Battery pressurization system

Abstract

The disclosed technology relates to a system for positively pressurizing a battery pack when the battery pack is submerged in water. In some embodiments, during a submersion event, a sensor detects the pressure inside the battery pack and generates a signal indicating the pressure inside the battery pack. The sensor then transmits a first signal to a pressure controller. The pressure controller adjusts the pressure inside the battery pack to a range based on the first signal in order to prevent liquid from entering the battery pack during the submersion event.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This patent application claims the benefit of priority of U.S. Provisional Patent Application No. 63 / 469,011, titled "BATTERY PRESSURIZATION SYSTEM," filed on May 25, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to systems and methods for protecting a battery from submersion. More particularly, some embodiments of this disclosure relate to a controller and sensors that can protect a voltage battery pack from water ingress by pressurizing with a gas (e.g., air).

Background Art

[0003] Electric vehicles typically require much more power, sometimes a thousand times more power, than typical consumer devices such as mobile devices. To achieve these power requirements, the battery packs of electric vehicles typically include a large - scale and high - density arrangement of individual cells. The useful life and performance of a battery pack often depend on the characteristics of the individual battery cells, the total number of individual cells incorporated into the battery pack, and the configuration / orientation of the cells and auxiliary components within the battery pack module. A battery pack can represent one of the most expensive and large - scale assemblies in the context of electric vehicle transportation and grid storage applications. Thus, it may be desirable to protect the battery pack from intrusion, interference, or contamination related to external substances in order to maintain or extend the useful life of the battery pack.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Each of the systems, methods, and devices disclosed herein has several innovative embodiments, but not one alone embodies all of the desirable characteristics disclosed herein. Details of one or more implementations of the subject matter described herein are given in the accompanying drawings and the following description.

[0005] Some examples of the present disclosure relate to battery pressurization systems designed for electric vehicles, particularly off-road vehicles such as trucks, that may be exposed to submersion events or require crossing bodies of water for extended periods. The exemplary systems aim to provide means for protecting battery packs from water ingress and for checking the integrity of sealing the battery packs over the lifespan of the vehicle. [Means for solving the problem]

[0006] Some examples utilize pressure sensors and pressure controllers to maintain internal pressure in the battery pack at a level that prevents water ingress during submersion events. Some exemplary systems can detect ambient pressure and adjust the internal pressure of the battery pack to be approximately 0.85 psi or 6 kPa above the detected ambient pressure. Other pressure ranges are also possible, as described below, for example. This pressurization effectively prevents water ingress by ensuring that air escapes from the leak rather than water flows into it.

[0007] Some exemplary battery pressurization systems include those that are normally closed and require energization to open. Exemplary valves are designed to have double seals to ensure robust closure. Exemplary systems also include hoses connecting the valves to various volumes within the battery pack, including auxiliary and enclosure volumes. In some examples, the auxiliary volume houses electronics, busbars, and other components, while the enclosure volume houses the battery cells.

[0008] Some exemplary systems are further equipped with spring-loaded pressure relief valves to prevent overpressurization of the battery pack. These valves open to release air when the pressure exceeds a certain threshold, aiming to ensure the safety of the system.

[0009] Several exemplary systems operate within a battery pack pressure range of approximately 80 kPa to 115 kPa and are designed to take into account a known leakage rate within the battery pack, allowing the pressure to be adjusted accordingly. The exemplary systems can also perform pack checks at any point in the vehicle's life to determine the integrity of the battery pack seal. If a leak is detected, the system can flag the error to the user, indicating that service may be required.

[0010] Some exemplary systems are designed to function effectively under a variety of environmental conditions, including changes in altitude and temperature, or pressure changes due to heat generation during battery charging. Some exemplary systems can withstand immersion in saltwater and freshwater.

[0011] Some exemplary systems include features for detecting thermal changes within the battery pack. For example, by monitoring pressure changes associated with heat generation during battery charging, an exemplary system may detect the degree of damage to the battery pack's seal. The exemplary features aim to leverage the vehicle's existing hardware and software and provide additional protective measures to ensure the integrity of the battery pack over the vehicle's lifespan.

[0012] The exemplary battery pressurization systems described herein aim to provide a robust solution for protecting the battery packs of electric vehicles, particularly those designed for off-road use. The system's ability to prevent water ingress and monitor the integrity of the battery pack seals aims to improve vehicle safety and reliability, ensuring user confidence under various operating conditions.

[0013] Therefore, one embodiment relates to a battery intrusion prevention system for vehicles. The battery intrusion prevention system includes at least a pressure sensor and a pressure controller. The battery intrusion prevention system can adjust the pressure inside the vehicle's battery pack to within a range by using air from an air source to create a positive pressure inside the battery pack.

[0014] In some embodiments, the technology described herein relates to a system for sealing a battery pack during a submersion event associated with the battery pack, the system including a first sensor configured to detect the pressure inside the battery pack, generate a first signal indicating the pressure inside the battery pack, and transmit the first signal to a pressure controller, the pressure controller configured to adjust the pressure inside the battery pack within a range based on the first signal to prevent liquid from entering the battery pack during a submersion event.

