DESC:Technical Field
[0001] The present subject matter relates to electric vehicles. More specifically, the present subject matter relates to energy storage devices on electric motor vehicle.
Background
[0002] A vehicle consists of a frame which supports a power unit and other components. These components are tightly packed within the dimensions of the vehicle and are supported by the frame. The vehicle is propelled forward by the power unit. The power unit can be an internal combustion (IC) engine or an electric motor. An IC engine has a combustion chamber where a mixture of air and fuel is burned in a pressurized environment to force a piston to undergo a linear motion, which is then transformed into rotational motion in the crankshaft. This rotational motion of the crankshaft is then transmitted to the driven wheel, which is the rear wheel of the vehicle, through the transmission system. The transmission system is generally either a manual transmission system or a continuously variable transmission system.
[0003] An electric vehicle on the other hand requires that a electric motor is used to propel the vehicle. The electric motor is power by electric current. The electric current is usually drawn from a plurality of energy storage devices (Batteries). Such energy storage devices contain a plurality of cells. Each cell has a positive terminal and a negative terminal. For electric current to flow, a positive terminal of a first cell has to be connected to the negative terminal of a second cell. The cells are arranged in rows, such that each row contains all its positive terminals on one side. The positive terminals of one row are connected to the negative terminals of the next row. The connections are made by the means of one or more interconnectors. The terminals of the rows of cells of the rows at the extreme ends are connected by bus bars, and the leads from the two terminal bus bars form the output terminals of the energy storage device.
Brief Description of Drawings
[0004] The detailed description is described with reference to an embodiment of a two wheeled saddle type motorized vehicle along with accompanying figures. The same numbers are used throughout the drawings to reference like features and components.
[0005] Figure 1 is an exemplary illustration of a saddle type two wheeled vehicle from a side view in a vehicle front rear direction.
[0006] Figure 2 is an exemplary illustration of an isometric view of the saddle type vehicle.
[0007] Figure 3 (a) is an exemplary illustration of the frame structure of the vehicle along with the energy storage devices from a top view perspective of the vehicle in a vehicle front rear direction.
[0008] Figure 3 (b) is an exemplary illustration of the frame structure of the vehicle along with the energy storage devices from a side perspective view of the vehicle along a cross section A-A’ in a vehicle front rear direction.
[0009] Figure 3 (c) is an exemplary illustration of the frame structure of the vehicle along with the energy storage devices from a front perspective of the vehicle along a cross section B-B’.
[00010] Figure 4 (a) is an exemplary illustration of s side perspective view of an energy storage device.
[00011] Figure 4 (b) is an exemplary illustration of a front perspective view of an energy storage device.
[00012] Figure 4 (c) is an exemplary illustration of a top perspective view of an energy storage device.
[00013] Figure 5 is an exemplary illustration of the front perspective view of an energy storage device along a cross section C-C’.
[00014] Figure 6 is an exemplary illustration of the front perspective view of an energy storage device along a cross section illustrating the position of the pressure valve of the device disposed below the floorboard.
[00015] Figure 7 is an exemplary illustration of an isometric view of the frame structure supporting the one or more energy storage devices of the vehicle illustrating the position of the pressure valves on the energy storage devices mounted to the rear part of the frame.
[00016] Figure 8 is an exemplary illustration of an exploded view of the energy storage device.

Detailed Description
[0001] An electric vehicle is only as efficient as the energy storage devices that provide the electricity for its electric motor. The efficiency of an electric vehicle depends upon the range of the vehicle, which is determined by the amount of charge stored in the batteries, and the efficiency of the motor driving the wheels. Generally, Lithium Ion (Li-ion) batteries are used are they provide a high charge density, and thus greater range.
[0002] The engine draws this charge from the batteries as an electric current, generating a voltage. The battery consists of a plurality of cells. These cells need to be recharged once they are sufficiently discharged. Usually, the cells are held in place by a cell holding structure. The battery may also consist of a battery cover to protect the battery from the external atmosphere, and also to protect the user from any potential electrocution. The battery also consists of a battery management system that monitors the health of the battery, and the state of charge of the cells. This is accomplished by connecting leads from the interconnectors to an inbuilt system that is communicatively connected to a vehicle control system. The batteries are generally mounted as individual replaceable units for ease of serviceability.
