Claims:
We claim:
1. An apparatus (100) for relieving pressure in battery pack, the apparatus (100) comprising:
a valve core (102);
a pin (103) for
detecting pressure in the battery pack; and
actuating, by the pin (103), in a direction to facilitate release of the pressure in the battery pack, if the pressure is greater than a predefined threshold;
a spring (104) for enabling actuation of the pin (103) at varying pressures, wherein the spring (104) is designed with variable spring tensions;
a bush (105);
at least one O-ring (106); and
at least one washer (107) for creating passage for release of pressure through the valve core (102).
2. An apparatus (200) for relieving pressure in battery pack, the apparatus (200) comprising:
a valve core (202);
a rubber ball (203) for
detecting pressure in the battery pack; and
actuating in a direction to facilitate release of the pressure in the battery pack, if the pressure is greater than a predefined threshold;
a spring (204) for enabling actuation of the rubber ball (203) at varying pressures, wherein the spring (204) is designed with variable spring tensions; and
a rib (205) for arresting the actuation of the rubber ball (203), if the pressure is less than the predefined threshold.
3. An apparatus (300) for relieving pressure in battery pack, the apparatus (300) comprising:
a valve core (302);
a rubber washer (303) for:
detecting pressure in the battery pack; and
actuating in a direction to facilitate release of the pressure in the battery pack, if the pressure is greater than a predefined threshold;
a spring (304) for enabling actuation of the rubber washer (303) at varying pressures, wherein the spring (304) is designed with variable spring tensions; and

a rib (305) for arresting the actuation of the rubber washer (303), if the pressure is less than the predefined threshold.
, Description:TECHNICAL FIELD
[001] Embodiments disclosed herein relate to safety systems for battery packs and more particularly to methods and systems for enabling safe operation of a battery pack by releasing pressure detected in the battery pack.
BACKGROUND
[002] Battery packs can be utilized for multiple purposes. In an example, a battery pack can be included in an electric vehicle, an airplane, a generator, and so on. Battery packs can generate gases while operating in a system. Due to improper maintenance, damage, leakage, and so on, of the battery pack, certain conditions may develop. These conditions can lead to generation of gases within the battery pack of the system. The gases can cause an excessive pressure in the battery pack of the system. If the system is an electric vehicle, then the excessive pressure at the battery pack can hamper the efficiency, comfort, safety, drivability, and so on, of the electric vehicle.
[003] It is imperative to remove the buildup of gases inside the battery pack, in order to release the excessive pressure generated at the battery pack. If the buildup of gases is not removed, there could be a possibility of occurrence of an explosion in the battery pack. One of the causes of the explosion could be a thermal runaway. Thermal runaway is caused due to excessive pressure at the battery pack. During thermal runaway, explosive gases may be generated in the battery pack at extremely high temperatures. These gases need to be expelled from the battery pack, prior to occurrence of a potential catastrophic incident such as damage to the battery, the system, and injury the persons operating the system.
OBJECTS
[004] The principal object of the embodiments disclosed herein is to provide a pressure relief valve for enabling safe operation of a battery pack, by releasing excessive pressure detected in the battery pack.
[005] Another object of the embodiments disclosed herein is to prevent a potential catastrophe, caused by excessive pressure due to release of gases from the battery pack.
[006] Another object of the embodiments disclosed herein is to provide a spring in the core of the pressure relief valve, which can actuate at a very low pressure, wherein the spring is designed with variable spring constants in order to enable the core of the pressure relief valve to open at different pressures.
[007] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF FIGURES
[008] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[009] FIG. 1 depicts a pressure relief valve for release of pressure from battery pack, according to embodiments as disclosed herein;
[0010] FIG. 2 depicts another pressure relief valve for release of pressure from the battery pack, according to embodiments as disclosed herein; and
[0011] FIG. 3 depicts yet another pressure relief valve for release of pressure from the battery pack, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0012] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0013] The embodiments herein methods and systems for enabling safe operation of a battery pack by providing a pressure relief valve. The pressure relief valve can release excessive pressure in the battery pack, caused by release of gases in the battery pack. In an example, the pressure relief valve can be mounted on a battery pack, which can be a part of an electric vehicle. The release of gases can prevent a potential catastrophe. The gases can be released by actuation of a pin/rubber ball/rubber washer if the pressure in the battery pack is more than a predefined threshold. A spring can be included in the core of the pressure relief valve, which can actuate at a very low pressure. The spring is designed with variable spring constants in order to enable the core of the pressure relief valve to open at different pressures. A rib is included in the pressure to arrest the movement of the pin/rubber ball/rubber washer, if the pressure in the battery pack is not excessive.
