Busbar, battery module, electrical equipment, battery pack and vehicle

Abstract

The application discloses a busbar, comprising a body which is adapted to be connected with an electrode of a battery cell and is configured as a curved surface structure to ensure the connection between the busbar and the electrode when the battery cell is deformed by swelling. The application can cope with the stress generated when the battery module is deformed by swelling, ensure the stable connection between the electrode and the busbar, and maintain the stability of the resistance.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to a busbar, battery module, electrical equipment, battery pack, and vehicle. Background Technology

[0002] A busbar is an important electronic component, usually made of metal, used to connect and transmit current and signals. It has higher current transmission capacity and better stability, and is widely used in power battery modules, large-capacity air-cooled battery modules, large-capacity liquid-cooled battery modules, and home energy storage battery modules. However, traditional rigid connection busbars are prone to connection failure when the battery cells expand and deform. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a busbar that can cope with the stress generated by the expansion and deformation of the battery module, ensure a stable connection between the electrodes and the busbar, and maintain stable resistance.

[0004] The second objective of this invention is to provide a battery module.

[0005] The third objective of this invention is to provide an electrical device.

[0006] The fourth objective of this invention is to provide a battery pack.

[0007] The fifth objective of this invention is to provide a vehicle.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] An embodiment of a first aspect of the present invention provides a busbar, comprising: a body adapted to be connected to an electrode of a battery cell, and the body being configured as a curved structure to ensure the connection between the busbar and the electrode when the battery cell expands and deforms.

[0010] According to an embodiment of the present invention, the curved structure of the busbar can cope with the stress generated when the battery module expands and deforms, ensuring a stable connection between the electrode and the busbar and maintaining stable resistance.

[0011] In some embodiments, the cross-section of the body includes corrugations distributed sinusoidally or cosinely along a first direction.

[0012] In some embodiments, the wavelength of the ripple is λ, satisfying: 0mm < λ ≤ 30mm; and / or, the wave height of the ripple is h, satisfying: 0mm < h ≤ 10mm.

[0013] In some embodiments, the wavelength λ of the ripple and the wave height h of the ripple satisfy: 3≤λ / h≤7.

[0014] In some embodiments, there is a height difference d between adjacent peaks, satisfying: 0.1mm≤d≤0.5mm; and / or, there is a height difference d between adjacent troughs, satisfying: 0.1mm≤d≤0.5mm.

[0015] In some embodiments, the body is constructed as a flexible structure.

[0016] In some embodiments, the main body includes a plurality of sub-bodies stacked sequentially along the wave height direction.

[0017] In some embodiments, each of the sub-body materials is any one of copper, aluminum, and nickel.

[0018] In some embodiments, the body includes a first sub-body, a second sub-body, and a third sub-body stacked sequentially along the wave height direction, wherein the first sub-body is made of copper.

[0019] In some embodiments, the second subbody is made of aluminum.

[0020] In some embodiments, the third sub-body is made of nickel and is adapted to be connected to the electrodes of the battery cell.

[0021] In some embodiments, the busbar further includes a sensor embedded in the body.

[0022] In some embodiments, the sensor is embedded at the troughs of the upper surface of the body and at the crests of the lower surface of the body.

[0023] In some embodiments, there are multiple sensors.

[0024] In some embodiments, the sensor is an optical fiber sensor, and the outer layer of the optical fiber sensor has a protective layer for protecting the optical fiber sensor.

[0025] A second aspect of the present invention provides a battery module comprising at least two battery cells and a busbar as described in the above embodiments, wherein the body of the busbar is connected to the electrodes of the battery cells.

[0026] According to the battery module of the present invention, the curved body of the busbar can cope with the stress generated when the battery module expands and deforms, ensuring a stable connection between the electrode and the busbar and maintaining stable resistance.

[0027] In some embodiments, one busbar is connected to the positive electrode of one battery cell and the negative electrode of another battery cell respectively, and the body disposed between the positive electrode and the negative electrode is constructed as a curved structure to ensure the connection between the busbar and the electrode when the battery cell expands and deforms.

[0028] In some embodiments, a plurality of the said busbars are included.

[0029] A third aspect of the present invention provides an electrical device comprising at least two battery modules as described in the above embodiments.

[0030] According to the embodiments of the present invention, when the battery cell expands and deforms, the curved body of the busbar can cope with the stress generated by the expansion and deformation of the battery cell, ensuring a stable connection between the electrode and the busbar and maintaining stable resistance; the multiple battery modules of the electrical equipment have a large energy storage capacity and can provide long battery life.

