battery monitoring IC 40 and the plurality of battery cells 11 to 18. More specifically, the circuit board 50 is connected to the plurality of battery cells 11 to 18 via a flexible board 30. The battery monitoring IC 40 corresponds to a battery monitoring circuit. Note that the battery monitoring device 70 only needs to be connected to the plurality of battery cells 11 to 18, and does not necessarily need to correspond to the unit of the assembled battery 10.

[0048] The flexible board 30 and the circuit board 50 are connected by a plurality of first terminal portions 81 and a plurality of second terminal portions 82. The first terminal portion 81 and the second terminal portion 82 indicate the portions where the connection terminals of the flexible board 30 and the connection terminals of the circuit board 50 are connected. The first terminal portion 81 and the second terminal portion 82 are included in the connector portion 60. A pair of the first terminal portion 81 and the second terminal portion 82 includes one terminal pair 60a. Therefore, it can be said that the flexible board 30 and the circuit board 50 include a plurality of pairs of the first terminal portion 81 and the second terminal portion 82. Also, the connection terminals of the circuit board 50 with the flexible board 30 include a plurality of terminal pairs 60a and the like.

[0049] The battery monitoring IC 40 and the circuit board 50 are connected by a plurality of third terminal portions 91 and a plurality of fourth terminal portions 92. The third terminal portion 91 and the fourth terminal portion 92 indicate the portions where the connection terminals of the battery monitoring IC 40 and the connection terminals of the circuit board 50 are connected.

[0050] The connection terminals in the battery monitoring IC 40 include a circuit terminal pair 40a. The circuit terminal pair 40a is a pair of two terminals of the battery monitoring IC 40. The battery monitoring IC 40 has a plurality of circuit terminal pairs 40a. The plurality of circuit terminal pairs 40a are individually connected to the first ADCs 41. The plurality of circuit terminal pairs 40a are also individually connected to a plurality of terminal pairs 60a. Thus, each differential pair wiring is connected to each circuit terminal pair 40a via each terminal pair 60a.

[0051] As shown in Fig. 6, the battery monitoring IC 40 includes a first ADC 41, a second ADC 42, a complex impedance measuring circuit 43, a first voltage measuring circuit 44, a second voltage measuring circuit 45, an equalization circuit 46, an equalization switch 47, and a control circuit 48. In the drawing, the complex impedance measuring circuit 43 is indicated as ZC, the first voltage measuring circuit 44 as 1VC, the second voltage measuring circuit 45 as 2VC, the equalization circuit 46 as EC, and the control circuit 48 as CC. ADC is an abbreviation for Analog to digital converter. The first ADC 41 corresponds to the first conversion circuit. The second ADC 42 corresponds to the second conversion circuit.

[0052] The battery monitoring IC 40 has circuit terminal pairs 40a connected to each of the first ADCs 41 and a target cell corresponding to each of the first ADCs 41. The circuit terminal pairs 40a are provided individually for each of the first ADCs 41.

[0053] The first ADC 41, the second ADC 42, the complex impedance measuring circuit 43, the first voltage measuring circuit 44, and the second voltage measuring circuit 45 are provided corresponding to each of the multiple battery cells 11 to 18. The equalization circuit 46 and the equalization switch 47 are provided corresponding to each of the multiple battery cells 11 to 18. The control circuit 48 is provided in common to the multiple battery cells 11 to 18.

[0054] As described above, the battery monitoring IC 40 is provided with two ADCs 41, 42 for one battery cell. Therefore, the battery monitoring IC 40 has a plurality of first ADCs 41 and a plurality of second ADCs 42. In Fig. 6, as an example, the ADCs 41, 42 for the battery cell 10m-1, the ADCs 41, 42 for the battery cell 10m, the ADCs 41, 42 for the battery cell 10m+1, and the ADCs 41, 42 for the battery cell 10m+2 are illustrated.

[0055] The first ADC 41 for the battery cell 10m-1 and the first ADC 41 for the battery cell 10m+1 can also be considered as conversion circuits adjacent to the first ADC 41 for the battery cell 10m. The battery monitoring IC 40 includes a pair of second ADCs 42 connected to the same battery cell as each of the first ADCs 41.

[0056] The ADCs 41 and 42 convert analog signals into digital signals (hereinafter, AD conversion). The start timing of the conversion period is instructed to the ADCs 41 and 42 by the control circuit 48. The ADCs 41 and 42 convert the analog signals into digital signals for a predetermined period from the start timing. Below, the first ADC 41 and the second ADC 42 corresponding to the same battery cell will be described as a set.

