Description:A BATTERY COOLING SYSTEM FOR HIGH VOLTAGE AGRICULTURAL VEHICLES AND A METHOD OF OPERATION THEREOF
FIELD OF INVENTION
The present invention relates to a battery cooling system in electric vehicles. In particular, the invention relates to a battery cooling system having both air and refrigerant assisted cooling for effective cooling of a battery pack for enhanced safety in a high voltage agricultural vehicles.
BACKGROUND OF INVENTION
Generally vehicles are based on internal combustion engines and require fuel for transportation. Considering the energy needs of the transportation sector, most countries import petroleum, and this covers a major share of the nation’s economy. However, electric vehicles utilizing electricity as their energy source support the economy as well as the energy security of the nation. As electric vehicles grow in popularity and usage, now research is going to develop a high voltage agricultural vehicles having a battery pack with good thermal management, which is challenging.

The high voltage agricultural vehicles depend on rechargeable batteries for mobility. As batteries supply electric power to the electric motors in high voltage agricultural vehicles which need a lot of power to do traditional activities like plowing and tilling. The batteries of the high voltage agricultural vehicles generate a lot of heat during operation and their temperature must be brought down within operating ranges for safety of the vehicle. At high temperatures (between 158°F and 212°F, or 70°C and 100°C), thermal runaways can occur, causing a chain reaction that destroys the battery pack. During fast charges, these batteries must be cooled down. This is because the high current going into the battery produces excess heat that must be extracted to preserve the high charging rate and not overheat the battery. The high temperature in the battery causes battery fluid evaporation and damage to the internal structure of the battery, which cannot be corrected.

The battery cooling system in electric vehicles regulates the temperature of the battery pack. Conventionally, the battery thermal management in the high voltage agricultural vehicles is done cooling loops that contain liquid coolants such as ethylene glycol. An electric pump or fan circulates the coolant through the batteries. Radiators are included in the cooling loop to release the heat to the ambient. However, the amount of heat generated in a batteries of the high voltage agricultural vehicles is more compared to normal electric vehicles as the output power required to drive any external load or implement connected, and it may be difficult to cool the high voltage agricultural vehicles only with the air or liquid in the vehicle compartment.

Some of the prior arts are:
CN104733804 discloses an air-conditioning system for an automotive battery includes a heat exchanger composed of a heat-absorbing pipe and a heat-discharging pipe, which partially overlap with each other, and a thermoelectric element interposed in the overlapping portion. A battery housing accommodates a battery and in which an end of the heat-absorbing pipe of the heat exchanger is inserted.
US9517678B2 discloses a high-voltage equipment cooling system for electric vehicle includes a motor, a high-voltage equipment, a blowing means for high-voltage equipment, an outlet valve, an air conditioning means, and an air inlet mode selection means, wherein the air outside the vehicle compartment is introduced by the air inlet mode selection means when supplying air cooled by an evaporator in the air conditioning means to the high-voltage equipment using the blowing means for high-voltage equipment.
The prior arts mentioned herein above are mainly related to the air cooling system and refrigerant based cooling system for battery in electric vehicles. None of the references have provided an effective battery cooling system, which has both air and refrigerant assisted cooling in a single system. Thus, there is a need in the art to provide a technically advanced battery cooling system, which has both closed loop air cooling system and refrigerant based cooling for effective cooling of a battery pack for enhanced safety in a high voltage agricultural vehicles. Also, there is a need in the art for a battery cooling system which assists in operating battery pack of a high voltage agricultural vehicles at sub-zero temperature environment.
OBJECTIVES OF THE INVENTION
The main objective of the present invention is to provide a battery cooling system having both air and refrigerant assisted cooling for effective cooling of a battery pack for enhanced safety in a high voltage agricultural vehicles.
Another objective of the present invention is to provide a battery cooling system which assists in operating battery pack of a high voltage agricultural vehicles at sub-zero temperature environment.
SUMMARY OF THE INVENTION
It is a primary aspect of the present invention to provide a battery cooling system for high voltage agricultural vehicles, comprising:
a blower connected with a battery casing forming a duct for a closed loop air circulation through a plurality of cell gaps, wherein the battery casing comprises plurality of cell guide holes arranged in a staggered form for guiding the air through the cell gaps;
a battery pack positioned within the respective cell gaps;
one or more air circulating devices positioned on sides of the one end of the battery casing to circulate the hot air exhausted from the blower towards the cell gaps through a evaporator;
plurality of first temperature sensors positioned near the battery pack respectively within the battery casing and a second temperature sensor positioned on the air circulating devices respectively for sensing the temperature of air exhausted from the battery casing and air input to the battery casing;
a battery management unit connected with output of the first temperature sensor and second temperature sensor for controlling the operation of the blower and air circulating devices as required;
a compressor, which compress a refrigerant from the evaporator pressure to the condenser pressure;
a condenser coupled to the outlet of the said compressor, wherein said condenser rejects refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator;
wherein the evaporator evaporates condensed cool refrigerant by means of an external air flow from the respective air circulating devices and circulate cool air to the battery pack; and
a piping circuit for the refrigerant flow connecting the path of system components including compressor, condenser, and evaporator positioned outside the battery casing as refrigerant loop,
wherein combination of the closed loop air within the battery casing and refrigerant cooling positioned outside the battery casing provides effective cooling of the battery pack in the said high voltage agricultural vehicles.

