Claims:WE CLAIM:
1. A battery module (10) comprising:
a plurality of battery cells (12);
a base plate (30) configured to receive the plurality of battery cells (12); and
a top cover (20) disposed above the plurality of battery cells (12), wherein the top cover (20) has a plurality of busbars (22) embedded therein, the plurality of busbars (22) configured to electrically connect to the plurality of battery cells (12).

2. The battery module (10) as claimed in claim 1, wherein each of the plurality of busbars (22) is configured to overlap with one or more cell tabs (14) of the plurality of battery cells (12).

3. The battery module (10) as claimed in claim 2, wherein each of the plurality of busbars (22) is configured to be welded to the corresponding one or more cell tabs (14) of the plurality of battery cells (12) to electrically connect the plurality of battery cells (12).

4. The battery module (10) as claimed in claim 1, wherein two or more of the plurality of busbars (22) are configured to be terminals of the battery module (10) to connect the battery module (10) to an external load.

5. The battery module (10) as claimed in claim 1 comprising a plurality of endplates (40) adjacent to an endmost battery cell of the plurality of battery cells, each endplate (40) extending between the base plate (30) and the top cover (20).

6. The battery module (10) as claimed in claim 1, wherein the base plate (30) has a plurality of ridges (32) intersecting to form a plurality of bays (35), each of the plurality of bays (35) accommodating a bottom portion of the plurality of battery cells (12).

7. The battery module (10) as claimed in claim 1, wherein the top cover (20) has a plurality of protuberances (24) projecting towards the plurality of battery cells (12), the plurality of protuberances (24) disposed between each of the plurality of battery cells (12).

8. The battery module (10) as claimed in claim 1 comprising an insulation sheet (50a, 50b) disposed between each of the plurality of battery cells (12).

9. The battery module (10) as claimed in claim 1, wherein the plurality of battery cells (12) comprises prismatic battery cells.

Dated this 11th day of February 2022
TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471 , Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[Refer Section 10, Rule 13]

TITLE OF INVENTION
A Battery Module

APPLICANT
TVS MOTOR COMPANY LIMITED, an Indian company, having its address at “Chaitanya”, No.12 Khader Nawaz Khan Road, Nungambakkam, Chennai 600 006, Tamil Nadu, India.

PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed. 
FIELD OF THE INVENTION
[001] The present invention generally relates to a battery module and more particularly relates to a top cover of the battery module.

