Description:TECHNICAL FIELD
[0001] The present subject matter relates to a battery module of a powered device. More particularly, heat dissipation in the battery module is disclosed. The present application is a patent of addition with respect to the patent application number 202041015498.

BACKGROUND
[0002] In recent years, rechargeable energy storage devices have been widely used as an energy source for several electronic and electrical units, hybrid and electric vehicles. Commonly used rechargeable energy storage devices include, for example, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and lithium rechargeable batteries. Lithium rechargeable energy storage devices are widely used in electric and hybrid vehicles because they are rechargeable, they can be made in a compact size with large capacity, they have a high operation voltage, and they have a high energy density per unit weight.
[0003] An existing energy storage device comprises one or more energy storage cells, such as, lithium-ion battery cells enclosed within a casing. The electrochemical reactions with the lithium-ion battery cells are responsible for the voltage and the current generated by the energy storage device. Also, during charging of the energy storage device, electrochemical reactions occur within the lithium-ion battery cells. These electrochemical reactions are highly exothermic, and the lithium-ion battery cells tend to heat up during the course of normal operation. The increased temperatures of the lithium-ion battery cells degrade the electrical performance of the energy storage device and may lead to catastrophic failure of the energy storage devices. There is a need to dissipate the generated heat and cool the lithium-ion battery cells of the energy storage device for the safety and longevity of the energy storage device.

BRIEF DESCRIPTION OF DRAWINGS
[0004] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.

[0005] Figs. 1A-1B exemplarily illustrate perspective views of a battery module, as pear an embodiment of the present invention.
[0006] Fig. 2 exemplarily illustrates an exploded perspective view of the battery module illustrated in Figs. 1A-1B, in accordance with an embodiment of application.
[0007] Fig. 3 exemplarily illustrates a front perspective view of a casing of a battery module.
[0008] Fig. 4 exemplarily illustrates a perspective view of a cell holder of a battery module as exemplarily illustrated in Fig. 2.
[0009] Fig. 5A exemplarily illustrates a perspective view of plurality of battery modules of a powered device, stacked together in a compact manner, in an accordance with an embodiment of the present application.
[0010] Fig. 5B exemplarily illustrates a perspective view of plurality of battery casings stacked together in a compact manner, in an accordance with an embodiment of the present application.
[0011] Fig. 6A exemplarily illustrates a front perspective view of a first end cover of one of the plurality of battery module(s) in an accordance with an embodiment of the present application.
[0012] Fig. 6B exemplarily illustrates a front perspective view of a second end cover of one of the plurality of battery module(s) in an accordance with an embodiment of the present application.

DETAILED DESCRIPTION OF THE INVENTION
[0013] Currently, for cooling the lithium-ion battery cells in the energy storage device, coolant channels with air or a coolant liquid are designed around individual battery cells or a cluster of battery cells. However, the design of the coolant channels within the casing of the energy storage devices makes the energy storage device bulky and no longer compact for space-constrained varied applications. Also, maintaining the temperatures, the pressures, and the sealing of the coolant flow into and outside the energy storage device adds to the heat dissipation problem being addressed.
[0014] In another implementation for cooling of the energy storage device, and in turn the lithium-ion battery cells, a heat exchange member in thermal contact with the casing of the energy storage device is used. The heat dissipated from the lithium-ion battery cells has to traverse through air-filled gap between the cells and the casing. The heat transfer between the battery cells and the casing is not efficient since the air is a poor conductor of heat. In order to ensure that heat is effectively dissipated from the battery cells, it is essential to ensure that the heat generating battery cells are reliably secured to be in thermal contact with the heat exchange member proximal to the casing. Further, there is also a need to ensure that there is no air gap between an upper surface of the lithium-ion battery cells and an inner surface of the outer casing, in order to ensure that heat is effectively transmitted to the metallic casing.
[0015] Typically, fasteners or clips are used to secure the lithium-ion battery cells proximal to the casing of energy storage device for establishing thermal contact between the battery cells and the heat exchange members. Particularly, the use of clips/fasteners only aid in establishing thermal contact of side and/or front and/or rear surfaces of the battery cells with the casing, and through the casing with the heat exchange member. Further, based on the application of the energy storage device, the capacity of the energy storage device is varied. Based on the capacity of the energy storage device, the number of battery cells, the mass of the battery cells, and the capacity of the battery cells, etc., are varied. If battery cells with reduced size or mass are to be enclosed within an existing casing, a gap may be formed between the casing and the battery cells. Such gaps will result in ineffective heat transfer from the energy storage cells in the energy storage device. Also, due to variation in the shape and size of the fasteners, it is difficult to establish consistent and effective thermal contact between the battery cells and the heat exchange members.
