Battery module and method for inspecting the battery module

Abstract

Provided are a battery module which can be efficiently inspected without applying an electrical load to the battery module and a method for inspecting the battery module.　This battery module has a battery 13 equipped with a battery container 13a accommodating battery elements, a thermistor 23 disposed in contact with an outer surface of the battery container 13a and thermally connected thereto, and an electrically-insulating, rigid insulation cover 17 partially covering the battery container 13a and pushing the thermistor 23 against the battery container 13a, wherein a through-hole 26 through which a heat-application means 28, 29 passes is formed in the insulation cover 17, and the thermistor 23 is disposed at a position outside a heat-application area formed when the through-hole 26 is orthographically projected on a planar section 21 of the battery container 13a.

Description

Technical Field

[0001] The present invention relates to a battery module configured by connecting a plurality of unit cells, and a method for inspecting the battery module.

Background Art

[0002] For example, an electrolyte battery including a positive electrode layer and a negative electrode layer capable of occluding / releasing lithium ions has been widely used as a high-energy density battery in various fields such as electric vehicles, power storage, and information devices. Note that an electrolyte battery using a liquid electrolyte or a solid electrolyte is known.

[0003] In a secondary battery using an electrolyte battery, a battery module is composed of a battery pack in which a plurality of unit cells (electrolyte batteries) are connected. By electrically connecting the unit cells to each other with an electrode member (hereinafter referred to as a bus bar) made of a conductive metal such as aluminum, copper, or iron, a large amount of power can be obtained.

[0004] In addition, the battery module includes a pair of external terminals that enable power transfer of the battery module. The bus bar and the pair of module external terminals are mainly composed of an insulating member made of engineering plastic that insulates adjacent bus bars from each other and insulates a high-voltage part including the module external terminals.

[0005] Here, the battery module includes a temperature detector such as a thermistor for detecting its own temperature, acquires battery temperature information, and uses it for charge / discharge control of the battery module. In particular, a battery module mounted on an automobile or the like is used under a wide range of ambient temperatures including a low temperature state to a high temperature state. Since the input / output characteristics and life characteristics of the battery are temperature-dependent, battery temperature information is essential for appropriately controlling the charge / discharge of the battery module.

[0006] In a battery module equipped with such a temperature detector, from the viewpoint of product quality, it is necessary to confirm whether the temperature detector is operating normally. For this reason, generally, the battery module is operated to raise the temperature of the battery module, and the operation of the temperature detector is confirmed based on whether this temperature change can be detected. However, this method is not a good solution because it applies an electrical load to the battery module.

[0007] As a method for solving such problems, for example, the technology described in Japanese Patent Application Laid-Open No. 2016-9663 (Patent Document 1) is known. In this Patent Document 1, a heat transfer plate provided in contact with the side surface of the battery is heated by an external heat source such as a heater, a temperature change is caused in a thermistor attached to the upper surface of the battery, and the operation of the thermistor is confirmed from this temperature change.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] By the way, in Patent Document 1, there is a problem that an efficient inspection cannot be performed well. For example, there are one or more problems such as the need for work processes for attaching and detaching the heat transfer plate, the inspection work is troublesome, or the power consumption of a heat source such as a heater for heating the heat transfer plate increases, or since heat is applied to the temperature detector through the heat transfer plate, the temperature rise is slow and it takes time to confirm the operation of the temperature detector.

[0010] An object of the present invention is to provide a battery module capable of performing an efficient inspection without applying an electrical load to the battery module, and an inspection method for this battery module.

Means for Solving the Problems

[0011] A typical feature of the present invention is that it comprises a battery having a battery container that houses a battery element, a temperature detector that is in contact with and thermally connected to the outer surface of the battery container, and a covering member that has electrical insulation and rigidity and covers a portion of the battery container and brings the temperature detector into contact with the battery container, the covering member having an inspection through-hole through which a heat-applying means passes, and the temperature detector is positioned outside the heat-applying area, which is the projection area of the inspection through-hole onto the outer surface of the battery container. [Effects of the Invention]

[0012] In the present invention, by directly heating or cooling the heat application area using a heat application means through an inspection through-hole provided in the covering member, the temperature near the temperature detector can be raised or lowered in a short time, allowing for efficient inspection. [Brief explanation of the drawings]

[0013]

Figure 1

Figure 2

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Figure 10

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Figure 12

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Figure 16

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments and includes various modifications and application examples within the scope of the technical concept of the present invention.

Examples

[0015] FIG. 1 shows a battery module according to an embodiment of the present invention as viewed obliquely from above. The descriptions of "up / down / left / right / front / rear" shown in FIGS. 1 and 2 indicate the viewing direction of the battery module shown in FIGS. 1 and 2. Therefore, when describing the directions of "up / down / left / right / front / rear" hereinafter, the description will be based on the viewing directions shown in FIGS. 1 and 2.

[0016] In FIGS. 1 and 2, the housing 11 constituting the battery module 10 has a generally elongated rectangular parallelepiped shape in which the dimension in the longitudinal direction (front-rear direction) is larger than the dimensions in the short-side direction (left-right direction) and the height direction (up-down direction), and holds a plurality of unit cells 13 (see FIG. 2) constituting the battery pack 12. More specifically, the housing 11 includes a plurality of cell holders 14 (see FIG. 2), a pair of end plates 15, a pair of side plates 16, an insulation cover (inner covering member) 17, and a module cover (outer covering member) 18. The end plates 15 and the side plates 16 are firmly fixed by fixing members 19 such as fixing bolts and rivets as shown in FIG. 1.

[0017] Incidentally, the unit cell 13 incorporates a battery element composed of an electrolyte, a positive electrode layer, a negative electrode layer, etc. inside. As the electrolyte, a liquid or solid one can be used.

[0018] The cell holder 14 (see FIG. 2) is made of a resin material, for example, polybutylene terephthalate (PBT). The cell holder 14 is interposed between adjacent unit cells 13 of a plurality of unit cells 13 laminated in the front-rear direction, and holds each unit cell 13 so as to sandwich it from both sides in the thickness direction (front-rear direction).

[0019] In the longitudinal direction (front-rear direction) of the plurality of unit cells 13 constituting the battery pack 12, battery pack terminals 10P and 10N (see FIG. 2), which are external terminals of the battery module 10, are respectively provided on a pair of cell holders 14 arranged at both ends of the battery pack 13. Here, the module terminal 10P is a battery pack positive electrode terminal, and the module terminal 10N is a battery pack negative electrode terminal.

[0020] The pair of end plates 15 are plate-shaped members made of metal. This pair of end plates 15 are arranged on both sides of the battery pack 12 via a pair of cell holders 14 arranged on both sides of the battery pack 12 in the stacking direction (front-rear direction) of the plurality of unit cells 13 that make up the battery pack 12. The pair of end plates 15 face each other so as to sandwich the plurality of unit cells 13 whose one surface is held by the cell holder 14, and a fixing portion 15a is provided on the other surface facing the outside opposite to the battery pack 12.

[0021] The fixing portion 15a provided on the pair of end plates 15 is generally formed in a cylindrical shape, and a part of the cylindrical side surface protrudes from the outer plane of the end plate 15 toward the front or rear direction of the assembled battery. The fixing portion 15a has a bolt hole along the central axis parallel to the height direction (vertical direction) of the end plate 15.