[0003] It is a general tendency of the battery pack to heat up. This can occur due to thermal runaway in the cells, or the interconnectors or the busbars being heated up due to conducting a continuous flow of high current. This heating of the metallic interconnectors also cause damage to the cells, as the cells are in direct conductive contact with the interconnectors, and the heat is transferred to them. The battery life lessens if the temperature of the cells is not kept within a limit. This can even lead to battery fire. Therefore serviceability and replaceability of the battery pack is of utmost importance. However, battery packs generally tend to be heavy in nature, and thus there use is difficult in lightweight vehicle.
[0004] A lightweight two or three wheeler with a step through frame consists of one or more front and rear wheels. Any electric vehicle will have electric motors mounted either on the wheels, known as hub mounted motors, or on the frame of the vehicle. The motor mounted on the frame will drive the vehicle through a chain, or belt or a shaft drive system.
[0005] Designing an electric vehicle is therefore always a compromise between the weight of the vehicle and the range of the vehicle. Efficiency of the battery pack therefore is of the utmost importance. Heating inside the battery pack can cause pressure to build up inside, which can cause explosion, or short circuit. An explosion can cause damage to the other parts of the vehicle. Such an explosion can lead to fire as well. Existing battery packs in vehicles usually contain a pressure valve that is located at the bottom cover. This is provided so that any hot gases built up inside the battery pack can be released,
[0006] However, a problem with the existing designs is that hot gases tend to go up in the atmosphere, and since the pressure valve is disposed at the bottom cover, the gases might not have the chance to escape, further increasing the risk of explosion or fire. This puts the safety of the rider at risk. To overcome this problem, the battery pack has to be redesigned.
[0007] A prior art design causes the wiring to melt on the exhaust cover in case of a short circuit, increasing the chance of the battery pack exploding in case of thermal runaway. Another prior art design causes explosion of the battery pack in case of extreme thermal runaway due to short circuiting and discharge of gases within. The present subject matter looks to provide a solution to the above mentioned problems.
[0008] Therefore, the present invention proposes a battery pack with a pressure valve for easier dissipation of hot gases, to avoid battery explosion and battery failure, improving the performance of the vehicle, and a proper guide way for the pressure valve.
[0009] In an embodiment of the present subject matter, an energy storage device for a saddle type vehicle comprises a top cover, a body shroud, a bottom cover, a plurality of interconnectors, a battery management system, a charging connector, and a pressure valve. The plurality of interconnectors are capable of conducting an electric current from an arrangement of a plurality of cells within the battery pack. The battery management system is capable of monitoring a status of said energy storage device. The charging connector is capable of being electrically connected to a charging mechanism for the battery pack. In another embodiment, the pressure valve is configured at a front most leftward position on the top cover (404) of the energy storage device. In yet another embodiment of the present embodiment, the pressure valve is located beside the charging connector. In a further embodiment, the charging connector is disposed substantially centrally on a front side of the top cover of the battery pack.
[00010] In an embodiment of the present subject matter, the battery pack is assembled so that the plurality of cess and the interconnectors are fully covered by the body shroud and the bottom cover. The top cover provides a space within the battery pack for the battery management system and the charging systems.
[00011] In an embodiment of the present subject matter, a saddle type vehicle is provided with one or more energy storage devices. The vehicle includes a frame structure. The frame structure includes a headtube, a downtube, one or more main tubes, a pair of rear tubes, a swingarm and a plurality of wheels. In another embodiment, the frame structure of the vehicle is a step through type frame.
[00012] In an embodiment of the present subject matter, the downtube extends downwardly from the headtube. The one or more main tubes extend rearwardly from a lower portion of the downtube. A pair of rear tubes extend upwardly and rearwardly from a rearmost portion of the one or more main tubes. The swingarm is connected to the frame structure at a rearmost portion of the one or more main tubes. A rear wheel is attached to a rear end of said swingarm.
[00013] In an embodiment of the present subject matter, the one or more main tubes forms a floor of the frame structure of the saddle type vehicle. The floor portion is covered by a floor board. In another embodiment, at least one energy storage device is disposed below the floorboard. According to this embodiment, the energy storage device is having a pressure valve. The pressure valve on the energy storage device is facing towards one of a left-hand side and a right hand side of the vehicle in a vehicle widthwise direction.
[00014] In yet another embodiment of the present subject matter, at least a first and a second energy storage device is disposed rearwards of the main tubes. The first and second energy storage device is mounted to the pair of rear tubes by one or more mounting means. As per this embodiment, the first and second energy storage devices each have a pressure valve. The first and second energy storage devices are disposed such that each pressure valve faces towards a rear of the vehicle in a vehicle front rear direction.
