Description:Technical Field of Invention
[0001] The present subject matter relates to a vehicle, more specifically the present subject matter is related to a vehicle with an electric propulsion system supported by an energy storage system.

Background
[0002] A vehicle with two or more wheels may be propelled by any of a number of propulsion means. The most common types of such propulsion means are an internal combustion engine, which generates power for propulsion by combusting a hydrocarbon-based fuel in a cylinder, which generates exhaust gases, which push down on a piston translating the combustion into forward motion. Such vehicles usually have a fuel storage unit mounted securely on the vehicle itself. Another method is to have a rechargeable electric power storage unit onboard the vehicle, which powers one or more electric motors, which drive the wheel. The electric motors may be mounted on the wheel hub itself, or on an axle, or on the frame of the vehicle, and be connected to the wheel through a shaft, a chain or a belt. There are also other power sources to drive a vehicle, such as a hydrogen fuel cell. A vehicle can also have a hybrid propulsion system, which is a combination of at least two of the known propulsion systems in vehicles. The most commonly used hybrid powertrains of vehicles are a combination of the internal combustion engine and the electric motor. Such a vehicle would require a storage for the hydrocarbon fuel as well as an electric power storage unit. An entirely electric vehicle will have one or more energy storage devices, also known as batteries, to power the one or more electric motors. Such batteries must have a high charge density and a high charge capacity, in order to ensure maximum utilisation of the vehicle, and maximum available range for the user of the vehicle. Such batteries are usually made with Lithium ion (Li-ion) cells, which have a very high charge density compared to other types of known cells (such as Lead Acid).