[0022] The fixing portion 15a of this end plate 15 is a fixing member attachment portion for fixing the battery module 10 to an external mechanism such as a vehicle or other machinery. The lower end surface of the fixing portion 15a of this end plate 15 is the support surface 11a of the housing 11 supported by the above external mechanism.

[0023] That is, the battery module 10 can be fixed to the external mechanism by supporting the support surface 11a of the housing 11, which is the bottom surface of the fixing portion 15a of the end plate 15, by the external mechanism, and screwing and fastening the bolt inserted through the bolt hole of the fixing portion 15a to the female screw or nut of the external mechanism. In other words, the battery module 10 is fixed to the external mechanism by bolts and is in a state of being supported by the external mechanism at least at the support surface 11a of the housing 11, which is the lower end surface of the fixing portion 15a of the end plate 15.

[0024] When the battery module 10 is mounted on a vehicle such as an electric vehicle or a hybrid vehicle, the external mechanism to which the battery module 10 is fixed is the vehicle body of these vehicles. Although not particularly limited, when the vehicle to which the battery module 10 is fixed is placed on a horizontal road surface, the length direction (front-rear direction) and the width direction (left-right direction) of the housing 11 of the battery module 10 are generally parallel in the horizontal direction, and the height direction (up-down direction) of the housing 11 of the battery module 10 is generally parallel in the vertical direction. Also, in this state, the support surface 11a of the housing 11 is generally parallel to the horizontal plane.

[0025] The pair of side plates 16 are arranged via cell holders 14 on both sides in the width direction (left-right direction) of the plurality of unit cells 13 constituting the battery pack 12. The pair of side plates 16 are generally rectangular plate-shaped metal members, and are arranged to face each other on both sides in the width direction (left-right direction) of the housing 11.

[0026] The pair of side plates 16 are generally rectangular, and the stacking direction (front-rear direction) of the plurality of unit cells 13 constituting the battery pack 12 is the long side direction, that is, the longitudinal direction, and the height direction (up-down direction) of the plurality of unit cells 13 constituting the battery pack 12 is the short side direction, that is, the short side direction.

[0027] Both end portions in the longitudinal direction of the pair of side plates 16 are respectively fastened to the pair of end plates 15 by fixing members 19 such as rivets and bolts. Both end portions in the short side direction of the pair of side plates 16 are respectively engaged with concave groove portions provided in the cell holders 14.

[0028] The insulation cover 17 is a plate-shaped member made of a resin having electrical insulation such as PBT and having a predetermined rigidity, and is arranged to face the upper end surface of the battery container 13a provided with the cell positive electrode terminal 13p and the cell negative electrode terminal 13n of the unit cell 13. Here, the predetermined rigidity means a rigidity such that the insulation cover 17 does not deform unnecessarily when attached to the battery module 10. That is, it is sufficient if the insulation cover 17 has sufficient rigidity.

[0029] The insulation cover 17 has openings that expose the upper end surfaces of the cell positive terminals 13p and cell negative terminals 13n of the multiple unit batteries 13, and partition walls that provide insulation between the cell positive terminals 13p and cell negative terminals 13n of adjacent unit batteries 13 and between adjacent bus bars 2.

[0030] The partition wall of the insulation cover 17 is provided to surround the cell positive terminal 13p, the cell negative terminal 13n, and the bus bar 20 of the unit battery 13. The insulation cover 17 also accommodates various electrical wiring connected to the battery group 12 and an electronic circuit board that constitutes a battery control device (not shown).

[0031] The electronic circuit board (not shown) is disposed between the insulation cover 17 and the module cover 18, i.e., on the opposite side of the insulation cover 17 from the battery group 12 in the height direction of the housing 11, and is electrically connected to a plurality of bus bars 20 and a temperature sensor (thermistor) (not shown) for detecting the temperature of the unit battery 1 via connecting conductors such as lead wires or printed wiring.

[0032] In FIG. 2, the battery module 10 mainly comprises module terminals 10P, 10N (see FIG. 2) which are external terminals, a battery group 12 including a plurality of unit batteries 13, and a bus bar 20 which electrically and mechanically connects the plurality of unit batteries 13 of the battery group 12 and electrically and mechanically connects the battery group 12 to the module terminals 10P, 10N.

[0033] The battery pack 12 is configured by stacking flat rectangular unit cells 13, that is, thin hexahedral or rectangular parallelepiped-shaped unit cells 13 whose thickness dimension is smaller than the width dimension and the height dimension, in the longitudinal direction (front-rear direction). The unit cell 13 is a rectangular lithium-ion battery, and includes a flat rectangular battery container 13a, an electrode group (not shown) housed inside the battery container 13a, an electrolytic solution, or a solid electrolyte sheet, and a pair of cell terminals 13p and 13n connected to the electrode group and disposed on the upper end surface in the height direction of the battery container 13a. Here, as described above, the cell terminal 13p is a positive electrode terminal, and the cell terminal 13n is a negative electrode terminal.

[0034] The cell terminals 13p and 13n of the unit cell 13 have a substantially rectangular parallelepiped three-dimensional shape protruding in the height direction from the upper end surface of the battery container 13a. Between the cell terminals 13p and 13n and the battery container 13a, and between the battery container 13a and the electrode group, they are electrically insulated by resin-made insulating members, respectively. The plurality of unit cells 13 constituting the battery pack 12 are alternately inverted by 180° so that the cell positive electrode terminal 13p of one unit cell 13 adjacent to each other and the cell negative electrode terminal 13n of the other unit cell 1 are adjacent in the stacking direction (front-rear direction) and stacked.

[0035] The bus bar 20 is a connection conductor that electrically and mechanically connects the plurality of unit cells 13 of the battery pack 12, and also electrically and mechanically connects the battery pack 12 and the module terminals 10P and 10N. The bus bar 20 that electrically and mechanically connects the plurality of unit cells 1 of the battery pack 12 is a plurality of bus bars 20A that electrically and mechanically connect between the unit cells 13, and is joined by welding to the upper end surfaces of the cell terminals 13p and 13n of the plurality of unit cells 13 of the battery pack 12 exposed in the opening of the insulation cover 17.

[0036] By electrically connecting the cell positive electrode terminal 13p of one unit cell 13 and the cell negative electrode terminal 13n of the other unit cell 13 among a pair of unit cells 13 adjacent to each other in the stacking direction by the bus bar 20A, a battery pack 12 in which all the unit cells 13 are electrically connected in series can be configured.

[0037] The bus bars 20 connecting the battery group 12 to the module terminals 10P, 10N are a pair of bus bars 20B arranged at both ends in the stacking direction of the unit batteries 13 of the battery group 12. One of the pair of bus bars 20B, 20B1, is electrically and mechanically connected to the cell positive terminal 13p of one of the pair of unit batteries 13 arranged at both ends in the stacking direction of the multiple unit batteries 13. The other of the pair of bus bars 20B, 20B2, is electrically and mechanically connected to the cell negative terminal 13n of the other of the pair of unit batteries 13 arranged at both ends in the stacking direction of the multiple unit batteries 13.