[0057] An input terminal of the first ADC 41 is connected to a third terminal unit 91 and a fourth terminal unit 92. The third terminal unit 91 is connected to the first terminal unit 81. Meanwhile, the fourth terminal unit 92 is connected to the second terminal unit 82. The first ADC 41 is connected to a positive terminal and a negative terminal of one battery cell via the third terminal unit 91 and the fourth terminal unit 92.

[0058] It can be said that the first terminal unit 81 and the second terminal unit 82 connected to the first ADC 41 include the terminal pair 60a corresponding to the first ADC 41. For example, the first terminal unit 81 connected to the positive terminal of the battery cell 10m and the second terminal unit 82 connected to the negative terminal of the battery cell 10m include the terminal pair 60a corresponding to the first ADC 41 for the battery cell 10m. The first terminal unit 81 connected to the positive terminal of the battery cell 10m+1 and the second terminal unit 82 connected to the negative terminal of the battery cell 10m+1 include the terminal pair 60a corresponding to the first ADC 41 for the battery cell 10m+1.

[0059] The battery cell connected to the first ADC 41 corresponds to the target cell. As will be described later, the first ADC 41 outputs an electrical signal for measuring the complex impedance of the battery cell. Therefore, the target cell can also be called a measurement target cell.

[0060] An output terminal of the first ADC 41 is connected to the complex impedance measuring circuit 43. The first ADC 41 converts the voltage across the target cell into a digital signal and outputs it as an electrical signal for measuring the complex impedance of the target cell. The complex impedance measuring circuit 43 is a digital circuit that uses the electrical signal to calculate a complex voltage of a specific frequency. The complex voltage is a voltage for measuring the complex impedance. The control circuit 48 measures (calculates) the complex impedance of the target cell using the complex voltage output from the complex impedance measuring circuit 43. More specifically, the control circuit 48 is configured to be able to acquire a complex current flowing through the battery pack 10. The control circuit 48 then calculates the complex impedance using the complex voltage and the complex current.

[0061] In addition, in this embodiment, control circuit 48 is adopted as an example of a control circuit that measures the complex impedance of a target cell. However, the present disclosure is not limited thereto. The complex impedance of the target cell may be measured by a microcomputer. That is, the microcomputer may measure the complex impedance of the battery cells in the plurality of battery packs 10. In this case, the microcomputer is configured to be able to acquire the complex current flowing through the battery pack 10 and to be able to acquire the complex voltage from each battery pack 10. Therefore, the microcomputer is included in the control circuit of the claims. The microcomputer may be configured to be able to acquire the complex voltage and the complex current via a communication interface. The battery monitoring device 70 may include a microcomputer.

[0062] Furthermore, the output terminal of the first ADC 41 is connected to the first voltage measurement circuit 44. The first ADC 41 converts the voltage across the target cell into a digital signal and outputs it as an electrical signal for detecting the state of the target cell. That is, the electrical signal output by the first ADC 41 is used for complex impedance measurement and state detection. The first voltage measurement circuit 44 is a digital circuit that measures the battery voltage of the target cell using the electrical signal output from the first ADC 41. Also, it can be said that the first voltage measurement circuit 44 calculates the battery voltage for state detection. The first voltage measurement circuit 44 can adopt, for example, a low-pass filter or the like. The second voltage measurement circuit 45, which will be described later, is configured in the same way.

[0063] The input terminal of the second ADC 42 is connected to the third terminal portion 91 and the fourth terminal portion 92. The output terminal of the second ADC 42 is connected to the second voltage measurement circuit 45. The second ADC 42 converts the voltage across the target cell into a digital signal and outputs it as an electrical signal for detecting the state of the target cell.

[0064] The second voltage measuring circuit 45 is a digital circuit that measures the battery voltage of the target cell using the electrical signal output from the second ADC 42. The second voltage measuring circuit 45 can also be said to calculate a battery voltage for state detection. The second ADC 42 and the second voltage measuring circuit 45 are provided to monitor failures as the state of the target cell. The state of the target cell may include the state of the path leading to the target cell.

[0065] The control circuit 48 monitors for faults by comparing the measurement results of the first voltage measurement circuit 44 and the second voltage measurement circuit 45. The control circuit 48 determines that a fault has occurred, for example, when the two measurement results are different, or when there is a discrepancy between the two measurement results of a predetermined value or more. The measurement result is the battery voltage of the target cell.