It is another aspect of the present invention, the battery cooling system is provided with an in-built ducting on the battery casing to guide the air through the battery pack and cool them.

It is another aspect of the present invention, the battery cooling system has an arrangement of sealing inside the cell guide holes aids in avoiding hot air mixing and improve the cooling efficiency.

It is another aspect of the present invention, the air circulating device is an axial fan.

It is another aspect of the present invention, the refrigerant is selected from group consisting of Haloalkanes, Chlorofluorocarbons (CFC) and Hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFCs), Perfluorocarbons, isobutane, propane and mixtures thereof.

It is another aspect of the present invention, the battery cooling system comprises a heater element positioned on the battery casing, said heater element is connected with the battery management unit for heating the battery pack when operating the said high voltage agricultural vehicles at sub-zero temperature environment.

It is another aspect of the present invention, the battery casing is a water proof enclosure to avoid moisture entry in the battery pack.

It is another aspect of the present invention, the battery pack comprises plurality of cylindrical cells.

It is another aspect of the present invention, the cylindrical cell is made up of lithium ion.

Another aspect of the present invention to provide a method of operation of the battery cooling system for high voltage agricultural vehicles, said method comprising steps:
obtaining the output of the first temperature sensor and second temperature sensor;
comparing the output of the first temperature sensor and second temperature sensor with their respective threshold values in the battery management unit;
activating the air circulating devices to circulate the hot air exhausted from the blower towards the cell gaps through the evaporator, if output of the first temperature sensor exceeds the pre-defined value in the battery management unit;
activating the blower to exhaust the heat generated from the battery pack, if output of the second temperature sensor exceeds the pre-defined value in the battery management unit;
compressing the refrigerant at high temperature and pressure into a hot, high pressure gas by means of a compressor;
directing the refrigerant flow through the condenser to reject refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator; and
evaporating condensed cool refrigerant in the evaporator by means of an external air flow from the respective air circulating devices and circulate cool air to the battery pack,
wherein combination of the closed loop air and refrigerant cooling provides effective cooling of the battery pack in the said high voltage agricultural vehicles.

It is another aspect of the present invention, direction of airflow towards and away from the battery pack is based on staggered cell arrangement of plurality of cell guide in the battery casing for heat dissipation.

It is another aspect of the present invention, a heater element is connected with the battery management unit for heating the battery pack when operating the said high voltage agricultural vehicles at sub-zero temperature environment.

It is another aspect of the present invention, the method of operation of the battery cooling system comprises activating the heater element for heating the battery pack, if output of the first temperature sensor is below the first pre-defined value in the battery management unit.

It is another aspect of the present invention, the the first pre-defined threshold value for the first temperature sensor (10) is in the range of 35o C to 37 o C.

It is another aspect of the present invention, the second pre-defined threshold value for the second temperature sensor is in the range of 33o C to 35 o C.