[0016] Typically, heat conductive packaging material may be used to establish thermal contact of the battery cells with a surface of the outer conductive casing. The heat conductive packaging material needs to be uniformly distributed along the length of the casing between the casing and the surface of the battery cells using a fastening means. However, the packaging material increases the weight, the manufacturing cost, and the assembling cost of the energy storage device. Also, while loading or unloading the assembly of the energy storage cells into the casing, the packaging material may hinder the ease in pushing in or pulling out of the energy storage cells from the casing. If the heat conductive packaging material that is rigid and firm is used, it may not allow for the flexibility of using an existing casing for different assemblies of the energy storage cells. This may lead to manufacture of different casings for different assemblies of the energy storage cells increasing material cost and manufacture cost of entities. Thus, to address this problem, the packaging material has to be made adequately flexible as well as rigid to not deform, while loading and unloading of the assembly of the energy storage cells with efficient heat transfer properties. Also, the packaging material needs to take care of the marginal deviation or tolerances in design of the casing or the design of cell holders holding the battery cells for effective heat transfer from the energy storage cells to the casing.
[0017] The present application is a patent of addition of the patent application number 202041015498. Henceforth patent application number 202041015498 is referred as “Main application” for the purpose of brevity. The main application discloses about an energy storage device, that is, a battery module with battery cells in gap-less thermal contact with a casing of the battery module for effectively as well as efficiently dissipating the heat generated by the battery cells. The battery module also aids in cooling the battery cells for safety, longevity, and ease and safety during assembly, use, maintenance, and servicing of the energy storage device. Such a battery module may be employed in powered devices, such as, vehicles, for example, electric vehicle, hybrid electric vehicles, IC engine vehicles, etc.
[0018] “The Main application”, further in an embodiment discloses the battery module comprising plurality of cells positioned within one or more cell holders and a casing enclosing the cells in the cell holders. The casing further comprises a first inner surface, a first outer surface, a second outer surface, and a second inner surface. The battery module further comprises a cell support structure integrated with the second inner surface of the casing for establishing a thermally conducting and electrically insulating contact between the cells and the second inner surface. The battery module further includes a single flexible member positioned between the first inner surface of the casing and one of the cell holders for exerting a pre-load pressure on the cell holders to establish the thermally conducting and electrically insulating contact between the cells and the second inner surface. The flexible member is longitudinally slacked forming a series of alternating crests and troughs. The flexible member is inserted into a gap between the first inner surface of the casing and one of the cell holders after the assembly of the cell holders and the at least one thermal interface member.
[0019] In essence, the battery module described and disclosed in the main application, focuses on achieving compact packaging of a single battery module and at the same time increasing heat transfer properties of the battery module efficiently. However, usually a plurality of battery modules is required to be placed within a vehicle, for multiple functioning. For example, one battery module may be required to act as the main battery delivering power for the main functioning of the vehicle, such as starting the vehicle. Similarly, another battery module may be required to act as an auxiliary battery, which provides power for auxiliary functioning of the vehicle, for example headlamp lighting, etc. Similarly, plurality of battery module(s) may be required to act as a backup battery, for the main battery or the auxiliary battery, when discharged. Further, similarly another battery module may be required for harnessing regenerative braking power and further using the energy harnessed through regenerative braking for recharging plurality of battery module(s). Thereby, owing to the required high mileage, high speed and plurality of functioning of the vehicle, usage of plurality of battery modules within the same vehicle becomes pertinent. However, in small vehicles, such as two wheelers, storage of plurality of battery modules becomes a challenge, due to the inherent space constraints.
[0020] Therefore, there exists a need to provide an overall compact packaging of plurality of battery modules stacked together, without substantial change in the adjoining parts of the battery modules and the frame of the vehicle.
[0021] Further, in absence of sufficient cooling vents and compact packaging of plurality of battery packs in a small space, it is often seen that the cooling efficiency of the overall power unit is compromised. Thereby, there exists a need to provide an overall compact packaging of plurality of battery modules stacked together while ensuring that the cooling efficiency of the overall power unit is not compromised.
[0022] The present application discloses a subject matter that has been devised in view of the above circumstances as well as solving other problems of the known art.
[0023] The present subject matter discloses about a powered device comprising plurality of battery module(s). Each of the plurality of battery module(s) comprises of at least one casing enclosing a plurality of cells.
[0024] As per an aspect of the present subject matter, at least one side of the at least one casing comprises a first inner surface, and a first outer surface. The first outer surface of at least one casing includes at least one first raised portion and at least one first depressed portion making a dovetail pattern.
[0025] As per another aspect of the present subject matter, at least one first raised portion of one of the at least one casing of one of the plurality of battery module(s) is capable of receiving the at least one first depressed portion of another of the at least one casing of another of the plurality of battery module.
[0026] As per another aspect of the present subject matter, the at least one first depressed portion of one of the at least one casing of one of the plurality of battery module(s) is capable of receiving the at least one first raised portion of another of the at least one casing of another of the plurality of battery module(s).