[0066] As described above, the paired ADCs 41, 42 are connected to the third terminal 91 and the fourth terminal 92. However, the terminals 91, 92 connected to the second ADC 42 are different from the terminals 91, 92 connected to the input terminals of the paired first ADC 41. In other words, the second ADC 42 is connected to a terminal pair 60a linked to a first ADC 41 different from the first ADC 41 that is in the pair.

[0067] As an example, the ADCs 41 and 42 for the battery cell 10m will be used for explanation. The first ADC 41 is connected to a third terminal 91 and a fourth terminal 92 connected to the differential pair wiring for the battery cell 10m. On the other hand, the second ADC 42 is connected to a fourth terminal 92 connected to one of the differential pair wiring for the battery cell 10m+1 and a third terminal 91 connected to one of the differential pair wiring for the battery cell 10m-1. That is, the first ADC 41 is connected to the differential pair wiring for the target cell. On the other hand, the second ADC 42 is connected to the differential pair wiring for the two battery cells adjacent to the target cell. In this way, the second ADC 42 can be said to be connected to the terminal pair 60a connected to the adjacent conversion circuit. The connected terminal pair 60a can also be said to be the corresponding terminal pair 60a.

[0068] The ADCs 41 and 42 may have the same or different conversion frequencies for performing AD conversion. Here, as an example, the ADCs 41 and 42 with different conversion frequencies are adopted. The first ADCs 41 include a first high-frequency circuit and a first low-frequency circuit with different conversion frequencies. Similarly, the second ADCs 42 include a second high-frequency circuit and a second low-frequency circuit with different conversion frequencies. The low-frequency and high-frequency are relative conversion frequencies. The low-frequency circuit has a lower conversion frequency than the high-frequency circuit.

[0069] The first high-frequency circuit and the second low-frequency circuit have the same target cell and are provided as a pair. The first low-frequency circuit and the second high-frequency circuit have the same target cell and are provided as a pair. For example, the ADCs 41 and 42 corresponding to the battery cell 10m+1 are such that the first ADC 41 is the first low-frequency circuit and the second ADC 42 is the second high-frequency circuit. The ADCs 41 and 42 corresponding to the battery cell 10m are such that the first ADC 41 is the first high-frequency circuit and the second ADC 42 is the second low-frequency circuit. The ADCs 41 and 42 corresponding to the battery cell 10m-1 are such that the first ADC 41 is the first low-frequency circuit and the second ADC 42 is the second high-frequency circuit.

[0070] The first high-frequency circuit and the second high-frequency circuit can be considered as a main ADC. The first low-frequency circuit and the second low-frequency circuit can be considered as a sub-ADC. The first voltage measurement circuit 44 connected to the first high-frequency circuit and the second voltage measurement circuit 45 connected to the second high-frequency circuit can be considered as a main voltage measurement circuit. On the other hand, the first voltage measurement circuit 44 connected to the first low-frequency circuit and the second voltage measurement circuit 45 connected to the second low-frequency circuit can be considered as a sub-voltage measurement circuit.

[0071] Also, all the first ADCs 41 may have a higher conversion frequency than all the second ADCs 42. In this case, the first ADCs 41 have the same conversion frequency. Similarly, the first ADCs 41 have the same conversion frequency. Furthermore, the ADC to which the complex impedance measuring circuit 43 is connected may be one that can perform AD conversion with higher accuracy than an ADC to which the complex impedance measuring circuit 43 is not connected.

[0072] The equalization switch 47 is a switch for equalizing the capacity variations among the multiple battery cells 11 to 18. In other words, the equalization switch 47 is a switch for passing a current to equalize the capacities of the multiple battery cells 11 to 18. The equalization switch 47 is turned on and off under the control of the equalization circuit 46.

[0073] The first ADC 41 includes a connection conversion circuit to which the equalization switch 47 is connected, and a non-connection conversion circuit to which the equalization switch 47 is not connected. The first ADC 41 for the battery cell 10m+1 and the first ADC 41 for the battery cell 10m-1 correspond to the connection conversion circuit. The first ADC 41 for the battery cell 10m corresponds to the non-connection conversion circuit.

[0074] The circuit board 50 includes an electrically insulating base material and conductive wiring provided on the base material. The circuit board 50 is a so-called printed circuit board.