BRIEF DESCRIPTION OF DRAWINGS
Figure 1 illustrates the battery cooling system for high voltage agricultural vehicles according to the present invention.
Figure 2 illustrates the enlarged view of the battery casing in the battery cooling system for high voltage agricultural vehicles according to the present invention.
Figure 3 illustrates the enlarged view of the battery casing with battery pack and temperature sensor located in the battery cooling system for high voltage agricultural vehicles according to the present invention.
Figure 4 illustrates the graph showing the of the battery cooling test trials performed on various vehicle operating condition while using the battery cooling system according to the present invention.
Figure 5 illustrates the enlarged view of the battery casing in the battery cooling system for high voltage agricultural vehicles according to the present invention and battery casing in the conventional battery cooling system battery temperature plots in steady state conditions.
Figure 6 illustrates the enlarged view of the battery casing in the battery cooling system for high voltage agricultural vehicles according to the present invention and battery casing in the conventional battery cooling system air flow velocity plots in steady state conditions.
DETAILED DESCRIPTION OF THE INVENTION
The present invention as embodied by a “Battery cooling system for high voltage agricultural vehicles and a method of operation thereof” succinctly fulfills the above-mentioned need[s] in the art. The present invention has objective[s] arising as a result of the above-mentioned need[s], said objective[s] having been enumerated hereinabove.
The following description is directed to a battery cooling system for high voltage agricultural vehicles and a method of operation thereof as much as the objective(s) of the present invention are enumerated, it will be obvious to a person skilled in the art that, the enumerated objective(s) are not exhaustive of the present invention in its entirety, and are enclosed solely for the purpose of illustration. Further, the present invention encloses within its scope and purview, any structural alternative(s) and/or any functional equivalent(s) even though, such structural alternative(s) and/or any functional equivalent(s) are not mentioned explicitly herein or elsewhere, in the present disclosure. The present invention therefore encompasses also, any improvisation[s]/modification[s] applied to the structural alternative[s]/functional alternative[s] within its scope and purview. The present invention may be embodied in other specific form[s] without departing from the essential attributes thereof.
Furthermore, the terms and phrases used herein are not intended to be limiting, but rather are to provide an understandable description. Throughout this specification, the use of the word "comprise" and variations such as "comprises" and "comprising" may imply the inclusion of an element or elements not specifically recited.
The present invention provides a battery cooling system having both air and refrigerant assisted cooling for effective cooling of a battery pack for enhanced safety in a high voltage agricultural vehicles.
Referring to Figures 1 to 3, in an embodiment of the present invention, the battery cooling system (100) for high voltage agricultural vehicles, said battery cooling system (100) comprising: a blower (1) connected with a battery casing (2) forming a duct for a closed loop air circulation through a plurality of cell gaps (4a), wherein the battery casing (2) comprises plurality of cell guide (9) arranged in a staggered form for guiding the air through the cell gaps (4a) as shown in Figure 2 and 3; a battery pack (4) positioned within the respective cell gaps (4a); one or more air circulating devices (5) positioned on the sides of one end of the battery casing (2) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through a evaporator (6); plurality of first temperature sensors (10) positioned near the battery pack (4) respectively within the battery casing (2) and a second temperature sensor (Not shown) positioned on the air circulating devices (5) respectively for sensing the temperature of air exhausted from the battery casing (2) and air input to the battery casing (2); a battery management unit (3) connected with output of the first temperature sensor (10) and second temperature sensor for controlling the operation of the blower (1) and air circulating devices (5) as required; a compressor (7), which compress a refrigerant from the evaporator (6) pressure to the condenser pressure; a condenser (8) coupled to the outlet of the said compressor (7), wherein said condenser (8) rejects refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6); wherein the evaporator (6) evaporates condensed cool refrigerant by means of an external air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4) connecting the exit point of the said condenser (8) to evaporate condensed cool refrigerant by means of an external air flow from the respective air circulating devices (5) and circulate cool air towards the battery pack (4); and a piping circuit for the refrigerant flow connecting the path of system components including compressor (7), condenser (8), evaporator (6) positioned outside the battery casing (2) as shown in Figure 1 as refrigerant loop.