[0014] Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0015] FIG. 1 depicts a pressure relief valve 100 for release of pressure from a battery pack, according to embodiments as disclosed herein. As depicted in FIG. 1, the pressure relief valve 100 comprises of a valve body 101, into which a valve core 102 is assembled. The valve core 102 comprises of a pin 103, a spring 104, a bush 105, at least one O-ring 106 and at least one washer 107. In an embodiment, the pressure relieve valve 100 can be mounted on a battery pack. In an example, the battery pack can be a part of an electric vehicle. Examples of the electric vehicle as referred to herein can be, but not limited to cars, vans, trucks, buses, tractors, scooters, motorcycles, bicycles, and so on.
[0016] The valve core 102 can be assembled into the valve body 101. The at least one washer 107 can act as a sealant. The pressure relief valve 100 can be mounted on the housing of the battery pack.
[0017] The pin 103 can be actuated automatically. The pin 103, in the pressure relief valve, can be actuated based on pressure caused by release of gases in the battery pack. The pin 103 can be actuated (downward movement, away from the battery pack), when the pressure at the battery pack increases beyond a particular predefined pressure. The pre-defined pressure can be defined as a range, wherein the range can be based on the application, battery enclosure size, customer requirement, and so on. In an example, the pre-defined pressure range can vary between 3-15 PSI. The weight of the pin can be decided at the design stage based on desired predefined pressure range.
[0018] The spring 104 can be designed to be actuated at very low pressures by designing the spring 104 with variable spring tensions. Designing the spring 104 with variable spring tensions can enable the valve core 102 to open at different pressures. In normal conditions, the pressure relief valve can be closed. The valve core can act as a non-returning valve.
[0019] By actuation of the pin 103, an air gap (cavity) can be created at the washer 107. The air gap provides a pathway for the gases in the battery pack to escape through the pressure release valve 100. The gases can escape from the cavities, created by the movement of the washer 107, with the actuation of the pin 103.
[0020] With a further increase of pressure at the battery pack, the pin 103 in the pressure relief valve can further actuate. The actuation of the pin 103 can increase the size of the cavities at the washer 107, so that the gases in the battery pack can find a path to escape. When pressure in the battery pack reduces due to the release of the gases, the pin 103 can actuate in the upward direction (towards the battery pack 100) hereby reducing the size of the cavities at the washer 107.
[0021] Consider an example scenario, wherein the battery pack is part of an electric vehicle. Gases can be released in the battery pack due to occurrence of certain conditions when the electric vehicle is operated. The gases can cause an increase in pressure in the battery pack. The pin 103 can be automatically actuated, when the pressure at the battery pack increases beyond a predefined pressure. In an example, the predefined pressure can be 0.1 bar (5 Psi). When the pressure in the battery pack of the electric vehicle increases beyond the predefined pressure, the pin 103 can actuate. The pin 103 can actuate in the downward direction (away from the battery pack), when the pressure in the battery pack, of the electric vehicle, increases beyond 0.1 bar.
[0022] FIG. 2 depicts a pressure relief valve 200 for release of pressure from battery pack, according to embodiments as disclosed herein. The pressure relief valve 200 comprises of a valve body 201, a valve core 202, a rubber ball 203, a spring 204, and a rib 205. The valve core 202 comprises of the rubber ball 203, the spring 204, and the rib 205. The functionality of the pin 103, the bush 105, the O-rings 106 and the washers 107 (as disclosed in FIG. 1) can be performed by the rubber ball 203 and the rib 205. In an embodiment, the pressure relieve valve 200 can be mounted on a battery pack. In an example, the battery pack can be a part of an electric vehicle.
[0023] The rubber ball 203 is attached to the spring 204. The spring 204 is connected at the bottom (from the perspective of the battery pack) of the rubber ball 203. The rib 205 is connected to the spring 204. The purpose of the rib 205 is to prevent movement of the rubber ball 203 when the battery pack is operating in normal conditions. In an embodiment, the rubber ball 203 can be made up of a suitable polymer that helps in maintaining Ingress Protection (IP) requirements, while serving as a pressure relief valve. The polymer can be a commercially available plastic, including but not limited to, synthetic or semi-synthetic organic polymer compounds of high molecular mass, malleable and can be molded into solid objects. The polymer can be a thermoplastic material with melting point range of 100 to 200 degree Celsius (roughly 130 degrees Celsius in the case of polypropylene). Examples of the plastic can be, but not limited to, Polyvinyl chloride (PVC), natural or artificial rubber (such as EPDM (ethylene propylene diene monomer), and so on. The rib 205 can arrest the movement of the rubber ball 203.
