An electric battery unit

Abstract

The present invention relates to an electric battery unit (400, 600), the electric battery unit comprising: at least two battery modules configured to be interconnected; wherein each of the at least two battery modules comprising external positive and negative connection terminals for connection to at least one other battery module; and wherein the external connection terminals are configured such that, when interconnecting an external connection terminal (403, 404, 413, 414, 613, 614) of one (401, 411, 602) a battery module with an external connection terminal (405, 406, 415, 416, 615, 616) of another (402, 412, 603) battery module, contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals arranged for providing interconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules are arranged at right angles with respect to each other.

Description

[0001] AN ELECTRIC BATTERY UNIT

[0002] Technical field

[0003] Aspects of the invention relate to an electric battery unit comprising a plurality of electric battery modules, each module comprising a plurality of electric battery cells.

[0004] Background

[0005] The following background description does not necessarily constitute prior art.

[0006] An electric battery cell can be seen as a container chemically storing energy. The electric battery cells may come in various forms and shapes. For example, electric battery cells may, e.g., have a cylindrical or a prismatic shape. The battery cells may be connected in series and / or in parallel, into an electric battery unit, which may be called an electric battery pack, in order to attain a desired total voltage and energy capacity. A conventional electric battery pack, or a plurality of battery packs, may form the complete enclosure or entity that delivers electric power to a product or equipment, for example an electric vehicle, such as a battery electric vehicle or a hybrid electric vehicle.

[0007] In general, a conventional electric battery pack includes or contains electric battery cells, a control or management system, which may be called a battery management system (BMS) and may, for example, be implemented partly as software, and often also a cooling and / or heating system. The electric battery cells of an electric battery unit, or pack, may be arranged in two or more modules, where a conventional module may comprise a frame holding a plurality of electric battery cells, e.g., of a cylindrical or prismatic design, and a conventional electric battery pack may be assembled by interconnecting the modules. Each battery module may comprise suitable electronics for monitoring the battery cells of the module.

[0008] The battery cells of a battery module may be interconnected using electrical conductors such as busbars or cables to provide for current distribution between the battery cells, and such busbars / cables may also be used to connect the battery cells to connector poles of the battery module, and also to interconnect battery modules, and finally also between the modules and the connectors of the battery pack.Summary

[0009] It is an object of the invention to provide a battery unit that provides for a reliable and optimized interconnection of battery modules of a battery unit.

[0010] According to a first aspect of the invention, the aforementioned and further objects are achieved through an electric battery unit, the electric battery unit comprising:

[0011] at least two battery modules, each battery module comprising a plurality of electric battery cells having a rectangular cuboid shape, wherein the battery modules of the electric battery unit are configured to be interconnected;

[0012] wherein upper faces of the battery cells of a battery module form an upper surface of the battery module, each of the at least two battery modules comprising external positive and negative connection terminals for connection to at least one other battery module, the external positive and negative connection terminals of a battery module being arranged in corner regions of different corners of the upper surface of the battery module; and

[0013] wherein the external connection terminals are configured such that, when interconnecting an external connection terminal of one of the at least two battery modules with an external connection terminal of another of the at least two battery modules, contact surfaces of the external connection terminals being arranged for providing interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other.

[0014] As was mentioned above, electrical conductors such as busbars or cables may be used in battery units such as, for example, battery packs, to provide for current distribution between the battery cells of the battery unit, and the connector poles of the battery pack. Also, electrical conductors may be used to interconnect battery modules of a battery unit, and also to interconnect battery units.

[0015] In order for a battery unit to operate in a desired manner it is essential that the electrical conductors connecting battery modules of the battery unit provide for reliable / robust / solid electrical connections. With the presented battery unit, a solid / robust interconnection between the battery modules is provided, which copes well with moving and / or vibrating battery modules.It is also beneficial if the overall, that is, the aggregated length of, and hence total length of the electrical conductors of this kind are made as short as possible to reduce weight and cost of material. Use of longer electrical conductors such as busbars or cables may also increase the risk for incorrect mounting and / or the risk of the electrical conductors becoming loose or otherwise faulty due to, e.g., vibrations or other conditions during vehicle operation. According to the invention, it is provided a solution that may improve solidity in the electrical connections when interconnecting battery modules of a battery unit. According to aspects of the invention it is also provided a solution that may reduce the overall aggregated length of busbars and / or cables being used in particular in a battery unit.

[0016] According to the invention, external connection terminals of the battery modules of the battery unit are configured such that, when interconnecting an external connection terminal of one battery module with an external connection terminal of another battery module, contact surfaces of the external connection terminals providing interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other. In this way interconnection of the battery modules can be accomplished through the use of similar interconnection means for each connection, while simultaneously ensuring solid electrical connection. It is hereby made possible to utilize the same interconnection means between all the battery modules. It is also made possible to utilize interconnection means of minimized length. This may also reduce problems caused by, e.g., battery modules having external connection terminals being arranged such that they overlap when the battery modules are in position to be interconnected. For example, in case a battery module of a battery unit needs to be replaced in such a solution, this may require a complete disassembly of the battery unit to be able to remove the battery module. According to the invention, on the other hand, it may be sufficient to remove one or more interconnection elements and then remove the battery module by leaving the remaining battery modules in place, still providing a solution with solid electrical connection.

[0017] According to aspects of the invention, the battery modules are configured to be aligned side-by-side when being interconnected. This is in general the manner inwhich battery modules are arranged in a battery unit, and the alignment may also ensure the relative relationship between surfaces being interconnected when interconnecting the battery modules.

[0018] According to aspects of the invention, the external connection terminals interconnecting the battery modules are arranged on the upper surfaces at right angles with respect to each other to thereby provide contact surfaces providing interconnection of the external connection terminals of the battery modules at right angles with respect to each other. Hence, the contact surfaces providing interconnection of the external connection terminals of the battery modules and being arranged at right angles with respect to each other may be provided by suitably designing the external connection terminals, where this may be carried out in various different manners.