In the preferred embodiment of the present invention, combination of the closed loop air positioned within the battery casing (2) and refrigerant cooling positioned outside the battery casing (2) as shown in Figure 1 provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.
In the preferred embodiment of the present invention, the battery cooling system (100) is provided with an in-built ducting on the battery casing (2) to guide the air through the battery pack (4) and cool the cell gaps (4a) as a sealed flow to avoid hot air re-circulation.
In the preferred embodiment of the present invention, an arrangement of sealing with cell guide holes (9) aids in avoiding hot air mixing and improve the cooling efficiency.
In the preferred embodiment of the present invention, the sealing is made up of a di-electric material.
In the preferred embodiment of the present invention, the air circulating device (5) is an axial fan.
In the preferred embodiment of the present invention, the refrigerant is selected from group consisting of Haloalkanes, Chlorofluorocarbons (CFC) and Hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFCs), Perfluorocarbons, isobutane, propane and mixtures thereof.
In the preferred embodiment of the present invention, the battery cooling system (100) comprises a heater element (not shown) positioned on the battery casing (2), said heater element is connected with the battery management unit (3) for heating the battery pack (4) when operating the said high voltage agricultural vehicles at sub-zero temperature environment.
In the preferred embodiment of the present invention, the battery casing (2) is a water proof enclosure to avoid moisture entry in the battery pack (4).
In the preferred embodiment of the present invention, the battery pack (4) comprises plurality of cylindrical cells.
In the preferred embodiment of the present invention, the cylindrical cell is made up of lithium ion.
Another embodiment of the present invention a method of operation of the battery cooling system (100) for high voltage agricultural vehicles, said method comprising steps of: obtaining the output of the first temperature sensor (10) and second temperature sensor; comparing the output of the first temperature sensor (10) and second temperature sensor with their respective threshold values in the battery management unit (3); activating the air circulating devices (5) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through the evaporator (6), if output of the first temperature sensor (10) exceeds the pre-defined value in the battery management unit (3); activating the blower (1) to exhaust the heat generated from the battery pack (4), if output of the second temperature sensor exceeds the pre-defined value in the battery management unit (3); compressing the refrigerant at high temperature and pressure into a hot, high pressure gas by means of a compressor (7); directing the refrigerant flow through the condenser (8) to reject refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6); and evaporating condensed cool refrigerant in the evaporator (6) by air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4).
In the preferred embodiment of the present invention, the combination of the closed loop air and refrigerant cooling provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.
In the preferred embodiment of the present invention, direction of airflow towards and away from the battery pack (4) is based on staggered cell arrangement of plurality of cell guide (9) in the battery casing (2) for heat dissipation.
In the preferred embodiment of the present invention, the direction of airflow is gradient of temperature across the battery casing (2) from lower to higher temperature as shown in Figure 2.
In the preferred embodiment of the present invention, a heater element (not shown) is connected with the battery management unit (3) for heating the battery pack (4) when operating the said high voltage agricultural vehicles at sub-zero temperature environment.
In the preferred embodiment of the present invention, the method of operation of the battery cooling system (100) for high voltage agricultural vehicles comprises activating the heater element for heating the battery pack (4), if output of the first temperature sensor (10) is below the first pre-defined value in the battery management unit (3).
In the preferred embodiment of the present invention, the first pre-defined threshold value for the first temperature sensor (10) is in the range of 35 to 37 o Celsius.
In the preferred embodiment of the present invention, the second pre-defined threshold value for the second temperature sensor is in the range of 33 to 35 o Celsius.
In the preferred embodiment of the present invention, the first temperature sensor (10) is a thermocouple.
In the preferred embodiment of the present invention, the second temperature sensor is a thermocouple.
In the preferred embodiment of the present invention, the battery management unit (3) is an electronic controller.
WORKING:
For illustration,
Referring to Figures 1 to 3, In an embodiment of the present invention, the battery cooling system (100) for high voltage agricultural vehicles, said battery cooling system (100) comprising: a blower (1) connected with a battery casing (2) forming a duct for a closed loop air circulation through a plurality of cell gaps (4a) to exhaust the heat generated from a battery pack (4), wherein the battery casing (2) comprises plurality of cell guide (9) arranged in a staggered form for guiding the air through the cell gaps (4a) as shown in Figure 2 and 3; a battery pack (4) positioned within the respective cell gaps (4a); one or more air circulating devices (5) positioned on sides of the one end of the battery casing (2) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through a evaporator (6); plurality of first temperature sensors (10) positioned near the battery pack (4) respectively within the battery casing (2) as shown in Figure 3 and a second temperature sensor positioned on the air circulating devices (5) respectively for sensing the temperature of air exhausted from the battery casing (2) and air input to the battery casing (2); a battery management unit (3) connected with output of the first temperature sensor (10) and second temperature sensor for controlling the operation of the blower (1) and air circulating devices (5) as required; a compressor (7), which compress a refrigerant from the evaporator (6) pressure to the condenser pressure; a condenser (8) coupled to the outlet of the said compressor (7), wherein said condenser (8) rejects refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6); wherein the evaporator (6) evaporates condensed cool refrigerant by means of an external air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4); and a piping circuit for the refrigerant flow connecting the path of system components including compressor (7), condenser (8), evaporator (6) positioned outside the battery casing (2) as shown in Figure 1 as refrigerant loop..
In the preferred embodiment of the present invention, wherein combination of the closed loop air positioned within the battery casing (2) and refrigerant cooling positioned outside the battery casing (2) as shown in Figure 1 provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.