[0075] The wiring of the circuit board 50 includes a portion connecting the first terminal portion 81 and the third terminal portion 91, and a portion connecting the second terminal portion 82 and the fourth terminal portion 92. The circuit board 50 includes a filter circuit including, for example, a resistor and a capacitor.

[0076] The battery monitoring IC 40 is mounted on the circuit board 50. The circuit board 50 has connection terminals to which a plurality of circuit terminal pairs 40a are connected. The connection terminals are connected to wiring on the circuit board 50. The connection terminals can also be considered as part of the wiring on the circuit board 50.

[0077] Moreover, the circuit board 50 has terminal pairs 60a connected to each of the first ADCs 41 and a target cell corresponding to each of the first ADCs 41. The terminal pairs 60a are provided individually for each of the first ADCs 41. Therefore, the circuit board 50 has a plurality of terminal pairs 60a. The plurality of terminal pairs 60a are connected to wiring of the circuit board 50. The plurality of terminal pairs 60a can also be regarded as a part of the wiring of the circuit board 50.

[0078] <Effects> As described above, the flexible substrate 30 includes the upper layer wiring 31, the lower layer wiring 32, and the wiring 3 having the via 33. Therefore, the flexible substrate 30 can improve the degree of freedom in routing the wiring 3 compared to a single-layer substrate in which the wiring 3 is in a single layer. Therefore, the flexible substrate 30 can prevent the gap between the positive wiring portion and the negative wiring portion in the differential pair wiring from becoming wider.

[0079] In other words, the flexible substrate 30 makes it easy to form a differential pair wiring with a positive wiring portion and a negative wiring portion by improving the degree of freedom of routing of the wiring 3. Therefore, the flexible substrate 30 can reduce noise in the differential pair wiring. More specifically, the flexible substrate 30 can reduce induced noise between the positive wiring portion and the negative wiring portion that constitute the differential pair wiring. The main source of induced noise is the excitation current.

[0080] It can also be said that the flexible substrate 30 can reduce the area Z1 between the positive and negative wiring parts that configure the differential pair wiring. Therefore, the flexible substrate 30 can reduce noise in the differential pair wiring. The area Z1 can also be said to be a noise-affected area.

[0081] Furthermore, the flexible substrate 30 configures a differential pair wiring with the upper layer wiring 31 and the lower layer wiring 32. Therefore, the distance between the positive wiring portion and the negative wiring portion configuring the differential pair wiring can be determined by the thickness of the base material 34 disposed between the positive wiring portion and the negative wiring portion. Therefore, the flexible substrate 30 can narrow the distance between the positive wiring portion and the negative wiring portion of the differential pair wiring compared to when the differential pair wiring is configured with wiring on the same layer.

[0082] The battery monitoring device 70 includes a plurality of first ADCs 41 that output battery voltages for complex impedance measurement of each of the battery cells 11-18. A terminal pair 60a connected to each of the first ADCs 41 and the cell to be measured is provided individually for each of the first ADCs 41. This makes it easy for the battery monitoring device 70 to connect the plurality of battery cells 11-18 with differential pair wiring. Therefore, the battery monitoring device 70 can output a battery voltage for state detection from the second ADC 42, and output a battery voltage for complex impedance measurement with reduced effects of noise from the first ADC 41.

[0083] Therefore, the battery monitoring device 70 can accurately measure the complex impedance of each of the battery cells 11 to 18. In other words, the battery monitoring device 70 can measure the complex impedance in a state where the influence of inductive noise entering between the positive and negative wiring parts constituting the differential pair wiring is reduced. Note that the battery monitoring device 70 can reduce the number of terminals between the battery monitoring IC 40 and the circuit board 50 compared to the configuration of the sixth embodiment described later.

[0084] The battery device also includes a flexible substrate 30 and a battery monitoring device 70. Therefore, the battery device can output a battery voltage for complex impedance measurement with reduced effects of noise from the first ADC 41. The battery device can then measure the complex impedance of each of the battery cells 11-18 with high accuracy.

[0085] The above describes preferred embodiments of the present disclosure. However, the present disclosure is not limited to the above embodiments, and various modifications are possible within the scope of the present disclosure. Hereinafter, the second to seventh embodiments will be described as other aspects of the present disclosure. The above embodiments and the second to seventh embodiments can be implemented independently, but can also be implemented in appropriate combination. The present disclosure is not limited to the combinations shown in the embodiments, and can be implemented in various combinations.