[0027] Advantageously, the gap between the two battery modules stacked together is obviated, when the first depressed portion of casing of one battery module receives the first raised portion of casing of another battery module. Thereby, compact packaging of the plurality of battery module is enabled within the powered device, without any substantial change in the battery modules or the adjoining parts.
[0028] As per another aspect of the present subject matter, the plurality of cells are disposed within one or more cell holders, and the one or more cell holders are further disposed within each of the plurality of battery module.
[0029] In an embodiment of the present subject matter, the at least one casing is defined by a pair of enclosing walls and a pair of peripheral walls. The at least one of the pair of enclosing walls of the at least one casing includes a second outer surface and a second inner surface. As per an aspect of the embodiment, the second outer surface has a heat dissipating structure for dissipating heat generated by the plurality of cells, wherein the plurality of cells is in thermally conducting and electrically insulating contact with the second inner surface of the at least one casing, and the at least one casing is in contact with the external environment. As per another aspect of the embodiment, the heat dissipating structure being one of a plurality of fins, a plurality of coolant channels, and an aeration device.
[0030] In an embodiment, the plurality of battery module(s) further comprises a first end cover and a second end cover. The first end cover and the second end cover aid in covering each battery module from opposite sides.
[0031] As per an aspect of the present embodiment, the at least one peripheral side of the first end cover and the second end cover includes an alternatively disposed at least one second depressed portions and at least one second raised portions. The at least one second depressed portions of the first end cover is capable of mating with peripheral end of at least one of the first depressed portion of one of plurality of battery module, and the at least one second raised portions of the first end cover is capable of mating with the peripheral end of the at least one first raised portion of one of the plurality of battery module(s). Such mating of the first raised portion with the second raised portion, and similarly the first depressed portion with the second depressed portion ensures obviation of any gap between the first end cover and the periphery of the casing of each battery module, ensuring compact and airtight packaging.
[0032] As per another aspect of the present embodiment, the at least one second depressed portions of the second end cover is capable of mating with peripheral end of at least one of the first depressed portion of one of plurality of battery module, and the at least one second raised portions of the second end cover is capable of mating with the peripheral end of the at least one first raised portion of one of the plurality of battery module(s). Such mating of the first raised portion with the second raised portion, and similarly the first depressed portion with the second depressed portion ensures obviation of any gap between the second end cover and the periphery of the casing of each battery module, ensuring compact and airtight packaging.
[0033] As per another embodiment, the first outer surface of one of the plurality of battery module(s), upon being stacked together, faces towards the first outer surface of another of the plurality of battery module(s). Further, the second outer surface of one of the plurality of battery module(s), upon being stacked together, faces away from the second outer surface of another of the plurality of battery module(s), ensuring placement of heat dissipating structure of each of the battery module away from each other. Such placement of heat dissipating structure of each of the battery module away from each other further ensures that the heat dissipated to the external environment is effectively performed without any disruption and unnecessary barrier.
[0034] Exemplary embodiments detailing features regarding the aforesaid and other advantages of the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present invention will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof. Further, it is to be noted that terms “upper”, “down”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom”, “exterior”, “interior” and like terms are used herein based on the illustrated state or in a standing state of the two wheeled vehicles with a driver riding thereon. Furthermore, arrows wherever provided in the top right corner of figure(s) in the drawings depicts direction with respect to the vehicle, wherein an arrow F denotes front direction, an arrow R indicates rear direction, an arrow Up denotes upward direction, an arrow Dw denotes downward direction, an arrow RH denotes right side, and an arrow LH denotes left side. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0035] Figs. 1A-1B exemplarily illustrate perspective views of a battery module 100, as pear an embodiment of the present invention. Fig. 1A illustrates a top perspective view of the battery module 100. Fig. 1B also illustrates a top perspective view of the battery module 100, with the battery module 100 in Fig. 1A in an inverted orientation. As exemplarily illustrated in Fig. 1A, the battery module 100 comprises a casing 101 and a first end cover 105. The casing 101 is a hollow rectangular cover enclosing a plurality of cells and other electrical and electronic components, such as, a BMS board of the battery module 100. The casing 101 comprises enclosing walls 102 and 108 exemplarily illustrated in Fig. 1B, peripheral walls 103 and 104 between the enclosing walls 102 and 108, and open ends (not shown). End covers of the battery module 100 close the open ends of the casing 101. The casing 101 has mounting provisions, such as, 106 to mount the end covers, such as, the first end cover 105 and the second end cover (not shown) at the open ends of the casing 101 using attachment means. The end covers have external electrical connections, such as, 107 of the battery module 100 for charging and discharging of the battery module 100. As exemplarily illustrated, an outer surface of the enclosing wall 102 comprises a dovetail pattern that facilitates in easy mounting and unmounting of the battery module 100 in a designated space in a powered device. In an embodiment, both the enclosing walls 102 and 108 have the dovetail pattern. Corresponding, inner surfaces of the enclosing walls 102 and 108 also have the dovetail pattern. In an embodiment, the outer surfaces of the peripheral walls 103 and 104 also have a dovetail pattern on them.