[0019] According to aspects of the invention, the external connection terminals interconnecting the battery modules are of a same shape. That is, the external connection terminals of the battery modules to be interconnected may have a same shape but where the external connection terminals of the modules having the same shape are arranged at right angles with respect to each other when the battery modules are in position to be interconnected.

[0020] According to aspects of the invention, the contact surfaces of the external connection terminals arranged for providing interconnection of the external connection terminals are arranged at right angles to the upper surface of the battery modules. Hence, the contact surfaces may form surfaces protruding from the upper surface of the battery module.

[0021] According to aspects of the invention, the external connection terminals may also protrude from the upper surfaces of the battery modules, where the contact surfaces may be orientated at other angles with respect to the upper surfaces of the battery modules, but still at right angles with respect to each other.

[0022] According to aspects of the invention, the contact surfaces of the external connection terminals are arranged at right angles with respect to the upper surface of the battery module, and being aligned with a side of the battery modules or arranged at an anglewith respect to the sides of the battery modules. The contact surfaces being at right angles with respect to the upper surface may hence be parallel with the side of the battery module but also be arranged at an angle with respect to the sides of the battery module, where the external connection terminal of the other battery module being interconnected may be similarly arranged but still such that the contact surfaces are arranged at a right angle to respect to each other.

[0023] According to aspects of the invention, an interconnection element for interconnecting the external connection terminals of the battery modules comprises contact surfaces being arranged at right angles with respect to each other for contacting contact surfaces of the external connection terminals of the battery modules. This arrangement of the interconnection element may further improve the solidity of the interconnection of the battery modules. The interconnection element may then contact the contact surfaces of the battery modules that are also arranged at right angles with respect to each other.

[0024] According to aspects of the invention, an interconnection element provides for interconnection of the external connection terminals, wherein the interconnection element is configured to contact at least one contact surface of the external connection terminals at least partly through spring action. In particular use of an interconnection element providing for contact surfaces that are arranged at right angles with respect to each other may provide, even inherently, the spring action that will further facilitate the obtaining of a secure interconnection.

[0025] According to aspects of the invention, the external connection terminals of the battery modules are configured such that contact surfaces of the external connection terminals arranged for providing interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other when interconnecting an external positive connection terminal of one of the at least two battery modules with an external negative connection terminal of another of the at least two battery modules. Consequently, the battery modules may be configured such that the interconnection according to the invention is provided for when an external positive connection terminal of one battery module is connected to an external negative connection terminal of another battery module.According to aspects of the invention, the external positive connection terminal and external negative connection terminal of each of the battery modules are configured such that the contact surfaces of the external connection terminals are arranged at right angles with respect to each other. That is, the external positive and negative connection terminals of a battery module may be differently configured in relation to each other so that contact surfaces of the external positive and negative connection terminal of the battery module are great at right angles respect to each other, with the result that the relationship according to the invention will be provided when an external positive connection terminal of one battery module is interconnected with an external negative in connection terminal of another battery module.

[0026] According to aspects of the invention, the external positive and negative connection terminals of each of the battery modules are arranged in diagonally opposite corner regions of the upper surface of the battery modules. This may provide for a solution where the overall length of interconnection elements for interconnecting battery modules may be reduced.

[0027] According to aspects of the invention, each of the battery modules comprises an odd number of electric battery cells, where the plurality of electric battery cells of at least one of the at least two battery modules are arranged in a first configuration, and where the plurality of electric battery cells of at least one other of the at least two battery modules are arranged in a second configuration. The first and second configuration, respectively, comprises the external positive and negative connection terminals arranged in different corner regions of the upper surface of the battery module in relation to the other of the first and second configuration, respectively. By the battery cells comprising an odd number of electric battery cells, it is provided a battery unit that comprises battery modules of two different configurations where in particular the external connection terminals are differently located in the two configurations, and where the external connection terminals may also be differently orientated or designed as described above. This provides for a possibility of arranging the battery modules of a battery unit in a way that allows use of shorter electrical connectors, such as busbars and / or cables, when interconnecting the battery units, and thereby a reduction of material being used for the interconnectionsof the battery unit. Also, a possible reduction of the probability of a fault arising caused by faulty busbars / cables may be provided, while still providing benefits of the invention according to the above. Short electric connector can here easily be connected between external positive and negative connection terminals of two adjacent battery modules if these two battery modules have mutually mirrored configurations and each comprises an odd number of electric battery cells.

[0028] According to aspects of the invention, the arrangement of the external connection terminals in the first configuration is mirrored in relation to the arrangement of the external connection terminals in the second configuration. This in particular may provide for ways of interconnecting battery modules that are beneficial in terms of reducing the overall aggregated length of electrical connectors.

[0029] According to aspects of the invention the external positive connection terminal of a battery module according to the first configuration is arranged at right angles with respect to the external negative connection terminal of a battery module according to the second configuration. In this way, e.g., the providing of contact surfaces arranged at right angles with respect to each other for interconnection of the external connection terminals of the battery modules may be provided by interconnecting a battery module according to the first configuration with a battery module according to the second configuration.

[0030] According to aspects of the invention, the electric battery unit comprises at least one row of M battery modules arranged in a first direction, M being an odd number equal to or greater than 3; M >3; and the M battery modules in each of the at least one row are arranged alternating between the first configuration and the second configuration. Hereby, on odd number of three or more electric battery cells each having an odd number of cells arranged in different first and second configurations may be utilized in the M battery modules to optimize the interconnection elements. In this way, identical interconnection elements may be used for connecting the modules to each other.