[0086] Second embodiment A battery device of the second embodiment will be described with reference to Figs. 7 to 10. In the second embodiment, differences from the first embodiment will be mainly described. The second embodiment differs from the first embodiment in the flexible substrate 30. The components of the flexible substrate 30 in the second embodiment are the same as those in the first embodiment, but the layout of the wiring 3 differs from that in the first embodiment. Fig. 7 is a plan view corresponding to Fig. 1. The battery monitoring device 70 is omitted in Fig. 7.

[0087] 7, 8, and 9, the differential pair wiring is such that the upper and lower relationship in the lamination direction of the positive and negative wiring parts is partially swapped. For example, the eighth negative wiring part 308n includes the upper layer wiring 31 and the lower layer wiring 32. Similarly, the ninth positive wiring part 309p includes the upper layer wiring 31 and the lower layer wiring 32.

[0088] In both wiring sections 308n, 309p, the upper layer wiring 31 and the lower layer wiring 32 are partially swapped with vias 33 and escape wiring sections 35. In the eighth negative wiring section 308n, the upper and lower relationships are swapped in the order of the lower layer wiring 32, the upper layer wiring 31, the lower layer wiring 32, and the upper layer wiring 31 from the eighth battery cell 18 side. In the ninth positive wiring section 309p, the upper layer wiring 31, the lower layer wiring 32, the upper layer wiring 31, and the lower layer wiring 32 are swapped in the order of the eighth battery cell 18 side.

[0089] It is also preferable that the differential pair wirings be switched in upper and lower positions every time the differential pair wirings cross an even-numbered battery cell from the end.It is also preferable that the differential pair wirings be switched in upper and lower positions every two battery cells.

[0090] 10, an example is adopted in which the positive wiring portions 303p-309p are configured with the lower layer wiring 32 and the negative wiring portions 302n-308n are configured with the upper layer wiring 31 at the end portion on the circuit board 50 side of the differential pair wiring. Furthermore, the positive wiring portion 302p is configured with the upper layer wiring 31. The negative wiring portion 301n is configured with the lower layer wiring 32. However, the flexible substrate 30 may have the positive wiring portion 302p configured with the lower layer wiring 32 and the negative wiring portion 301n configured with the upper layer wiring 31 at the end portion on the circuit board 50 side.

[0091] The second embodiment can achieve the same effects as the first embodiment. Furthermore, in the flexible substrate 30, each differential pair wiring configures a twisted pair wiring. Therefore, the flexible substrate 30 can further reduce noise in the differential pair wiring.

[0092] In other words, a current flows between the positive and negative wiring parts that make up the differential pair wiring when magnetic flux passes between the two wiring parts. However, the direction of the current is reversed between adjacent wiring parts that are upside down. Therefore, the currents cancel each other out. Therefore, the electrical signals that flow through the differential pair wiring are less susceptible to external influences.

[0093] In addition, the magnetic flux generated by the electrical signals flowing through the differential pair wiring is inverted between adjacent wires that are upside down. Therefore, the magnetic fluxes cancel each other out. Therefore, the flexible substrate 30 is less likely to emit noise to the outside due to the electrical signals flowing through the differential pair wiring.

[0094] The battery monitoring device 70 is connected to each of the battery cells 11-18 via the flexible substrate 30. Therefore, the battery monitoring device 70 can measure the complex impedance in a state where the influence of inductive noise entering between the positive wiring portions 302p-309p and the negative wiring portions 301n-308n is further reduced.

[0095] Third embodiment With reference to FIGS. 11 to 14, the battery device according to the third embodiment will be described. In the third embodiment, mainly, the differences from the first embodiment will be described. In the third embodiment, the flexible substrate 30 is different from that in the first embodiment. The flexible substrate 30 in the third embodiment has the same components as those in the first embodiment, but the routing of the wiring 3 is different from that in the first embodiment. FIG. 11 is a plan view corresponding to FIG. 1. In FIG. 11, the battery monitoring device 70 is omitted.

[0096] As shown in FIGS. 11, 12, and 13, in the flexible substrate 30, the positive electrode wiring portions 302p to 309p and the negative electrode wiring portions 301n to 308n do not overlap in the stacking direction. That is, the differential pair wiring is arranged such that the positive electrode wiring portion and the negative electrode wiring portion are displaced in the width direction orthogonal to the plate thickness direction of the base material 34. For example, the positive electrode wiring portion 309p and the negative electrode wiring portion 308n are in a displaced positional relationship in the width direction. Therefore, the positive electrode wiring portion and the negative electrode wiring portion constituting the differential pair wiring face each other and run parallel in an oblique positional relationship.