[0036] As exemplarily illustrated in Fig. 1B, the outer surface of the other enclosing wall 108 of the casing 101 comprises a heat dissipating structure 109, such as, fins. The cells (not shown) enclosed within the casing 101 generate heat and the heat is transferred to the casing 101 of the battery module 100 to be dissipated to the surroundings of the battery module 100. The heat dissipating structure 109 on the outer surface of the enclosing wall 108 facilitates the exchange of the heat transferred to the casing 101 with the air or a liquid coolant. The heat dissipating structure 109 may be the fins, coolant channels for air or a liquid, and/or an aeration device. The heat dissipating structure 109 extracts the heat in the casing 101 and cools the battery module 100 using either natural convection or forced convection based on the installation and the application of the battery module 100. From the cells to the casing 101, the heat is transferred using conduction due to thermal contact established between the cells and the casing 101 by the construction of the battery module 100 as will be disclosed in Figs. 2-4. For effective thermal conduction, the casing 101 is made of a heat conducting material and is formed using an extrusion process. The heat generated by the cells and also by other electronic components, such as, the BMS board, when dissipated to the surroundings, ensures efficient performance of the battery module 100. Hereafter, the outer surface of the enclosing wall 102 is referred to as a first outer surface 102b and an inner surface of the enclosing wall 102 facing towards the cells is referred to as a first inner surface 102a. Similarly, hereinafter the outer surface of the enclosing wall 108 is referred to as a second outer surface 108b and an inner surface of the enclosing wall 108 facing towards the cells is referred to as a second inner surface 108a.
[0037] Fig. 2 exemplarily illustrates an exploded perspective view of the battery module 100 illustrated in Figs. 1A-1B, in accordance with an embodiment of application. As exemplarily, the battery module 100 comprises the first end cover 105, the second end cover 110, the casing 101, and a battery pack 202. The external casing 101 encloses the battery pack 202 from top and bottom. The second end cover 110 and the first end cover 105 are fastened at the open ends of the casing 101 and enclose the battery pack 202 from rear and front respectively. A gasket (not shown) being disposed in between the second end cover 110 and the open ends of the casing 101. Another gasket (not shown) is disposed in between the first end cover 105 and the open ends of the casing 101. The battery pack 202 comprises a plurality of cells 203 arranged in a particular sequence between cell holders 204 and 205. The cells 203 are electrically connected in series and/or parallel configuration to form an array of cells using one or more interconnect sheets, such as, 206. Such arrays of cells are electrically connected to a battery management system (BMS) 201 within the battery module 100. The BMS 201 is a printed circuit board with one or more integrated circuits integrally. The battery pack 202 has mounting provisions for the BMS board 201. The BMS board 201 is screwably attached to the cell holders 204 and 205 of the battery pack 202. The BMS board 201 is located between the battery pack 202 and the first end cover 105. The dovetail pattern formed on the interior side of the casing 101 allows easy sliding of the battery pack 202 into the casing 101.
[0038] The second outer surface 108b of the casing 101 comprises the heat dissipating structure 109 as exemplarily illustrated in Fig. 1B. On the second inner surface 108a, a cell support structure 210 is integrated to the casing 101. In addition to the battery pack 202, a thermal interface member 207 and a flexible member 209 are positioned within the casing 101. In an embodiment, a coupling member 208 is also positioned in the casing 101 as exemplarily illustrated. As exemplarily illustrated, the thermal interface member 207, the flexible member 209, the cell support structure 210, and the coupling member 208 are positioned around the plurality of cells 203 to establish thermal contact of the cells 203 to the heat dissipating structure 109 on the body of the casing 101.
[0039] As exemplarily illustrated, the thermal interface member 207 is positioned in contact with the interconnect sheet 206, proximal to the cell holder 205. In an embodiment, another thermal interface member, such as, 207 may be positioned underneath the cells 203, proximal to the cell holder 204 and the cell support structure 210. In an embodiment, a thermal interface member, such as, 207 may be positioned only between the cell holder 204 and the cell support structure 210. The flexible member 209 is positioned proximal to first inner surface 102a. The coupling member 208 is positioned between the flexible member 209 and the thermal interface member 207. Further, once the single piece of the flexible member 209 is inserted in between the cell holders 204 and the at least one thermal interface member 207.