[00015] The present subject matter will now be disclosed with the help of exemplary illustrations. These illustrations are with respect to one exemplary embodiment of the present subject matter.
[00016] Figure 1 exemplarily illustrates a saddle type vehicle (100) with a step through frame. The vehicle (100) comprises a handlebar (103), rear view mirrors (103), a suspension system (104), front body panels (108), rear body panels (112), a front wheel (114), a rear wheel (116) and a swingarm cover (106). In an embodiment where the electric motor is hub mounted, the motor is mounted on the rear wheel (116), and the swingarm cover (106) is only covering the swingarm (310) from the natural elements. The vehicle has a floor portion, which is ergonomic in a vehicle with such a frame structure. He rider and the pillion can be seated on the seat structure (110). Additionally in such vehicles (100), a storage compartment is also provided below the seat assembly (110).
[00017] Figure 2 exemplarily illustrates an isometric view of the saddle type vehicle (200) with step through frame shown in figure 1. In this view, the floorboard (204) is clearly visible. In this exemplary embodiment, the vehicle has a monoshock suspension system on the left side of the vehicle (200). The motor is hub mounted such that during forward motion, the rotation of the wheel is clockwise with respect to the hub. One or more electric storage devices are disposed on this vehicle (200). At least one such device (308) is disposed below the floorboard. At least a first and a second such device (306) are disposed on the vehicle at a location where it is covered by the rear panels (112).
[00018] Figure 3 (a) and 3 (b) exemplarily illustrate the frame structure of the saddle type vehicle (100, 200). Figure 3 (a) is a top perspective view while figure 3 (b) is a side perspective view in a vehicle front rear direction. The frame structure (300a, 300b) consists of a head tube (302), a downtube (303), one or more main tubes (305), a pair of rear tubes (304) and a swingarm. The downtube (303) extends downwardly and rearwardly from the headtube (302). The one or more main tubes (305) extend rearwardly from the lowermost portion of the downtube (303). A pair of rear tubes (304) emerge from a rear most portion of said one or more main tubes (305), and extend rearwardly and upwardly. A first energy storage device (308) is disposed below the floorboard (204), in a space created by the one or more main tubes (305). A second and a third energy storage device (306) are mounted on the frame (300a, 300b) by mounting means such that the devices (306) are covered by the rear body panels (112), and are disposed above the swingarm (310) of the vehicle (100, 200). In the first device (308), the top cover is facing rearwards, whereas in the second and third devices (306), the front side of the devices (400b) is facing rearwards. Figure 3(b) illustrates the view of the vehicle frame structure at the cross sectional plane (A-A’).
[00019] Figure 3(c) exemplarily illustrates a front perspective view of the saddle type vehicle (100, 200). A cross bar (312) is used to join the pair of rear tubes (304). This illustration shows the energy storage device (308) disposed below the floorboard without its bottom cover. This illustration is at the cross sectional plane (A-A’) shown in figure 3 (b).
[00020] Figure 4(a), 4(b) and 4(c) illustrate the shape and structure of the individual energy storage devices. Figure 4 (a) is a side perspective view, figure 4(b) a front perspective view and figure 4 (c) a top perspective view. The energy storage device has a top cover (404), a body shroud (406), a bottom cover (804) a pressure valve (402) and a charging outlet (408). The charging outlet (408) is disposed substantially centrally at a front side of the top cover (404). The pressure valve (402) is disposed on a side of the charging outlet (408) at the front side of the top cover (404). The top cover (404) is attached to the body shroud (406) with a plurality of fasteners (shown in 400c).
[00021] Figure 5 exemplarily illustrates the front perspective view of the energy storage device (400b) along the cross section (C-C’). A guiding portion of the pressure valve (402) is configured which allows excess gasses to pass easily. The charging connector (408) is connected to the circuit boards disposed inside the top cover (404).
[00022] Figure 6 is an exemplary illustration of the orientation of the pressure valve (402) on the energy storage device (308) disposed below the floorboard. In this embodiment, the pressure valve (402) is disposed on the upward side of the device being disposed horizontally.