[0097] Also, as shown in FIG. 14, at the end on the circuit board 50 side of the differential pair wiring, the positive electrode wiring portions 302p to 309p are constituted by the upper layer wiring 31, and the negative electrode wiring portions 301n to 308n are constituted by the lower layer wiring 32.

[0098] Note that the width direction coincides with the longitudinal direction of each of the battery cells 11 to 18. Also, it can be said that the width direction is orthogonal to the plate thickness direction of the base material 34 and is also orthogonal to the arrangement direction of the plurality of battery cells 11 to 18.

[0099] The third embodiment can achieve the same effects as the first embodiment.

[0100] (Fourth Embodiment) With reference to FIGS. 15 to 18, the battery device according to the fourth embodiment will be described. In the fourth embodiment, mainly, the differences from the second embodiment will be described. The fourth embodiment is different from the second embodiment in that the flexible substrate 30 is different. The flexible substrate 30 in the fourth embodiment has the same components as those in the second embodiment, but the routing of the wiring 3 is different from that in the second embodiment. FIG. 15 is a plan view corresponding to FIG. 1. In FIG. 15, the battery monitoring device 70 is omitted.

[0101] As shown in FIGS. 15, 16, and 17, in the width direction orthogonal to the thickness direction of the base material 34, the differential pair wiring is arranged such that the positive electrode wiring portion and the negative electrode wiring portion are displaced in position. Further, in the vertical relationship in the stacking direction of the positive electrode wiring portion and the negative electrode wiring portion, the differential pair wiring is partially interchanged. That is, it can be said that the fourth embodiment is a combination of the second embodiment and the third embodiment. Therefore, in the flexible substrate 30, each differential pair wiring constitutes a twisted pair wiring.

[0102] For example, the eighth negative electrode wiring portion 308n includes the upper layer wiring 31 and the lower layer wiring 32. Similarly, the ninth positive electrode wiring portion 309p includes the upper layer wiring 31 and the lower layer wiring 32. And in the upper layer wiring 31, a part of the ninth positive electrode wiring portion 309p and a part of the eighth negative electrode wiring portion 308n are alternately arranged. In the lower layer wiring 32, a part of the ninth positive electrode wiring portion 309p and a part of the eighth negative electrode wiring portion 308n are alternately arranged.

[0103] As shown in FIG. 18, the differential pair wiring is configured in the same manner as in the second embodiment at the end on the circuit board 50 side. However, at the end on the circuit board 50 side of the flexible substrate 30, the positive electrode wiring portion 302p may be constituted by the lower layer wiring 32 and the negative electrode wiring portion 301n may be constituted by the upper layer wiring 31.

[0104] The fourth embodiment can achieve the same effects as the second embodiment and the third embodiment.

[0105] (Fifth Embodiment) A battery device of the fifth embodiment will be described with reference to Fig. 19. In the fifth embodiment, differences from the first embodiment will be mainly described. The fifth embodiment differs from the first embodiment in the battery monitoring IC 40. Fig. 19 is a circuit diagram corresponding to Fig. 6.

[0106] In the battery monitoring IC 40, a common first ADC 41 is provided for adjacent conversion circuits. That is, one first ADC 41 is provided corresponding to two adjacent battery cells. As in the first embodiment, a complex impedance measuring circuit 43 and a first voltage measuring circuit 44 are connected to the first ADC 41. On the other hand, a second voltage measuring circuit 45 is connected to the second ADC 42.

[0107] For example, one first ADC 41 corresponds to battery cell 10m and battery cell 10m+1. The target cells of this first ADC 41 are battery cell 10m and battery cell 10m+1. Furthermore, another first ADC 41 corresponds to battery cell 10m-1 and battery cell 10m-2. The target cells of this first ADC 41 are battery cell 10m-1 and battery cell 10m-2.

[0108] Therefore, the second ADC 42 and the first ADC 41 are connected to the battery cell 10m+1 and the battery cell 10m-1. When monitoring for faults in the battery cell 10m+1 and the battery cell 10m-1, the control circuit 48 compares the measurement results of the first voltage measurement circuit 44 and the measurement results of the second voltage measurement circuit 45.

