FIELD OF THE INVENTION

[0001] The present invention relates generally to an automotive vehicle and more particularly, but not exclusively, to an electrical power source for providing power to the vehicle and fulfilling its other electrical load requirements.

BACKGROUND OF THE INVENTION

[0002] Conventionally a two wheeled automotive vehicle functioning as an electric vehicle or a hybrid vehicle is powered by an electrical power source. Using lead acid type batteries as the electrical power source has many disadvantages. Generally a lead acid battery is heavier, prone to acid spills and has shorter shelf life. It provides lower power and delivers poor performance. It is also harmful to the environment as it contains heavy metals, for example lead and sulphuric acid. Further, lead acid batteries with sufficient capacity and starting performance are subject to packaging constraints as it is difficult to mount them in the limited spaces of a two wheeled vehicle requiring further structural innovation.

[0003] Therefore, a battery container housing a plurality of battery cells is used in the automotive vehicle. The battery container is typically kept air tight and water resistant so as to protect the battery cells from undesirable damage which may result in electrical disturbances or electrical shorts. However, one of the drawbacks of conventional batteries for electric and hybrid vehicles is the inability to gain 'access' to the individual battery cells within the battery container because the battery container is sealed tight. This becomes a problem because the vehicle operator is unable to get the damaged individual battery cell replaced in the service center, and therefore has to discard the entire battery and purchase a new one. This is an expensive and environment unfriendly process.

[0004] Further, such battery container is fraught with mounting and packaging issues. In the context of a scooter type electric or hybrid two wheeled vehicle, the battery container is supported in the rear frame of the motorcycle. In one case, the battery container is mounted within a storage container supported on the rear frame of the vehicle. The battery container uses up the storage space and severely compromises the utility space available in the vehicle for storing goods due to its bigger size. For example, in this configuration, the user is unable to store a full face helmet in the storage container. This configuration also limits the consumer's ability to easily access the battery cells within the battery container. Several components are required to be detached by a technician at the service centre to access the battery cells. In another case where the battery container is. mounted on the front frame, the battery size causes problems related to vehicle handing issues and weight balance. U.S. Pat. No. 5,613,569 disclose electric scooter type motorcycle powered by a battery but access to the battery container requires significant disassembly of the vehicle body and access to individual battery cells within the battery is limited. SUMMARY OF THE INVENTION

[0005] The present subject matter is directed to overcome all or any of the problems as set forth above and thereby to obviate a lacunae in the prior art. It is therefore an object of present invention to disclose an electrical power source for powering a vehicle facilitating easy accessibility and easily serviceability. It is yet another object of the present invention to disclose an easily serviceable electrical power source with replaceable components. It is another object of the present invention to provide an electrical power source packaged within a storage container without compromising the storage space and providing easy accessibility and easy disassembly. [0006] To this end, the present invention discloses an electrical power source comprising one or more stacks connected in series and formed from a plurality of individual battery cells arranged together wherein the one or more stacks are supported in at least one trench formed between an inner surface and an outer surface of at least one wall of a storage container in an insertable and removable manner. The one or more stacks are electrically coupled to a communicative cell management system. This configuration does not compromise the available storage space within the storage container.

[0007] According to a feature of the present invention, each stack from the one or more stacks includes at least two or more cell packs. Further, each cell pack from the two or more cell packs comprises of two or more individual battery cells connected in parallel to each other and supported by at least one cell holder. The two or more cell packs are mechanically lockable to each other through a plurality of couplers provided on both sides of the long axis of the cell holder of each cell pack. [0008] According to another feature of the present invention, each trench is covered, either solely or jointly with another trench, by a closable trench cover having a locking mechanism. This facilitates easy accessibility to individual battery cells. Further, the cell management system is attached and supported on an outer surface of at least one of the walls of the storage container. [0009] The foregoing objectives and summary is provided to introduce a selection of concepts in a simplified form, and is not limiting. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[00010] The above and other features, aspects and advantages of the subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

FIG. 1 shows a front perspective view of a two wheeled vehicle exemplified in the form of a two wheeled scooter type motorcycle according to the present invention. FIG. 2 shows a side view of the scooter type motorcycle according to the present invention. FIG. 3 shows a front perspective view of a storage container of the scooter type motorcycle according to the present invention.

FIG. 4 shows a rear perspective view of the storage container of the scooter type motorcycle according to the present invention.

FIG. 5(a) and FIG. 5(b) respectively show a cell pack made of plurality of interconnected battery cells, and a stack comprising a plurality of cell packs.

