The present subject matter described herein relates to a vehicle battery. In particular, the present subject matter relates to a system and a method for cooling the vehicle battery. BACKGROUND [0002] Batteries are a critical technology for transforming the power production industry. Rechargeable lithium ion batteries, in particular, have emerged as the energy storage technology of choice for a wide range of applications that require high energy density, good battery life, high electrical discharge rate, low self-discharge qualities, no memory effect, and low maintenance. [0003] Existing batteries, on the other hand, have limitations due to the limited stability of their internal chemistry. Because of their internal resistance, the individual cells in a battery pack generate a lot of heat when they are charged or discharged at a high rate. The core temperature of the battery cells will escalate if the rate of heat generation exceeds the rate of heat dissipation. [0004] As the core temperature of the battery rises, it not only shortens battery life, but also puts the battery at risk of thermal runaway and catastrophic failure. Moreover, flammable liquids are presently being used in lithium ion batteries with very high power densities to improve lithium ion mobility within the cell. Overheating of these batteries may cause a fire hazard. [0005] There are a range of thermodynamic cooling technologies, such as forced air cooling, liquid cooling, use of coolants, cooled air from Heating, Ventilation, and Air Conditioning (HVAC), heat pipes, etc. These technologies can improve the rate of heat dissipation from the battery cells. For an instance, forced air cooling, which involves blowing of ambient or cooled air over a battery pack, is simple to set up but produces ineffective heat dissipation. Because of weight and form factor constraints, indirect cooling, in which the battery pack is connected to an external radiator or heat exchanger through a manifold, is often unfeasible for an electric car. For similar reasons, heat pipes are also impractical. [0006] Also, huge temperature differences between cells makes the indirect cooling of large battery packs difficult. Direct immersion in a liquid with a high specific heat capacity allows for cooling by thermal conduction and convection in the liquid; however, the enormous volume and weight of the liquid is a considerable disadvantage. [0007] Therefore, there is a need to provide an efficient and cost effective battery cooling system for a vehicle. OBJECTS OF THE DISCLOSURE [0008] It forms an object of the present disclosure to overcome the aforementioned and other drawbacks/limitations in the existing solutions available in the form of related prior arts. [0009] It is a primary object of the present disclosure to provide a system and a method for effectively cooling a vehicle battery. [0010] It is another object of the present disclosure to provide an environment friendly battery cooling system and method. [0011] It is another object of the present disclosure to provide a cost effective and efficient system. [0012] It is another object of the present disclosure to cool the vehicle battery using an evaporative cooling medium. [0013] These and other objects and advantages of the present subject matter will be apparent to a person skilled in the art after consideration of the following detailed description taken into consideration with accompanying drawings in which preferred embodiments of the present subject matter are illustrated. SUMMARY [0014] A solution to one or more drawbacks of existing technology and additional advantages are provided through the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be a part of the claimed disclosure. [0015] The present disclosure offers a solution in the form of a system for cooling a battery of a vehicle, including an evaporative cooling unit facing the battery, a liquid storage unit to store liquid, a pump placed on the liquid storage unit and adapted to direct the liquid, stored in the liquid storage unit, to the evaporating cooling unit to wet the evaporating cooling unit, a fan to provide air flow towards the evaporative cooling unit and as a result, the air passes through the wet evaporating cooling unit towards the battery and cools the battery, a plurality of sensors, wherein a first sensor out of the plurality of sensors is placed on the battery, wherein a second sensor of the plurality of sensors is placed before the evaporative cooling unit, and wherein a third sensor of the plurality of sensors is placed after the evaporative cooling unit and a control unit coupled to the plurality of sensors, the pump and the fan, wherein the control unit controls the air flow of the fan and the operation pump based on output values of the sensors. [0016] In an aspect of the invention, the evaporative cooling unit includes liquid absorbing pads. [0017] In an aspect of the invention, the liquid in the liquid storage unit is water. [0018] In an aspect of the invention, the plurality of sensors includes temperature sensors and humidity sensors. [0019] In an aspect of the invention, the second sensor determines a temperature and humidity of the air before passing the evaporative cooling unit, the third sensor determines a temperature and humidity of the air passed through evaporative cooling unit, and wherein the first sensor determines a temperature of the battery, and wherein when the determined temperature of the battery is more than a predetermined value, the control unit controls the air flow of the fan. [0020] In another aspect of the invention, a method for cooling a battery in a vehicle is provided. It includes determining a temperature and humidity of the battery, starting an operation of a fan when the determined temperature is greater than a first predefined value, determining whether the determined humidity is less than a second predetermined value (a), starting an operation of the pump at a first speed for a predetermined time period when the determined humidity is less than the second predetermined value, after starting the operation of the pump, reducing the pump speed by a third predetermined value and running the pump for a predetermined time period when determined humidity is greater than the second predetermined value (a) or a saturation effectiveness is less than a fifth predetermined value (]i). [0021] In an aspect of the invention, when the determined temperature is less than the first predefined value, stopping the operation of the fan and the pump. [0022] In an aspect of the invention, when the determined humidity is less than the second predetermined value (a) or a saturation effectiveness is greater than the fifth predetermined value (]i), maintaining a same speed of the fan and determining whether the determined temperature