[0038] One end of one 20B1 of the pair of bus bars 20B is joined by welding to the upper end surface of the cell positive terminal 13p of the unit battery 13, and the other end is fastened by a fastening member such as a rivet or bolt to a module positive terminal 10P arranged on one side of the battery group 10 in the stacking direction of the unit batteries. One end of the other 20B2 of the pair of bus bars 20B is joined by welding to the upper end surface of the cell negative terminal 13n of the battery group 13, and the other end is fastened by a fastening member such as a rivet or bolt to a module negative terminal 10N arranged on the other side of the battery group 12 in the stacking direction of the unit batteries 13.

[0039] Returning to Fig. 1, module cover 18 is a plate-like member made of electrically insulating resin such as PBT, and is arranged at the upper end of housing 11 on the opposite side of housing 11 from battery group 12 in the height direction (vertical direction) of housing 11 so as to cover insulation cover 17 and the electronic circuit board. Terminal cover 18a is provided at a position on module cover 18 corresponding to module terminals 10P, 10N so as to cover the upper parts of module terminals 10P, 10N. Module cover 18 is fixed to the top of insulation cover 17 by engaging engagement claws 17b provided on frame portion 17a of insulation cover 17 with the side edges.

[0040] As will be described later, in this embodiment, inspection is performed after the battery module 10 has been assembled and before it has been sealed with the module cover 18.

[0041] The battery module 10 configured as described above has module terminals 10P, 10N electrically connected to an external generator or motor via an inverter device, which is a power conversion device, so that power can be exchanged between the battery module 10 and an external generator or motor via the inverter device.

[0042] Next, an embodiment of the present invention will be described. Fig. 3 shows a configuration for explaining the concept of an embodiment of the present invention, showing the state before the temperature detector is inspected. In this state, most of the components of the battery module 10 are assembled as shown in Fig. 2, and the battery module 10 is ready for inspection, and is in a state before the module cover 18 is sealed.

[0043] 3, as described above, the upper surface of the battery container 13a constituting the unit battery 13 has a cell positive terminal 13p and a cell negative terminal 13n, and a flat area 21 in which a temperature detector (hereinafter referred to as a thermistor) is disposed is formed between the cell positive terminal 13p and the cell negative terminal 13n. The battery container 13a is formed from a metal plate, which facilitates temperature transfer to the thermistor disposed in the flat area 21. Note that a thermistor may be provided for each battery container 13a, or a thermistor may be provided for each group of multiple battery containers 13a.

[0044] An insulation cover 17 is attached and fixed to the upper side of the side plates 16 that are integrated and sandwich the battery pack 12. The insulation cover 17 is formed with a terminal storage section 22 that stores the cell positive terminal 13p and the cell negative terminal 13n, and when the insulation cover 17 is attached to the battery pack 12, the cell positive terminal 13p and the cell negative terminal 13n are stored in this terminal storage section 22.

[0045] A storage recess 24 for storing the thermistor 23 is formed on the surface of the insulation cover 17 facing the battery group 12, and a spring means 25 having the function of pressing the thermistor 23 against the flat area 21 on the upper surface of the battery container 13a is disposed in this storage recess 24. The spring means 25 can be in various forms (for example, a coil spring, a leaf spring, etc.).

[0046] In this way, by storing the thermistor 23 in the insulation cover 17, the thermistor 23 and the insulation cover 17 can be handled together. This improves ease of handling during assembly, and because the inspection through-hole 26, which will be described later, is also formed in the insulation cover 17, the positional relationship between the thermistor 23 and the inspection through-hole 26 can be accurately determined, and further, wiring can be easily routed.

[0047] As shown by the dashed line, the thermistor 23 can be attached to the flat area 21 of the battery container 13a and pressed into contact with it by a resilient means 25 provided on the insulation cover 17. In either case, in this embodiment, the thermistor 23 contacts the flat area 21 of the battery container 13a to ensure a heat transfer path.

[0048] Therefore, when the insulation cover 17 is attached, the thermistor 23 is pressed against the flat area 21 on the upper surface of the battery container 13a by the elastic means 25, thereby forming a heat transfer path. As a result, the heat of the flat area 21 is detected by the thermistor 23 and used to control the charge and discharge of the battery module 10.

[0049] The thermistor 23 is pressed against the flat area 21 by the elastic means 25 to form a heat transfer path, but the contact state between the thermistor 23 and the flat area 21 of the battery container 13a may change for some reason. For example, if the thermistor 23 makes contact with the flat area 21 in a partially abutting state, the heat transfer area decreases, causing a problem in which the detection accuracy of the thermistor decreases.

[0050] Also, it is assumed that the thermistor 23 may malfunction or become abnormal during the assembly process. If the assembly is completed as it is, the battery module 10 itself will become a defective product, resulting in a problem.

[0051] Therefore, it is necessary to efficiently inspect whether the thermistor 23 is correctly attached and whether the thermistor itself has malfunctioned or become abnormal with a simple configuration.

[0052] Therefore, in the present embodiment, in a state where the insulation cover 17 is viewed from above, a test through-hole 26 is formed in the insulation cover 17 adjacent to the thermistor 23 attached to the insulation cover 17. Therefore, the test through-hole 26 and the thermistor 23 are necessarily arranged adjacent to each other while ensuring a predetermined distance.

[0053] In a state where the insulation cover 17 is assembled to the battery container 13a (see FIG. 4), in the planar region 21 of the battery container 13a, when viewed in a direction orthogonal to the planar region 21 of the battery container 13a, a heat application region 27 obtained by orthogonally projecting the test through-hole 26 onto the planar region 21 is virtually formed. Here, in the present embodiment, since the test through-hole 26 is circular, the heat application region 27 is also formed in a circular shape. Note that the test through-hole 26 is not limited to a circular shape and may be a rectangular shape, an elliptical shape, a polygon with five or more sides, etc. In short, it only needs to have a function that allows the heat application means described later to pass through.

[0054] Therefore, with the thermistor 23 placed on the planar region 21, the thermistor 23 and the heat application region 27 do not overlap, and the positional relationship between the inspection through-hole 26 formed in the insulation cover 17 and the thermistor 23 is directly reflected. For this reason, as will be described later, since the thermistor 23 is positioned outside the heat application region 27, it is possible to avoid contact between the heat application means and the thermistor 23. If the heat application means and the thermistor 23 were to come into direct contact, the contact state between the thermistor 23 and the planar region 21 of the battery container 13a would not be reflected, and there would be a risk that accurate inspection would become impossible.

[0055] Next, a specific inspection method for the thermistor 23 will be described with reference to FIGS. 4 and 5. Here, the difference between FIGS. 4 and 5 lies in that they have the same configuration except for the difference in the heat application means.

[0056] First, in FIG. 4, a battery module 10 that has been completely assembled is prepared before the module cover 18 is attached. In this state, the insulation cover 17 is attached to the battery container 13a, and the cell positive terminal 10P and the cell negative terminal 13n are housed in the terminal housing portion 22 of the insulation cover 17. In this state, the thermistor 23 is pressed and placed on the planar region 21 of the battery container 13a by the elastic means 25.

[0057] Next, the temperature control member 28, which is the heat application means, is moved so as to pass through the inspection through-hole 26 until it contacts the heat application region 27. For this reason, the inspection through-hole 26 is formed in a shape with a size through which the temperature control member 28 can pass. Also, in this embodiment, the temperature control member 28 uses a resistive heating element and is controlled to apply a certain amount of heat energy to the battery container 13a. As a result, a stable amount of heat can be continuously applied directly to the planar region 21 of the battery container 13a.