[0031] According to aspects of the invention, the electric battery unit comprises at least one row of M battery modules arranged in a first direction, M being an even number equalto or greater than 2; M >2. In this way, an electric battery unit of suitable size may be flexibly and easily compiled / assembled.

[0032] According to aspects of the invention, the electric battery unit comprises at least one column of N battery modules arranged in a second direction, wherein N is one in the group of an even number equal to or greater than 2; N >2; and an odd number equal to or greater than 1 ; N >1. In this way, an electric battery unit of suitable size may be and easily compiled / assembled.

[0033] According to aspects of the invention, all interconnection elements used for interconnecting the external connection terminals of the battery modules are identical. In this way, the assembly of the electric battery module is simplified and made more efficient, and the manufacturing costs for the electric battery module is reduced.

[0034] According to aspects of the invention, the electric battery unit comprises M*N battery modules, wherein M, N is >2, wherein M is the number of battery modules arranged in a first direction, and N is the number of battery modules arranged in a second direction being perpendicular to the first direction. When the battery modules are interconnected the external connection terminals are configured such that, when interconnecting an external connection terminal of one of the battery modules with an external connection terminal of another of the battery modules, contact surfaces providing interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other in both the first and the second direction. In this way, solid interconnection of the battery modules can be accomplished also for battery units comprising various different battery module configurations.

[0035] According to aspects of the invention, the battery unit is designed to be mounted in a vehicle with the upper surface formed by the upper surfaces of the battery modules in various different orientations in relation to a horizontal plane of the vehicle. That is, the fact that the battery modules may be described to comprise upper surfaces does not necessarily mean that the battery unit is installed in, e.g., a vehicle with the uppersurfaces of the battery modules facing upwards when the vehicle is in a horizontal position, but the battery units may be inclined in relation to the horizontal axis of the vehicle. Still, the battery units will have a general upper surface when being assembled, and such an upper surface is also used in the description for reasons of clarity.

[0036] According to another aspect of the invention, aforementioned and further objectives are achieved through a vehicle comprising a battery unit according to aspects of the invention.

[0037] Further advantageous aspects of the battery unit and the vehicle according to the present invention and further advantages within the aspects of the invention emerge from the following detailed description.

[0038] Brief Description of the Drawings

[0039] Aspects of the invention will now be illustrated, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, where similar references are used for similar parts, in which:

[0040] Fig. 1 illustrates an exemplary battery electric vehicle in which aspects of the invention may be utilized;

[0041] Fig. 2 illustrates an exemplary battery module of a battery unit according to the prior art;

[0042] Fig. 3A illustrates an exemplary interconnection of battery cells of a battery module;

[0043] Fig. 3B illustrates exemplary interconnection of battery modules of a battery unit according to prior art;

[0044] Figs. 4A-4B illustrates battery modules according to aspects of the invention;

[0045] Fig. 5A illustrates a first example of external connection terminals according to aspects of the invention;Fig. 5B illustrates a further example of external connection terminals according to aspects of the invention;

[0046] Fig. 6A illustrates an exemplary interconnection of battery modules according to aspects of the invention;

[0047] Figs. 6B-C illustrates examples of external interconnection terminals according to the invention for the exemplary battery unit configuration of Fig. 6A;

[0048] Figs. 7A-B illustrates another example of external connection terminals according to aspects of the invention;

[0049] Figs. 8A-B illustrates yet another example of external connection terminals according to aspects of the invention.

[0050] Detailed Description

[0051] With reference to Fig. 1, an embodiment of a vehicle 100 according to aspects of the invention is schematically illustrated. The vehicle 100 is illustrated as a tractor vehicle. However, for other embodiments, the vehicle 100 may, for example, be of any other kind of heavy vehicle, such as a bus or a truck. The vehicle may also, e.g., be a passenger car. The vehicle may also be another type of vehicle. Although not illustrated in Fig. 1, the vehicle 100 may be equipped with a trailer. The vehicle 100 comprises a powertrain configured as an electric vehicle EV, for example a hybrid electric vehicle, HEV, or a battery electric vehicle, BEV.

[0052] The vehicle 100 may further, as illustrated, be a vehicle comprising wheels 102, of which only wheels 102 of the left-hand side of the vehicle 100 are visible in Fig. 1. It is to be understood that the vehicle 100 may have fewer or more wheels than what is shown in Fig. 1.

[0053] The powertrain comprises at least one electrical machine 101 configured to apply a propulsive power and / or a braking power to one or more of the wheels 102 of the vehicle 100. The at least one electrical machine 101 may be arranged essentially anywhere, for as long as power is provided to one or more of the wheels 102 of the vehicle 100. Various applicable examples exist in the art.The vehicle 100 is configured to comprise a plurality of electric battery units 103, 104, 105, such as battery stacks, and may also comprise further non-disclosed battery units. Each battery unit may be designed according to aspects of the invention. The battery units may form part of a battery arrangement 106 of the vehicle 100.

[0054] The components of the powertrain of the vehicle 100, as well as other components in the vehicle may be controlled by a vehicle control system forming part of a vehicle electrical system via a control arrangement 120. The control arrangement 120 may be distributed over a plurality of control units configured to control different parts of the vehicle 100. The control arrangement 120 may, e.g., include a control unit for controlling the applying of a propulsive power and / or regenerative brake power of the electrical machine 101. The control arrangement may also comprise a control unit for diagnosing battery units and otherwise controlling use of the battery units. Such a control unit may, e.g., for part of a battery management system (BMS) that may be responsible for various other functions involving the battery.

[0055] As is realized, the vehicle 100 may comprise a large number of control units and sensors for controlling various part of the vehicle, as is known in the art. Fig. 1 , only illustrates units / devices / entities of the vehicle that are required for a general understanding. The present invention does not per se rely on use of such control units.