[0015] In some embodiments, the technology described herein relates to a system in which a pressure controller opens a valve connected to a pressure source to adjust the pressure inside the battery pack toward the upper limit of a range.

[0016] In some embodiments, the technology described herein relates to a system in which a pressure controller closes a valve connected to a pressure source when a first signal indicates that the pressure inside the battery pack has reached the upper limit of a range.

[0017] In some embodiments, the technology described herein relates to a system in which a pressure controller opens a valve connected to a pressure source when a first signal indicates that the pressure inside the battery pack has reached the lower limit of a range.

[0018] In some aspects, the technology described herein relates to a system in which a pressure controller opens a valve when the pressure inside the battery pack drops below a predetermined range and closes the valve when the pressure inside the battery pack exceeds the predetermined range.

[0019] In some aspects, the technology described herein relates to a system in which a pressure source is a stand-alone reservoir or part of a vehicle's air suspension system.

[0020] In some aspects, the technology described herein relates to a system that further includes a second sensor configured to detect a water intrusion event associated with the battery pack.

[0021] In some aspects, the technology described herein relates to a system in which, in response to the battery pack detecting a water intrusion event, the second sensor generates a second signal to enable the pressure controller to adjust the pressure inside the battery pack within a range.

[0022] In some aspects, the technology described herein relates to all of the embodiments described and discussed above.

Brief Description of the Drawings

[0023] Throughout the drawings, reference numerals are reused to indicate corresponding relationships of the elements being referenced. The drawings are provided to illustrate examples of the subject matter described herein and are not intended to limit its scope.

[0024] [Figure 1] An exemplary representation of an electric vehicle 100 in which embodiments of the present disclosure may be implemented is shown.

[0025] [Figure 2A] Various perspective views of at least a portion of the battery intrusion prevention system shown in FIG. 1 are shown, together with other components of an electric vehicle according to some embodiments of the present disclosure. [Figure 2B] Various perspective views of at least a part of the battery intrusion prevention system shown in FIG. 1, together with other components of an electric vehicle according to some embodiments of the present disclosure. [Figure 2C] Various perspective views of at least a part of the battery intrusion prevention system shown in FIG. 1, together with other components of an electric vehicle according to some embodiments of the present disclosure.

[0026] [Figure 3] A block diagram showing at least some of the components of the system shown in FIG. 1 according to some embodiments of the present disclosure.

[0027] [Figure 4] An exemplary process for protecting a battery pack by pressurizing the battery pack during a water incident according to some embodiments of the present disclosure is shown.

MODE FOR CARRYING OUT THE INVENTION

[0028] Generally speaking, one or more aspects of the present disclosure correspond to systems and methods for protecting a battery pack from submersion, water intrusion, or liquid intrusion. More specifically, some embodiments of the present disclosure disclose a mechanism and assembly for sealing any voltage battery pack (e.g., a high voltage, low voltage, or any voltage battery pack having cells inside) against the intrusion of a liquid (e.g., water) by pressurizing the battery pack. In some embodiments, when the battery pack is pressurized, the pressure inside the battery pack can result in being higher than the ambient pressure (e.g., the pressure outside the battery pack) by a predetermined value (e.g., 0.8 psi) or range. Further, the predetermined value or range can be adjustable according to the degree of submersion. For example, when the battery pack is submerged to a greater depth, the predetermined value or range can increase.

[0029] In some embodiments, while the battery pack is submerged, a sensor may track the pressure inside the battery pack to adjust the pressure level inside the battery pack to be above a reference pressure level. In some embodiments, a gas (e.g., air) may flow from a gas reservoir into the battery pack. In some embodiments, the system controls the flow rate by operating a valve connected between the gas reservoir and the battery pack. In some embodiments, the gas flows through the orifice of the valve. Furthermore, the system may adjust the diameter of the orifice in the battery pack or one or more breather valves to control the rate of gas flow from the reservoir to the battery pack so that the battery pack is not overpressurized.

[0030] In some embodiments, a vehicle sensor suite may detect whether a battery pack or the vehicle to which the battery pack is installed is submerged in water, and may generate a control signal in response to the detection of submersion of the battery pack. The control signal may cause a pressure controller to activate a water-removal mode in which a pressure sensor measures the pressure inside the battery pack to trigger positive pressure on the battery pack. In some embodiments, the vehicle sensor suite generates a control signal when certain criteria are met (e.g., submersion exceeding 30% of the battery pack height) so as not to over-sensitize the vehicle sensor suite in detecting the submersion event. Advantageously, this can prevent the battery pack assembly from entering water-removal mode in situations where pressurization of the battery pack is not required to protect the battery pack from liquid ingress. Alternatively, instead of being triggered by a control signal generated by the vehicle sensor suite, the activation of the water-removal mode may be triggered by the driver / passenger of the electric vehicle.