[0031] A fourth aspect of the invention provides a battery pack comprising at least two battery modules as described in the above embodiments.

[0032] According to the battery pack of the present invention, when the battery cell expands and deforms, the curved body of the busbar can cope with the stress generated by the expansion and deformation of the battery cell, ensuring a stable connection between the electrode and the busbar and maintaining stable resistance; multiple battery modules enable the battery pack to have a large energy storage capacity, providing high range for loads such as vehicles.

[0033] A fifth aspect of the present invention provides a vehicle including a battery pack as described in the above embodiments, the battery pack being connected to the load of the vehicle. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a busbar body according to an embodiment of the present invention;

[0036] Figure 2 A waveform diagram of the busbar body according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic cross-sectional view of the busbar body according to an embodiment of the present invention;

[0038] Figure 4 This is a partial schematic diagram of a battery module according to an embodiment of the present invention.

[0039] Figure label:

[0040] 1-Mother row; 11-First daughter row; 12-Second daughter row; 13-Third daughter row;

[0041] 2-Cell; 21-Electrode;

[0042] 3-Fiber optic sensor. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Unless otherwise specified, the above-described orientation can be flexibly set in practical applications, provided that the relative positional relationship shown in the accompanying drawings is satisfied.

[0045] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a communication between the internal components of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In embodiments of the invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0048] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0049] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0050] Cell 2 is the smallest energy storage and conversion unit of a battery, and it is the core carrier for realizing the "interconversion of chemical energy and electrical energy". Whether it is consumer electronics (mobile phones, laptops), electric vehicles, or energy storage systems, the energy supply and charging / discharging functions of all battery products are essentially realized by Cell 2 alone or in combination. Cell 2 may expand during charge-discharge cycles, high-temperature storage, or overcharge and over-discharge processes. This is essentially due to volume expansion inside Cell 2 (changes in the positive electrode material structure, electrolyte decomposition and gas generation, SEI film rupture and reconstruction, etc.), resulting in an increase in the thickness / width of Cell 2. Busbar 1 usually connects the positive and negative electrodes of Cell 2, and is connected to the electrode 21 of Cell 2 by welding or bolts. Its core function is "low-impedance transmission of large current". The expansion of Cell 2 can disrupt the connection between Busbar 1 and electrode 21 through mechanical displacement and stress transmission, posing a safety hazard.

[0051] The following is for reference. Figures 1-4 This invention describes a busbar 1, a battery module, an electrical device, a battery pack, and a vehicle, according to embodiments of the present invention.

[0052] An embodiment of the first aspect of the present invention provides a busbar 1, comprising: a body adapted to be connected to an electrode 21 of a battery cell 2, and the body being configured as a curved structure to ensure the connection between the busbar 1 and the electrode 21 when the battery cell 2 expands and deforms.

[0053] Specifically, such as Figure 4As shown, the main body of busbar 1 connects to the positive and negative terminals of two battery cells 2 respectively, connecting the two battery cells 2 in series. To cope with the stress caused by the expansion and deformation of the battery cells 2, this embodiment designs the main body as a curved structure. That is, at least this part of the main body between the positive and negative terminals connected by busbar 1 is designed as a curved structure to ensure the connection between busbar 1 and electrode 21 when the battery cells 2 expand and deform. It can be understood that compared with the straight partial main body connecting the positive and negative terminals in related technologies, the curved main body of this embodiment can withstand greater stress, effectively improving the stability of the connection between electrode 21 and busbar 1 and maintaining the stability of resistance.

[0054] In some embodiments, the cross-section of the body includes corrugations distributed sinusoidally or cosinely along a first direction.

[0055] Specifically, such as Figure 2 As shown, the cross-section of the body includes corrugations sinusoidally distributed along a first direction, the corrugations having continuous crests and troughs; the first direction may be, but is not limited to, […]. Figure 2 The direction of the current (X-axis) can also be other directions, such as the direction of the connection between the positive and negative electrodes of the same battery cell; the continuous peaks and troughs give busbar 1 a strong resistance to deformation.

[0056] In some embodiments, the wavelength of the ripple is λ, satisfying: 0mm < λ ≤ 30mm; and / or, the wave height of the ripple is h, satisfying: 0mm < h ≤ 10mm.

[0057] Specifically, such as Figure 2 As shown, the wavelength of the ripple is λ, where 0 mm < λ ≤ 30 mm; preferably, λ is 10 mm, 11 mm, 12 mm, or 13 mm. The wave height of the ripple is h, where 0 mm < h ≤ 10 mm; preferably, h is 2 mm, 3 mm, 4 mm, or 5 mm. This ensures that the single peak-to-trough spacing meets the 0.5-1% thermal expansion requirement between the two cells 2, effectively improving the stability of the connection between electrode 21 and busbar 1, and maintaining stable resistance.