[0040] The thermal interface member 207 establishes direct thermal contact between the terminals of the cells 203 between the top cell holder 205 and the bottom cell holder 204 with the cell support structure 210 integrated to the second inner surface 108a of the casing 108. The thermal interface member 207 is pre-formed and removably positioned between the bottom cell holder 204 and the cell support structure 210. In an embodiment, the thermal interface member 207, made of materials, such as, silicone, rubber, that adheres to the rear of the planar surface 302 of the bottom cell holder 204. In an embodiment, the thermal interface member 207 is relatively firm or stiff at room temperatures and softens and fills the gap between the bottom cell holder 204 and the cell support structure 210 at higher temperatures. Since the thermal interface member 207 is electrically insulating, the thermal interface member 207 prevents occurrence of short circuit between the cells 203 in the bottom cell holder 204 and the cell support structure 210 of the casing 101. In an embodiment, the thermal interface member 207 has cut-outs corresponding to the cut-outs in one or more interconnect sheets, such as, 206 for heat and reaction gases in the cells 203 to exhaust out of the cell holders 204 and 205.
[0041] Fig. 3 exemplarily illustrates a front perspective view of the casing 101 of the battery module 100. The casing 101 of the battery module 100 comprises the enclosing walls 102 and 108, the peripheral walls 103 and 104, and the open ends 301 and 302. The open ends 301 and 302 have the mounting provisions, such as, 303 for mounting the end covers 105 and 110 as exemplarily illustrated in Fig. 2. In the second inner surface 108a of the enclosing wall 108, the cell support structure 210 is integrated. In an embodiment, the cell support structure 210 is modular and may be positioned above the second inner surface 108a of the casing 101. The cell support structure 210 is a raised slab, of a predetermined thickness, onto which the cell holder such as, 204 is positioned. The cell support structure 210 is made of a thermally conductive material, such as, Aluminum. The cell support structure 210 establishes contact between the cells 203 in the cell holder 204 and the casing 101 and in turn with the heat dissipating structure 109 on the second outer surface 108b. The cell support structure 210 transfers the heat to the second outer surface 108b and the heat dissipating structure 109, such as, the fins allowing natural air to cool the second outer surface 108b. The heat dissipating structure 109 on the second outer surface 108b guides cool air or liquid around the second outer surface 108b. The temperature of the cell support structure 210 is reduced and in turn the cells 103 that are in contact with the cell support structure 210.
[0042] In an embodiment, a thermal interface member 207 may be positioned beneath the cell holder 204 and in thermal contact with the cells 203. The thermal interface member 207 is, then, in thermal contact with the cell support structure 210. Such an assembly of the cell holder 204, the thermal interface member 207, and the cell support structure 210 ensures there no gap for air to accumulate in the casing 101 for effective heat transfer from the cells 203 to the casing 101. The cell support structure 210 is strong and adequately rigid to not deform under frequent loading and unloading of the battery pack 202 from the casing 101 as well as at higher temperatures. In an embodiment, the cell support structure 210 has guides on its sides to aid in loading and unloading of the battery pack 202 from the casing 101. In an embodiment, the cell support structure 210 extends over the area of the second inner surface 108a.
[0043] Fig. 4 exemplarily illustrates a perspective view of a cell holder 204 of a battery module 100 as exemplarily illustrated in Fig. 2. As disclosed earlier, the battery module 100 comprises the cell holders 204 and 205 and the BMS board 201 is removably attached to the cell holders 204 and 205. The cell holder 204 is a bottom cell holder and the cell holder 205 is a top cell holder. Each of the cell holders, such as, 204 comprise placeholders 401 for holding the cells 203 in each cell holder 204. Each of the cell holders 204 comprises a planar surface, such as, 402 with the placeholders 401 and raised walls, such as, 403, 404, 405, and 406 at the sides of the planar surface 402. The bottom cell holder 204 is positioned at the bottom of the cells 203 and the top cell holder 205 is positioned on top of the cells 203. The cell holders 204 and 205 are fixed together using a plurality of fasteners to tightly hold the cells 203 in the placeholders 401. The raised walls, such as, 403, 404, 405, and 406 of the cell holders 204 and 205 come in contact with each other, when the cell holders 204 and 205 are fixed together. To fasten the cell holders 204 and 205 together, recesses to position the fasteners are provided in the cell holders 204 and 205. As an embodiment, the cell holders 204 and 205 may be rectangular in shape and holding cylindrical cells 203 in the placeholders 401. The bottom cell holder 204 is exemplarily illustrated in Fig. 4. The placeholders 401 are tubular structures on the planar surface 402 with openings for the terminals of the cells 203 to protrude and make contact with the interconnect sheets 206. The construction of the top cell holder 205 is similar to the construction of the bottom cell holder 204 exemplarily illustrated on Fig. 2.