FIG. 6 shows the assembly of the stacks in the storage container according to the present invention.

FIG. 7 shows a rear view of the storage container illustrating power transmission by stacks.

FIG. 8 shows a plan view of the arrangement of stacks in the storage container according to the present invention.

FIG. 9(a) and 9(b) respectively show the thermocouples of respective stacks connected to a cell management system.

FIG. 10 shows a frame of the vehicle of FIG. 1 showing the positioning of the storage container according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[00011] The present subject matter discloses an electrical power source for a two wheeled electric or a hybrid vehicle comprising a plurality of individual battery cells electrically coupled together and configured to jointly provide power to fulfill the electrical load requirements of the vehicle. The load requirements include either propelling a traction motor of the vehicle, or powering lighting and signalling devices associated with the vehicle, or both. In an embodiment, the battery cells are configured to form one or more stacks accomodated within a storage container provided in the vehicle in an insertable and removable manner. In an implementation, each stack is accommodated within a trench formed between an inner surface and an outer surface of a wall of the storage container. In this way, the battery cells are mounted in the vehicle without compromising the storage area and the need for a separate battery container carrying a battery is eliminated. [00012] In an embodiment, the storage container has at least four walls. Each wall excluding one is provided with a trench. The trenches are opened only on one side and permanently closed on the other side. Each trench is covered, either singly or jointly, by a closable trench cover having a locking mechanism. One or more stacks are inserted into each trench and are connected to a communicative cell management system. In the event of a cell damage, the concerned stack is taken out from the trench after opening the closable trench cover thus making the battery cells easily accessible. The battery cells of the stack are uncoupled so as to replace only the damaged battery cell. Thus, the electrical power source is easily serviceable and cost effective. Further, the arrangement of the battery cells in the storage container also maintains the centre of gravity of the vehicle unlike a heavy battery container as the cells are equally distributed around the storage container.

[00013] In the ensuing description, the present invention is exemplified with a two wheeled scooter type motorcycle for better illustration. Further "front" and "rear", and "left" and "right" wherever referred to in the ensuing description refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the scooter type motorcycle. Furthermore, a longitudinal axis refers to a front to rear axis relative to the motorcycle, while a lateral axis refers generally to a side to side, or left to right axis relative to the motorcycle. Various other features of the electrical power source according _, to the present subject matter here will be discernible from the following further description thereof, set out hereunder. The detailed explanation of the constitution of parts other than the subject matter which constitutes an essential part has been omitted at suitable places.

[00014] FIG. 1 shows a front perspective view of a scooter type motorcycle 100 according to the present invention. Typically such vehicle includes a body frame made up of several tubes welded together which usually supports the body of the said vehicle. The body frame assembly of the scooter type motorcycle is an elongated structure, which typically extends from a forward end to a rearward end of the vehicle. It is generally convex in shape, as viewed from a side elevation view. The body frame assembly includes a head pipe (not shown) and a branched down pipe (not shown) that extends downward from the head pipe. The vehicle has a steerable anterior wheel 106 and a driven rear wheel 107 driven by driving force generated by a power source. The body frame of the vehicle is covered with a plurality of vehicle body covers including a front panel 102 and side panels 110 present on both sides of the vehicle longitudinal plane. The vehicle body covers are made of resin or sheet metal to form an external appearance of the vehicle. The front panel 102 is located in an anterior portion of the vehicle and covers the front portion of the frame whereas the side panels 110 are located in the rear portion of the vehicle and cover a rear portion of the frame. A handlebar 119 for steering the motorcycle and a seat 111 for motorcycle occupants is supported at opposing ends of the frame assembly and a generally open area is defined therebetween known as floorboard 108 which functions as a step through space. The anterior portion of the scooter type motorcycle further comprises of a head lamp 101, a plurality of direction lamps 103 supported on the front panel 102, a front suspension assembly 105 (commonly a telescopic fork arrangement) operatively positioned between the anterior wheel 106 and the frame assembly. A front fender 104 is provided to prevent undesirable impurities like water, mud etc. from falling on the motorcycle operator and other components of the motorcycle 100.

[00015] According to an aspect, the power source includes a mechanical power source, or an electrical power source, or a mechanical and an electrical power source co-operatively working to propel the vehicle and fulfilling other electrical load requirements of the vehicle. In an embodiment, the motorcycle 100 comprises of a mechanical power source and an electrical power source. The mechanical and the electrical power source can work either simultaneously or in series or in parallel mode.