[0056] Fig. 2 schematically illustrates the general principle of an exemplary battery module 200. The battery module 200 may form part of a battery unit 103, 104, 105 comprising a plurality of battery modules. The battery module 200 comprises a plurality of battery cells, n according to the present example, denoted 201_1, 201_2, 201_3,..., 201_n. The battery cells 201_1, ..., 201_n are interconnected by means of electrical connectors, such as busbars and / or cables 202. According to the illustrated example, and for information purposes only, the battery cells each comprises a cell fuse 204 in order to, for example, provide for a short-circuit and / or overvoltage protection. Such fuses may or may not be present.

[0057] The battery module 200 further comprises connectors 205, 206 to be connected, either to further battery modules of a battery pack and / or to the external connectionterminals of the battery pack, where the connections of the connection terminals to the battery cells may also be realized through the use of electrical connector elements such as busbars. According to the illustrated example, the battery module 200 further comprises a cell management controller (CMC) 210. The cell management controller 210 may, inter alia, be utilized to monitor the battery cells of the battery module through various connections 211. The general principle of operation of Fig. 2 is applicable for prior art battery modules as well as battery modules being configured according to aspects of the invention.

[0058] Fig. 3A schematically illustrates the general principle according to Fig. 2 in a manner more resembling the actual physical appearance of a battery module. The exemplary battery module 300 comprises a plurality of battery cells, specifically four battery cells 301-304 according to the present example. Each of the electric battery cells are of a rectangular cuboid shape, and comprises a positive terminal and a negative terminal arranged at opposite ends regions of an upper surface of the battery cells, respectively. Such battery cells are commonly known as prismatic battery cells. The positive terminal 301 A of battery cell 301 forms an external positive connection terminal for a connection to, e.g., a load such as an electrical machine or an external connection terminal, in general an external negative connection terminal, of another battery module, where the battery modules form part of a battery unit.

[0059] Such connection may be realized, e.g. at least in part using an electrical conductor such as a busbar and / or a cable. Similarly, the negative terminal 304B of battery cells 304 forms an external negative connection terminal intended to, similarly, be connected to a load or an external connection terminal, in general an external positive connection terminal, of a further battery module.

[0060] Furthermore, the battery cells 301-304 of the battery module 300 are also interconnected using electrical connectors such as busbars 305-307. According to the illustrated example, the negative terminal of the battery cell 301 is connected to the positive terminal of battery cell 302 using busbar 305. Similarly, the negative terminal of battery cell 302 is connected to the positive terminal of battery cell 303 using busbar 306. Finally, the negative terminal of battery cell 303 is connected to the positive terminal of battery cell 304 using busbar 307. Consequently, the externalpositive connection terminal 301 A and external negative connection terminal 304B represents the aggregated cell voltages of the battery cells of the battery module 300. The present invention relates to interconnection of such external connection terminals, and the interconnection of individual battery cells of a battery unit 103, 104, 105 is therefore not discussed further herein.

[0061] However, the aggregated total cell voltage of the battery cells of one battery module is in general not sufficient to provide the voltage that, e.g., is required or desired when used, e.g. in a battery electric vehicle. For this reason, a plurality of battery modules are in general interconnected using the external connection terminals in order to provide the desired voltage. Battery modules may also be connected in parallel in order to thereby increase the possible overall current that the battery unit 103, 104, 105 is capable to deliver.

[0062] Battery module interconnection is schematically illustrated in Fig. 3B, where four different battery modules according to the example illustrated in figure 3A are shown and being interconnected in series, and where for simplicity only the external connection terminals are illustrated, and connections between battery modules but not the connections of all individual battery cells.

[0063] In Fig. 3B the battery modules 311-314 are positioned side-by-side, where the external positive connection terminal 311 A on battery module 311 is connected to the external negative connection terminal 312B on battery module 312. Similarly, the external positive connection terminals 312A on battery module 312 is connected to the external negative connection terminal 313B on battery module 313. Finally, the external positive connection terminal 313A on battery module 313 is connected to the external negative connection terminal 314B on battery module 314. The battery modules 311-314 form battery unit 310, where the positive connection terminal of the battery unit 310 is provided by the external positive connection terminal 314A of battery module 314 and the negative connection terminal of battery unit 310 is given by the external negative connection terminal 311 B of module 311.

[0064] These two connection terminals may be connected to the load, such as the one or more electrical machines of the vehicle to provide power for propelling and brakingthe vehicle, and / or to further battery units as the case may be. It is to be noted that the battery unit may comprise further battery modules. It is further to be noted that every second battery module has been positioned “upside down”. Hence, battery modules 312 and 314 have been turned “upside down”, i.e. in an opposite direction in comparison to battery modules 311 and 313. This may have a positive impact on the overall aggregated, i.e., total length of the busbars being used to interconnected battery modules, where in general the design illustrated in Fig. 3B may be more efficient in terms of use of busbar material than designs where all battery modules are aligned with the same rotation. However, as will be further discussed below, a considerable improvement in the use of busbar material may be obtained by combining battery modules using different configurations of the battery cells.

[0065] Irrespective of the particular way of arranging battery modules of a battery unit, it is important that the interconnection of battery modules is as solid as possible to reduce losses and the possibility of other problems arising. According to aspects of the invention, such solid interconnection may be improved. This is accomplished by providing the battery modules with external connection terminals that are configured such that contact surfaces that provide interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other when an external connection terminal of one battery module is interconnected with an external connection terminal of another battery module. This may provide for a more flexible / bendable interconnection of the battery modules than is provided when the contact surfaces, e.g., face the same direction. Hereby, a solid / robust interconnection which copes well with mutually moving and / or vibrating battery modules is provided. Consequently, according to the invention, a contact surface of one of the battery modules to be interconnected is arranged at right angles with respect to the contact surface of the other of the battery modules being interconnected. It is to be noted in this regard and that the contact surfaces are defined as the principal contact surfaces that are designed to provide for the transfer of the current between the battery modules.