[00023] Figure 7 exemplarily illustrates an isometric view of the frame structure of the saddle type vehicle (100, 200). The pressure valve (402) on the electric storage device (308) disposed below the floorboard is disposed horizontally such that the front of the electric storage device (308) is disposed towards a left hand side of the vehicle (100, 200) in a vehicle front rear direction. The electric storage devices (306) disposed below the rear tubes (304) are disposed such that the front side (400b) of the devices (306) are facing rearwards. The electric storage devices (306, 308) at either location is disposed such that the pressure valve (402) on each storage device (306, 308) are towards a vertically top portion of the respective device (306, 308). This is to allow the gases being built up to pass easily as gasses have a natural tendency to go up in open atmosphere.
[00024] Figure 8 is an exemplary illustration of an exploded view of an energy storage device (400a, 400b, 400c). The energy storage device (800) comprises a top cover (404), a body shroud (406) and a bottom cover (804). The top cover (404) and the bottom cover (804) are attached to the body shroud (406) by a plurality of fasteners. In addition to the pressure valve (402), one or more circuit boards (806) for implementing the battery management system are also disposed in the electric storage device (800), such that the circuit boards are accessible on removing only the top cover (404). The electric storage device (800) consists of a plurality of cells connected to each other by interconnectors (802). The interconnectors have leads that are pressed towards the terminals of the cells. The cells are pre arranged in a cell holding structure, which is assembled into the body shroud (406) and the bottom cover (804). The top cover (404) is attached to the shroud (406) along with the the circuit boards (806), the charging connector (408) and the pressure valve (402).

List of Reference Signs:

100 – Vehicle (Figure 1)
102 – Handlebar
103 – Rear view mirror
104 – Suspension system
106 – Swingarm cover
108 – Front body panel
110 – Seat assembly
112 – Rear body panel
114 – Front wheel
116 – Rear Wheel
200 – Isometric view of the vehicle (Figure 2)
204 – Floor board
300a – Top view of the frame structure of the vehicle (Figure 3(a))
300b – Side view of the frame structure of the vehicle along the cross section A-A’ (Figure 3(b))
300c – Front view of the frame structure of the vehicle along the cross section B-B’ (Figure 3(c))
302 – Head tube
303 – Down tube
304 – Rear tubes
306 – Electric storage devices disposed at the rear
308 – Electric storage devices disposed at the front
310 – Swingarm
312 – Cross Bracket
400a – Side view of a single energy storage device (Figure 4(a))
400b – Front view of a single energy storage device (Figure 4(b))
400c – Top view of a single energy storage device (Figure 4(c))
402 – Pressure valve
404 – Top Cover
406 – Shroud for energy storage device
408 – Charging connecter
500 – Front view of the single energy storage device along a cross section C-C’ (Figure 5)
600 – Front view of the energy storage device disposed at the front along a cross section depicting the location of the pressure valve (Figure 6)
700 – Isometric view of the energy storage device disposed on the vehicle depicting the location of the pressure valve (Figure 7)
800 – Exploded view of a single energy storage device (Figure 8)
802 – Interconnectors and busbars
804 – Bottom cover
,CLAIMS:We Claim:
1. An energy storage device (400a, 400b, 400c) for a saddle type vehicle (100, 200), said energy storage device comprising,
a top cover (404),
a body shroud (406),
a bottom cover (804),
a plurality of interconnectors (802), said plurality of interconnectors (802) being capable of conducting an electric current from an arrangement of a plurality of cells,
a battery management system (806), said battery management system being capable of monitoring a status of said energy storage device,
a charging connector (408), said charging connector being capable of being electrically connected to a charging mechanism, and
a pressure valve (402),
wherein,
said pressure valve (402) being configured at a front most leftward position on said top cover (404) of said energy storage device (400a, 400b, 400c).
2. The energy storage device (400a, 400b, 400c) as claimed in claim 1, wherein said a first and a second interconnector of said plurality of interconnectors (802) being busbars, said busbars transmitting said electric current to an electric motor of said vehicle (100, 200), said current being conducted by said plurality of interconnectors (802).
3. The energy storage device (400a, 400b, 400c) as claimed in claim 1, wherein said pressure valve (402) being configured on a top portion of said device (400a, 400b, 400c) to allow passage of gases forming inside said device (400a, 400b, 400c).
4. The energy storage device (400a, 400b, 400c) as claimed in claim 1, wherein each unitary cells of said arrangement of plurality of cells being disposed horizontally within said device (400a, 400b, 400c, 800) with respect to a ground of said device (400a, 400b, 400c, 800).