[0031] Battery packs for electric vehicles, or battery packs of any voltage (e.g., high voltage, low voltage, or any other voltage), can be sealed using adhesives, molded sealants, foam sealants, or similar materials. One common method of sealing a battery pack is by adding a temperature-curing adhesive (RTV) around the battery pack cover. Another sealing technique involves adding a foam or molded sealant around the battery pack enclosure. However, these techniques may not result in the desired level of sealing (e.g., approaching 100% leak prevention), such as when the air pressure outside the battery pack is substantially higher than the air pressure inside the battery pack. Furthermore, surface defects and manufacturing limitations can also hinder the desired level of sealing. Sealing can also be improved by further combining fasteners, punching reinforcements, or welding techniques to increase clamping force, but this incurs additional manufacturing costs. Additionally, since electric vehicle battery packs are generally leak-tested towards the end of the production cycle, sealing performance may not be monitored over the battery pack's effective lifespan.

[0032] Furthermore, breathers or breather valves are typically deployed to regulate pressure within a battery pack by allowing airflow or exchange (e.g., ventilation from the inside of the battery pack to the surrounding environment), which can generally be beneficial to the battery pack. Therefore, it may be desirable to develop sealing technologies that can work in conjunction with breather valves to provide an appropriate level of sealing in the presence of the resulting pressure drop from the breather valve.

[0033] According to some embodiments of this disclosure, a method and system for protecting an electric vehicle battery pack by positive pressure is disclosed. In particular, when a submersion event (e.g., when the battery pack is partially or completely submerged in water) is detected, a valve connected to a pressure source may open to inject air from the pressure source into the battery pack. If the air pressure inside the battery pack exceeds a certain range above the ambient pressure, the valve may close again. Thus, the air pressure inside the battery pack may exceed a lower limit to prevent liquid ingress and fall below an upper limit to prevent overpressurization. In some embodiments, if the battery pack is not partially or completely submerged, the valve is normally closed to prevent positive pressure from being applied to the battery pack.

[0034] In some embodiments, the battery pack assembly may include a vehicle sensor suite (e.g., pressure sensors) for detecting submersion events. Upon detection of a submersion event, the vehicle sensor suite may generate a control signal and transmit the control signal to a pressure controller. Upon receiving the control signal, the pressure controller may enter a water drainage mode to trigger positive pressure on the battery pack. In some embodiments, the vehicle sensor suite may include a vehicle height sensor, a vision sensor, or a tire pressure sensor. Additionally or optionally, some or all of the vehicle sensor suite may be mounted on a printed circuit board (PCB) or integrated as part of an electronic control unit (ECU) associated with an electric vehicle.

[0035] More specifically, in water-free mode, a pressure sensor inside the battery pack can continuously measure the pressure inside the battery pack and provide the measured pressure value to a pressure controller, which can then adjust the air pressure inside the battery pack to remain within a predetermined range by opening and closing a valve connected to the pressure source. In some embodiments, the pressure sensor can measure the pressure inside the battery pack before the valve opens or before air begins to flow from the pressure source into the battery pack. For example, the pressure sensor can measure a reference pressure value inside the battery pack while the battery pack is submerged in water, but before air begins to flow from the pressure source into the battery pack.

[0036] The pressure controller may cause a valve to open to allow airflow from the pressure source into the battery pack until a pressure sensor measures the current pressure value inside the battery pack and transmits to the pressure controller that the value has reached an upper limit. In some embodiments, the upper limit is 0.8 psi, 0.85 psi, or 1 psi above a reference pressure value. Thus, positive pressurization may stop when the pressure inside the battery pack is 0.8 psi, 0.85 psi, or 1 psi above the pressure outside the battery pack. Advantageously, this prevents the battery pack from being overpressurized.

[0037] In some embodiments, after the system stops the airflow from the pressure source into the battery pack, the pressure sensor may continue measuring the pressure inside the battery pack and transmit the current pressure value inside the battery pack to the pressure controller. If the current pressure value falls below a lower limit, the pressure controller may activate the valve again to positively pressurize the battery pack. In some embodiments, the lower limit may be 0.65 psi or 0.7 psi above the reference pressure value. Therefore, positive pressurization may be restarted to ensure that the pressure inside the battery pack is 0.65 psi or 0.7 psi above the pressure outside the battery pack.

[0038] Thus, the battery pack is sufficiently pressurized to prevent water ingress. Once the submersion event is over, the battery pack assembly exits the water drainage mode, and the valve closes to ensure that no water flows from the pressure source into the battery pack. If the battery pack is not sealed, the pressure inside the battery pack may gradually dissipate and return to the ambient pressure outside the battery pack. In some embodiments, the battery packs relating to some embodiments of this disclosure may be implemented to meet specific standards (IP ratings IP65, IP67, or IP67 or higher).