[0066] A first exemplary embodiment of the invention is illustrated in Fig. 4A. Fig. 4A may, for example, illustrate interconnection of two battery modules, such as e.g. batterymodules 311 , 312 in Fig. 3B, to form a battery unit 400. According to the example of Fig. 4A, a battery module 402 has been rotated 180° in relation to battery module 401. The figure further illustrates an external positive connection terminal 403 and an external negative connection terminal 404 of battery module 401. Similarly, the figure illustrates an external positive connection terminal 405 and an external negative connection terminal 406 of battery module 402. According to the illustrated example, the external positive connection terminal and the external negative connection terminal of each battery module are rotated with respect to each other such that the connection terminals are arranged at right angles with respect to each other. This may provide for a more robust and reliable interconnection of the battery modules 401, 402, because the interconnection is flexible / bendable.

[0067] The interconnection may be realized, e.g. through the use of L-shaped interconnection elements or any other suitable type of interconnection element. This is exemplified by L-shaped interconnection element 407, which interconnects a contact surface 403A of the external connection terminal 403 with a contact surface 406B of external connection terminal 406, where, as can be seen, the contact surfaces 403A and 406B are arranged at right angles with respect to each other to thereby provide a more flexible / bendable interconnection, and thereby a more reliable / solid interconnection, of the battery modules 401, 402. The L-shaped interconnection elements also reduce the risk for faulty coupling of the interconnection elements.

[0068] As an alternative to interconnecting contact surfaces 403A, 406B, interconnection may, instead, for example, be realized through interconnection of the contact surfaces 403B and 406A, which is illustrated by a dashed interconnection element 408. As a further exemplary alternative, illustrated for external connection terminals 404, 405, for reasons of intelligibility, interconnection may instead be realized through interconnection contact surfaces 404A and 405B, illustrated by dashed interconnection element 409. The attachment of the interconnection element to the contact surfaces may be realized in any suitable manner using screws or other suitable means such as spring action or any combination thereof. The use of an angled interconnection element further has the advantage that the interconnectionelement inherently will provide a spring action, such that the interconnection may resiliently mitigate problems related to vibrating and / or moving battery modules, which further ensures proper connection between the contact surfaces of the connection terminals and the interconnection element and thereby between the battery modules. It is further to be noted that the interconnection element may contact further surfaces of the external connection terminals and hence not only the contact surfaces being arranged at right angles with respect to each other. This may be the case, e.g. with interconnection element 407. Still, the principal contact surfaces providing interconnection of the battery modules are arranged at right angles with respect to each other.

[0069] The particular arrangement of the external connection terminals and the particular design thereof may be of various different orientations and designs for as long as contact surfaces interconnecting the battery modules are arranged at right angles with respect to each other. A further example is illustrated in Fig. 4B, which illustrates battery modules 411, 412. The battery modules 411, 412 are arranged in the same manner as battery modules 401, 402 and also each comprises external positive connection terminals 413, 415 and external negative connection terminals 414, 416 respectively. The external positive and negative connection terminals of a battery module are still arranged at right angles with respect to each other, however not in parallel with any of the sides of the battery modules but instead the external connection terminals are arranged at an angle with respect to the sides of the battery modules, for example at an 450angle, or any other suitable angle, to the sides of the battery modules. Still, the solution according to Fig. 4B provides for the same kind of interconnection as Fig. 4A, which is illustrated by interconnection elements 417, 418 and 419. Various other general designs and orientations of the external connection terminals exist.

[0070] With regard to a further aspect of the invention, as can be seen from Fig. 3B, the schematically illustrated interconnection elements may be of varying length. It is to be noted that the invention is applicable for such differences in length of the interconnection elements. However, according to aspects of the invention, it isprovided a solution for further reducing the amount of connection material being used.

[0071] Fig. 5A and 5B illustrate a general concept according to such aspects of the invention. Fig. 5A illustrates, similar to Fig. 3A, a general layout of a battery module 500 comprising a plurality of battery cells. According to the illustrated example, the battery module 500 comprises five battery cells 501-505. It is to be understood that battery modules according to this aspect of the invention may comprise any number of battery cells, however with the prerequisite that the number of battery cells is an odd number of battery cells. Also, similar to Fig. 3A, each of the electric battery cells are of a rectangular cuboid shape, and each cell comprises a positive terminal and a negative terminal arranged at opposite ends regions of an upper surface of the battery cells. The positive terminal 501 A of battery cell 501 forms an external positive connection terminal, and the negative terminal 505B of battery cell 505 forms a external negative connection terminal, where the external connection terminals are intended for use as described above.

[0072] The battery cells 501- 505 of the battery module 500 are interconnected using electrical connectors 506-509 in a manner similar to what has been described above, so that the external connection terminals 501 A, 505B represents the aggregated battery cell voltages of the battery cells 501-505 of the battery module 500.

[0073] Furthermore, in difference to prior art solutions, according to aspects of the invention, two different battery module configurations are utilized to provide for more efficient packing of battery modules in a battery unit. This is illustrated in Fig. 5B, which illustrates a battery module 510, being similar to the battery module of Fig. 5A, but where the battery module of Fig. 5B comprises the external positive and negative connection terminals arranged in different corner regions of the upper surface of the battery module 510 in relation to the battery module 500 illustrated in Fig. 5A.

[0074] This can be seen by comparing figures 5A and 5B, where in Fig. 5A the external positive connection terminal 501 A is located in the upper right corner of the upper surface of the battery module 500. Furthermore, the external negative connection terminal 505B of battery module 500 is located in the lower left corner of the uppersurface of the battery module 500. With regard to Fig. 5B, the external positive connection terminal 511 A is instead located in the upper left corner of the upper surface of the battery module 510, and the external negative connection terminal 515B is located in the lower right corner of the upper surface of the battery module 510. According to the illustrated example, the two configurations of battery modules may be realized by arranging the interconnection of the battery cells differently in the two different configurations as can be seen from figures 5A and 5B.