[0058] Moreover, by applying a certain amount of thermal energy, an accurate temperature change can be obtained. In this embodiment, since the temperature before and after a predetermined time has elapsed is detected to obtain a temperature difference, it is important to apply a certain amount of thermal energy for at least the predetermined time.

[0059] The heat applied to the heat application region 27 is transmitted through the planar region 21 of the battery container 13a and reaches the thermistor 23. The thermistor 23 changes its electrical resistance value in response to the heat thus transmitted, and the temperature can be measured. That is, the temperature can be measured by converting the electrical resistance value detected by the thermistor 23 into temperature using a conversion table.

[0060] Thus, in this embodiment, since thermal energy can be directly applied to the battery container 13a, a small amount of thermal energy is sufficient and the power consumption can be kept low. Also, since the thermistor 23 and the temperature control member 28 as the heating source are close to each other, heat is quickly transmitted to the thermistor 23, and it becomes possible to check the operation of the thermistor in a short time. Furthermore, since the temperature control member 28 is inserted into the inspection through-hole 26 formed in the insulation cover 17 to apply heat and then simply pulled out after the inspection is completed, the inspection work becomes simple.

[0061] And when no electrical resistance change of the thermistor 23 occurs even when heat is applied, it can be detected that a failure or abnormality has occurred in the thermistor 23 itself. Also, based on the amount of temperature change within a predetermined time, it can be detected whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept good. Note that the method for determining the contact between the thermistor 23 and the planar region 21 of the battery container 13a will be described later.

[0062] The temperature control member 28 described above used a resistance heating element to apply "warmth" to the battery container 13a, but it is also possible to apply "cold" to the battery container 13a using a Peltier element instead of the resistance heating element. In this case as well, the inspection method is the same as the method described above.

[0063] Further, in the present embodiment, it is important that the thermistor 23 is not exposed to the heat application region 27 formed by the inspection through-hole 26 so that the thermistor 23 and the temperature control member 28 do not mechanically interfere with each other. Further, in order to reduce the heat energy and the inspection time, it is necessary that the thermal resistance between the thermistor 23 and the heat application region 27 is small. For this reason, it is important that the thermistor 23 is installed in the vicinity of the heat application region 27.

[0064] Therefore, the positions of the thermistor 23 and the inspection through-hole 26 may be determined in a positional relationship that satisfies such conditions. In the present embodiment, as shown in FIG. 3, by bringing the thermistor 23 and the inspection through-hole 26 as close as possible to each other, the inspection through-hole 26 and the thermistor 23 are necessarily arranged adjacent to each other while ensuring a predetermined distance.

[0065] Next, another example of the heat application means will be described. FIG. 5 is different from the embodiment of FIG. 4 in that a laser irradiation device 29 is used as the heat application means.

[0066] First, in FIG. 5, a completed battery module 10 before mounting the module cover 18 is prepared. In this state, the insulation cover 17 is attached to the battery container 13a, and the cell positive electrode terminal 10P and the cell negative electrode terminal 13n are stored in the terminal storage portion 22 of the insulation cover 17. In this state, the thermistor 23 is pressed and placed on the flat region 21 of the battery container 13a by the elastic means 25.

[0067] Next, the laser irradiation member 29, which is the heat application means, is moved so as to be positioned on the upper surface of the inspection through-hole 26. For this reason, the inspection through-hole 26 is formed in a shape and size such that the laser beam 30 of the laser irradiation member 29 can reach the flat region 21 without interfering with the insulation cover 17 or the like. Further, in the present embodiment, a certain amount of light energy is managed so as to be applied to the battery container 13a. As a result, a stable light energy can be continuously applied directly and non-contact to the flat region 21 of the battery container 13a.

[0068] The laser light 30 applied to the heat application area 27 is converted into heat, travels through the planar area 21 of the battery container 13a, and reaches the thermistor 23. The thermistor 23 can measure the temperature by changing its resistance value in response to the heat conducted thereto. That is, the temperature can be measured by converting the output voltage from the thermistor 23 using a conversion table.

[0069] Thus, in this embodiment, since light energy can be directly applied to the battery container 13a, a small amount of light energy is sufficient and the power consumption can be kept low. Further, since the irradiation position of the thermistor 23 and the laser irradiation member 29 which is a heating source is close, heat is quickly transmitted to the thermistor 23, and it becomes possible to check the operation of the thermistor in a short time. Furthermore, since the laser irradiation member 29 is moved to irradiate the laser light 30 on the upper surface of the inspection through hole 26 formed in the insulation cover 17, and the laser irradiation member 29 is only moved after the inspection is completed, the inspection work becomes simple.

[0070] When the output voltage of the thermistor 23 is not generated even when heat is applied by the laser light 30, it can be detected that a failure or abnormality has occurred in the thermistor 23 itself. Further, it is possible to detect whether the contact between the thermistor 23 and the planar area 21 of the battery container 13a is kept good based on the amount of temperature change within a predetermined time.

[0071] Next, the configuration of the inspection system for the thermistor 23 and the method for inspecting whether the contact between the thermistor 23 and the planar area 21 of the battery container 13a is kept good will be described.

[0072] FIG. 6 shows the configuration of the inspection system necessary for the inspection. Note that the configurations and arrangement positions of the battery container 13a, the temperature control member 28, and the thermistor 23 in FIG. 6 are the same as those shown in FIG. 4.

[0073] In FIG. 6, the temperature control member control unit 32 provided in the inspection control device 31 executes heating control of the temperature control member 28 via the wiring 32L, and controls the heating start time, heating time, heating end time, heating energy amount, etc. The output voltage of the thermistor 23 generated by this heating is input to the temperature measurement unit 33 provided in the inspection control device 31 at a predetermined time period via the wiring 23L and is converted into temperature information. The temperature information can be obtained by using the "output voltage - temperature table". This temperature information is stored in the RAM area (not shown) of the inspection control device 31 at a predetermined time period.

[0074] The inspection control device 31 is provided with a temperature change value calculation unit 34, which calculates how much the temperature of the thermistor 23 has changed (difference) during a predetermined time, and this is input as the actual temperature change value (ΔTact) to the subsequent diagnosis unit 36. This actual temperature change value (ΔTact) can be obtained by reading the temperature information stored in the RAM area.

[0075] That is, it can be obtained by subtraction processing between the temperature information (T1) stored at a certain time and the temperature information (T2) stored at a time after a predetermined time from the time when the temperature information (T1) was obtained. The actual temperature change value (ΔTact) will be described with reference to FIG. 7. In addition, in this embodiment, when the temperature information (T1) and the temperature information (T2) are obtained, the heating by the temperature control member 28 is stopped for the temperature control member control unit 32.

[0076] The inspection control device 31 includes a storage unit 35 composed of a flash ROM or the like, and this storage unit 35 stores a temperature change threshold value (ΔTref), and this temperature change threshold value (ΔTref) is used as a judgment reference value for whether the contact between the thermistor 23 and the planar area 21 of the battery container 13a is kept good. This temperature change threshold value (ΔTref) is input to the subsequent diagnosis unit 36. The temperature change threshold value (ΔTref) will be described with reference to FIG. 7.