[0044] One or more interconnect sheets, such as, 206 (shown in Fig 2) that connect the terminals of the cells 203 in series and/or parallel connection is positioned on the rear side of the planar surface 402. The rear side of the planar surface 402 with the raised walls 403, 404, 405, and 406 can safely hold the interconnect sheets 206. Each interconnect sheet 206 electrically connects the terminals of a cluster of cells 203. In an embodiment, one or more interconnect sheets 206 is positioned only on the rear planar surface, such as, 402 of either of the top cell holder 205 or the bottom cell holder 204. In an embodiment, one or more interconnect sheets 206 may be positioned in the rear surface of the planar surface 402 of both the cell holders 204 and 205. The interconnect sheet 206 is electrically conductive and connects the terminals of the cells 203 to the electrical connections 107 of the battery module 100. Also, the interconnect sheet 206 is thermally conductive. In an embodiment, the interconnect sheet 206 has a profile to the lock the cells 203 in the cell holders 204 and 205. Since, the interconnect sheet 206 is in direct contact with the terminals of the cells 203, the heat generated by the cells 203 is transferred to the interconnect sheet 206 at the terminals. Further, the interconnect sheet 206 in the bottom cell holder 204 is in contact with the thermal interface member 207 or the cell support structure 210 directly and transfers the heat to the first inner surface 108a and subsequently to the first outer surface 108b of the casing 101. The interconnect sheet 206 is rigid and is made of electrically and thermally conductive material, such as, copper, nickel, etc. In an embodiment, the battery module 202 further comprises a protective sheet (not shown) positioned above the interconnect sheet 206 of the battery module 202 for protecting the soldered points of electrical connection on the interconnect sheet 206. The protective sheet (not shown) is electrically insulated, while being thermally conductive. The protective sheet is also accommodated in the rear side of the planar surface 402 and in direct contact with the interconnect sheet 206. In an embodiment, the thermal interface member 207 may be positioned on the protective sheet.
[0045] Fig. 5A exemplarily illustrates a perspective view of plurality of battery modules (100, 200, 300, 400) of a powered device, stacked together in a compact manner, in an accordance with an embodiment of the present application. In an embodiment the plurality of battery modules (100, 200, 300, 400) include a first battery module 100 and a second battery module 200. Fig. 5B exemplarily illustrates a perspective view of plurality of battery casings (101, 101a, 101b, 101c) stacked together in a compact manner, in an accordance with an embodiment of the present application.
[0046]
[0047] In an embodiment, a powered device comprises plurality of battery modules (100, 200, 300, 400) packaged together as a single unit, mainly to ensure compact packaging. Each of the plurality of battery module(s) (100, 200, 300, 400) comprises of at least one casing (101, 101a, 101b, 101c) enclosing a plurality of cells 203 (shown in Fig 2). For example, the first battery module 100 comprising a first casing 101, and the second battery module 200 comprises a second casing 101a. As disclosed in Figure 2, at least one side of the at least one casing (101, 101a, 101b, 101c), for example, the first casing 101 and the second casing 101a, comprises of the first inner surface 102a, and the first outer surface 102b. The first outer surface 102b of at least one casing (101, 101a, 101b, 101c), for example, the first casing (101) and the second casing (101a), includes at least one first raised portion 102c and at least one first depressed portion 102d in an alternative manner making a dovetail pattern. The dovetail pattern formed because of the first raised portion 102c and the first depressed portion 102d on the outer surfaces of both the first battery module 100 and the second battery module 200 enables tight packaging of both the first battery module 100 and the second battery module 200, when stacked together. Thereby enabling obviation of gap between the first battery module 100 and the second battery module 200 and ensuring compact packaging.As shown in marked region A in the Fig 5B, the at least one first raised portion 102c of one of the at least one casing (101, 101a, 101b, 101c), for example, the first casing 101 of one of the plurality of battery module(s) (100, 200, 300, 400) for example, the first battery module 100, is capable of receiving the at least one first depressed portion 102d of adjoining one of the at least one casing (101, 101a, 101b, 101c), for example, the second casing 101a, of adjoining one of the plurality of battery modules (100, 200, 300, 400), for example, the second battery pack (200). The at least one first depressed portion 102d of one of the at least one casing (101, 101a, 101b, 101c), for example, the first casing (101), of one of the plurality of battery module(s) (100, 200, 300, 400), for example, the first battery module (100), is capable of receiving the at least one first raised portion 102c of the adjoining one of the at least one casing (101, 101a, 101b, 101c), for example, the second casing (101a)of another of the plurality of battery module(s) (100, 200, 300, 400), for example, the second battery module 200.
[0048] Thereby, plurality of battery modules (100, 200, 300, 400) are capable of being stacked upon each other, in a compact manner. This is because the gap between any of the two battery modules (100, 200, 300, 400) stacked together is obviated, when the first depressed portion 102d of the casing (101, 101a, 101b, 101c) of one battery module (100, 200, 300, 400) receives the first raised portion 102c of the casing (101, 101a, 101b, 101c) of another battery module (100, 200, 300, 400). Thereby, compact packaging of the plurality of battery module (100, 200, 300, 400 is enabled within the powered device, without any substantial change in the battery modules (100, 200, 300, 400) or the adjoining parts.
[0049] As exemplarily illustrated, the dovetail pattern formed by the at least one first raised portion 102c and at least one first depressed portion 102d provided on the first outer surface 102b of at least one casing (101, 101a, 101b, 101c) also facilitates in easy mounting and unmounting of plurality of battery module (100, 200, 300, 400) in a designated space in a powered device.