In the preferred embodiment of the present invention, the battery cooling system (100) is provided with an in-built ducting on the battery casing (2) to guide the air through the battery pack (4) and cool the cell gaps (4a) as a sealed flow to avoid hot air re-circulation.
In the preferred embodiment of the present invention, an arrangement of sealing with the cell guide holes (9) aids in avoiding hot air mixing and improve the cooling efficiency.
In the preferred embodiment of the present invention, the sealing is made up of a Di-electric material.
In the preferred embodiment of the present invention, the air circulating device (5) is an axial fan.
In the preferred embodiment of the present invention, the refrigerant is selected from group consisting of Haloalkanes, Chlorofluorocarbons (CFC) and Hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFCs), Perfluorocarbons, isobutane, propane and mixtures thereof.
In the preferred embodiment of the present invention, the battery cooling system (100) comprises a heater element positioned on the battery casing (2), said heater element is connected with the battery management unit (3) for heating the battery pack (4) when operating the said high voltage agricultural vehicles at sub-zero temperature environment.
In the preferred embodiment of the present invention, the battery casing (2) is a water proof enclosure to avoid moisture entry in the battery pack (4).
In the preferred embodiment of the present invention, the battery pack (4) comprises plurality of cylindrical cells.
In the preferred embodiment of the present invention, the cylindrical cell is made up of lithium ion.
Another embodiment of the present invention a method of operation of the battery cooling system (100) for high voltage agricultural vehicles, said method comprising steps of: obtaining the output of the first temperature sensor (10) and second temperature sensor; comparing the output of the first temperature sensor (10) and second temperature sensor with their respective threshold values in the battery management unit (3); activating the air circulating devices (5) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through the evaporator (6), if output of the first temperature sensor (10) exceeds the pre-defined value in the battery management unit (3); activating the blower (1) to exhaust the heat generated from the battery pack (4), if output of the second temperature sensor exceeds the pre-defined value in the battery management unit (3); compressing the refrigerant at high temperature and pressure into a hot, high pressure gas by means of a compressor (7); directing the refrigerant flow through the condenser (8) to reject refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6); and evaporating condensed cool refrigerant in the evaporator (6) by means of an external air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4) and circulate cool air towards the battery pack (4).
In the preferred embodiment of the present invention, the combination of the closed loop air and refrigerant cooling provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.
In the preferred embodiment of the present invention, direction of airflow towards and away from the battery pack (4) is based on staggered cell arrangement of plurality of cell guide holes (9) in the battery casing (2) for heat dissipation.
In the preferred embodiment of the present invention, the direction of airflow is gradient of temperature across the battery casing (2) from lower to higher temperature as shown in Figure 2.
In the preferred embodiment of the present invention, a heater element is connected with the battery management unit (3) for heating the battery pack (4), when operating the high voltage agricultural vehicles at sub-zero temperature environment.
In the preferred embodiment of the present invention, the method of operation of the battery cooling system (100) for high voltage agricultural vehicles comprises activating the heater element for heating the battery pack (4), if output of the first temperature sensor (10) is below the first pre-defined value in the battery management unit (3).
In the preferred embodiment of the present invention, the first pre-defined threshold value for the first temperature sensor (10) is in the range of 35 to 37 o Celsius.
In the preferred embodiment of the present invention, the second pre-defined threshold value for the second temperature sensor is in the range of 33 to 35 o Celsius.
Referring to Figure 4, the graphical representation of the battery cooling test trials performed on various vehicle operating condition while using the battery cooling system (100) according to the present invention in high voltage agricultural vehicles.
The test plot as shown in Figure 4 is temperatures of 14 battery pack (4) in the battery casing (2) along with the evaporator (6) outlet temperatures in 2 locations. The plot shows the drop in output of the first temperature sensor (10) positioned on the battery pack (4) temperatures when the cooling system is switched on when the battery pack (4) temperatures reach 35°C. The air temperature outlet of the evaporator (6) drops corresponding to the evaporator surface temperatures and the cooling system cycle.
Referring to Figure 5, illustrates the enlarged view of the battery casing in the battery cooling system for high voltage agricultural vehicles according to the present invention and battery casing in the conventional battery cooling system battery temperature plots in a steady state continuous charging conditions. The battery pack is maintained at the temperature in the range of 13 o C to 50 o C using battery cooling system (100) according to the present invention compared to 50 o C to 150 o C using conventional battery cooling system as shown in gradient scale in Figure 5.
Referring to Figure 6, illustrates the enlarged view of the battery casing in the battery cooling system for high voltage agricultural vehicles according to the present invention and battery casing in the conventional battery cooling system battery air flow velocity plots in a steady state continuous charging conditions. The battery pack is maintained at the air flow velocity in the range of 0.5 m/s to 2.18 m/s using battery cooling system (100) according to the present invention due to positioning of air circulating devices (5) compared air flow velocity in the range of 0 m/s to 0.5 m/s using conventional battery cooling system as shown in gradient scale in Figure 6.
Advantages:
1. Safe Battery charging within 1 hour from 0% to 80% can be done due to effective thermal management of the battery in the high voltage agricultural vehicles.
2. Increases life of the battery in the high voltage agricultural vehicles.
3. Has a Heater option to operate in subzero ambient conditions.
4. The battery cooling system is provided with a in-built ducting on the battery casing to guide the air through the battery pack and cool them.
5. Arrangement of sealing with the cell guide holes aids in avoiding hot air mixing and improve the cooling efficiency.