[0075] This further provides for advantages in terms of interconnecting the battery modules of a battery unit. This is illustrated and exemplified in Figs. 6A, where battery modules of the configuration in Fig. 5A are illustrated by being filled with a hashed pattern, whereas battery modules of the configuration in Fig. 5B are illustrated without filling. The individual battery cells have not been explicitly illustrated, but instead only the external positive and negative connection terminals are illustrated, where these are located as described above. Furthermore, some of the battery modules are arranged “upside down” in relation to the illustrations in Figs. 5A-B in a manner similar to what is illustrated in Fig. 3B. The battery modules are arranged with every second battery module being of the first configuration, and every second battery module being of the second configuration.

[0076] As can be seen from Fig. 6A, such an arrangement results in a battery unit layout providing for various different possibilities regarding interconnection of the various battery modules of the battery unit, where Fig. 6A illustrates an example of a battery unit 600 comprising nine battery modules 601-609, where all nine battery modules 601-609 are interconnected using only very short electrical connectors such as busbars and / or cables. Also, the length of each one of the interconnection elements, comprising e.g. busbars, may here have the same length. It is, to be noted that there exist various connection possibilities for interconnecting the battery modules of the battery unit of Fig. 6A.

[0077] The external positive and negative connection terminals of the battery unit 600 are illustrated by circles in Fig. 6A. According to the illustrated example, the battery modules are connected in the order 609-606-603-602-605-608-607-604-601, with identical interconnection elements 620, such as e.g. busbars of the same length.However, as is realised, the use of two different battery module configurations according to the invention provides for various other alternatives in regard of possible interconnections of nine battery modules in place of the example illustrated in Fig. 6A. The external connection terminals may, e.g. be connected to a load and / or one or more further battery units have the same or a different layout.

[0078] Fig. 6B illustrates the example of Fig. 6A for a situation where the battery modules 601, 602, 603, 604, 605, 606, 607, 608, 609 comprises external connections terminals 613, 614, 615, 616 in accordance with the general example illustrated in Fig. 4A, where interconnection is accomplished such that when interconnecting an external connection terminal 613 of a battery module 602 of one configuration with an external connection terminal 616 of a battery module 603 of the other of the battery module configuration, contact surfaces providing interconnection of the external connection terminals 613, 616 of the battery modules 602, 603 are arranged at right angles with respect to each other. This is schematically illustrated by interconnection elements 620.

[0079] Fig. 6C illustrates a similar situation, but where the external connections terminals 613, 614, 615, 616 instead are arranged in accordance with the general example illustrated in Fig. 4B, i.e. arranged at right angles with respect to each other and at an angle to the sides of the battery modules. This is schematically illustrated by interconnection elements 620. Again, it is to be noted that there exist various connection possibilities for interconnecting the battery modules of the battery unit 600 of Fig. 6A-C.

[0080] The battery units 600 of Figs. 6A-C are only illustrative examples, and there exist various other possibilities using battery units comprising fewer or more battery modules than what is illustrated in these figures, and with battery modules comprising fewer or more battery cells, where interconnection may be carried out in various different ways, still in accordance with the invention.

[0081] Generally, according to an embodiment, the electric battery unit 600 comprises at least one row of M battery modules 601 , 602, 603; 604, 605, 606; 607, 608, 609 arranged in a first direction, where M is an odd number equal to or greater than 3; M>3. The M battery modules 601, 602, 603; 604, 605, 606; 607, 608, 609 in each of the at least one row then each comprise an odd number of battery cells, and are arranged alternating between the first configuration and the second configuration, i.e. such that every other battery module in the row is arranged in the first configuration and every other module is arranged in the second configuration. This means that each battery module 601, 602, 603; 604, 605, 606; 607, 608, 609 is turned / rotated 180° in relation to its neighbouring / adjacent battery modules. For an odd number of 3 or more battery modules being sideways coupled in a row in this way, i.e. with alternating configurations, and where each module comprises an odd number of battery cells, interconnection elements having the same length and / or being identical may be used for interconnecting the battery modules.

[0082] Thus, the electric battery unit 600 here comprises an odd number of 3 or more columns of battery modules 601,604, 607; 602, 605, 608; 603, 606, 609 arranged in a second direction, where each column comprises N battery modules, and N is a number for providing an electric battery unit of suitable size MxN e.g. for its implementation. If each of the battery modules comprises an odd number of battery cells, they may be configured in alternating first and second different configurations in each row. An odd number M of 3 or more battery modules arranged in a row alternating like this may be connected together with interconnection elements being identical and / or having the same length. An electric battery unit 600 comprising one or more such rows thus has an odd number of 3 or more columns, each column comprising an arbitrary number N of modules. All battery MxN modules of the electric battery unit may then be cost-efficiently connected by utilization of identical and / or common length interconnection elements.

[0083] According to an embodiment, the electric battery unit 600 comprises at least one row of M battery modules 601, 602, 603; 604, 605, 606; 607, 608, 609 arranged in a first direction, wherein M is even number equal to or greater than 2; M >2. Thus, the electric battery unit 600 here comprises an even number of two or more columns, each column comprising N battery modules arranged in a second direction, where N is any number for creating the electric battery unit of a suitable size MxN.It should be noted that for electric battery units comprising any suitable number of N rows, where each row comprises only one module, i.e. for electric battery units comprising 1xN battery modules, the battery modules of the electric battery unit may be connected together with interconnection elements being identical and / or having the same length. This is possible for battery modules having either of an even or odd number of cells.