[0109] On the other hand, the battery cell 10m and the battery cell 10m-2 are connected to two first ADCs 41. When monitoring for faults in the battery cell 10m and the battery cell 10m-2, the control circuit 48 compares the measurement result of one first voltage measurement circuit 44 with the measurement result of the other first voltage measurement circuit 44.

[0110] In this embodiment, ADCs 41, 42 with different conversion frequencies may also be used. For example, in the ADCs 41, 42 corresponding to the battery cell 10m+1 and the battery cell 10m-1, the first ADC 41 is the first low-frequency circuit and the second ADC 42 is the second high-frequency circuit. In the ADCs 41, 42 corresponding to the battery cell 10m and the battery cell 10m-2, the common first ADC 41 is the first low-frequency circuit and the other first ADC 41 is the first high-frequency circuit. However, the first ADC 41 and the second ADC 42 may have the same conversion frequency.

[0111] In this way, the battery monitoring IC 40 includes a first ADC 41 provided in common to the two battery cells. Therefore, the common first ADC 41 is connected to the battery cells via a multiplexer (MUX) 49. The multiplexer 49 is controlled by a control circuit 48. Therefore, the common first ADC 41 is selectively connected to the two battery cells.

[0112] The third embodiment can achieve the same effects as the first embodiment. Furthermore, the third embodiment can reduce the number of first ADCs 41 compared to the first embodiment. The fifth embodiment can be implemented in combination with the second to fourth embodiments and the seventh embodiment.

[0113] Sixth embodiment A battery device of the sixth embodiment will be described with reference to Fig. 20. In the sixth embodiment, differences from the first embodiment will be mainly described. The sixth embodiment differs from the first embodiment in the battery monitoring IC 40. Fig. 20 is a circuit diagram corresponding to Fig. 6.

[0114] The first ADC 41 has a higher conversion frequency than the second ADC 42. Moreover, each of the first ADCs 41 has the same conversion frequency. Similarly, each of the first ADCs 41 has the same conversion frequency.

[0115] 20 , the battery monitoring device 70 includes a fifth terminal unit 93 in addition to the third terminal unit 91 and the fourth terminal unit 92. The fifth terminal unit 93 is a terminal unit that connects the battery monitoring IC 40 and the circuit board 50. The fifth terminal unit 93 is a terminal unit for the second ADC 42.

[0116] Although the battery monitoring device 70 has a larger number of terminals than the first embodiment, like the first embodiment, it can output a battery voltage for complex impedance measurement with reduced effects of noise from the first ADC 41. The sixth embodiment can be implemented in combination with the second to fourth embodiments and the seventh embodiment.

[0117] Seventh embodiment A battery device according to a seventh embodiment will be described with reference to Fig. 21. In the seventh embodiment, differences from the first embodiment will be mainly described. The seventh embodiment differs from the first embodiment in the flexible substrate 30. Fig. 21 is a circuit diagram corresponding to Fig. 4.

[0118] 21, similarly to the first embodiment, the multiple differential pair wirings are arranged side by side in the width direction perpendicular to the plate thickness direction of the substrate 34. The positive and negative wiring parts of adjacent differential pair wirings have different widths. For example, the differential pair wirings connected to even-numbered battery cells have a wider wiring width than the differential pair wirings connected to odd-numbered battery cells. Or, the differential pair wirings connected to odd-numbered battery cells have a wider wiring width than the differential pair wirings connected to even-numbered battery cells.

[0119] The seventh embodiment can achieve the same effects as the first embodiment. Furthermore, in the flexible substrate 30, the wiring that passes the current is arranged alternately to equalize the capacitance variation. Therefore, it is preferable that the flexible substrate 30 has a wide wiring width as described above to increase the allowable current and reduce the resistance. The seventh embodiment can be implemented in combination with the second to fourth embodiments.