Summary of the Invention
[0003] Conventionally, the application of electric powertrains in vehicles has been limited by the capacity of the existing energy storage devices to power the electric motor for extended periods of time. Each energy storage device is made up of one or more energy storage cells, which are interconnected with each other to store electric charge. Li-ion cells are currently the most commonly used battery cells in the automotive and other industries due to their high charge capacity and density. Compared to other existing battery cells, the Li-ion cell provides a higher range of operation for the vehicle due to its high charge capacity. Also, with the development of faster charging ports, the viability of electric vehicles is increasing.
[0004] However, such energy storage devices generate a lot of heat. Li-ion batteries are prone to discharge heat when charging or discharging. Additionally, the electrical and electronic components such as high-capacity conductors and transistors, specifically Metal Oxide Semiconductor Field Effect Transistor (MOSFETs) generate a lot of heat during operation. Appropriate heat dissipation methods also have to be arranged around the battery for the same. This heating can damage the cells, and generally affects the life and longevity of the cells in the battery. Heating in a Li-ion cell can lead to a failure mode of the Li-ion battery known as thermal runaway. Li-ion thermal runaway occurs when heat generated by a cell exceeds the amount of heat being dissipated, which causes a chain reaction in the form of propagating thermal runaway in surrounding Li-ion cells and batteries. Overall heat dissipation of the battery pack as a whole has to be increased from existing levels in order to ensure that such failure modes can be avoided.
[0005] A battery pack includes one or more electrical and electronic elements for establishing electrical connections between the energy storage cells of the battery pack. This is further facilitated by a battery management service (BMS), which is very crucial for efficient working of the energy storage device. An interconnector plate made up of metal is used to form the connection between the one or more cells and the BMS. The interconnector plate is welded on the one or more cells and is connected to the BMS through wiring harness. The BMS plays a vital role in monitoring the health of the battery pack. The BMS monitors the voltage, charging current, temperature, state of charge, and the like of the one or more cell for ensuring effective working and long life of the battery pack.
[0006] Existing battery packs are known to have outer covers which encapsulate the assembly of the cells with the electrical and electronic connections. Such covers are configured to protect the individual cells of the energy storage device. The cells, the interconnectors and other electrical connectors, and the BMS are usually included within the covers. In a moving vehicle, the energy storage device is usually disposed in a place where the battery pack can lower the centre of gravity of the vehicle to give the vehicle more stability. This location is usually in the vertically lower portion of the vehicle with respect to a ground level. The energy storage device, therefore, can be exposed to the elements of nature such as rain, mud and dust, especially in a two wheeled vehicle. It therefore vital that the outer covers of the battery pack are configured to efficiently protect the components within from the natural elements, and that the joints between the various parts of the outer cover are sealed with a suitable sealing material which prevents the entry of water and dust inside the battery. Such ingress of external elements can damage the cells, as well as the electrical and electronic elements connecting the cells. Water and dust can cause short circuiting, as well as increased oxidation of the metallic components, which decrease the usable life of the energy storage device.
[0007] It is known that these outer covers be either made of plastic or metallic materials. While metal is a better conductor of heat than a plastic, plastic is an electric insulator. Heat dissipation is therefore a problem in such energy storage devices with plastic outer covers as plastic is an insulator of heat. Also, a plastic outer cover lacks the strength and rigidity of a metallic outer cover. However, a plastic outer covers offers protection of electrical insulation from the electrical connections in the energy storage device. Under operational conditions, it is possible that the electrical and electronic connections may touch the outer covers, which can short circuit the connections inside, and cause injury to any person.
[0008] This problem has been addressed in the known art by coating the top outer cover in a dielectric material. This will provide insulation, but is a time intensive and cost intensive process. It is also known in the art to separately provide insulating material against the exposed ends of the one or more electrical and electronic components. This is also a time intensive and cost intensive process. Therefore, the known solutions in the art increase the manufacturing time of the energy storage device. Moreover, these processes increase the weight of the energy storage device, which reduces its efficiency when it is used to provide electrical power to the powertrain of a vehicle.
[0009] In view of the above, there is a need for an energy storage device with a metallic outer cover assembly, which will have an insulation as well as sealing means, without increasing the weight of the energy storage device and the assembly time cycle is maintained.
[00010] In one aspect, an energy storage device is disclosed. The energy storage device comprises one or more electrical connectors. The energy storage device also comprises a top cover, a bottom cover, and one or more side covers. Further, the energy storage device also includes a gasket. The gasket is configured for sealing an assembly of the top cover with the one or more side covers. The gasket is also configured for electrically insulating the one or more electrical connectors from the top cover. The gasket includes a base portion and a wall portion. The wall portion of the gasket is configured to conform to a first portion of an inner surface of the top cover. Further, the wall portion insulating the top cover from the one or more electrical connectors.
[00011] In an embodiment, the base portion of the gasket is perpendicular to the wall portion of the gasket.
[00012] In an embodiment, the inner surface of the top cover comprises the first portion and a second portion, the first portion is a side wall of the top cover, and the second portion is a ceiling wall of the top cover
[00013] In an embodiment, the gasket is interposed at a contact interface between the top cover with the one or more side covers. The wall portion of the gasket mating with the first portion of the inner surface of the top cover enables the base portion of the gasket to be removably settled along a contact face of the top cover. Further, one or more contact faces of the one or more side covers are aligned with the base portion of the gasket.
[00014] In an embodiment, a contact face of the top cover is configured with a groove to enable the gasket to be removably attached to the top cover.
[00015] In an embodiment, the top cover is attached to the one or more side covers through one or more fasteners. The base portion of the gasket is interposed between the top covers and the one or more side covers, sealing the attachment of the top cover with the one or more side covers.
[00016] In an embodiment, the base portion of the gasket comprises one or more holes for one or more fasteners.
[00017] In an embodiment, the gasket is made of rubber.
[00018] In an embodiment, the energy storage device further comprises one or more energy storage cells. The one or more electrical connectors are configured to interconnect the one or more energy storage cells in series and parallel connection.
[00019] In an embodiment, the energy storage device further comprises a battery management system (BMS), wherein the one or more electrical connectors being connected to the BMS for transmission of electrical power to one or more electrical loads.
[00020] In an embodiment, the energy storage device is used in one of an electric propulsion system and a hybrid propulsion system of a vehicle.
[00021] In another embodiment, the vehicle is one of a two wheeled vehicle, a three wheeled vehicle, and a four wheeled vehicle.