BACKGROUND OF THE INVENTION
[002] A battery module or a battery pack includes many battery cells interconnected to each other. The battery module achieves desired voltage by connecting several battery cells in series, such that each battery cell adds its voltage potential to derive the total terminal voltage. Similarly, the battery module achieves desired current by connecting several battery cells in parallel. If higher voltages or currents are needed and larger battery cells are not available or do not fit the design constraint, one or more battery cells can be connected in series or parallel to achieve the desired electrical output. Generally, the battery module or the battery pack employs a combination of series and parallel connections for its many battery cells. This enables for design flexibility and achieves the desired voltage and current ratings with a standard battery cell size.
[003] Conventionally, the battery cell is provided with two cells tabs, one positive and other negative to connect the battery cell to another battery cell or to an external load. The aforementioned series and/or parallel connections between the individual battery cells of the battery module are achieved by electrically connecting the cell tabs of different battery cells. The cell tabs are electrically connected using conductive wires or busbars. While conductive wires are easy to install, generally by soldering the conductive wires to the cell tabs, the connections are fragile and are best suited for stationary battery modules. In the battery modules that undergo regular movement or that are exposed to vibrations, such as battery modules used in automobiles or heavy machinery, fragile conductive wires will break and disconnect often requiring maintenance. In these conditions busbars are more suited to electrically connect battery cells.
[004] Conventionally, busbars are bolted on or welded to the cell tabs of the adjacent battery cells of the battery module. These busbars are assembled individually for a pair of adjacent battery cells. Assembling the busbars one by one is a time consuming and complicated process. Once all the busbars are assembled a top cover of the battery module has to be assembled covering the busbars. Further, provision has to be made for output terminals of the battery module on the top cover to connect the battery module to the external load. All these additional steps in assembling the battery module cause inconvenience and increases the production time of the battery module. Complexity of the assembly and large number of non-modular components involved increases the probability of errors.
[005] In some cases, the cell tabs are provided with locking mechanisms to lock the busbars during assembly. This secures the busbars on to the respective cell tab. However, this mechanism is feasible only in case of cylindrical tabs and cannot be employed in the case of all prismatic battery cells. In yet another case, the busbars may be laid out on a base and the battery cells assembled on the base in an inverted manner so that the cell tabs contact the busbars to establish electrical connection between the battery cells. However, this results in excess loads on the cell tabs as weight of the battery is transferred to the cell tabs. This leads to premature mechanical failure of the cell tabs.
[006] Furthermore, spacers are used between adjacent battery cells to achieve a compact secured fit for the battery cells within the battery pack. The spacers ensure constant pressure on the sides of the individual battery cells to ensure a tight packing of the battery cells within the battery module. However, the use of spacers increases the total footprint and the overall space requirement for the battery module. This creates challenges in applications where space limitation exists.
[007] Thus, there is a need in the art for a battery module which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[008] In one aspect, the present invention is directed to a battery module. The battery module includes a plurality of battery cells, a base plate and a top cover. The base plate is adapted to receive the plurality of battery cells and the top cover is provided above the plurality of battery cells. The top cover includes a plurality of busbars embedded therein. The plurality of busbars is adapted to electrically connect to the plurality of battery cells.
[009] In an embodiment, the plurality of busbars embedded in the top cover overlap with one or more cell tabs of the plurality of battery cells.
[010] In another embodiment, each of the plurality of busbars is adapted to be welded to the corresponding one or more cell tabs of the plurality of battery cells. The welding electrically connects the plurality of busbars to the plurality of battery cells.
[011] In a further embodiment, two or more of the plurality of busbars are adapted to become terminals of the battery module. The battery module is electrically connected to an external load and/or to the ground through the terminals.
[012] In an embodiment, the battery module further includes a plurality of endplates adjacent to an endmost cell of the plurality of battery cells. The endplate extends between the base plate and the top cover.
[013] In another embodiment, the base plate includes a plurality of ridges. The plurality of ridges intersects with each other to form a plurality of bays. Each bay of the plurality of bays is adapted to accommodate a bottom portion of the plurality of battery cells.
[014] In yet another embodiment, the top cover includes a plurality of protuberances. The plurality of protuberances projects towards the plurality of battery cells and is adapted to be disposed between each of the plurality of battery cells.
[015] In a further embodiment, the battery module includes an insulation sheet adapted to be disposed between each of the plurality of battery cells.
[016] In yet another embodiment, the plurality of battery cells are prismatic battery cells.