[0058] In some embodiments, the wavelength λ of the ripple and the wave height h of the ripple satisfy: 3≤λ / h≤7.

[0059] Specifically, to achieve maximum compensation efficiency within the limited space for arranging the battery cells 2, the wavelength λ and wave height h of the ripple satisfy: 3 ≤ λ / h ≤ 7. Preferably, the wavelength λ = 15 mm and the wave height h = 3 mm. This effectively improves the stability of the connection between the electrode 21 and the busbar 1, maintaining stable resistance.

[0060] In some embodiments, there is a height difference d between adjacent peaks, satisfying: 0.1mm≤d≤0.5mm; and / or, there is a height difference d between adjacent troughs, satisfying: 0.1mm≤d≤0.5mm.

[0061] Specifically, to absorb the mechanical stress caused by the assembly tolerance between busbar 1 and electrode 21, a height difference d is designed between adjacent wave crests, satisfying: 0.1mm ≤ d ≤ 0.5mm; and / or, a height difference d is designed between adjacent wave troughs, satisfying: 0.1mm ≤ d ≤ 0.5mm, where d can be, but is not limited to, 0.2mm. It is understood that, to facilitate the connection between electrode 21 and busbar 1, the wave trough region of busbar 1 can be connected to electrode 21, i.e., the aforementioned height difference d is designed between adjacent wave troughs. Adding a vertical wave height difference to the planar wave structure forms a three-dimensional wave structure, enhancing the multi-directional deformation compensation capability, such as... Figure 2 As shown by the solid and dashed corrugations, the transverse corrugations compensate for expansion in the X and Y directions, while the longitudinal corrugations absorb expansion in the Z direction. The corrugated structure generates a dynamic stress response during thermal cycling. During the expansion phase of cell 2, the spacing between the wave crests automatically increases to compensate for the tensile stress between electrodes 21; during the contraction phase, the radius of curvature of the wave troughs changes to absorb compressive stress. (See diagram for details.) Figure 2 As shown, the dashed lines represent the primary ripples, and the solid lines represent the secondary ripples; the surface is represented as:

[0062]

[0063] Where A is the amplitude of the cosine term's principal ripple (mm), B is the amplitude of the sine term's secondary ripple (mm), and λ x The main ripple wavelength (mm), λ z The wavelength of the secondary ripple in the Z direction (mm), φ s This is the phase offset, which is π / 2.

[0064] In some embodiments, the body is constructed as a flexible structure.

[0065] Specifically, to ensure a more stable connection between busbar 1 and electrode 21 and to enhance resistance to plastic deformation, this embodiment designs the main body as a flexible structure. It must simultaneously meet the requirements of "high conductivity (low loss)" and "high flexibility (bendability)." The mainstream material is metal foil, which can be used to balance current carrying capacity and flexibility through "single or multiple sheets stacked." Flexible structures can be, but are not limited to, oxygen-free copper foil, aluminum foil, copper-aluminum composite foil, tin-plated / nickel-plated copper foil, etc.

[0066] In some embodiments, the main body includes a plurality of sub-bodies stacked sequentially along the wave height direction.

[0067] Specifically, such as Figure 3 As shown, the main body includes multiple sub-bodies stacked together. The multiple sub-bodies are arranged sequentially along the wave height direction. The busbar 1 of the multi-layered sub-bodies has higher strength and rigidity, and can cope with the greater mechanical stress caused by the expansion of the battery cell 2 on the basis of the corrugated structure.

[0068] In some embodiments, each subbody is made of any one of copper, aluminum, or nickel.

[0069] Specifically, copper busbars have a conductivity of 98%-100%, and a 10mm × 100mm copper busbar can carry approximately 2000A of current at 25°C, making them the preferred choice for "high conductivity, high current" applications. For the same specifications, aluminum busbars are the lightest, making them the preferred choice for "lightweight" applications. Nickel busbars possess extremely strong corrosion resistance and high / low temperature resistance, making them the best adaptable to complex environments. Each busbar in this embodiment can be any of the above-mentioned materials; this embodiment does not impose specific limitations.

[0070] In some embodiments, the body includes a first sub-body 11, a second sub-body 12 and a third sub-body 13 stacked sequentially along the wave height direction, wherein the first sub-body 11 is made of copper.