[0050] In an embodiment of the present subject matter, each of the casing (101, 101a, 101b, 101c) of the plurality of battery modules (100, 200, 300, 400) includes at least two enclosing walls (102, 108). One of the enclosing wall 102 of each of the plurality of battery modules (100, 200, 300, 400), includes the first outer surface 102b and the first inner surface 102a. The other enclosing wall 108 of each of the plurality of battery modules (100, 200, 300, 400), includes the second outer surface 108b and the second inner surface 108a. The second outer surface 108b of the enclosing wall 108 of each of the plurality of battery modules (100, 200, 300, 400), has a heat dissipating structure 109 (as shown in Fig. 2) for dissipating heat generated by the plurality of cells 203, wherein the plurality of cells 203 are in thermally conducting and electrically insulating contact with the second inner surface 108a of each of the casing (101, 101a, 101b, 101c) of the plurality of battery modules (101, 101a, 101b, 101c), and the at least one casing (101, 101a, 101b, 101c) is in contact with the external environment. As per another aspect of the embodiment, the heat dissipating structure 109 being one of a plurality of fins, a plurality of coolant channels, and an aeration device.
[0051] In an embodiment, the first outer surface 102b of each of the plurality of battery modules (100, 200, 300, 400) face each other, when plurality of battery module(s) (100, 200, 300, 400) being stacked upon each other. For example, the first outer surface 102b of the first battery module 100, upon being stacked together faces the first outer surface 102b of the second battery module 200. Further, the second outer surface 108b of each of the plurality of battery modules (100, 200, 300, 400) face in opposite direction upon being stacked upon each other. In another words, the second outer surface 108b of one of the plurality of battery module(s) (100, 200, 300, 400) faces away from the second outer surface 108b of another of the plurality of battery module(s) (100, 200, 300, 400), upon being stacked together. For example, For example, the second outer surface 108b of the first battery module 100, upon being stacked together faces the second outer surface 108b of the second battery module 200. Such placement ensures disposal of heat dissipating structures 109 of each of the battery module(s) (100, 200, 300, 400) away from each other, thereby ensuring that the heat dissipated by the plurality of cells 203, to the external environment is effectively performed without any disruption and unnecessary barrier.
[0052] Fig. 6A exemplarily illustrates a front perspective view of a first end cover 115 of one of the plurality of battery module(s) (100, 200, 300, 400) in an accordance with an embodiment of the present application. Fig. 6B exemplarily illustrates a front perspective view of a second end cover 110 of one of the plurality of battery module(s) (100, 200, 300, 400) in an accordance with an embodiment of the present application. In an embodiment, the plurality of battery module(s) (100, 200, 300, 400) further comprises the first end cover 115 and the second end cover 110. The first end cover 115 and the second end cover 110 aid in covering each battery module from opposite sides. The at least one peripheral side of the first end cover 115 and the second end cover 110 includes alternatively disposed at least one second depressed portions 115a and at least one second raised portions 115b. The at least one second depressed portions 115a of the first end cover 115 is capable of mating with peripheral end of at least one of the first depressed portion 102d of one of plurality of battery modules (100, 200, 300, 400), and the at least one second raised portions 115b of the first end cover 115 is capable of mating with the peripheral end of the at least one first raised portion 102c of one of the plurality of battery module(s) (100, 200, 300, 400). Such mating of the first raised portion 102c with the second raised portion 115b, and similarly the first depressed portion 102d with the second depressed portion 115a ensures obviation of any gap between the first end cover 105 and the periphery of the casing (101, 101a, 101b, 101c) of each battery module (100, 200, 300, 400), ensuring compact and airtight packaging.
[0053] Similarly, the at least one second depressed portions 115a of the second end cover 110 is capable of mating with peripheral end of at least one of the first depressed portion 102d of one of plurality of battery modules (100, 200, 300, 400), and the at least one second raised portions 115b of the second end cover 110 is capable of mating with the peripheral end of the at least one first raised portion 102c of one of the plurality of battery module(s) (101, 101a, 101b, 101c). Such mating of the first raised portion 102c with the second raised portion 115b, and similarly the first depressed portion 102d with the second depressed portion 115a ensures obviation of any gap between the second end cover 110 and the periphery of the casing (101, 101a, 101b, 101c) of each battery module (100, 200, 300, 400), ensuring compact and airtight packaging.