[00016] FIG. 2 shows a side view of the scooter type motorcycle according to the present invention. The rear portion of the motorcycle comprises of a fuel tank 116 disposed above the rear wheel 107 and rearwardly of the seat assembly 111. It stores fuel supplied to the mechanical power source. The fuel tank 116 is covered substantially from the sides by the side panel 110 and partially from the top by the seat 111. A storage container 150 having an upwardly facing storage space 151 is provided for storing useful articles below the seat 111. At least two side tubes 115, 118 are connected to the down tube of the body frame. The storage container 150 is housed in the space between the side tubes 115, 118 and is supported on one or more cross tubes provided therein extending laterally from one side tube to the other side tube. The seat 111 is connected to the storage container 150 to be vertically pivotable around a hinge mechanism 112 at a front portion thereof, and is openable and closable vertically to allow access to the storage space 151 for storing useful articles. The seat 111 serves as a lid of the storage container 150.

[00017] The mechanical power source of the vehicle is a four stroke internal combustion engine 109 mounted to a hub of the rear wheel 107 at one end and to the body frame at the other end through a toggle link mechanism 117 in such a way that the mechanical power source is angularly disposed to the ground. In one of the embodiment, the mechanical power source is mounted on the swing arm. Since the basic construction of the internal combustion engine is known to those versed in the art, the details have been omitted.

[00018] The electrical power source comprises of a plurality of electrically coupled individual battery cells forming one or more stacks. FIG. 3 and FIG. 4 illustrate the storage container in detail. The storage container 150 is configured to accommodate the electrical power source. At least one trench is formed between an inner surface and an outer surface of at least one wall of the storage container. The at least one trench accommodates the one or more stacks in an insertable and removable manner.

[00019] In an implementation, the storage container has a plurality of walls namely a front wall 155 at the front, a rear wall 156 located opposite to the front wall 155, and at least two side walls, a first side wall 153 and a second side wall 154 located laterally on each side of the storage container. The arrow shows the front and rear direction of the vehicle along the vehicle longitudinal axis. The side walls are extended along the longitudinal axis to form a front portion 157 and a rear portion 161 of the storage container 150. The seat 111 is attached to the front portion of the storage container through the hinge mechanism 112. The front portion 157 is at a lower elevation than the rear portion 161 to accommodate seat assembly and provide better seat orientation.

[00020] The inner surfaces of all walls are connected to each other via a common base to form the storage space 151 below the seat 111. At least one trench is formed between an inner surface and an outer surface of at least one wall to accommodate one or more stacks. In a preferred embodiment, the storage container 150 is provided with three trenches formed between the inner and outer surfaces of three walls to sufficiently accommodate more number of stacks. Thus, a front trench 162 is formed between the inner and outer surface of the front wall 155. Likewise, the inner and outer surface of the first side wall 153 includes a first side trench 164 and that of second side wall 154 has a second side trench 163. The front trench 162, the first side trench 164 and the second side trench 163 individually accommodate one or more 'stacks' in an insertable and removable manner. The stacks are electrically coupled together to power the motorcycle and also cater to its electrical load requirements like powering signalling lamps, horns, headlamp, tail lamp etc. Each trench is covered from all sides except one through which one or more stacks are inserted into it.

[00021] The electrical power source made of stacks is now described in detail with the help of FIG. 5(a) to 8. It is made of one or more stacks housed in trenches and connected in series. Each stack from one or more stacks includes at least two or more cell packs. Each 'cell pack' comprises two or more individual battery cells electrically connected in parallel to each other and supported by at least one cell holder. FIG. 5(a) describes an individual cell pack 177. In an implementation, each cell pack 177 comprises of at least six individual battery cells (170, 171, 172, 170a, 171a, 172a) electrically coupled in parallel configuration and supported by in groove of a cell holder 174. In an embodiment, the six battery cells are arranged one above another in two layers of three cells each. The two layers of cells have an upper and lower negative plate 173 connected by a connecting wire 178. [00022] Further, the cell holder 174 is made of an insulating polymer material and assists in keeping the battery cells (170, 171, 172, 170a, 171a, 172a) intact so as to resist any shock. The cell holder 174 has at least six wire outlets of which two are positive couplers and two negative couplers housed in the sides of the cell holder 174. The cell holder 174 has a negative coupler 175a and a positive coupler 175b on each side of its long axis. The two or more cell packs 177 are mechanically lockable to each other these couplers provided on both sides of the long axis of the cell holder of each pack to form one stack. FIG. 5(b) describes a stack made of multiple cell packs electrically connected to each other. The negative coupler 175a and the positive coupler 175b of one cell holder 174 of one cell pack 177 is connected to a positive coupler 176b and a negative coupler 176a of adjacent cell pack. The couplers form a mechanical lock through which the cell packs remain connected to each other.