5. The energy storage device (400a, 400b, 400c) as claimed in claim 1, wherein said plurality of interconnectors (802) being disposed vertically within said device (400a, 400b, 400c, 800) with respect to a ground of said device (400a, 400b, 400c, 800), said plurality of interconnectors (802) being disposed internally parallelly along said body shroud (406).
6. A saddle type vehicle (100, 200) with one or more energy storage devices (400a, 400b, 400c), said vehicle comprising
a frame structure (300a, 300b), said frame structure including a headtube (302), a downtube (303), one or more main tubes (305), a pair of rear tubes (304), a swingarm (310) and a plurality of wheels (114, 116),
said downtube (303) extending downwardly from said headtube (302), said one or more main tubes (305) extending rearwardly from a lower portion of said downtube (303), a pair of rear tubes (304) extending upwardly and rearwardly from a rearmost portion of said one or more main tubes (305), said swingarm (310) being connected to said frame structure (300b) at a rearmost portion of said one or more main tubes (305), at least one of said plurality of wheels (116) being attached to a rear end of said swingarm (310),
said one or more main tubes (305) forming a floor portion of said frame structure (300), said floor portion being covered by a floor board (204) on said vehicle (200), and
at least one of said one or more energy storage devices (308) being disposed below said floorboard (204),
wherein,
said at least one energy storage device (308) having a pressure valve (402), said at least one energy storage device (308) being disposed below said floorboard (204) to have said pressure valve (402) facing towards one of a left hand side and a right hand side of said vehicle (100, 200) in a vehicle widthwise direction.
7. The saddle type vehicle (100, 200) as claimed in claim 6, wherein a top cover (404) of said at least one energy storage device (308) disposed below said floorboard (204) facing rearwards in a vehicle (100, 200) front rear direction.
8. A saddle type vehicle (100, 200) with one or more energy storage devices (400a, 400b, 400c), said vehicle (100, 200) comprising
a frame structure (300a, 300b), said frame structure including a headtube (302), a downtube (303), one or more main tubes (305), a pair of rear tubes (304), a swingarm (310) and a plurality of wheels (114, 116),
said downtube (303) extending downwardly from said headtube (302), said one or more main tubes (305) extending rearwardly from a lower portion of said downtube (303), a pair of rear tubes (304) extending upwardly and rearwardly from a rearmost portion of said one or more main tubes (305), said swingarm (310) being connected to said frame structure (300b) at a rearmost portion of said one or more main tubes (305), at least one of said plurality of wheels (116) being attached to a rear end of said swingarm (310),
said one or more main tubes (305) forming a floor portion of said frame structure (300), said floor portion being covered by a floor board (204) on said vehicle (200), and
at least a first and a second energy storage device (400a, 400b, 400c) of said one or more energy storage devices (310) being disposed rearwards of said one or more main tubes (305), said first and second energy storage device (310) being mounted to said pair of rear tubes (304) by one or more mounting means,
wherein,
said at least a first and second energy storage devices (310) each having a pressure valve (402), said first and second energy storage devices (310) being disposed to have said each pressure valve (402) facing towards a rear of said vehicle (100, 200) in a vehicle front rear direction.
9. The vehicle (100, 200) as claimed in claim 6 or claim 8, wherein said pressure valve (402) being disposed on said energy storage device (400a, 400b, 400c) beside a charging connector.
10. The vehicle (100, 200) as claimed in claim 6 or claim 8, wherein said one or more energy storage devices (308, 310) powering a motor mounted to a hub of a rear wheel (116) of said plurality of wheels.
11. The vehicle (100, 200) as claimed in claim 6 or claim 8, wherein said one or more energy storage devices (308, 310) driving an electric motor mounted on said frame structure (300a, 300b), said motor being capable of driving a rear wheel (116) of said plurality of wheels by one of a chain drive, a belt drive, and a shaft drive.
12. The vehicle (100, 200) as claimed in claim 6 or claim 8, wherein said swingarm (310) being mounted to said pair of rear tubes (304) by a suspension system (104).
13. The vehicle (100, 200) as claimed in claim 12, wherein said suspension system (104) comprising a hydraulic shock absorber and one or more springs, said suspension system (104) being one of a monoshock suspension system and a dual shock suspension system.
14. The vehicle (100, 200) as claimed in claim 13, wherein said suspension system (104) system being a monoshock suspension system, said system (104) being disposed at one of a right hand side of said vehicle (100, 200) and a left hand side of said vehicle (100, 200).