[0077] When the diagnostic unit 36 of the inspection control device 31 determines whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept in good condition, the result is sent to the output unit 37 and displayed on a display or the like, so that the operator can grasp the diagnostic result of the output unit 37.

[0078] If the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept in good condition, the operator attaches the module cover 18 to complete the assembly work. On the other hand, if the contact between the thermistor 23 and the planar region 21 of the battery container 13a is not kept in good condition, the operator corrects the mounting state of the thermistor 23 of the insulation cover 17, repeats the assembly again, and executes the same inspection again.

[0079] FIG. 7 explains how to obtain the actual temperature change value (ΔTact) and the temperature change threshold value (ΔTref). The horizontal axis represents the elapsed time, and the vertical axis represents the measured temperature of the thermistor 23. The solid line indicates the actual temperature, and the dashed line indicates the temperature when the contact state between the thermistor 23 and the planar region 21 is deliberately set to be poor. The temperature shown by the dashed line is used to obtain the above-described temperature change threshold value (ΔTref).

[0080] When heating starts at time (t0) by the temperature control member 28, the temperature of the thermistor 23 rises as shown by the solid line, and the temperature information measured by the thermistor is obtained at time (t1). The actual temperature at this time is temperature (T1). Then, at time (t2) after a predetermined time, the temperature information measured by the thermistor is obtained again. The actual temperature at this time is temperature (T2). Then, the temperature (T1) at time (t1) is subtracted from the temperature (T2) at time (t2) to obtain the actual temperature change value (ΔTact).

[0081] On the one hand, the temperature change threshold (ΔTref) is obtained in advance by means of experiments or simulations. In this case, as shown by the dashed line, the contact state between the thermistor 23 and the planar region 21 of the battery container 13a is assumed to be a non - qualified contact state (abnormal contact state) with slightly less reliable temperature information of the thermistor 23 compared to the qualified contact state (normal contact state) where the temperature information is reliable enough.

[0082] Therefore, if the actual temperature change value (ΔTact) is greater than the temperature change threshold (ΔTref), it is qualified (normal), and if the actual temperature change value (ΔTact) is less than the temperature change threshold (ΔTref), it is unqualified (abnormal).

[0083] Under the non - qualified contact state, when heating starts at time (t0) by the temperature control member 28, as shown by the dashed line, the temperature of the thermistor 23 rises, but its slope is smaller compared to the solid line. Then, the temperature information measured by the thermistor 23 at time (t1) is obtained. The actual temperature at this time is temperature (T1ref). Then, at time (t2) after a predetermined time, the temperature information measured by the thermistor 23 is obtained again. The actual temperature at this time is temperature (T2ref). Then, the temperature (T1ref) at time (t1) is subtracted from the temperature (T2ref) at time (t2) to obtain the temperature change threshold (ΔTref). Note that this temperature change threshold (ΔTref) serves as a judgment reference value and is stored in the flash ROM.

[0084] Therefore, by judging the relationship between the temperature change threshold (ΔTref) and the actual temperature change value (ΔTact), it can be determined whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept in good condition. When this judgment is executed, the inspection ends at time (t3).

[0085] It is preferable to stop heating the temperature adjustment member 28 after measuring the actual temperatures (T1) and (T2) and storing them in the RAM area before the step of determining the contact state (step S16) described later. This makes it possible to avoid unnecessary power consumption and to prevent thermistor 23 from being heated more than necessary.

[0086] Here, if the time required from time (t0) to time (t1) and the time required from time (t1) to time (t2) are set to the same length, the temperature change measurement conditions will match, allowing for accurate judgment. Alternatively, the temperature change rate may be determined by calculating (T2-T1) / (t2-t1). Using the temperature change rate in this way reduces the influence of variations, etc., allowing for more accurate judgment.

[0087] Next, a specific control flow executed by the inspection control device 31 will be described with reference to Fig. 8. This control flow is started when the inspection is to be performed (when an instruction to start inspection is issued from the inspection control device), and is thereafter executed at predetermined time intervals.

[0088] <Step S10> In step S10, the temperature adjustment member 28 is brought into contact with the flat area 21 of the battery container 13a at time (t0) in Fig. 7, and heating is initiated. Once heating is initiated, the process proceeds to step S11.

[0089] <Step S11> In step S11, at time (t1) when a predetermined time has elapsed since time (t0) in Fig. 7, temperature information (T1) is obtained from the thermistor 23 and stored in a predetermined area of RAM. Once the temperature information (T1) is obtained, the process proceeds to step S12.

[0090] <Step S12> In step S12, at time (t2) when a predetermined time has elapsed since time (t1) in FIG. 7, temperature information (T2) is acquired from the thermistor 23 and stored in a predetermined area of the RAM. When the temperature information (T2) is acquired, the process proceeds to step S13.

[0091] ≪Step S13≫ In step S13, since the temperature information (T1) is detected in step S11 and the temperature information (T2) is detected in step S12, and the first temperature (T1) and the second temperature (T2) are already stored in the RAM area, there is no need to heat the temperature control member 28, so the heating of the temperature control member 28 is stopped. When the heating of the temperature control member 28 is stopped, the process proceeds to step S14. This can prevent the consumption of extra power and can also prevent the thermistor 23 from being heated more than necessary.

[0092] ≪Step S14≫ In step S14, the temperature information (T1) stored in the RAM area and the temperature information (T2) stored in the RAM area are read out, the actual temperature change value (ΔTact) is calculated, and it is stored in a new RAM area. The calculation formula is "ΔTact = T2 - T1". When the actual temperature change value (ΔTact) is calculated, the process proceeds to step S14.

[0093] ≪Step S15≫ In step S15, the temperature change threshold value (ΔTref) stored in the flash ROM for the comparison determination to be executed in the next step is read out and stored in the RAM area. When the temperature change threshold value (ΔTref) is read out, the process proceeds to step S16.

[0094] ≪Step S16≫ In step S16, the actual temperature change value (ΔTact) obtained in step S14 and the temperature change threshold value (ΔTref) obtained in step S15 are compared and calculated. If the actual temperature change value (ΔTact) is large, the process proceeds to step 17; if the actual temperature change value (ΔTact) is small, the process proceeds to step 18.

[0095] When the actual temperature change value (ΔTact) is large, it indicates that the heat from the temperature control member 28 is being well transferred to the thermistor 23. That is, it means that the contact state between the thermistor 23 and the planar region 21 of the battery container 13a is normal.

[0096] On the other hand, when the actual temperature change value (ΔTact) is small, it indicates that the heat from the temperature control member 28 is not being well transferred to the thermistor 23. That is, it means that the contact state between the thermistor 23 and the planar region 21 of the battery container 13a is abnormal.

[0097] ≪Step S17≫ In step S16, since it has been determined that the contact state between the thermistor 23 and the planar region 21 of the battery container 13a is good, in step S17, the display device of the output unit 37 executes a display indicating normality (OK display). When the display indicating normality (OK display) is executed, the process proceeds to step S19.

[0098] ≪Step S18≫ On the other hand, in step S16, since it has been determined that the contact state between the thermistor 23 and the planar region 21 of the battery container 13a is not good, in step S17, the display device of the output unit 37 executes a display indicating abnormality (NG display). When the display indicating abnormality (NG display) is executed, the process exits to the end and the process is terminated. In this case, since the contact between the thermistor 23 and the planar region 21 of the battery container 13a is not kept good, the operator corrects the mounting state of the thermistor 23 of the insulation cover 17, reassembles it again, and executes the same inspection again.