[0039] In some embodiments, the pressure in the pressure source may be maintained at approximately 20 bar. Air in the pressure source may flow into the battery pack through a valve and hose connecting the pressure source to the battery pack. In some embodiments, an orifice that allows airflow from the pressure source to the battery pack is designed to control the velocity of the airflow into the battery pack. For example, the velocity of the airflow may be between 0.01 psi and 0.02 psi per second. In particular, the controlled velocity of the airflow helps prevent overpressurization of the battery pack. In some embodiments, the valve may be a solenoid valve that can be driven to open and close by a solenoid driver. In some embodiments, in addition to being triggered to open by a pressure controller, the valve may open in response to user-triggered actions. For example, a user interface associated with a display (e.g., a center display) or other components of the electric vehicle may present a user interface element that allows the user to manually turn on the valve to initiate positive pressure on the battery pack.

[0040] In some embodiments, some or all of the vehicle sensor suite, pressure controller, pressure sensors, and valves may be structurally integrated into the electric vehicle's battery pack or high-voltage battery pack. Thus, the integrated battery pack may include components for positive pressurizing the battery pack. In some embodiments, existing components of the electric vehicle may be utilized to positive pressurize the battery pack. For example, instead of using a separate pressure source to positive pressurize the battery pack, the battery pack assembly may reuse or utilize a reservoir used in the electric vehicle's air suspension system. Therefore, the additional costs associated with deploying a battery pack assembly to positive pressurize the battery pack in the event of submersion or when it is necessary to prevent external liquid from entering the battery pack can be reduced.

[0041] While various embodiments are described according to exemplary combinations of embodiments and features, those skilled in the art will understand that the examples and combinations of features are illustrative in nature and should not be interpreted as limiting. More specifically, embodiments of this application may be applicable to various types of batteries, battery packs, and battery pack enclosures in various circumstances, such as when mounted on the bottom, rear, front, or surface of a vehicle; when mounted on a fixed structure (e.g., a building); or when mounted on various types of transport tools, including but not limited to aircraft, spacecraft, trucks, ships, shipping, ferries, and vans.

[0042] Furthermore, while specific architectures of battery pack assemblies or battery intrusion prevention systems (e.g., pressure sensors, vehicle sensor suites, pressure controllers, and valves) for positively pressurizing battery packs are described, such exemplary battery pack assembly designs or architectures should not be construed as limiting. Therefore, those skilled in the art will understand that embodiments of this application are not necessarily limited to applications to specific types of battery pack assemblies, battery intrusion prevention systems, battery pack infrastructure, battery pack enclosures, or integrated battery packs.

[0043] Figure 1 shows an exemplary electric vehicle 100 in which embodiments of the present disclosure may be implemented. As shown in Figure 1, the electric vehicle 100 has one or more battery packs 104, a battery intrusion prevention system 108, and a plurality of wheels 110. In some embodiments, the battery pack 104 may include a plurality of battery cells 106. The configuration of the battery pack 104 and the battery cells 106 may be determined based on a particular application. The battery intrusion prevention system 108 may be configured to positively pressure the battery pack 104. For example, the battery intrusion prevention system 108 may monitor or track the pressure inside the battery pack 104 and maintain the pressure inside the battery pack 104 above the pressure outside the battery pack 104 if the battery pack 104 is submerged in water.

[0044] Although an automobile is shown in Figure 1 as an exemplary electric vehicle 100, the electric vehicle 100 may be a variety of transport tools, including but not limited to aircraft, spacecraft, trucks, ships, maritime vessels, ferries, and vans, which utilize high-voltage battery packs to supply energy to the transport tool. Additionally, the battery pack 104 and the battery intrusion prevention system 108 may be deployed in structures that are not very mobile or immobile (e.g., buildings).

[0045] In some embodiments, the battery intrusion prevention system 108 may include a pressure sensor, a pressure source, and a pressure controller for tracking and regulating the pressure within the battery pack 104. It should be noted that some or all of the components of the battery intrusion prevention system 108, although shown separately, may be integrated into the battery pack 104 or reused from other existing components of the electric vehicle 100 (not shown in Figure 1). For example, the pressure source of the battery intrusion prevention system 108 may be the same as the pressure source for the air suspension system of the electric vehicle 100. Alternatively, in other embodiments, the battery intrusion prevention system 108 may have its own components separate from the other components of the electric vehicle 100.

[0046] As will be discussed below, in some embodiments, the battery intrusion prevention system 108 can seal the battery pack 104 against liquid (e.g., water) intrusion during a submersion event by positively pressurizing the battery pack 104. In some embodiments, positively pressurizing the battery pack 104 may result in the pressure inside the battery pack 104 being higher than the ambient pressure (e.g., the pressure outside the battery pack 104) by a predetermined value or range. In some embodiments, the predetermined value or range may be adjustable depending on the degree of submersion. For example, the battery intrusion prevention system 108 may positively pressurize the battery pack 104 to a higher pressure if the battery pack 104 is submerged to a greater depth. In some embodiments, if the water level outside the battery pack 104 is about 700 to 900 millimeters, the pressure inside the battery pack 104 adjusted by the battery intrusion prevention system 108 may prevent water from entering the battery pack 104.