[0084] Also, for electric battery units comprising any suitable number of N rows, where each row comprises two modules, i.e. for electric battery units comprising 2xN battery modules, the battery modules of the electric battery unit may be connected together with interconnection elements being identical and / or having the same length. This is possible for battery modules having either of an even or odd number of cells. Also, the two battery modules in each row may be arranged in one and the same configuration, i.e. in either of the first and second configuration, or may be arranged in alternating first and second configurations.

[0085] According to an embodiment, the electric battery unit 600 comprises at least one column of N battery modules 601,604, 607; 602, 605, 608; 603, 606, 609 arranged in a second direction, wherein N an even number equal to or greater than 2; N >2.

[0086] Further, according to an embodiment, the electric battery unit 600 comprises at least one column of N battery modules 601,604, 607; 602, 605, 608; 603, 606, 609 arranged in a second direction, wherein N an odd number equal to or greater than 1; N >1.

[0087] The N battery modules 601,604, 607; 602, 605, 608; 603, 606, 609 in each of the at least one column may all be arranged in one and the same configuration, i.e. in either of the first and second configuration, or may be arranged as alternating between the first configuration and the second configuration, i.e. such that every other battery module in the column is arranged in the first configuration and every other module is arranged in the second configuration. The N battery modules of each column may be connected together with interconnection elements being identical and / or having the same length.Generally, the electric battery unit may comprise N rows, each row comprising M battery modules, i.e. may have a size of MxN battery modules, where M and N are any suitable number. However, by carefully choosing M and N, and the configuration of the electric battery unit 600 and its modules, at least some the at least two interconnection elements 620 used for interconnecting the external connection terminals 613, 615, 614, 616 of the battery modules 601, 602, 603, 604, 605, 606, 607, 608, 609 may be identical, i.e. may have equal shape and / or length.

[0088] The external connection terminals of the battery modules may be of various different designs, where the designs of Figs. 4A-B are only exemplary, and further examples of such designs are illustrated in Figs. 7-8.

[0089] Fig. 7A illustrates an example where the external connection terminal 701 comprises two orthogonal contact surfaces 701 A, 701 B, where the external connection terminal is configured to be connected in a corner of the battery module, and to function as the external positive or negative connection terminal. The use of two different contact surfaces on the external connection terminal provides for even more possibilities regarding interconnection.

[0090] Figure 7B schematically illustrates an example where four corners of battery modules meet. For reasons of simplicity only the external connection terminals 701-704 are illustrated. For example, Fig. 7B may illustrate a configuration such as the configuration in Fig. 6B, where battery modules 601, 602, 604, 605 all meet in a corner, but where the battery modules are pairwise interconnected. For example, again with reference to the example of Fig. 6B, battery module 601 is connected to battery module 604, while battery module 602 is connected to battery module 605, although various other alternatives exist, as explained above. The interconnection may be accomplished, e.g., through the use of L-shaped elements as is schematically indicated for interconnection of external connection terminals 702, 704 by using an L-shaped interconnection element 705, e.g. in form of an L-shaped busbar. Hereby, a solid / robust interconnection which copes well with mutually moving and / or vibrating battery modules is provided, thanks to the flexible / bendable L-shaped interconnection elements 705. Also, L-shaped interconnection elements reduce the risk for incorrect coupling of the interconnection elements.Figs. 8A-B illustrates examples of interconnection elements 901, 902 for use when interconnecting the battery modules. The two contact surfaces 901 A, 901 B and 902A and 902B, respectively, providing for interconnection of right angles may in these examples form part of the respective interconnection element 901, 902. The illustrated horizontal parts with holes may only be provided for handling purposes. The modules have corresponding connection surfaces, e.g. provided with springs to assure sufficient contact pressure. Positive and negative connection on module have orthogonal contact surfaces.

[0091] It is also to be noted that more than one contact surface may be used for each battery module, where still the contact surface are arranged at right angles with respect to the contact surfaces of the other battery module.

[0092] The invention is not limited to the above-described aspects. Instead, the invention relates to, and encompasses all different aspects being included within the scope of the independent claims.

Claims

Claims1. An electric battery unit (400, 600), the electric battery unit (400, 600) comprising:at least two battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609), each battery module (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) comprising a plurality of electric battery cells having a rectangular cuboid shape, wherein the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) of the electric battery unit (400, 600) are configured to be interconnected;wherein upper faces of the battery cells of a battery module (401 , 402, 601 , 602, 603, 604, 605, 606, 607, 608, 609) form an upper surface of the battery module (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609), each of the at least two battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) comprising external positive and negative connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) for connection to at least one other battery module (401 , 402, 601 , 602, 603, 604, 605, 606, 607, 608, 609), the external positive and negative connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of a battery module being arranged in corner regions of different corners of the upper surface of the battery module (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609); andwherein the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) are configured such that, when interconnecting an external connection terminal (403, 404, 413, 414, 613, 614) of one (401 , 411, 602) of the at least two battery modules with an external connection terminal (405, 406, 415, 416, 615, 616) of another (402, 412, 603) of the at least two battery modules, contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) being arranged for providing interconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602,603, 604, 605, 606, 607, 608, 609) are arranged at right angles with respect to each other.

2. An electric battery unit (400, 600) according to claim 1, wherein the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are configured to be aligned side-by-side when being interconnected.

3. An electric battery unit (400, 600) according to claim 1 or 2, wherein the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) interconnecting the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are arranged on the upper surfaces at right angles with respect to each other to thereby provide contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) providing interconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules at right angles with respect to each other.

4. An electric battery unit (400, 600) according to claim 3, wherein the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) interconnecting the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are of a same shape.

5. An electric battery unit (400, 600) according to any one of the claims 1-4, wherein the contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) arranged for providing interconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) are arranged at right angles to the upper surface.