[0099] ≪Step S19≫ In step S19, it is determined that good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, and the internal resistance of the battery group 12 is finally measured to check the resistance value. When this check is complete, the process skips to END and ends. In this case, it is determined that good contact is maintained between the thermistor 23 and the flat area 21 of the battery container 13a, and the internal resistance of the battery group 12 is normal, so the worker attaches the module cover 18 to the insulation cover 17, completing the assembly of the battery module 10.

[0100] The order of the process of determining the actual temperature change value (ΔTact) in step S14 and the process of determining the temperature change threshold value (ΔTref) in step S15 may be reversed. Also, the process of ending heating in step S13 may be executed between steps S14 and S18.

[0101] Furthermore, as described above, the "thermistor inspection" in steps S10 to S18 and the "battery resistance inspection" in step S19 can be carried out completely separately and independently, thereby enabling the inspection work to be carried out accurately.

[0102] Thus, in this embodiment, the battery 13 includes a battery container 13a containing a battery element, a thermistor 23 that is in contact with and thermally connected to the outer surface of the battery container 13a, and an insulation cover 17 that has electrical insulation and rigidity and covers part of the battery container 13a and presses the thermistor 23 against the battery container 13a, and the insulation cover 17 has an inspection through-hole 26 through which heat-applying means 28, 29 pass, and the thermistor 23 is positioned outside the heat-applying area when the inspection through-hole 26 is projected onto the flat surface 21 of the battery container 13a.

[0103] According to this, by directly heating or cooling the heat application area with heat application means 28, 29 through the inspection through-hole 26 provided in the insulation cover 17, the temperature near the thermistor 23 can be raised or lowered in a short time, allowing for efficient inspection.

[0104] Incidentally, the inspection through-hole 26 may be closed by a lid portion (not shown) provided on the insulation cover 17, or may be shielded from the outside by the module cover 18 without the lid portion on the insulation cover 17.

[0105] Furthermore, an inspection through-hole is also provided in the module cover 18 facing the insulation cover 17. After the module cover 18 is attached, it is also possible to perform an inspection by applying heat to the battery container 13 with a heat application means through the inspection through-holes formed in the module cover 18 and the insulation cover 17. According to this, the inspection can be performed after the assembly of the battery module 10 is completed.

Embodiment

[0106] Next, a second embodiment of the present invention will be described. The same reference numerals as in FIG. 3 denote components having the same functions, and the description will be omitted if not necessary.

[0107] The feature of this embodiment lies in that a heat application mark 38 is provided in the heat application region 27. In the heat application region 27 corresponding to the inspection through-hole 26, there is an optimal location for the heat application site. For example, considering the heat transfer efficiency, it is the site closest to the thermistor 23.

[0108] In FIG. 9, in the circular heat application region 27 formed in the planar region 21 of the battery container 13a, a heat application mark 38 is formed at the site closest to the thermistor 23 placed on the planar region. The heat application mark 38 is selected from, for example, a recessed hole, a dimple, a protrusion, and a paint coating. The recessed hole, the dimple, and the protrusion are preferably formed integrally with the planar region 21 by deforming the planar region 21. This is because the presence of the heat application mark 38 can suppress the inhibition of heat conduction to the thermistor 23 compared to a structure in which the heat application mark 38 is composed of a member different from the planar region 21. In addition, there is also an advantage that the processing cost of the heat application mark 38 can be kept low. Providing such a heat application mark 38 can facilitate the positioning of the temperature control member 28 and simplify the inspection work.

[0109] Also, when using laser light as the heat application means, if the heat application mark 38 is painted black, the temperature can be raised quickly. In this case, since it is only necessary to arrange the laser irradiation member 29 on the upper outer side of the insulation cover 17, it is not necessary to insert the temperature control member 28 into the inspection through hole 26, and the inspection work can be simplified.

Embodiment

[0110] Next, a third embodiment of the present invention will be described. The same reference numerals as those in FIG. 3 indicate components having the same functions, and the description will be omitted if not necessary.

[0111] The feature of this embodiment is that a protective sheet 39 is provided on the planar region 21 on the upper surface of the battery container 13a, but the protective sheet 39 is not provided at the site of the heat application region 27.

[0112] In FIG. 10, a protective sheet 39 is attached to the planar region 21 of the battery container 13a for insulation and protection. This protective sheet 39 is laid on the planar region 21 of the battery container 13a except for the portions surrounding the cell positive terminal 13p, the cell negative terminal 13n, and the thermistor 23. Thereby, insulation and protection are provided to the upper surface side of the battery container 13a. However, the protective sheet 39 is not laid in the heat application region 27 corresponding to the inspection through-hole 26 so as not to reduce the heat transfer efficiency. Therefore, the heating of the heat application region 27 by the temperature control member 28 and the laser irradiation member 29 is not obstructed by the protective sheet 39. Thus, since the movement of heat is not inhibited by the protective sheet 39, it is possible to improve the inspection accuracy and shorten the inspection time.

Embodiment

[0113] Next, a fourth embodiment of the present invention will be described. The same reference numerals as in FIGS. 1 and 2 denote components having the same functions, and the description will be omitted if not necessary.

[0114] The feature of this embodiment lies in that the lead wire of the thermistor 23 is placed on the upper surface of the insulation cover 17, that is, the surface on the opposite side of the battery pack 12. The insulation cover 17 of this embodiment is formed in a plate shape having a planar portion as a whole, different from the insulation cover 17 shown in FIG. 2, and the battery pack 12 is covered by the insulation cover 17.

[0115] In FIGS. 11 and 12, an opening 40 having a predetermined size is formed at one end of the insulation cover 17. The insulation cover 17 is plate-shaped with a planar portion as a whole and extends in the longitudinal direction along the stacking direction of the battery pack 12. The battery pack 12 is covered by the insulation cover 17.

[0116] The opening 40 is opened in a direction orthogonal to the stacking direction of the battery pack 12. Through this opening 40, a battery voltage detection terminal holder 41 made of synthetic resin and a thermistor voltage detection terminal holder 42 are exposed. A lid portion 43, also made of synthetic resin, is attached to the opening 40 so as to close the opening, excluding the battery voltage detection terminal holder 41 and the thermistor voltage detection terminal holder 42.

[0117] A battery voltage detection line housing portion 45 for housing a battery voltage detection line 44, which is a signal lead wire, is attached to the battery voltage detection terminal holder 41. Similarly, a thermistor voltage detection line housing portion 47 for housing a thermistor voltage detection line 46, which is a signal lead wire, is attached to the thermistor voltage detection terminal holder 42. Also, the battery voltage detection line 44 is connected to a socket 48, and the thermistor voltage detection line 46 is also connected to a socket 49.

[0118] The sockets 48 and 49 are fixed to the upper surface of the insulation cover 17 by appropriate fixing means (such as bolts, adhesion, engagement mechanisms, etc.). The socket 48 is connected to a battery control device provided in the battery module 10, and the socket 49 is connected to an inspection control device 31 (see FIG. 6).

[0119] As described above, the insulation cover 17 extends along the stacking direction (longitudinal direction) of the battery pack 12. Accordingly, inspection through-holes 26 are also formed along this direction. The inspection through-holes 26 are formed in two rows intermittently and continuously near both end faces in the short-side direction of the insulation cover 17.