[0047] Figure 2A shows a perspective view of at least a portion of the battery intrusion prevention system 108 of Figure 1, along with other components of the electric vehicle 100 according to several embodiments of the present disclosure. As shown in Figure 2A, the battery intrusion prevention system 108 includes various components such as a pressure source 202, a valve 204, a hose 206, a pressure sensor 208, and a pressure controller 210. The battery pack 104 of the electric vehicle 100 is also shown in Figure 2A. Although not readily observable from Figure 2A, when the valve 204 is open, air in the pressure source 202 can flow into the battery pack 104 through the hose 206. In some examples, as shown, the pressure sensor 208 and the pressure controller 210 are mounted on or connected to an auxiliary battery enclosure. The auxiliary enclosure may house electronics, busbars, and other components, while the adjacent enclosure volume (or main battery enclosure) houses the battery cells of the battery pack 104.

[0048] In some embodiments, the pressure sensor 208 may be integrated as part of a component or controller associated with the electric vehicle 100. Additionally, the pressure sensor 208 may be deployed and configured to detect pressure within the battery pack 104. In some embodiments, if the battery pack 104 is submerged, the pressure sensor 208 may track the pressure within the battery pack 104 to adjust the pressure level within the battery pack 104 to be above a reference pressure level. If the battery pack 104 is submerged, the pressure controller 210 may cause a valve 204 to open to allow air to flow from the pressure source 202 into the battery pack 104. While the valve 204 is open, the pressure sensor 208 may continue to measure the pressure within the battery pack 104 to provide the pressure controller 210 with the measured pressure value. When the pressure value reaches a predetermined value (e.g., an upper pressure limit), the pressure controller 210 may cause the valve 204 to close to stop air from flowing from the pressure source 202 into the battery pack 104.

[0049] In some embodiments, after the valve 204 closes and stops allowing air to flow from the pressure source 202 into the battery pack 104, the pressure sensor 208 may continue measuring the pressure in the battery pack 104 and provide the measured pressure value in the battery pack 104 to the pressure controller 210. If the measured pressure value in the battery pack 104 falls below a predetermined value (e.g., a pressure lower limit) and the battery pack 104 is submerged in water, the pressure controller 210 may turn on the valve 204 to bring the battery pack 104 into positive pressure.

[0050] In some embodiments, the battery intrusion prevention system 108 may include a vehicle sensor suite (not shown in Figure 2A) for detecting whether the battery pack 104 is submerged in water. In some embodiments, the vehicle sensor suite may be, or include, a vehicle height sensor, a vision sensor, or a tire pressure sensor. In response to detecting that the battery pack 104 is partially or completely submerged, the vehicle sensor suite may generate a control signal and transmit the control signal to the pressure controller 210. Upon receiving the control signal, the pressure controller 210 may enter a water removal mode to trigger positive pressure buildup of the battery pack 104. During positive pressure buildup, the pressure inside the battery pack 104 may be adjusted by the pressure controller 210 by controlling a valve 204 based on the measured pressure inside the battery pack 104 provided by the pressure sensor 208. In some embodiments, the pressure inside the battery pack 104 may be adjusted by the pressure controller 210 to be 0.6 psi to 1.0 psi higher than the pressure outside the battery pack 104.

[0051] Figures 2B–2C show various perspective views of at least a part of the battery ingress prevention system 108 shown in Figure 2A in Figure 1. Figures 2B–2C show a pressure source 202, a valve 204, a hose 206, and a pressure sensor 208 and a pressure controller 210. The battery pack 104 of the electric vehicle 100 is also shown in Figures 2B–2C. As shown in Figures 2B–2C, when the valve 204 opens based on a measurement associated with the pressure sensor 208, air in the pressure source 202 may flow into the battery pack 104 through the hose 206 to prevent liquid ingress into the battery pack 104.

[0052] In some embodiments, the pressure source 202 may be any air source present in the electric vehicle 100, such as an air pump, compressor, pressure vessel, or part of an air suspension system that may be deployed within the electric vehicle 100. Advantageously, the cost associated with the battery intrusion prevention system 108 can be controlled by reusing existing components associated with the electric vehicle 100. In other embodiments, the pressure source 202 may be dedicated to positively pressurizing the battery pack 104. Thus, the design or control of the battery intrusion prevention system 108 can be simplified.

[0053] Figure 3 shows a block diagram representing at least some of the components of the battery intrusion prevention system 108 of Figure 1 according to some embodiments of the present disclosure. As shown in Figure 3, the battery intrusion prevention system 108 may include a pressure sensor 208 in an HV (high voltage) auxiliary device 212, a pressure controller 210, and a vehicle sensor suite (not shown in Figure 3). Additionally, the battery intrusion prevention system 108 may further include a valve 204 and a hose 206. Air may enter the battery pack 104 by flowing from a pressure source 202 through the valve 204 and hose 206 so that the battery pack 104 can be positively pressurized when the battery pack 104 is partially or completely submerged by liquid during operation. The pressure source 202 may be a standalone reservoir storing air or may be integrated into other components of the electric vehicle 100 (e.g., an air suspension system, or a pump, or similar).