BRIEF DESCRIPTION OF THE DRAWINGS
[017] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a perspective view of an exemplary battery module, in accordance with an embodiment of the present invention.
Figure 2 illustrates an exploded view of the battery module, in accordance with an embodiment of the present invention.
Figure 3 illustrates a perspective view of an exemplary top cover of the battery module, in accordance with an embodiment of the present invention.
Figure 4 illustrates protuberances in top cover of the battery module, in accordance with an embodiment of the present invention.
Figure 5 illustrates a perspective view of an exemplary base plate of the battery module, in accordance with an embodiment of the present invention.
Figure 6 illustrates a perspective view of an exemplary endplate of the battery module, in accordance with an embodiment of the present invention.
Figure 7 illustrates exemplary insulation sheets of the battery module, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[018] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. The present invention generally relates to a battery module. Particularly, the present invention applies to a top cover, a base plate, endplates and insulator sheets of the battery module.
[019] Figure 1 illustrates a perspective view of an exemplary battery module 10 and Figure 2 illustrates an exploded view of the battery module 10, in accordance with an embodiment of the present subject matter. The battery module 10 includes a plurality of battery cells 12. In the illustrated embodiment, the battery module 10 is of a cuboidal shape and the plurality of battery cells 12 are prismatic battery cells. However, the battery module 10 may be of any shape and the plurality of battery cells 12 of any other kind, including cylindrical battery cells. Thus, it is to be understood that the illustrated battery module 10 should not be construed to be limiting the scope of the present invention. The plurality of battery cells 12 are provided with one or more cell tabs 14 to electrically connect the battery cells 12 in series and/or parallel.
[020] As illustrated in Figure 2, the battery module 10 includes a base plate 30. The base plate 30 is adapted to receive the plurality of battery cells 12. The battery module 10 further includes a top cover 20. The top cover 20 is disposed above the plurality of battery cells 12. The top cover 20 acts as a sheath protecting the plurality of battery cells 12 from above. The top cover 20 also eliminates safety hazards by electrically isolating interconnects of the plurality of battery cells 12 and the one or more cell tabs 14 from contacting external surfaces.
[021] A plurality of busbars 22 are embedded in the top cover 20. The plurality of busbars 22 are embedded during the manufacturing of the top cover 20 in predetermined locations. In an embodiment, the plurality of busbars 22 are slide fitted on the top cover 20 during casting of the top cover 20. The locations for embedding the plurality of busbars 22 are determined such that, each of the plurality of busbars 22 overlaps with the one or more cell tabs 14 when seen in a top view of the battery module 10. The plurality of busbars 22 are embedded in a manner to have the surfaces of the plurality of busbars 22 exposed on an upper side and a lower side of the top cover 22. The plurality of busbars 22 contact the one or more cell tabs 14 at its surfaces exposed on the lower side of the top cover 20. The plurality of busbars 22 are aligned exactly over the one or more cell tabs 14. At its surfaces exposed on the upper side of the top cover 20, the plurality of busbars 22 are welded onto the one or more cell tabs 14 to make robust electrical contact between them. In an embodiment, the plurality of busbars 22 are welded using laser welding, which is a non-contact process using a laser beam to melt a specific area of the plurality of busbars 22 in a predefined weld pattern. The weld pattern may include a series of spots or concentric circles. The molten areas of the plurality of busbars 22 form precise connection with the one or more cell tabs 14. In a further embodiment, two or more of the plurality of busbars 22 are adapted to become terminals of the battery module 10 at its surfaces exposed on the upper side of the top cover 20. The battery module 10 is electrically connected to an external load and/or to the ground through the terminals.
[022] In an embodiment, the battery module 10 further includes a plurality of endplates 40 provided adjacent to an endmost battery cell of the plurality of battery cells 12. Each endplate 40 extends between the base plate 30 and the top cover 20. The plurality of endplates 40 protect the plurality of battery cells 12 at the sides of the battery module 10. The plurality of endplates 40 also increases the aesthetic appeal of the battery module 10 and gives it a compact shape. The plurality of battery cells 12 are held securely in place within the battery module 10 under pressure exerted by the top cover 20, the base plate 30 and the plurality of endplates 40. In the illustrated embodiment, two endplates 40 each opposite to the other is provided along the sides of the battery module 10. However, multiple endplates 40 may be used to cover the sides of the battery module 10 depending on the shape of the battery module 10.