Thus, the battery cooling system having both air and refrigerant assisted cooling according to the present invention provides effective cooling of a battery pack for enhanced safety in a high voltage agricultural vehicles. Also, the battery cooling system according to the present invention assists in operating battery pack of a high voltage agricultural vehicles at sub-zero temperature environment.
It will be apparent to a person skilled in the art that the above description is for illustrative purposes only and should not be considered as limiting. Various modifications, additions, alterations, and improvements without deviating from the spirit and the scope of the invention may be made by a person skilled in the art.
, Claims:WE CLAIM:
1. A battery cooling system (100) for high voltage agricultural vehicles, comprising:
a blower (1) connected with a battery casing (2) forming a duct for a closed loop air circulation through a plurality of cell gaps (4a) , wherein the battery casing (2) comprises plurality of cell guide holes (9) arranged in a staggered form for guiding the air through the cell gaps (4a);
a battery pack (4) positioned within the respective cell gaps (4a);
one or more air circulating devices (5) positioned on sides of the one end of the battery casing (2) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through a evaporator (6);
plurality of first temperature sensors (10) positioned near the battery pack (4) respectively within the battery casing (2) and a second temperature sensor (not shown) positioned on the air circulating devices (5) respectively for sensing the temperature of air exhausted from the battery casing (2) and air input to the battery casing (2);
a battery management unit (3) connected with output of the first temperature sensor (10) and second temperature sensor for controlling the operation of the blower (1) and air circulating devices (5) as required;
a compressor (7), which compress a refrigerant from the evaporator (6) pressure to the condenser pressure;
a condenser (8) coupled to the outlet of the said compressor (7), wherein said condenser (8) rejects refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6);
wherein the evaporator (6) evaporates condensed cool refrigerant by means of an external air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4); and
a piping circuit for the refrigerant flow connecting the path of system components including compressor (7), condenser (8), and evaporator (6) positioned outside the battery casing (2) as refrigerant loop,
wherein combination of the closed loop air within the battery casing (2) and refrigerant cooling positioned outside the battery casing (2) provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.