[00023] In a preferred embodiment, each stack is formed from at least three cell packs and the storage container accommodates at least three stacks. FIG. 6 shows the various stacks namely a front stack 182, a first side stack 181 and a second side stack 180 and their assembly in the storage container according to the present invention. The front stack 182 is laterally inserted in the front trench 162, the first side stack 181 longitudinally inserted in the first side trench 164 and the second side stack 180 longitudinally inserted in the second side trench 163. Each trench is covered, either singly or jointly with other trench, by a closable trench cover having a locking mechanism. In an embodiment, a front trench cover 165 is provided to cover the front trench 162 after the first stack 182 has been inserted and opens laterally. The first side trench 164 and the second side trench 163 are jointly covered through a side trench cover 166 which opens rearwardly. The side trench cover 166 spans the width of the storage container 150 and covers the first side trench 164 and the second side trench 163.

[00024] In a preferred embodiment, the first side stack 181 comprises of four cell packs 177, the second side stack 180 comprises four cell packs and the front stack 182 comprises six cell packs. More number of cell packs in the front stack would enable more power supply and eliminate the need for siginifcant lateral expansion of the storage container 150.

[00025] The cell packs are connected to each other through couplers housed in the respective cell holder which enables all the cell packs to be connected as a single stack. Moreover, all cell packs in a particular stack are connected in series. All stacks are connected in series and jointly form the electrical power source. In an embodiment, the electrical power source comprises of a total of at least eighty four battery cells in three stacks and fourteen cell packs wherein each individual battery cell has a capacity of 3 Ah and 4.2V. The battery cell, however, can also have a higher capacity of around 4 Ah or 5 Ah depending upon the electrical load requirement. Each individual battery cell is of Lithium-ion type and has a shape from a group consisting of a rectangle, a square, a prism and a cylinder. In an embodiment, the individual battery cells are cylindrical in shape. However, prismatic shaped individual battery cells can also be used. The number of cells forming one cell pack can vary. But in the preferred embodiment, a cell pack contains six battery cells and a total of fourteen cell packs are provided in the vehicle to obtain the required electrical output.

[00026] Each stack from the one or more stacks is electrically connected to a communicative cell management system (CMS) 183 or a battery management system (BMS) as shown in FIG. 6 which controls the battery cells. The CMS 183 is electrically coupled with the stacks comprising plurality of battery cells and monitors the metadata of each of the plurality of battery cells. In an embodiment of the present invention, the CMS 183 is any electronic device that manages each battery cell, such as by monitoring its state, calculating secondary data, reporting the data, protecting the battery cell, controlling its environment, and/or balancing the charge in each cell. The CMS may monitor various aspects of a pack as a whole and/or each individual battery cell, such as energy input, energy output and temperature etc. The CMS is connected to a central control unit and has CAN communication capabilities.

[00027] FIG. 7 shows the rear view of the storage container 150 illustrating power transmission from the stacks to the CMS 183. The electrical output of each stack is provided to the CMS 183 through a plurality of metal plate units (184, 185, 186) having connection terminals. Each metal plate unit comprises of at least two metal plates (one for positive and one for negative terminal) to carry power from each stack to the CMS 183. The metal plates are enmoulded in the storage container 150 and hence only the ends with connection terminals are visible. A front metal plate unit 184 is provided for front stack 182, a first side metal plate unit 185 is provided for first side stack 181 and a second side metal plate unit 186 is provided for second side stack 180. One end of each metal plate is connected to the wire output of the respective stack whereas the other end of it is connected to the CMS 183. The output of each stack is carried to the CMS 183 through a connector 179. The connector 179 is connected to the last cell pack of a particular stack and takes the battery output to the CMS through wires. As shown in FIG. 9(b), studs 191a, 191b are provided on both ends of the metal plates. The wires from the connector 179 are connected to these studs which then supply the power to the CMS through the metal plates. Within the CMS, the stacks are connected in series. The CMS then supplies output to power the vehicle and fulfilling other electrical load requirements of the vehicle. As shown in top view in FIG. 8, the CMS 183 thus receives six inputs through a total of six metal plates, two each connected to a stack.

[00028] According to a feature, the CMS 183 is attached and supported on an outer surface of the rear wall 156 of the storage container 150. It is located near to the rear portion 161 of the storage container 150. By keeping the CMS near the stacks, the length of the wiring harness is significantly reduced and also leads to optimum space utilization. The CMS 183 is supported on the studs provided at the ends of metal plates.