[0054] Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

 
LIST OF REFERENCE NUMERAL

100, 200, 300, 400: Battery Module
100: First Battery Module
200: Second Battery Module
101, 101a, 101b, 101c: Casing
101: First casing
101a: Second casing
102, 108: Enclosing walls
102a: First inner surface
102b: First outer surface
102c: First Raised portion
102d: Second Depressed portion
103, 104: Peripheral walls
105: First end cover
105a: Second depressed portion
105b: Second raised portion
106: Mounting Provision
107: Electrical connections
108a: First inner structure
108b: First outer structure
109: Heat dissipating structure
110: Second end cover
201: BMS board
202: Battery pack
203: Plurality of cells
204, 205: Cell holders
206: Interconnect sheet
207: Thermal interface member
208: Coupling member
209: Flexible member
210: Cell support structure
, Claims:I/We Claim:
1. A powered device having a plurality of battery module(s) (100, 200, 300, 400), each of said plurality of battery module(s) (100, 200, 300, 400) comprising:
at least one casing (101, 101a, 101b, 101c) enclosing a plurality of cells (203),
at least one side of said at least one casing (101, 101a, 101b, 101c) comprises a first inner surface (102a), and a first outer surface (102b);
wherein, said first outer surface (102b) of said at least one casing (101, 101a, 101b, 101c) includes at least one first raised portion (102c) and at least one first depressed portion (102d) formed in an alternate manner;
wherein said at least one first depressed portion (102d) of at least a first battery module (100) of said plurality of battery module(s) (100, 200, 300, 400) being capable of receiving said at least one first raised portion (102c) of at least an adjoining second battery module (200) of said plurality of battery module(s) (100, 200, 300, 400), and
said at least one first raised portion (102c) of at least a first battery module (100) of said plurality of battery module(s) (100, 200, 300, 400) being capable of receiving said at least one first depressed portion (102d) of adjoining at least one second battery module (200) of said plurality of battery module(s) (100, 200, 300, 400), enabling obviation of gap between said first battery module (100) and adjoining said at least one second battery module (200) thereby providing compact packaging of said plurality of battery module(s) (100, 200, 300, 400).
2. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 1, wherein said plurality of cells (203) being disposed within one or more cell holders (204, 205), and said one or more cell holders (204, 205) being disposed within each of said plurality of battery module(s) (100, 200, 300, 400).
3. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 1, wherein said at least one casing (101) being defined by a pair of enclosing walls (102, 108) and a pair of peripheral walls (103, 104).
4. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 3, wherein said at least one of said pair of enclosing walls (102, 108) of said at least one casing (101, 101a, 101b, 101c) includes a second outer surface (108b) and a second inner surface (108a).
5. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 4, wherein said second outer surface (108b) having a heat dissipating structure (109) for dissipating heat generated by said plurality of cells (203), wherein said plurality of cells (203) being in thermally conducting and electrically insulating contact with said second inner surface (108a) of said at least one casing (101, 101a, 101b, 101c), wherein said at least one casing (101, 101a, 101b, 101c) being in contact with the external environment.
6. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 5, wherein said heat dissipating structure (109) being one of a plurality of fins, a plurality of coolant channels, and an aeration device.
7. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 1, wherein said plurality of battery module(s) (100, 200, 300, 400) comprises a first end cover (105) and a second end cover (110), wherein at least one of said first end cover (105) and said second end cover (110), covers at least one side of said plurality of battery module(s) (100, 200, 300, 400).
8. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 7, wherein at least one peripheral side of at least one of said first end cover (105) and said second end cover (110) includes an alternatively formed at least one second depressed portions (105a) and at least one second raised portions (105b).
9. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 8, wherein said at least one second depressed portions (105a) of said first end cover (105) being capable of mating with periphery of at least one of first depressed portion (102d) of one of said plurality of battery module(s) (100, 200, 300, 400), and said at least one second raised portions (105b) of said first end cover (105) being capable of mating with periphery of at least one first raised portion (102c) of one of said plurality of battery module(s) (100, 200, 300, 400).
10. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 8, wherein said at least one second depressed portions (105a) of said second end cover (110) being capable of coherently mating with periphery of at least one of first depressed portion (102d) of one of plurality of battery module (100, 200, 300, 400), and said at least one second raised portions (105b) of said second end cover (110) being capable of coherently mating with periphery of at least one first raised portion (102c) of one of said plurality of battery module(s) (100, 200, 300, 400).
11. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 1, wherein said first outer surface (102b) of one of said plurality of battery module(s) (100, 200, 300, 400) faces towards said first outer surface (102b) of another of said plurality of battery module(s) (100, 200, 300, 400), when plurality of battery module(s) (100, 200, 300, 400) being stacked upon each other.
12. The powered device having plurality of battery module(s) (100, 200, 300, 400) as claimed in claim 4, wherein said second outer surface (108b) of one of said plurality of battery module(s) (100, 200, 300, 400) faces away from said second outer surface (108b) of another of said plurality of battery module(s) (100, 200, 300, 400), when plurality of battery module(s) (100, 200, 300, 400) being stacked upon each other, thereby ensuring placement of each of heat dissipating structure (109) disposed on said second outer surface (108b) of each of said plurality of battery module(s) (100, 200, 300, 400) away from each other.