Brief Description of Drawings
[00022] 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.
[00023] Figure 1 is an exemplary illustration of the energy storage device, including the top cover, the one or more side covers, and the bottom cover, from a side view of the energy storage device.
[00024] Figure 2 is an exemplary illustration of the energy storage device in an exploded form, including the top cover, the one or more side covers, the gasket, the one or more fasteners, and the bottom cover, from a side view of the energy storage device.
[00025] Figure 3 is an exemplary illustration of the inner surface of the top cover of the energy storage device, including the gasket, in an isometric orientation of the top cover.
[00026] Figure 4 is an exemplary illustration of the top cover of the energy storage device, excluding the gasket, in an isometric orientation of the energy storage device.
[00027] Figure 5 is an exemplary illustration of the gasket for the energy storage device.
Detailed Description
[00028] Various features and embodiments of the present invention here will be discernible from the following description thereof, set out hereunder.
[00029] Figure 1 is an exemplary illustration of the energy storage device 100, including the top cover 101, the one or more side covers 102a, 102b, and the bottom cover 103, from a side view of the energy storage device. In this exemplary illustration, an energy storage device 100 with one or more energy storage cells is being considered. Each of the covers 101, 102a, 102b, 103 are configured to be removably attached to each other by the means of one or more fasteners 104. The one or more energy storage cells are disposed in a predetermined pattern in one or more cell holders. The one or more cells holders are usually made of a rigid of a semi rigid material, and one or more slots are created in the cell holders to accommodate the one or more energy storage cells. The one or more energy storage cells are accommodated in the slots created in the cell holder. In order to protect the energy storage cells, the cells are placed in a secure housing. The housing consists of individual cover parts. In the present embodiment, the housing for the cells comprise one or more cover panels, which in the present embodiment consist of a top cover 101, a bottom cover 103, and one or more side covers 102a, 102b. Also, as per the present embodiment, each of the covers 101, 102a, 102b, 103 are removably attached to each other with one or more fasteners 104. Each of the cover 101, 102a, 102b, 103 are configured with one or more fastening holes to facilitate the one or more fasteners 104 being fixed. The top cover 101 additionally has at least one electrical outlet 105 so that the electric power from the energy storage device 100 can be provided to one or more electrical loads situated external to the energy storage device 100. Usually, the energy storage device 100 will provide a high voltage electrical current which can be used to run high voltage electrical loads, such as an electrical motor in an automobile. Low voltage electrical loads can also be powered by the energy storage device 100, by using a DC-DC converter to step down the high voltage power to a low voltage power.
[00030] In the present embodiment, the battery management system (BMS) of the energy storage device 100 is disposed at the top of the energy storage device 100, and the top cover 101 is configured to accommodate the BMS within. Also, there are one or more electrical and electronic components which connect the one or more cells in the energy storage device 100 with the BMS. In order to adequately protect the one or more cells, the BMS, and the one or more electrical and electronic components, the housing of the energy storage device 100 has to be constructed with a metallic material. Whereas constructing the housing is known in the art to be constructed with a plastic-based material, it does not match the rigidity and strength of a metal. Each of the covers 101, 102a, 102b, 103 are therefore metallic. Metallic cover panels further facilitate easier heat dissipation from the one or more cells, and the one or more electrical and electronic components, which generate heat during normal operations of the energy storage device 100, including charging and discharging. Joining one or more metallic components with fasteners always has a scope of a gap remaining in the joint between the various cover panels of the housing. Sealing the joints between the various covers is vital to the energy storage device 100 as ingress of external elements such as dust and water can damage the one or more cells, or the one or more electrical and electronic components, or the BMS. The metallic cover panels however are good electrical conductors, and therefore can possibly short circuit the cells and the electrical and electronic components within the housing if any of the current carrying components come in contact with the metallic cover panels. It is therefore vital to electrically insulate the cover panels from the exposed current carrying components. Insulation of the metallic cover 101 can be accomplished by coating the panels with a dielectric material, or a powder coating of any other insulating material, which is a complex time intensive process. Also, the current carrying components can be individually insulated, which is also a complex, cumbersome, and time intensive process.
[00031] Figure 2 is an exemplary illustration of the energy storage device 100 in an exploded form, including the top cover 101, the one or more side covers 102a, 102b, the gasket 106, the one or more fasteners 104, and the bottom cover 103, from a side view of the energy storage device. This figure also illustrates the one or more electrical and electronic components of the energy storage device 100, in the gap between the gasket 106, and the topmost portion of the one or more side covers 102a, 102b. the one or more interconnectors 107 of the one or more electrical and electronic components, which connect the energy storage cells in series and parallel connections with the BMS are also shown. As can be seen in the figure 2, there are multiple current carrying components which can accidentally come in contact with the metallic top cover 101 during operating conditions of the energy storage device 100. The gasket 106 is made of a rubber-based material, which gives it the flexibility to be compressed between the contact surfaces of the top cover 101 and the one or more side covers 102a, 102b, when the covers are attached to each other with the one or more fasteners. This compression allows the joint between the top cover 101 and the one or more side covers 102a, 102b to be sealed so that ingress of external materials into the energy storage device 100. The gasket according to the present embodiment of the invention, is also configured to insulate the top cover from the current carrying components which can come in contact with the top cover 101. The side covers 102a, 102b, and the bottom cover 103 have a larger surface area in close proximity with the electrical current carrying components, such as the interconnectors 107. These covers 102a, 102b, 103 usually comprise a thermally conducting electrically insulating inner layer. However, the same cannot be said of the top cover 101, which is configured to accommodate other electrical connectors in addition to the energy storage cells and their interconnectors 107. Adding an insulation layer on the entire inner surface of the top cover 101 will therefore increase the weight of the top cover 101, and therefore the energy storage device 100 as a whole. The gasket 106 is configured to conform to the shape of the inner surface of the top cover 101. As can be seen in the figure, a cover element, such as the top cover 101, has multiple crests and troughs, which are constructed according to various considerations, such as enabling the fastening holes, ease of manufacturability, saving weight of the part, structural rigidity and strength, and shape & size of the components to be accommodated within.
[00032] Figure 3 is an exemplary illustration of the inner surface of the top cover 101 of the energy storage device 100, including the gasket 107, in an isometric orientation of the top cover 101. As stated above, the inside surface of the top cover 101 is non uniform, and has multiple troughs and crests. The top cover 101 has a first portion 101a, which is a side wall of the top cover 101, and a second portion 101b, which is a ceiling wall of the top cover 101. The gasket 106 comprises a base portion 106a and a wall portion 106b. The base portion 106a of the gasket 106 is configured to be interposed between the contact surfaces of the top cover 101 and the side covers 102a, 102b. The base portion 106a compresses between the two contact surfaces when the top cover 101 is attached to the one or more side covers 102a, 102b by the one or more fasteners 104. The top cover is configured with one or more fastening holes to allow the one or more fasteners 104 to pass through. The base portion 106a of the gasket 106 is also configured with one or more fastening holes 106c. The one or more fastening holes 106c on the gasket 106 correspond to each of the one or more fastening holes on the top cover 101. The wall portion 106b of the gasket 106 is perpendicular to the base portion 106a. The wall portion 106b is configured to abut on the first portion 101a of the top cover 101. The wall portion 106b is configured to conform to the shape of the first portion 101a. A height of the wall portion 106b is configured as a fraction of a height of the first portion 101a. The wall portion 106b being made of rubber, insulates the current carrying elements of the one or more electrical and electronic components including the interconnectors 107, from the top cover 101. This saves weight as the wall portion does not cover the entire inner surface of the top cover 101. Also, the gasket 106 being made of rubber, is easily moldable to conform to the shape of the first portion 101a of the top cover, so that the wall portion 106b can abut on it. Also as per the present embodiment, the top cover 101 is also configured to provide at least one outlet 105 for electrical connectors to be connected to external loads. The top cover may also have a thermal runaway valve to protect the energy storage device against thermal runaway of the Li-ion energy storage cells.
[00033] Figure 4 is an exemplary illustration of the inner surface of the top cover 101 of the energy storage device 100, excluding the gasket 106, in an isometric orientation of the top cover 101. This illustration shows the one or more fastening holes 101c on the top cover 101. As stated above, the gasket 106 is also configured with one or more fastening holes 106c each of which correspond to each of the one or more fastening holes 101c. Also, as per the present embodiment, the contact surface 101d of the top cover 101 is shown without the gasket 106. In the present embodiment, the contact surface 101d is configured with a groove / cavity along the length of the contact surface 101d. The wall portion 106b of the gasket 106 mating with the first portion 101a of the top cover 101 enables the base portion 106a of the gasket 106 to be removably settled along the contact surface 101d of the top cover 101. As a result, a surface of the base portion 106a of the gasket 106 in contact with the contact surface 101d of the top cover 101 is also configured with a groove complimentary to the groove on the contact surface 101d. This enables the gasket 106 to be removably fixed with the top cover 101. This provides the advantage during servicing or maintenance of the energy storage device 100 that the gasket 106 does not come loose when the top cover 101 is disassembled from the rest of the device 100, and therefore the gasket is not lost or misplaced when the energy storage device is disassembled. Also, the gasket 106 is easily detachable from the top cover 101 in case the gasket 106 needs to be replaced, as there are no fasteners between the gasket 106 and the top cover 101 once the one or more fasteners 104 are removed. This also allows the base portion 106a to be compressed between the contact surface 101d of the top cover 101, and the contact surfaces of the one or more side covers 102a, 102b, without any risk of slippage or sliding of the rubber gasket 106 due to the compression, thus effectively sealing the contents of the energy storage device against ingress of external elements such as dust and water.
[00034] Figure 5 is an exemplary illustration of the gasket 106 for the energy storage device 100. As described above, the gasket 106 has a base portion 106a and a wall portion 106b. The base portion 106a is configured to interpose between the two contact surfaces of the top cover 101 and the one or more side covers 102a, 102b. the base portion 106a also has one or more fastening holes 106c, corresponding to the one or more fastening holes 101c on the top cover 101. The wall portion 106b is configured to be perpendicular to the base portion 106a. The wall portion 106b abuts on the first portion 101a of the inner surface of the top cover 101. The wall portion 106b is also configured to have a height which is a fraction of the height of the first portion 101a. The wall portion 106b is also configured to conform to the profile of the inner surface of the top over 101, specifically the first portion 101a of the top cover 101. This allows the wall portion 106b to insulate the top cover 101 from the current carrying components of the one or more electrical and electronic components, including the BMS, and the one or more interconnectors.
 