[0071] Specifically, the first sub-body 11 is the side of the main body away from the electrode 21. It is a copper foil layer with low contact resistance conductivity, and its thickness can be, but is not limited to, 0.2 mm. The first sub-body 11 is subjected to interface treatment - laser texturing to form a micro-bump array, which breaks the oxide layer, reduces contact resistance, and improves current carrying capacity. At the same time, the "recessed gaps" of the micro-bump array can play the role of "accommodating contaminants" and maintain connection stability.

[0072] In some embodiments, the second subbody 12 is made of aluminum.

[0073] Specifically, the second sub-body 12 is the intermediate layer of the main body. It is an aluminum core layer that meets the requirements for lightweighting and has strong mechanical strength. Its thickness can be, but is not limited to, 2mm. The second sub-body 12 undergoes interface treatment - anodizing to generate an Al2O3 transition layer, which can effectively isolate corrosive media and extend the life of the second sub-body 12.

[0074] In some embodiments, the third sub-body 13 is made of nickel and is adapted to be connected to the electrode 21 of the battery cell 2.

[0075] Specifically, the third sub-body 13 is the bottom layer of the main body and is directly connected to the electrode 21. It is a nickel-based transition layer that can suppress electrochemical corrosion. Its thickness can be, but is not limited to, 0.1 μm. The third sub-body 13 is subjected to interface treatment - chemical plating to form a nanocrystalline structure, which can effectively reduce contact resistance and improve conductivity stability.

[0076] In some embodiments, busbar 1 further includes a sensor embedded in the body.

[0077] Specifically, busbar 1 also includes sensors embedded in its body, facilitating direct measurement of its status, such as temperature, current, stress, and insulation condition, with high accuracy: the error can be controlled within ±1%, and it is unaffected by external magnetic fields. This allows for early identification of potential faults, ensuring safe, efficient, and long-life operation. Furthermore, busbar 1 is subject to stress and deformation during installation and operation; the embedded sensors can capture its mechanical state in real time, preventing mechanical failure. The types of sensors can include, but are not limited to, temperature sensors, current sensors, stress sensors, and miniature insulation resistance sensors.

[0078] In some embodiments, the sensor is embedded at the troughs of the upper surface of the body and at the crests of the lower surface of the body.

[0079] Specifically, such as Figure 3 As shown, in order to facilitate the composite multilayer sub-body and assembly, this embodiment uses laser micromachining to create grooves at the troughs on the upper surface of the body and the crests on the lower surface of the body. The groove width can be, but is not limited to, 0.3 mm, and the groove depth can be, but is not limited to, 0.2 mm. The sensor of the above embodiment is then embedded in the groove.

[0080] In some embodiments, there are multiple sensors.

[0081] Specifically, such as Figure 3 As shown, in this embodiment, sensors are respectively installed at the troughs on the upper surface of the body and the crests on the lower surface of the body, arranged along the X, Y, and Z directions, covering the main stress area of ​​the cell 2 expansion, to achieve real-time monitoring of both strain and temperature parameters. A multi-parameter decoupling algorithm is used to separate the strain and temperature signals through wavelength offset, enabling real-time feedback of deformation and temperature to systems such as the BMS of a vehicle. The temperature-strain decoupling formula is:

[0082] ε=(Δλ-α·ΔT) / K ε

[0083] Among them, the temperature compensation coefficient α = 0.015 pm / ℃ and the strain sensitivity coefficient Kε = 1.2 pm / με.

[0084] In some embodiments, the sensor is an optical fiber sensor 3, and the outer layer of the optical fiber sensor 3 has a protective layer for protecting the optical fiber sensor 3.

[0085] Specifically, in this embodiment, a light sensor is embedded in the body, the diameter of which may be, but is not limited to, 125μm. After pre-embedding, it is filled with flexible epoxy resin (Shore hardness 40A) and fixed in the groove of the body. Each busbar 1 integrates 3 optical fibers, which are arranged along the X / Y / Z directions respectively, covering the main stress area of ​​the expansion of the battery cell 2. At the same time, a low temperature (<200℃) adhesive is used for encapsulation to avoid damage to the optical fiber coating.

[0086] A second aspect of the present invention provides a battery module comprising at least two battery cells 2 and a busbar 1 as described in the above embodiment, wherein the body of the busbar 1 is connected to the electrode 21 of the battery cells 2.

[0087] Specifically, such as Figure 4 As shown, the main body of busbar 1 in the battery module connects the positive terminal of one battery cell 2 and the negative terminal of another battery cell 2. The curved body of busbar 1 can cope with the stress generated when the battery module expands and deforms, ensuring a stable connection between electrode 21 and busbar 1 and maintaining stable resistance.