is less than the first predefined value. [0023] In an aspect of the invention, a saturation effectiveness is n =T2-T3/T2-Tw2 where T2 is temperature of air before passing through the evaporating cooling unit, where T3 is temperature of air after passing through the evaporating cooling unit, and where Tw2 is wet bulb temperature of air before passing through the evaporating cooling unit. [0024] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS [0025] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the present disclosure may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which: [0026] Fig. 1 illustrates a block diagram of the system of the present disclosure; [0027] Fig. 2 illustrates a flow chart representing a method according to the present disclosure. [0028] The figures depict embodiments of the present subject matter for illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein. DETAILED DESCRIPTION OF INVENTION [0029] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. [0030] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof. [0031] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved. [0032] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. [0033] In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense. [0034] Hereinafter, a description of an embodiment with several components in communication with each other does not imply that all such components are required. On the contrary, a variety of optional components are described to illustrate the wide variety of possible embodiments of the present disclosure. [0035] The present invention relates to a system and a method of cooling a battery present in a vehicle. The present disclosure uses an evaporative cooling media for cooling and maintaining the temperature of the battery at a predefined temperature level. [0036] Fig. 1 shows a system (100) for cooling a battery of a vehicle. The system (100) includes a battery (101), a cooling unit (102), a fan (103), a water pump (107), a liquid storage unit (104), and a plurality of sensors (109, 110, 111). The battery (101) can be a Li-ion battery, for example. The battery (101) is coupled to the cooling unit (102) and works efficiently when the temperature of the battery (101) is between 10 degrees Celsius and 35 degrees Celsius. A first sensor (109) of the plurality of sensors is provided near the battery (101). A second and third sensors (110, 111) are provided before the cooling unit (102) and after the cooling unit (102), respectively. Further, the system (100) includes a control unit (108) coupled to the sensors (109, 110, 111). [0037] In order for cooling process to take place, water is used. In an embodiment, the water is obtained from a drain pipe (105) of a HVAC unit (106) . The water that is waste and not used by the vehicle is drained out through the drain pipe (105). The drain pipe (105) is connected to a liquid storage unit (104) and the water is further collected in the liquid storage unit (104). The liquid storage unit (104) has a pump (107) for the purpose of continuously circulating the water to the evaporative cooling unit (102). A pump (107) is placed on the liquid storage unit (104). The pump (107) directs the liquid stored in the liquid storage unit (104) to the evaporating cooling unit (102). The liquid used here is water and the water is used to wet the evaporating cooling unit (102). [0038] The evaporative cooling unit (102) is composed of liquid absorbing pads that is made of cellulose, plant based material or any polymer based material. The evaporative cooling unit (102) can be a single layered pad or multi layered pads. Whenever liquid such as water drips on the cooling unit (102), it gets absorbed quickly due to high absorbant power of the pads. [0039] The fan (103) is located before the evaporative cooling unit (102) to send air flow towards the evaporative cooling unit (102). The flow of air passes through the wet evaporative cooling unit (102) to the battery (101). The hot air that enters the evaporative cooling unit (102) becomes cool after it passes through the wet evaporative cooling unit (102) as there is heat transfer between the air and the water droplets. This heat interaction or heat transfer promotes an adiabatic cooling of the water and the dry and hot air becomes cool. [0040] The sensors (109, 110, 111) are provided by the system (100). The first sensor (109) is located on the battery (101) for determining the temperature and humidity values of the battery (101). Similarly, the second sensor (110) is located before the cooling unit (102) for taking the temperature and humidity values in the ambient environment or before the air gets cooled in the evaporating cooling unit (102) and the third sensor (111) is located after the cooling unit (102) for determining the temperature and humidity value of the cool air after passing through the evaporating cooling unit (102). [0041] The sensor values are determined to check the effectiveness of the evaporative cooling unit (102) using the control unit (108). The control unit (108) is coupled to the sensors (109, 110, 111) and processes the values received from the sensors (109, 110, 111). The control unit (108) is also linked to the fan (103) and the pump (107). The control unit (108) controls the air flow coming out of fan (103) or water that is directed to the evaporating cooling unit (102) via the pump (103) using the values received from the sensors (109, 110, 111). After processing the values, a command signal is given to the fan (103) or the pump (107) to start them depending upon the requirement as obtained from the method explained in Fig. 2. [0042] Referring to Fig. 2, it shows a method (200) for cooling a battery (101) in a vehicle. [0043] In the step (201), the method (200) determines temperature and humidity values of the battery (101). The temperature (Tl) and humidity (HI) values from the battery (101) are determined by the sensor (109). [0044] In the step (202), the method (200) determines whether the value of temperature as determined in the step (201) that are received from the sensor (109) is above a first predefined value or not. Here the first predefined value is in the range of 0°-35°. [0045] In the step (203), if NO, or the value of the temperature received (Tl) is below the first predefined value, for example 35°, which is assumed, then the system (100) does not turn on the fan (103) or the pump (107). In this case, it means that the temperature of the battery (101) is adequate to work normally. [0046] In the step (204), if YES, or if the temperature of the battery (101) exceeds the first predefined value, then the fan (103) is turned ON automatically. [0047] In the step (205), the method (200) determines whether the value of humidity is less than a second predetermined value 'a' or Hla' OR 'r|