[0054] As shown in Figure 3, in some embodiments, both the pressure controller 210 and the pressure sensor 208 can be integrated within the HV auxiliary device 212. In some embodiments, the HV auxiliary device 212 may include other components such as a power conversion system, an HV controller, a busbar, or similar high-voltage components, but not limited to these.

[0055] The vehicle sensor suite can detect whether or not the battery pack 104 is submerged in water. Some or all of the vehicle sensor suite may be integrated as part of the trailer electronic control unit (ECU) of the electric vehicle 100. The vehicle sensor suite may include a visual sensor, a vehicle height sensor, a tire pressure sensor, or similar to send a control signal to the pressure controller 210 indicating that the battery pack 104 is submerged in water.

[0056] Upon receiving a signal indicating that the battery pack 104 is submerged in water, the pressure controller 210 may enter a water drainage mode to initiate positive pressure buildup in the battery pack 104. During water drainage mode, the pressure controller 210 may control the position of the valve 204 based on pressure information provided by the pressure sensor 208. Specifically, the pressure sensor 208 may track and measure the pressure inside the battery pack 104 and provide the measured pressure value to the pressure controller 210. Based at least in part on the measured pressure value, the pressure controller 210 may open or close the valve 204 connected to the pressure source 202 to adjust the air pressure inside the battery pack 104 to a predetermined range that prevents the ingress of water or other liquids.

[0057] In some embodiments, the pressure sensor 208 may measure the pressure inside the battery pack 104 before the valve 204 opens or before air begins to flow from the pressure source 202 into the battery pack 104. For example, the pressure sensor 208 may measure a reference pressure value inside the battery pack 104 even when the battery pack 104 is submerged in water, but before air begins to flow from the pressure source 202 into the battery pack 104.

[0058] Based on the pressure value measured by the pressure sensor 208, the pressure controller 210 may open a valve to allow airflow from the pressure source 202 into the battery pack 104 until the pressure in the battery pack 104 reaches an upper limit (e.g., 0.85 psi, or 1 psi above the reference pressure value). In some embodiments, after the valve 204 closes and stops the airflow from the pressure source 202 into the battery pack 104, the pressure sensor 208 may continue measuring the pressure in the battery pack 104 and provide the pressure controller 210 with pressure information related to the battery pack 104. If the pressure in the battery pack 104 falls below a lower limit (e.g., 0.65 psi or 0.7 psi above the reference pressure value) and the battery pack 104 is still submerged based on information provided by the vehicle sensor suite, the pressure controller 210 may turn on the valve 204 to positively pressurize the battery pack 104 toward the upper limit.

[0059] When the vehicle sensor suite detects that the battery pack 104 is not submerged in water, the pressure controller 210 may exit water drainage mode and close valve 204 to prevent air from flowing from the pressure source 202 into the battery pack 104. In some embodiments, after the battery ingress prevention system 108 exits water drainage mode, the pressure inside the battery pack 104 may gradually decrease to the ambient pressure outside the battery pack 104, since the battery pack 104 is not 100% sealed against air or water leakage.

[0060] As discussed above, when the valve 204 is opened based on the measurement from the pressure sensor 208, air can flow from the pressure source 202 through the hose 206 into the battery pack 104 so that the battery pack 104 can be pressurized when it is partially or completely submerged in liquid.

[0061] In some embodiments, the pressure in the pressure source 202 may be 21 bar at a temperature of 0°C, given that the amount of air stored in the pressure source 202 is 17.4 liters (L). In other embodiments, the pressure and amount of air stored in the pressure source 202 may differ from 21 bar and 17.4 pounds. In some embodiments, the hose 206 may be approximately 2267 millimeters (mm) between the valve 204 and the pressure sensor 208, and approximately 747 mm between the pressure sensor 208 and the battery pack 104. In other embodiments, the hose 206 may be shorter or longer than those described above. In some embodiments, the diameter of the orifice that allows air from the pressure source to flow into the battery pack 104 may be 0.45 mm. In other embodiments, the diameter of the orifice may be greater than or less than 0.45 mm. In yet another embodiment, the diameter of the orifice may be adjusted to control the velocity of the airflow from the pressure source to the battery pack so that the battery pack is not overpressurized.

[0062] In some embodiments, if the pressure measured by the pressure sensor 208 is below 0.75 psi, the pressure controller 210 may cause valve 204 to open to allow air to flow from the pressure source 202 through hose 206 into the battery pack 104, so as to prevent the pressure inside the battery pack 104 from rising and causing liquid to enter. If the pressure measured by the pressure sensor 208 is above 0.85 psi, the pressure controller 210 may cause valve 204 to close to stop or reduce the flow of air from the pressure source 202 through hose 206 into the battery pack 104, so as to prevent the pressure inside the battery pack 104 from continuing to increase to prevent overpressurization of the battery pack 104. In other embodiments, the pressure measured by the pressure sensor 208 that causes the pressure controller to open or close valve 204 may differ from 0.75 psi and / or 0.85 psi. In some embodiments, after the valve 204 is closed, as air escapes the battery pack 104 through the leak orifice of the battery pack 104, the pressure inside the battery pack 104 may gradually decrease to the ambient pressure.