2. The battery cooling system (100) as claimed in Claim 1, is provided with an in-built ducting on the battery casing (2) to guide the air through the battery pack (4) and cool them.

3. The battery cooling system (100) as claimed in Claim 1 has an arrangement of sealing with the cell guide holes (9) aids in avoiding hot air mixing and improve the cooling efficiency.

4. The battery cooling system (100) as claimed in Claim 1, wherein the air circulating device (5) is an axial fan.

5. The battery cooling system (100) as claimed in Claim 1, wherein the refrigerant is selected from group consisting of Haloalkanes, Chlorofluorocarbons (CFC) and Hydrochlorofluorocarbons (HCFC), hydrofluorocarbons (HFCs), Perfluorocarbons, isobutane, propane and mixtures thereof.

6. The battery cooling system (100) as claimed in Claim 1 comprises a heater element positioned on the battery casing (2), said heater element (not shown) is connected with the battery management unit (3) for heating the battery pack (4) when operating the said high voltage agricultural vehicles at sub-zero temperature environment.

7. The battery cooling system (100) as claimed in Claim 1, wherein the battery casing (2) is a water proof enclosure to avoid moisture entry in the battery pack (4).

8. The battery cooling system (100) as claimed in Claim 1, wherein the battery pack (4) comprises plurality of cylindrical cells.

9. The battery cooling system (100) as claimed in Claim 1, wherein the cylindrical cell is made up of lithium ion.

10. A method of operation of the battery cooling system (100) for high voltage agricultural vehicles as claimed in Claim 1, said method comprising steps of:
obtaining the output of the first temperature sensor (10) and second temperature sensor;
comparing the output of the first temperature sensor (10) and second temperature sensor with their respective threshold values in the battery management unit (3);
activating the air circulating devices (5) to circulate the hot air exhausted from the blower (1) towards the cell gaps (4a) through the evaporator (6), if output of the first temperature sensor (10) exceeds the pre-defined value in the battery management unit (3);
activating the blower (1) to exhaust the heat generated from the battery pack (4), if output of the second temperature sensor exceeds the pre-defined value in the battery management unit (3);
compressing the refrigerant at high temperature and pressure into a hot, high pressure gas by means of a compressor (7);
directing the refrigerant flow through the condenser (8) to reject refrigerant heat to the ambient air and outputs condensed cool refrigerant as liquid to the evaporator (6); and
evaporating condensed cool refrigerant in the evaporator (6) by means of an external air flow from the respective air circulating devices (5) and circulate cool air to the battery pack (4),
wherein combination of the closed loop air and refrigerant cooling provides effective cooling of the battery pack (4) in the said high voltage agricultural vehicles.

11. The method as claim in Claim 10, wherein direction of airflow towards and away from the battery pack (4) is based on staggered cell arrangement of plurality of cell guide (9) in the battery casing (2) for heat dissipation.

12. The method as claim in Claim 10, wherein a heater element is connected with the battery management unit (3) for heating the battery pack (4) when operating the said high voltage agricultural vehicles at sub-zero temperature environment.

13. The method as claim in Claim 10 comprises activating the heater element for heating the battery pack (4), if output of the first temperature sensor (10) is below the first pre-defined value in the battery management unit (3).

14. The method as claim in Claim 10, wherein the first pre-defined threshold value for the first temperature sensor (10) is in the range of 35o C to 37 o C.

15. The method as claim in Claim 10, wherein the second pre-defined threshold value for the second temperature sensor is in the range of 33o C to 35 o C.

Dated this 16th day of December, 2022