[0120] Although the present disclosure has been described based on the embodiment, it is understood that the present disclosure is not limited to the embodiment or structure. The present disclosure also encompasses various modifications and modifications within the equivalent range. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and concept of the present disclosure. [Explanation of symbols]

[0121] 10... battery pack, 11... first battery cell, 12... second battery cell, 13... third battery cell, 14... fourth battery cell, 15... fifth battery cell, 16... sixth battery cell, 17... seventh battery cell, 18... eighth battery cell, 30... flexible substrate, 3... wiring, 31... upper layer wiring, 32... via, 33... lower layer wiring, 34... substrate, 302p... second positive electrode wiring portion, 303p... third positive electrode wiring portion, 304p... fourth positive electrode wiring portion, 305p... fifth positive electrode wiring portion, 306p... sixth positive electrode wiring portion, 307p... seventh positive electrode wiring portion, 308p... eighth positive electrode wiring portion, 309p... ninth positive electrode wiring portion, 3 01n...first negative wiring section, 302n...second negative wiring section, 303n...third negative wiring section, 304n...fourth negative wiring section, 305n...fifth negative wiring section, 306n...sixth negative wiring section, 307n...seventh negative wiring section, 308n...eighth negative wiring section, 40...battery monitoring IC, 40a...circuit terminal pair, 41...first ADC, 42...second ADC, 43...complex impedance measuring circuit, 44...first voltage measuring circuit, 45...second voltage measuring circuit, 46...equalizing circuit, 47...equalizing switch, 48...control circuit, 50...circuit board, 60a...terminal pair, 70...battery monitoring device

Claims

1. A battery monitoring device connected to a plurality of battery cells (11 to 18), A battery monitoring circuit (40) that monitors a plurality of battery cells, and a circuit board (50) that connects the battery monitoring circuit and the battery cells, The battery monitoring circuit includes: a plurality of first conversion circuits (41) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for measuring the complex impedance of each battery cell; a plurality of second conversion circuits (42) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for detecting the state of each battery cell; the first conversion circuit and the second conversion circuit are connected in pair to each battery cell; The circuit board includes: a plurality of terminal pairs (60a) connected to the first conversion circuit and a target cell which is the battery cell corresponding to the first conversion circuit; The battery monitoring device according to claim 1, wherein the terminal pair is provided individually for the first conversion circuit.

2. a complex impedance measuring circuit (43) connected to each of the first conversion circuits and configured to calculate a complex voltage for measuring complex impedance based on an electrical signal output from the first conversion circuit; 2. The battery monitoring device according to claim 1, further comprising: a control circuit (48) for measuring a complex impedance of the target cell based on the complex voltage.

3. the first conversion circuits output electrical signals for measuring the complex impedance and for detecting the state, a first voltage measurement circuit (44) connected to each of the first conversion circuits and configured to calculate the battery voltage for state detection based on the electrical signal output from the first conversion circuit; a second voltage measurement circuit (45) connected to each second conversion circuit and configured to calculate the battery voltage for state detection based on the electrical signal output from the second conversion circuit; The battery monitoring device described in claim 2, characterized in that the control circuit detects the state of the target cell based on the battery voltages output from the first voltage measurement circuit and the second voltage measurement circuit connected to a pair of the first conversion circuit and the second conversion circuit.

4. The plurality of first conversion circuits include a first high-frequency circuit and a first low-frequency circuit having different conversion frequencies; The plurality of second conversion circuits include a second high-frequency circuit and a second low-frequency circuit having different conversion frequencies, 4. A battery monitoring device according to claim 3, wherein the first high-frequency circuit and the second low-frequency circuit are provided in a pair, and the first low-frequency circuit and the second high-frequency circuit are provided in a pair.

5. 4. The battery monitoring device according to claim 3, wherein the first conversion circuit performs conversion more frequently than the second conversion circuit.

6. The battery monitoring device according to any one of claims 1 to 5, characterized in that the second conversion circuit is connected to the terminal pair of the first conversion circuit that is different from the first conversion circuit that forms a pair with the second conversion circuit.

7. an equalization switch (47) for equalizing capacity variations among the plurality of battery cells; A battery monitoring device as described in any one of claims 2 to 5, characterized in that the multiple first conversion circuits include a connection conversion circuit to which the equalization switch is connected and a non-connection conversion circuit to which the equalization switch is not connected.

8. A battery monitoring circuit connected to a plurality of battery cells (11 to 18) via a circuit board (50) and monitoring the battery cells, a plurality of first conversion circuits (41) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for measuring the complex impedance of each battery cell; a plurality of second conversion circuits (42) connected to the positive and negative terminals of each battery cell, converting an analog signal into a digital signal, and outputting an electrical signal for detecting the state of each battery cell; a circuit terminal pair (40a) connected to each of the first conversion circuits and a target cell which is the battery cell corresponding to each of the first conversion circuits; the first conversion circuit and the second conversion circuit are connected in pair to each battery cell; The battery monitoring circuit is characterized in that the circuit terminal pair is provided individually for each first conversion circuit.

Images