[0063] Referring to Figure 4, an exemplary process 400 for sealing a battery pack by positive-pressureizing it during a submersion event is described. Process 400 may be implemented by a battery intrusion prevention system 108, as described in Figures 1-3. For simplicity of explanation and to avoid limiting the present disclosure, process 400 will be described in relation to specific elements or systems. The flow charts described below may show the operation as a sequential process, although some operations may be performed in parallel or simultaneously. In addition, the order of operations may be rearranged. A process terminates when its operation is complete. A process may correspond to a method, procedure, algorithm, etc. The operation of a method may be performed in whole or in part, in conjunction with some or all of the operation of other methods, or by any number of different systems, such as the systems described herein, or any part thereof, such as a processor, contained in any of the systems.

[0064] The process begins at 402, where the vehicle sensor suite detects a submersion event or leakage due to damage to the underside of the battery pack 104. Alternatively, the user may activate or trigger a submersion event by interacting with a user interface to positive-pressure the battery pack. Thus, the submersion event may be triggered or user-defined by the user, thereby allowing the user to positive-pressure the battery pack 104 when the user deems it appropriate or necessary. As discussed above, the vehicle sensor suite may include a vehicle height sensor, a vision sensor, or a tire pressure sensor. Optionally, some or all of the vehicle sensor suite may be integrated as part of the electronic control unit (ECU) of the electric vehicle and mounted on a printed circuit board (PCB). In some embodiments, the vehicle sensor suite detects a submersion event after the battery pack has been partially or completely submerged for a certain period (e.g., 60 seconds). Thus, the battery intrusion prevention system 108 may prevent the battery pack 104 from being positive-pressurized too frequently. In some embodiments, in response to the vehicle sensor suite detecting a submersion event, the battery intrusion prevention system 108 may enter a water drainage mode in which air inside the pressure source 202 can flow into the battery pack 104. If the battery intrusion prevention system 108 is not in water drainage mode, air may not flow from the pressure source 202 into the battery pack 104.

[0065] In block 404, the pressure sensor 208 detects the pressure inside the battery pack 104 and generates a first signal. The first signal may indicate the pressure inside the battery pack 104.

[0066] In block 406, the pressure sensor 208 transmits a first signal to the pressure controller 210 indicating the pressure inside the battery pack 104.

[0067] In block 408, the pressure controller 210 adjusts the pressure inside the battery pack 104 within a range based on the first signal. In some embodiments, the range may be 0.65 psi to 0.85 psi higher than the pressure outside the battery pack 104. example

[0068] Therefore, some embodiments may include one or more of the following examples.

[0069] Example 1 A system for protecting a battery pack during a submersion event, comprising a first sensor configured to detect the pressure inside the battery pack, generate a first signal indicating the pressure inside the battery pack, and transmit the first signal to a pressure controller, wherein the pressure controller is configured to adjust the pressure inside the battery pack within a range based on the first signal to prevent liquid from entering the battery pack during a submersion event.

[0070] Example 2: The pressure controller is the same as in Example 1, but causes a valve connected to a pressure source to adjust the pressure inside the battery pack toward the upper limit of the range.

[0071] Example 3: The system described in Example 2, wherein the pressure controller closes a valve connected to the pressure source when a first signal indicates that the pressure inside the battery pack has reached the upper limit of the range.

[0072] Example 4: The upper limit is within a pressure range of 0.8 to 1 psi above the reference pressure value, as described in Example 2 or 3.

[0073] Example 5: The pressure controller opens a valve connected to the pressure source when a first signal indicates that the pressure inside the battery pack has reached the lower limit of the range, as described in any one of Examples 2 to 4.

[0074]

[0075] Example 6: The system described in Example 5, where the lower limit is within a pressure range 0.65 to 0.7 psi above the reference pressure value.

[0076] Example 7: The system described in Example 2, wherein the pressure source is a standalone reservoir or part of the vehicle's air suspension system.

[0077] Example 8: The system according to any one of Examples 1 to 7, further comprising a second sensor configured to detect a submersion event related to the battery pack.

[0078] Example 9: The system as in Example 8, wherein, in response to detecting a submersion event related to the battery pack, the second sensor generates a second signal to allow the pressure controller to adjust the pressure inside the battery pack within a range.

[0079] Example 10: A system according to any one of Examples 1 to 9, wherein adjusting the pressure inside the battery pack includes positively pressurizing the battery pack such that the pressure inside the battery pack is higher than the ambient pressure by a predetermined value or range.

[0080] Example 11: The system according to Example 10, wherein a predetermined value or range is adjustable according to the degree of submersion.

[0081] Example 12: The system according to any one of Examples 1 to 11, wherein the pressure controller is further configured to adjust the pressure inside the battery pack based on the detected ambient pressure so that the pressure inside the battery pack is maintained at a predetermined value that is above the detected ambient pressure.

[0082] Example 13: The system according to any one of Examples 1 to 12, further comprising a valve that is normally closed and requires energization to open.