[023] In another embodiment, the battery module 10 includes an insulation sheet 50a, 50b disposed between each of the plurality of battery cells 12. The insulation sheet 50a, 50b is disposed in between adjacent battery cells of the plurality of battery cells 12 to electrically isolate the plurality of battery cells 12 from each other. The insulation sheet 50a, 50b also allows the individual components of the battery module 10 to achieve a tight fit when assembled, under pressure exerted by the top cover 20, the base plate 30 and the plurality of endplates 40. In the illustrated embodiment, two types of insulation sheets 50a, 50b are used. The insulation sheet 50a is provided along the length of the battery cell 12 and the insulation sheet 50b is provided along the thickness of the battery cell 12. The type and number of insulation sheets 50a, 50b may be varied depending on the shape and construction of the battery module 10.
[024] Figure 3 illustrates a perspective view of an exemplary top cover 20 of the battery module 10, in accordance with an embodiment of the present subject matter. In an embodiment, the top cover 20 includes a wall portion 26 projecting downwardly from the edges of the top cover 20. The wall portion 26 covers outer surfaces of the endmost battery cells of the plurality of battery cells 12 at a top portion of each of the endmost battery cells. The wall portion 26 ensures a secure fit for the top cover 20 on top of the plurality of battery cells 12. In another embodiment, the top cover 20 includes an overhang 25 extending downwardly from the wall portion 26. As illustrated in Figure 6, the plurality of endplates 40 includes a depression 45 corresponding to each overhang 25 of the top cover 20. On assembly of the battery module 10, the overhang 25 mates with the depression 45 to provide for a secure fit between the top cover 20 and the plurality of endplates 40.
[025] Referring to Figure 4, the top cover 20 includes a plurality of protuberances 24 projecting downwardly towards the plurality of battery cells 12. The plurality of protuberances 24 are adapted to be disposed between each of the plurality of battery cells 12. The plurality of protuberances 24 enhances the assembly process by acting as guides for the top cover 20 and ensures a tight fit between the top cover 20 and the plurality of battery cells 12 thus making the battery module 10 more stable. The plurality of protuberances 24 also prevents the top cover 20 from sliding on the plurality of battery cells 12 thereby reducing the mechanical stresses that may be experienced by the plurality of cell tabs 14 welded to the plurality of bus bars 22 embedded in the top cover 20.
[026] Figure 5 illustrates a perspective view of an exemplary base plate 30 of the battery module 10, in accordance with an embodiment of the present subject matter. The base plate 30 includes a plurality of ridges 32 intersecting with each other to form a plurality of bays 35. The plurality of ridges 32 project upwardly towards the plurality of battery cells 12 from an inner surface of the base plate 30. Each bay of the plurality of bays 35 is adapted to accommodate a bottom portion of the plurality of battery cells 12. Each battery cell of the plurality of battery cells 12 is placed in the corresponding bay of the plurality of bays 35. The plurality of bays 35 allows the base plate 30 to act as a battery cell holder whereby the plurality of battery cells 12 can be placed without the risk of slipping and displacement within the battery module 10. In another embodiment, the base plate 30 includes a wall protrusion 36 projecting upwardly from the edges of the base plate 30. The wall portion 36 covers outer surfaces of the endmost battery cells of the plurality of battery cells 12 at the bottom portion of each of the endmost battery cells. The wall portion 36 ensures a secure fit for the plurality of battery cells 12 on the base plate 30.
[027] In an embodiment, components of a Battery Management System (BMS) are mounted on the battery module 10. The BMS components may be mounted to the top cover 20 and are adapted to electrically communicate with the plurality of bus bars 22 which are electrically connected to the plurality of cell tabs 14. In another embodiment, the battery module 10 is inserted into an outer casing to protect the battery module 10 from its surroundings. The outer casing includes a cover housing top, a cover housing bottom, and a pair of side cover housings. In an embodiment, the cover housing top, the cover housing bottom, and the pair of side cover housings are joined together using fasteners to form the outer casing and their mating surfaces are sandwiched with a rubber gasket in between to have a leakproof joint. In a further embodiment, the outer casing is made of aluminium. This improves manufacturing feasibility in application of thermal paste on top and bottom of battery cell interconnects and enhances ease of assembly.
[028] The battery module 10 described hereinabove can be employed in automobiles including two wheeled vehicles, three wheeled vehicles and four wheeled vehicles. The battery module 10 can further be employed in any other applications without defeating the scope of the present invention.
[029] In tightly packed vehicle layout of two wheeled vehicles, it is challenging to find space for an engine control unit (ECU). When the ECU is disposed between a side box and a storage box of the vehicle, a special structure could be required as anti-heat countermeasure since heat from the vehicle’s engine may damage the ECU. The rear portion of the two wheeled vehicle is usually tightly packed with style panes. As a solution, the ECU may be mounted on a side of the vehicle in a position sandwiched between a frame and a side panel. However, positioning the ECU here will hinder serviceability since the side panel has to be completely removed .to access the ECU. Further, placing the ECU near the storage box decreases the storage capacity of the storage box. Placing the ECU near a fuel tank will decrease the storage capacity of the fuel tank and will require the fuel tank to be redesigned resulting in a complex structure of the fuel tank. Furthermore, amount of heat generated from the ECU is increased due high functionality or multi-functionality of controlling the vehicle. Hence, it is imperative to position the ECU in the vehicle at a location having better air flow, good cooling characteristics and lesser temperature.