[0120] And between these two rows of inspection through-holes 26, the above-described opening 40, battery voltage detection terminal holder 41, thermistor voltage detection terminal holder 42, lid portion 43, battery voltage detection line 44, battery voltage detection line housing portion 45, thermistor voltage detection line 46, thermistor voltage detection line housing portion 47, and sockets 48 and 49 are arranged.

[0121] By adopting the arrangement configuration as shown in FIGS. 11 and 12 in this way, the upper surface of the insulation cover 17 can be efficiently utilized.

Embodiment

[0122] In the embodiment described above, heat is applied to the flat region 21 on the upper surface of the battery container 13a from the outside of the insulation cover 17. However, a temperature control member can also be directly arranged on the flat region 21 on the upper surface of the battery container 13a. Next, a fifth embodiment of the present invention will be described. The same reference numerals as those in FIG. 3 indicate components having the same functions, and the description will be omitted if not necessary.

[0123] In FIG. 13, a temperature control member 50 is attached in a heat-transferable manner at a position corresponding to the heat application region 27 shown in FIG. 3. Although the temperature control member 50 is exemplarily arranged at a position corresponding to the heat application region 27, the point is that as long as the temperature control member 50 and the thermistor 23 are not in mechanical contact, the contact state between the thermistor 23 and the flat region 21 can be judged, so there is no need to be the heat application region 27. However, it is desirable to arrange them as close as possible.

[0124] The temperature control member 50 is made of a heating element having an electric resistance, and those using a nichrome wire, those using a PTC element, and those using a semiconductor element can be used. Needless to say, heating elements other than these can also be used, and a Peltier element that gives cold and heat can also be used.

[0125] This temperature control member 50 is arranged in the flat region 21 on the upper surface of the battery container 13a even after the assembly of the battery module 10 is completed. Therefore, by connecting the wiring 51 of the thermistor 23 and the wiring of the temperature control member 50 to the inspection control device 53, the same operations and effects as those of the above-described embodiment can be obtained. Here, the inspection control device 53 is the same as the inspection control device 31 shown in FIG. 6, and the method for judging the contact of the thermistor 23 is also the same as the control flow shown in FIG. 8.

[0126] Thus, in this embodiment, since the temperature control member 50 can directly apply thermal energy to the battery container 13a, a small amount of thermal energy is sufficient and the power consumption can be kept low. Further, since the thermistor 23 and the temperature control member 50 are close to each other, heat is quickly transferred to the thermistor 23, and it becomes possible to check the operation of the thermistor in a short time.

[0127] And when no output voltage of the thermistor 23 is generated even when heat is applied by the temperature control member 50, it can be detected that a failure or abnormality has occurred in the thermistor 23 itself. Further, it is possible to detect whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept good based on the amount of temperature change within a predetermined time.

Example

[0128] In the fifth embodiment described above, the inspection control device 53 provided outside is configured to determine whether the contact state between the thermistor 23 and the planar region 21 is good or not. However, it is also possible to determine whether the contact state between the thermistor 23 and the planar region 21 is good or not on board by the battery control device provided in the battery module 10 instead of the inspection control device 53. Note that the same reference numerals as those in FIG. 13 indicate components having the same functions, and the description will be omitted if not necessary.

[0129] In FIG. 14, the battery control device (which can be referred to as a heat application control device) 54 is disposed between the insulation cover 17 and the module cover 18. That is, the battery control device 54 is disposed on the side opposite to the side of the battery group 12 (see FIG. 2) of the insulation cover 17 in the height direction of the housing 11 (see FIG. 1), and is electrically connected to a plurality of bus bars 20 (see FIG. 2), the thermistor 23, the temperature control member 50, etc. via connection conductors such as lead wires and printed wirings. Note that the battery control device 54 can be attached to the insulation cover 17 or the module cover 18.

[0130] The battery control device 54 has a function of controlling the charge and discharge of the battery module 10, but since this is not related to the present invention, the description thereof will be omitted. Further, the battery control device 54 is provided with a function of determining whether the contact state between the thermistor 23 and the planar region 21 is good or not. The functional block thereof is shown in FIG. 15, and the function is substantially the same as that shown in FIG. 6.

[0131] In FIG. 15, the temperature control member control unit 55 provided in the battery control device 54 executes heating control of the temperature control member 50 via the wiring 52, and controls the heating start time, heating time, heating end time, heating energy amount, etc. The output voltage of the thermistor 23 generated by this heating is input to the temperature measurement unit 56 provided in the battery control device 54 at a predetermined time period via the wiring 51 and is converted into temperature information. The temperature information can be obtained by using the "output voltage - temperature table". This temperature information is stored in the RAM area (not shown) of the battery control device 54 at a predetermined time period.

[0132] The battery control device 54 is provided with a temperature change calculation unit 57, which calculates how much the temperature of the thermistor 23 has changed (difference) during a predetermined time, and this is input to the subsequent diagnosis unit 58 as an actual temperature change value (ΔTact). This actual temperature change value (ΔTact) can be obtained by reading the temperature information stored in the RAM area, and can be obtained by subtracting the temperature information (T1) stored at a certain time from the temperature information (T2) stored at a time after a predetermined time from the time when the temperature information (T1) was obtained.

[0133] The battery control device 54 is provided with a storage unit 59 composed of a flash ROM or the like, and this storage unit 59 stores a temperature change threshold value (ΔTref), and this temperature change threshold value (ΔTref) is used as a determination reference value for whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept good. This temperature change threshold value (ΔTref) is input to the subsequent diagnosis unit 58. The temperature change threshold value (ΔTref) is as described in FIG. 7.

[0134] When the diagnostic unit 58 of the battery control device 54 determines whether the contact between the thermistor 23 and the planar area 21 of the battery container 13a is kept in good condition, the result is sent to and stored in the storage unit 59. In this case, an error code is stored, and by reading this error code with a dedicated inspection device, an operator can grasp the diagnostic result.

[0135] FIG. 16 is a control flow for determining whether the contact between the thermistor 23 and the planar area 21 of the battery container 13a in the battery control device 54 is kept in good condition. Since most of the control steps are the same as the control flow in FIG. 8, the description of the same control steps is omitted.

[0136] ≪Step S10≫ - ≪Step S16≫ Since it is substantially the same as the control flow shown in FIG. 8, the description is omitted. However, in control step S10 of FIG. 8, the temperature control member 28 is used, while in control step S10 of FIG. 16, the temperature control member 50 is used, which is different.

[0137] ≪Step S20≫ If it is determined in step S16 that the contact between the thermistor 23 and the planar area 21 of the battery container 13a is not kept in good condition, then in step S20, an error code is stored in the storage unit 59. Since the storage unit 59 is composed of a flash ROM, the error code will not be lost even if the power is shut down. After storing the error code, it exits to the end and the process ends.

[0138] As a result of the operator analyzing the error code, since the contact between the thermistor 23 and the planar area 21 of the battery container 13a is not kept in good condition, the operator will correct the mounting state of the thermistor 23 on the insulation cover 17 and reassemble it again to deal with the situation. Then, by newly executing the control flow (replay flow) in FIG. 16, it is only necessary to confirm that the contact between the thermistor 23 and the planar area 21 of the battery container 13a is kept in good condition.