List of reference signs:
100 – energy storage device
101 – top cover
101a – first portion of inner surface of the top cover
101b – second portion of inner surface of the top cover
101c – one or more fastening holes in the top cover
101d – contact surface of the top cover
102a, 102b – one or more side covers
103 – bottom cover
104 – one or more fasteners
105 – at least one electrical outlet
106 – gasket
106a – base portion of gasket
106b – wall portion of gasket
106c – one or more fastening holes of the gasket
107 – one or more interconnectors
, Claims:We claim:
1. An energy storage device (100), the energy storage device (100) comprising:
one or more electrical connectors (107);
a top cover (101);
a bottom cover (103), and
one or more side covers (102a, 102b), and
a gasket (106), the gasket (106) is configured for sealing an assembly of the top cover (101) with the one or more side covers (102a, 102b), and electrically insulating the one or more electrical connectors (107) from the top cover (101),
wherein,
the gasket (106) includes a base portion (106a) and a wall portion (106b),
the wall portion (106b) of the gasket (106) is configured to conform to a first portion (101a) of an inner surface of the top cover (101), and
the wall portion (106b) insulating the top cover (101) from the one or more electrical connectors (107).
2. The energy storage device (100) as claimed in claim 1, wherein the base portion (106b) of the gasket (106) is perpendicular to the wall portion (106a) of the gasket (106).