[0088] In some embodiments, a busbar 1 is connected to the positive terminal of one battery cell 2 and the negative terminal of another battery cell 2 respectively. The body disposed between the positive and negative terminals is constructed as a curved structure to ensure the connection between the busbar 1 and the electrode 21 when the battery cell 2 expands and deforms.

[0089] In some embodiments, a plurality of busbars 1 are included.

[0090] Specifically, within the battery module, one busbar 1 connects two battery cells 2, another busbar 1 connects two more battery cells 2, and multiple busbars 1 connect multiple battery cells 2 in series to achieve "precise connection of series and parallel topology".

[0091] A third aspect of the present invention provides an electrical device comprising at least two battery modules as described in the above embodiments. When the battery cell 2 expands and deforms, the curved surface of the busbar 1 can cope with the stress generated by the expansion and deformation of the battery cell 2, ensuring a stable connection between the electrode 21 and the busbar 1 and maintaining stable resistance; the multiple battery modules provide the electrical device with large energy storage and can provide long battery life.

[0092] A fourth aspect of the invention provides a battery pack comprising at least two battery modules as described in the above embodiments. While providing a long battery life, it ensures a stable connection between electrode 21 and busbar 1, maintaining stable resistance.

[0093] A fifth aspect of the present invention provides a vehicle including a battery pack as described in the above embodiments, the battery pack being connected to the vehicle's load.

Claims

1. A busbar, characterized in that, The busbar includes: The body is adapted to connect to the electrodes of the battery cell; the body is constructed as a curved structure to ensure the connection between the busbar and the electrodes when the battery cell expands and deforms.

2. The busbar according to claim 1, characterized in that, The cross-section of the body includes corrugations distributed sinusoidally or cosinely along a first direction.

3. The busbar according to claim 2, characterized in that, The wavelength of the ripple is λ, which satisfies: 0mm < λ ≤ 30mm; and / or the wave height of the ripple is h, which satisfies: 0mm < h ≤ 10mm.

4. The busbar according to claim 2, characterized in that, The wavelength λ of the ripple and the wave height h of the ripple satisfy: 3≤λ / h≤7.

5. The busbar according to claim 2, characterized in that, There is a height difference d between adjacent wave crests, satisfying: 0.1mm≤d≤0.5mm; and / or, there is a height difference d between adjacent wave troughs, satisfying: 0.1mm≤d≤0.5mm.

6. The busbar according to claim 1, characterized in that, The body is constructed as a flexible structure.

7. The busbar according to claim 1, characterized in that, The main body comprises multiple sub-bodies stacked sequentially along the wave height direction.

8. The busbar according to claim 7, characterized in that, Each of the aforementioned sub-body materials can be any one of copper, aluminum, or nickel.

9. The busbar according to claim 8, characterized in that, The main body includes a first sub-body, a second sub-body, and a third sub-body stacked sequentially along the wave height direction, wherein the first sub-body is made of copper.

10. The busbar according to claim 9, characterized in that, The second sub-body is made of aluminum.

11. The busbar according to claim 10, characterized in that, The third sub-body is made of nickel and is adapted to be connected to the electrodes of the battery cell.

12. The busbar according to claim 1, characterized in that, The busbar also includes a sensor embedded in the body.

13. The busbar according to claim 12, characterized in that, The sensor is embedded in the trough of the upper surface of the body and the crest of the lower surface of the body.

14. The busbar according to claim 12, characterized in that, There are multiple sensors.

15. The busbar according to claim 12, characterized in that, The sensor is an optical fiber sensor, and the outer layer of the optical fiber sensor has a protective layer for protecting the optical fiber sensor.

16. A battery module, characterized in that, It includes at least two battery cells and a busbar as described in any one of claims 1-15, wherein the body of the busbar is connected to the electrodes of the battery cells.

17. The battery module according to claim 16, characterized in that, One of the busbars is connected to the positive terminal of one of the battery cells and the negative terminal of another battery cell. The body disposed between the positive terminal and the negative terminal is constructed as a curved surface structure to ensure the connection between the busbar and the electrode when the battery cell expands and deforms.

18. The battery module according to claim 16, characterized in that, This includes multiple of the aforementioned motherboards.

19. An electrical appliance, characterized in that, It includes at least two battery modules as described in any one of claims 16-18.

20. A battery pack, characterized in that, It includes at least two battery modules as described in any one of claims 16-18.

21. A vehicle, characterized in that, The vehicle includes the battery pack as described in claim 20, the battery pack being connected to the load of the vehicle.

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