[030] In an embodiment of the present invention, the ECU is mounted on the battery module 10 as a solution to the aforementioned problems. In an embodiment, the ECU may be mounted on the top cover 20 of the battery module. Due to modular style panel design, electrical components can be accessed by removing only a part of the style panel. In this layout, a battery box is located at a front of the vehicle and the battery box can be easily accessed by removing a small part of a front panel owing to its modularity. There is a space available between a top of the battery box and the front style panel. This space can be used to locate the ECU. In another embodiment, the top cover 20 can be adapted to mount a rubber boot and the ECU can be mounted onto the rubber boot. The ECU is encircled by the rubber boot that has provision to mount the ECU on the top cover 20 of the battery module 10. In yet another embodiment, a top of the battery box has provision to insert the rubber boot. The ECU is placed such that it lies below the removable part of the front style panel. In yet another embodiment, provision provided for mounting the rubber boot on the top of the battery box is adapted to mount the rubber boot in an inclined manner such that after mounting, the ECU is positioned in a tilted fashion. This is to drain water that might enter during rainy condition and prevent water stagnation in and around the ECU. In a further embodiment, the ECU is positioned on the top of the battery box and at a bottom of the front style panel. The front style panel above the ECU can be partly disassembled, which allows for access to the ECU without disassembling the front style panel completely. In yet another embodiment, the rubber boot is of a predetermined height which is greater than or equal to a distance between the ECU and the top of the battery box, such that the ECU is prevented from striking the top of the battery box under vibration of the vehicle. Placement of the ECU such that it does not hinder operation of a horn, mounting the ECU in a tilted manner so that there is no water stagnation in case of water entry and mounting mechanism of the ECU such that it is safeguarded even during enormous vibration of the vehicle are advantages of the aforementioned embodiments.
[031] A battery holder is typically used to provide support to the battery module 10. A bottom portion of the battery module 10 is kept in the battery holder. Usually, a clamp is attached to a battery support part to secure the mounting of the battery module 10 in the battery holder. In an embodiment, a fuse is mounted on the battery holder on a left side of battery module 10 and in front of an air filter when viewed from a right side of the vehicle. When viewed from top, a fuse box is packaged on the right side of the air filter and behind the battery module 10 in a vehicle front rear direction.
[032] Additionally, in existing vehicles, an ignition coil has higher mounting pitch when the ignition coil is directly mounted to a vehicle frame with fasteners. For cost reduction, the ignition coil may be modified to have a lower mounting pitch. However, this requires an additional bracket to mount the ignition coil to a vehicle mounting bracket. Therefore, in an embodiment, the ignition coil is mounted to the frame bracket using an intermediate bracket.
[033] Advantageously, the present claimed invention provides a battery module. The battery module as claimed in the aforementioned embodiments, increases ease of manufacture and ease of assembly of the battery module by providing for bus bars embedded in the top cover of the battery module. The battery module is also made mechanically stable since the top cover has projections extending downwardly towards the plurality of battery cells which fits between the plurality of battery cells and makes the assembly intact. It also prevents relative movement between the individual components of the battery module enhancing safety and reliability of the battery module. Further, mechanical strain on the cell tabs of the plurality of battery cells caused in case of inverted battery module is prevented. Mechanical failure of the plurality of battery cells due to the use of inverted cells is also resolved.
[034] The claimed configurations of the battery module as discussed above are not routine, conventional, or well understood in the art, as the claimed configurations of the battery module enable the following solutions to the existing problems in conventional technologies. Specifically, by embedding the busbars into the top cover solves the technical problem of having to weld individual busbars on the cell tabs of the plurality of battery cells. By providing bays on the base plate the plurality of battery cells can be securely seated on the base plate without slipping. By providing the plurality of protuberances the assembly process of the battery module can be enhanced and the top cover can be prevented from sliding on the plurality of battery cells thereby reducing the mechanical stresses that may be experienced by the plurality of cell tabs welded to the plurality of bus bars embedded in the top cover.
[035] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

List of Reference Numerals
10 – battery module
12 – plurality of battery cells
14 – one or more cell tabs
20 – top cover
22 – plurality of busbars
24 – plurality of protuberances
25 – overhang
26 – wall portion
30 – base plate
32 – plurality of ridges
35 – plurality of bays
36 – wall portion
40 – plurality of endplates
45 – depression
50a, 50b – insulation sheet