[00029] Further, as illustrated in FIGs. 9(a) and 9(b), each cell pack 177 includes at least one thermocouple 187 and the thermocouples of two or more cell packs are connected to each other through at least one thermocouple wire 190 further connected to the CMS 183 through a coupler 189. In a preferred embodiment, for the front stack 182, six thermocouples are provided for six cell packs. The thermocouple 187 senses the temperature of each cell pack and when in excess, disables the CMS output supply. The respective thermocouple wires from each stack are merged and the output of all the thermocouples is fed into the CMS through the coupler 189. Each thermocouple wire 190 is held on the outer surface of the storage container 150 through button straps. For each stack, a button strap is provided (shown by numeral 188a, 188b, 188c) for a wire. The wires are then collated and supported on a common button strap 188d and connected to the coupler 189.

[00030] As the stacks of battery cells ^" provide power, they generate heat inside the respective trenches. Therefore, efficient heat dissipation is required to maintain a normal operating temperature within the trenches. In an embodiment, enmoulded fins 159 and air openings 160 are provided on the outer surface of the first side wall 153, front wall 155 and the second side wall 154 to enable heat dissipation. The fins can be horizontal or vertical to the vehicle longitudinal plane. They increase the surface area for heat dissipation from the cells. When the vehicle is moving, the atmospheric air hits the fins and dissipates the heat generated in the side trenches. Further, the air entering through air openings 160 can traverse the length of the side trenches and can escape out from the perforations provided in the side trench cover 166. Thus, air openings 160 improve the air circulation through the battery cells. They can be smaller or bigger in diameter depending upon the heat dissipation required. The perforations and the air openings may be directed downwards or may be sealed for water entry. In another embodiment, the outer casing of the stacks is made of heat conductive metal to increase the rate of heat dissipation. This metal casing may be fastened to the storage container outer surface.

[00031] Each of the front trench 162, the first side trench 164 and the second side trench 163 are integrally formed with the storage container 150. In an embodiment, to enable more power, more number of cell packs can be provided in the trenches. To enable this, the width of the storage container is increased for accommodating the respective bigger side trenches and length to be increased to accommodate front trenches. According to an aspect, the space between the side tubes 115, 118 may be increased to house a bigger and wider storage container resulting in the increase in the width of the vehicle. Further, in the scooter type motorcycle, space is a not a constraint unlike motorcycle and hence front trench 162 can be easily accommodated by slightly increasing the length of the storage container 150.

[00032] From the foregoing description, it will be appreciated that the present invention offers many advantages including those described above. Diagnostic facility can be integrated to monitor the performance of each pack via CMS. A malfunction indicator may be provided to the user for each pack and in case of failure, all stacks need not be replaced. The current construction of electrical power source helps gain easy access to the battery cells without significant disassembly of the vehicle. The stacks are easily insertable into the trenches and the trench covers are closed after that. In case of a damage, to remove the damaged cell pack, the user needs to take the vehicle to the service station. The mechanic would take out the storage container 150 from the vehicle after opening the seat 111 without removing the side panel 110. Thereafter, a particular stack is removable from a particular trench of the storage container and each cell pack can be separated or serviced by pulling it out from the connectors. Each cell pack and hence stack is thus serviceable in the present electrical power source. Thus, when individual battery cells get damaged or malfunction, the consumer has the advantage to get the concerned sole damaged pack replaced at the service center with a minimal amount of disassembly. This feature of the present invention is advantageous as it increases the usability of the vehicle, reduces cost to the vehicle consumer and simplifies its maintenance. Further, the storage container space is utilized for providing power to the vehicle and no special battery mounting space is required. The battery cells within the storage container act as the complete battery and do not compromise the storage space already available in the storage container, for example, to put a full face helmet 201 as shown in FIG. 10. Furthermore, the arrangement of battery cells in the storage container also maintains the center of gravity of the vehicle as the cells are equally distributed on both sides of storage container. [00033] The present invention is thus described. It is to be noted that the present subject matter is not dependent on the type of vehicle and therefore is equally workable with any vehicle capable of accommodating the storage container including a scooter type gasoline powered motorcycle, a scooter type electric motorcycle and a scooter type hybrid motorcycle with required modifications. For example, if the vehicle is a gasoline powered scooter type motorcycle, the present electrical power source can still fulfil the electrical load requirements like signalling lamps, head lamp, tail lamp, powering the starter motor for electric start etc. In this scenario, the small capability battery cells can be used. The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results. The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary. It will also be obvious that the present invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the present invention.