6. An electric battery unit (400, 600) according to any one of the claims 1-5, wherein the contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) are arranged at right angles with respect to the upper surface of the battery module (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) and being aligned with a side of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) or arranged at an angle with respect to thesides of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609).

7. An electric battery unit (400, 600) according to any one of the claims 1-6, wherein the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) protrude from the upper surfaces of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609).

8. An electric battery unit (400, 600) according to any one of the claims 1-7, wherein an interconnection element (407, 408, 409, 417, 419, 620, 901, 902) for interconnecting the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) comprises contact surfaces (901 A, 901 B, 902A, 902B) being arranged at right angles with respect to each other for contacting contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609).

9. An electric battery unit (400, 600) according to any one of the claims 1-8, wherein an interconnection element (407, 408, 409, 417, 418, 419, 620, 901, 902) provides for interconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616), wherein the interconnection element (407, 408, 409, 417, 418, 419, 620, 901, 902) is configured to contact at least one contact surface (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) at least partly through spring action.

10. An electric battery unit (400, 600) according to any one of the claims 1-9, wherein the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are configured such that contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) arranged for providinginterconnection of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are arranged at right angles with respect to each other when interconnecting an external positive connection terminal (403, 413, 613) of one (401 , 411, 602) of the at least two battery modules with an external negative (406, 416, 616) connection terminal of another (402, 412, 603) of the at least two battery modules.

11. An electric battery unit (400, 600) according to any one of the claims 1-10, wherein the external positive connection (403, 405, 413, 415, 613, 615) terminal and external negative connection terminal (404, 406, 414, 416, 614, 616) of each of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are configured such that the contact surfaces (403A, 406B, 403B, 406A, 404A, 405A) of the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) are arranged at right angles with respect to each other.

12. An electric battery unit (400, 600) according any one of the claims 1-11, wherein the external positive (403, 405, 413, 415, 613, 615) and negative (404, 406, 414, 416, 614, 616) connection terminals of each of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are arranged in diagonally opposite corner regions of the upper surface of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609).

13. An electric battery unit (400, 600) according to any one of the claims 1-12, wherein each of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) comprises an odd number of electric battery cells;wherein the plurality of electric battery cells (311, 312, 313, 314) of at least one (401 , 411, 602) of the at least two battery modules (401 , 402, 601 , 602, 603, 604, 605, 606, 607, 608, 609) are arranged in a first configuration;wherein the plurality of electric battery cells (311, 312, 313, 314) of at least one other (402, 412, 603) of the at least two battery modules (401 , 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are arranged in a second configuration;wherein the first and second configuration, respectively, comprises the external positive (403, 405, 413, 415, 613, 615) and negative (404, 406, 414, 416, 614, 616) connection terminals arranged in different corner regions of the upper surface of the battery module (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) in relation to the other of the first and second configuration, respectively.

14. An electric battery unit (400, 600) according to claim 13, wherein in the first configuration, the arrangement of the external connection terminals (403, 404, 413, 414, 613, 614) is mirrored in relation to the arrangement of the external connection terminals (405, 406, 415, 416, 615, 616) in the second configuration.

15. An electric battery unit (400, 600) according to claim 13 or 14, wherein the external positive connection terminal (403, 413, 613) of a battery module (401, 411 , 602) according to the first configuration is arranged at right angles with respect to the external negative connection terminal (406, 416, 616) of a battery module (402, 412, 603) according to the second configuration.

16. An electric battery unit (400, 600) according to any one of the claims 13-15, whereinthe electric battery unit (400, 600) comprises at least one row of M battery modules (601, 602, 603; 604, 605, 606; 607, 608, 609) arranged in a first direction, M being an odd number equal to or greater than 3; M >3; and the M battery modules (601, 602, 603; 604, 605, 606; 607, 608, 609) in each of the at least one row are arranged alternating between the first configuration and the second configuration.

17. An electric battery unit (400, 600) according to any one of the claims 13-15, whereinthe electric battery unit (400, 600) comprises at least one row of M battery modules (601, 602, 603; 604, 605, 606; 607, 608, 609) arranged in a first direction, M being an even number equal to or greater than 2; M >2.

18. An electric battery unit (400, 600) according to any one of the claims 13-17, whereinthe electric battery unit (400, 600) comprises at least one column of N battery modules (601,604, 607; 602, 605, 608; 603, 606, 609) arranged in a second direction, wherein N is one in the group of:an even number equal to or greater than 2; N >2; andan odd number equal to or greater than 1 ; N >1.

19. An electric battery unit (400, 600) according to any one of the claims 16-17, wherein all interconnection elements (407, 408, 409, 417, 419, 620, 901, 902) used for interconnecting the external connection terminals (403, 405, 404, 406, 413, 415, 414, 416, 613, 615, 614, 616) of the battery modules (401, 402, 601, 602, 603, 604, 605, 606, 607, 608, 609) are identical.

20. An electric battery unit (600) according to any one of the claims 1-17, wherein the electric battery unit (600) comprises M*N battery modules (601, 602, 603, 604, 605, 606, 607, 608, 609), wherein M and N are equal to or greater than 2; M >2, N >2; wherein M is the number of battery modules arranged in a first direction, and N is the number of battery modules arranged in a second direction being perpendicular to the first direction, wherein the battery modules (601, 602, 603, 604, 605, 606, 607, 608, 609) are interconnected, wherein the external connection terminals are configured such that, when interconnecting an external connection terminal of one of the battery modules with an external connection terminal of another of the battery modules, contact surfaces providing interconnection of the external connection terminals of the battery modules are arranged at right angles with respect to each other in both the first and the second direction.

21. A vehicle comprising an electric battery unit (400, 600) according to any one of the claims 1-18.

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