[0024] The rubber ball 203 can be actuated automatically. The rubber ball 203 can be actuated based on pressure caused by release of gases in the battery pack. The rubber ball 203 can be actuated (downward movement, away from the battery pack) when the pressure at the battery pack increases beyond the particular predefined pressure. The spring 204 can be designed to actuate at very low pressures by designing the spring 204 with variable spring tensions. Designing the spring 204 with variable spring tensions can enable the valve core 202 to open at different pressures. In normal conditions, the pressure relief valve 200 can be closed.
[0025] By actuation of the rubber ball 203, an air gap (cavity) can be created. The air gap provides a pathway for the gases in the battery pack to escape through the pressure release valve 200. The gases can escape from the cavity with the actuation of the rubber ball 203.
[0026] With a further increase of pressure at the battery pack, the rubber ball 203 in the pressure relief valve 200 can further actuate. The actuation of the rubber ball 203 can increase the size of the cavity, so that the gases in the battery pack can find a path to escape. When pressure in the battery pack reduces due to the release of the gases, the rubber ball 203 can actuate in the upward direction (towards the battery pack).
[0027] Consider an example scenario, wherein the battery pack is part of an electric vehicle. Gases can be released in the battery pack due to occurrence of certain conditions, when the electric vehicle is operated. The gases can cause an increase in pressure in the battery pack. The pressure release valve 200 can open in order to release the pressure in the battery pack. The rubber ball 203 can automatically actuate, when the pressure at the battery pack increases beyond the predefined pressure. In an example, the predefined pressure can be 0.1 bar (5 Psi). When the pressure in the battery pack of the electric vehicle increases beyond the predefined pressure, the rubber ball 203 can actuate. The rubber ball 203 can actuate in the downward direction (away from the battery pack), when the pressure in the battery pack, of the electric vehicle, increases beyond 0.1 bar.
[0028] FIG. 3 depicts a pressure relief valve 300 for release of pressure from the battery pack, according to embodiments as disclosed herein. The pressure relief valve comprises of a valve body 301, a valve core 302, a rubber washer 303, a spring 304, and a rib 305. The valve core 302 comprises of the rubber washer 303, the spring 304, and the rib 305. The functionality of the pin 103, the bush 105, the O-rings 106 and the washers 107 can be performed by the rubber washer 303 and the rib 305. In an embodiment, the pressure relieve valve 300 can be mounted on a battery pack. In an example, the battery pack can be a part of an electric vehicle.
[0029] The rubber washer 303 is attached to the spring 304. The spring 304 is connected at the bottom (from the perspective of the battery pack) of the rubber washer 303. The rib 305 is connected to the spring 304. The purpose of the rib 305 is to prevent movement of the rubber washer 303 when the battery pack is operating in normal conditions. In an embodiment, the rubber washer 303 can be made up of a polymer. The rib 205 can arrest the movement of the rubber washer 303.
[0030] The polymeric rubber washer 303 is fitted to the valve core 302. The interference 307 between the rubber washer 303 and the inner wall of the valve core 302 can be designed appropriately to allow the pressure release valve 300 to open at different pressure values.
[0031] The rubber washer 303 can be actuated automatically. The rubber washer 303 can actuate based on pressure caused by release of gases in the battery pack. The rubber washer 303 can be actuated (downward movement, away from the battery pack) when the pressure at the battery pack increases beyond the particular predefined pressure. The spring 304 can be designed to actuate at very low pressures by designing the spring 304 with variable spring tensions. Designing the spring 304 with variable spring tensions can enable the valve core 302 to open at different pressures. In normal conditions, the pressure relief valve 300 can be closed.
[0032] The rubber washer 303 can actuate in the downward direction (away from the battery pack 100), when the pressure in the battery pack, of the electric vehicle, increases beyond 0.1 bar. By actuation of the rubber washer 303, an air gap (cavity) can be created. The air gap provides a pathway for the gases in the battery pack to escape through the pressure release valve 300. The gases can escape from the cavity with the actuation of the rubber washer 303.
[0033] With a further increase of pressure at the battery pack, the rubber washer 303 in the pressure relief valve 300 can further actuate. The actuation of the rubber washer 303 can increase the size of the cavity, so that the gases in the battery pack can find a path to escape. When pressure in the battery pack reduces due to the release of the gases, the rubber washer 303 can actuate in the upward direction (towards the battery pack).
[0034] Consider an example scenario, wherein the battery pack is part of an electric vehicle. Gases can be released in the battery pack due to occurrence of certain conditions, when the electric vehicle is operated. The gases can cause an increase in pressure in the battery pack. The pressure release valve 300 can open in order to release the pressure in the battery pack. The rubber washer 303 can automatically actuate, when the pressure at the battery pack 100 increases beyond the predefined pressure. In an example, the predefined pressure can be 0.1 bar (5 Psi). When the pressure in the battery pack of the electric vehicle increases beyond the predefined pressure, the rubber washer 303 can actuate.
[0035] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.