3. The energy storage device (100) as claimed in claim 1, wherein the inner surface of the top cover (101) comprises the first portion (101a) and a second portion (101b), the first portion (101a) is a side wall of the top cover (101), and the second portion (101b) is a ceiling wall of the top cover.

4. The energy storage device (100) as claimed in claim 1, wherein the gasket (106) is interposed at a contact interface between the top cover (101) with the one or more side covers (102a, 102b), wherein
the wall portion (106b) of the gasket (106) mating with the first portion (101a) of the inner surface of the top cover (101) enables the base portion (106a) of the gasket (106) to be removably settled along a contact surface (101d) of the top cover (101),
one or more contact surfaces of the one or more side covers (102a, 102b) are aligned with the base portion (106a) of the gasket (106).

5. The energy storage device (100) as claimed in claim 1, wherein a contact surface (101d) of the top cover (101) is configured with a groove to enable the gasket (106) to be removably attached to the top cover (101).

6. The energy storage device (100) as claimed in claim 1, wherein the top cover (101) is attached to the one or more side covers (102a, 102b) through one or more fasteners (104), the base portion (106a) of the gasket (106) being interposed between the top cover (101) and the one or more side covers (102a, 102b), sealing the attachment of the top cover (101) with the one or more side covers (102a, 102b).

7. The energy storage device (100) as claimed in claim 1, wherein the base portion (106a) of the gasket (106) comprises one or more fastening holes (106c) for one or more fasteners (104).

8. The energy storage device (100) as claimed in claim 1, wherein the gasket (106) is made of rubber.

9. The energy storage device (100) as claimed in claim 1 further comprising one or more energy storage cells, wherein the one or more electrical connectors (107) are configured to interconnect the one or more energy storage cells in series and parallel connection.

10. The energy storage device (100) as claimed in claim 1 further comprising a battery management system (BMS), wherein the one or more electrical connectors (107) being connected to the BMS for transmission of electrical power to one or more electrical loads.

11. The energy storage device (100) as claimed in claim 1, wherein the energy storage device (100) is used in one of an electric propulsion system and a hybrid propulsion system of a vehicle.

12. The energy storage device (100) as claimed in claim 11, wherein the vehicle is one of a two wheeled vehicle, a three wheeled vehicle, and a four wheeled vehicle.