[0139] Thus, also in this embodiment, since thermal energy can be directly applied to the battery container 13a by the temperature control member 50, a small amount of thermal energy is sufficient and the power consumption can be kept low. Further, since the thermistor 23 and the temperature control member 50 are close to each other, heat is quickly transferred to the thermistor 23, and it becomes possible to check the operation of the thermistor in a short time.

[0140] And when heat is applied by the temperature control member 50 but the output voltage of the thermistor 23 is not generated, it is possible to detect that a failure or abnormality has occurred in the thermistor 23 itself. Further, it is possible to detect whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept good based on the amount of temperature change within a predetermined time.

[0141] Furthermore, in this embodiment, since the battery control device 54 is made to determine whether the contact between the thermistor 23 and the planar region 21 of the battery container 13a is kept good, the above-described diagnosis can be performed at an arbitrary timing while the battery module 10 is operating. For example, the control flow shown in FIG. 16 can be executed at the time of shipment or every time a predetermined time has elapsed after being mounted on a vehicle.

[0142] As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the spirit of the present invention described in the claims. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, or replace other configurations for a part of the configuration of each embodiment.

Explanation of Reference Numerals

[0143] 10…Battery module, 11…Housing, 12…Battery pack, 13…Unit cell, 13a…Battery container, 13p…Cell positive electrode terminal, 13n…Cell negative electrode terminal, 14…Cell holder, 15…End plate, 16…Side plate, 17…Insulation cover, 18…Module cover, 21…Planar region, 22…Terminal storage part, 20…Module cover, 23…Thermistor, 24…Storage recess, 25…Elastic means, 26…Inspection through hole, 27…Heat application region, 28…Temperature control member, 29…Laser irradiation member, 31…Control device, 32…Temperature control member control unit, 33…Temperature measurement unit, 34…Temperature change calculation unit, 35…Memory unit, 36…Diagnosis unit, 37…Output unit.

Claims

1. A battery including a battery container housing battery elements, a temperature detector in thermal contact with an outer surface of the battery container, and a covering member having electrical insulation and rigidity that covers a part of the battery container and brings the temperature detector into contact with the battery container, wherein an inspection through-hole through which a heat application means passes is formed in the covering member, and the temperature detector is disposed at a position outside a heat application region orthogonally projected onto the outer surface of the battery container through the inspection through-hole. A battery module characterized by the above.

2. The battery module according to Claim 1, wherein the temperature detector is disposed on the outer surface on the side of a cell positive terminal and a cell negative terminal provided on the battery container, the covering member is disposed so as to cover the temperature detector, and the temperature detector is disposed adjacent to the heat application region formed by the inspection through-hole. A battery module characterized by the above.

3. The battery module according to Claim 2, wherein the temperature detector is provided on the covering member at a position adjacent to the inspection through-hole formed in the covering member. A battery module characterized by the above.

4. The battery module according to Claim 2, wherein the heat application means transfers warm heat or cold heat to the battery container in contact with the heat application region. A battery module characterized by the above.

5. The battery module according to Claim 4, wherein the heat application means is made of a resistive heating element and transfers heat to the battery container in contact with the heat application region. A battery module characterized by the above.

6. The battery module according to Claim 2, wherein the heat application means applies heat to the battery container without contact with the heat application region. A battery module characterized by the above.

7. The battery module according to Claim 6, wherein the heat application means is made of a laser irradiation member and applies heat to the battery container by irradiating laser light onto the heat application region. A battery module characterized by the above.

8. The battery module according to any one of Claims 2 to 7, wherein a heat application mark is provided in the heat application region. A battery module characterized by the above.

9. The battery module according to any one of Claims 2 to 7, A protective sheet is laid in the region on the side where the temperature detector, the cell positive electrode terminal, and the cell negative electrode terminal of the battery container are located, excluding the heat application region. A battery module characterized by the above.

10. The battery module according to any one of Claims 2 to 7, wherein a plurality of the batteries are stacked in one direction to form a battery group, the covering member extends in the one direction so as to cover the battery group, and has an opening opened at a predetermined position, a signal lead wire of the temperature detector is drawn out from the opening, and the signal lead wire is arranged along the one direction of the covering member. A battery module characterized by the above.

11. The battery module according to Claim 10, wherein two rows of the inspection through holes are formed intermittently and continuously along the one direction at both ends in the direction orthogonal to the one direction in the covering member, and the signal lead wire is arranged between the two rows of the inspection through holes. A battery module characterized by the above.

12. The battery module according to Claim 11, wherein the signal lead wire is connected to a socket fixed to the covering member. A battery module characterized by the above.

13. An inspection method for a battery module, comprising: a heat application step of applying heat by the heat application means through the inspection through hole to the heat application region of the battery container of the battery module according to Claim 1; a temperature change value measurement step of obtaining temperature change values from the temperature detector before and after a predetermined time has elapsed after the heat application step; a diagnosis step of comparing the temperature change value with a predetermined temperature change threshold value after the temperature change value measurement step, and determining that the contact state between the temperature detector and the battery container is normal if the temperature change value is greater than the temperature change threshold value, and determining that the contact state between the temperature detector and the battery container is abnormal if the temperature change value is less than the temperature change threshold value. An inspection method for a battery module, characterized by performing the above steps.

14. An inspection method for a battery module, comprising: [[ID=2 ​ After the temperature change rate measurement step, compare the predetermined temperature change rate threshold value with the temperature change rate value. If the temperature change rate value is greater than the temperature change rate threshold value, it is determined that the contact state between the temperature detector and the battery container is normal. If the temperature change rate value is less than the temperature change rate threshold value, it is determined that the contact state between the temperature detector and the battery container is abnormal. A diagnosis step A method for inspecting a battery module, characterized by executing the above steps.

15. The method for inspecting a battery module according to claim 13, wherein The temperature change threshold value is a judgment reference value for judging whether the contact between the temperature detector and the outer surface of the battery container is kept good A method for inspecting a battery module, characterized by the above steps.

16. The method for inspecting a battery module according to claim 14, wherein The temperature change rate threshold value is a judgment reference value for judging whether the contact between the temperature detector and the outer surface of the battery container is kept good A method for inspecting a battery module, characterized by the above steps.

17. The method for inspecting a battery module according to claim 13 or claim 14, wherein When performing the heat application step, the heat application means contacts the heat application area and transfers heat, either warm or cold, to the battery container A method for inspecting a battery module, characterized by the above steps.

18. The method for inspecting a battery module according to claim 17, wherein The heat application means is a resistance heating element, and transfers heat to the battery container in contact with the heat application area A method for inspecting a battery module, characterized by the above steps.

19. The method for inspecting a battery module according to claim 13 or claim 14, wherein When performing the heat application step, the heat application means applies heat to the battery container without contact with the heat application area A method for inspecting a battery module, characterized by the above steps.

20. The method for inspecting a battery module according to claim 19, wherein The heat application means is a laser irradiation member, and irradiates the heat application area with laser light to apply heat to the battery container A method for inspecting a battery module, characterized by the above steps.

21. The method for inspecting a battery module according to claim 13 or claim 14, wherein After the diagnosis step, an internal resistance diagnosis step is performed to measure the internal resistance of the battery and determine the quality of the battery A method for inspecting a battery module, characterized by the above steps.

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