[0083] Example 14: The system described in Example 13, wherein the valve is configured to provide a double seal when closed.

[0084] Example 15: The system described in Example 1, further comprising a pressure relief valve.

[0085] Example 16: The system as in Example 15, wherein the pressure release valve is spring-driven (loaded) to prevent overpressurization of the battery pack by releasing air when the pressure inside the battery pack exceeds a predetermined pressure threshold.

[0086] Example 17: The system is configured to perform a pack check to determine the integrity of the battery pack seal and to flag an error (notify an error) if a leak is detected, as described in any one of Examples 1 through 16.

[0087] Example 18: The system is the same as in Example 2, but includes hoses connecting valves to an auxiliary volume and enclosure volume within the battery pack.

[0088] Example 19: The system described in any one of Examples 1 through 18, configured to operate within a pressure range inside the battery pack from approximately 80 kPa to 115 kPa.

[0089] Example 20: The system described in any one of Examples 1 to 19, wherein the system is configured to adjust the pressure inside the battery pack in response to environmental conditions, including changes in altitude and temperature.

[0090] Example 21: The system according to any one of Examples 1 to 20, further comprising a function for detecting thermal changes within the battery pack in order to determine the extent of damage in the sealing of the battery pack.

[0091] Example 22: The system described in Example 21, in which the function for detecting thermal changes utilizes pressure changes related to heat generation during battery pack charging.

[0092] Example 23: The system according to any one of Examples 1 to 22, further comprising a user interface element that allows the user to manually initiate positive voltage conversion of the battery pack.

[0093] It should be noted that the above descriptions and figures, along with the examples described herein, merely illustrate the principles of this subject matter and should not be interpreted as limiting the subject matter. Therefore, it should be understood that various configurations embodying the principles of this subject matter may be devised, even if not explicitly described or shown herein. Furthermore, all descriptions of the principles, aspects, and implementations of this subject matter enumerated herein are intended to encompass their equivalents as well as their specific examples.

[0094] It should be understood that not all objectives or benefits are necessarily achieved according to any particular embodiment described herein. Therefore, for example, those skilled in the art will recognize that some embodiments may operate in a manner that achieves or optimizes one benefit or group of benefits taught herein, without necessarily achieving other objectives or benefits that may be taught or suggested herein.

[0095] All processes described herein can be embodied in software code modules executed by a computing system including a computer or processor, thereby enabling complete automation. The code modules can be stored in any type of non-temporary computer-readable medium or other computer storage device. Some or all of these methods can be embodied in dedicated computer hardware.

[0096] Many variations beyond those described herein will become apparent from this disclosure. For example, depending on the embodiment, some of the operations, events, or functions of any of the algorithms described herein may be executed in a different order, and may be added, merged, or completely excluded (e.g., not all described operations or events are necessary for the practice of the algorithm). Furthermore, in some embodiments, operations or events may be executed in parallel, not sequentially, for example, through multithreading, interrupt handling, or through multiple processors or processor cores, or on other parallel architectures. In addition, different tasks or processes may be executed by different machines and / or computing systems that can work together.

[0097] The various exemplary logic blocks and modules described in relation to the embodiments disclosed herein may be implemented or executed by machines such as processing units or processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. The processor may be a microprocessor, but in alternative examples, the processor may be a controller, microcontroller, or state machine, or a combination thereof. The processor may include electrical circuits that process computer-executable instructions. In some embodiments, the processor includes an FPGA or other programmable device that performs logical operations without processing computer-executable instructions. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, a microprocessor combined with a DSP core, or any other such configuration. While this specification primarily describes digital technologies, the processor may also include primarily analog components. Computing environments can include, but are not limited to, any type of computer system based on a microprocessor, mainframe computer, digital signal processor, portable computing device, device controller, or in-device computing engine, to name a few.

[0098] Elements of methods, processes, routines, or algorithms described in relation to embodiments disclosed herein may be embodied directly in hardware, software modules executed by a processor device, or a combination of the two. Software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of non-temporary computer-readable storage medium. Exemplary storage media may be coupled to a processor device so that the processor device can read information from and write information to the storage media. Alternatively, the storage media may be integrated into the processor device. The processor device and storage media may reside within an ASIC. The ASIC may reside within a user terminal. Alternatively, the processor device and storage media may exist as separate components within a user terminal.

[0099] The processes described herein or shown in the figures of this disclosure may be initiated on demand when started by a user or system administrator in response to an event such as a predetermined or dynamically determined schedule, or in response to any other event. When such a process is initiated, a set of executable program instructions stored in one or more non-temporary computer-readable media (e.g., hard drives, flash memory, removable media) may be loaded into the memory (e.g., RAM) of a server or other computing device. The executable instructions may then be executed by the hardware-based computer processor of the computing device. In some embodiments, such a process or part thereof may be implemented in series or in parallel on multiple computing devices and / or multiple processors.

[0100] Unless otherwise specified or understood in the context in which they are used, conditional language such as “can,” “could,” “might,” or “may” is generally used to suggest that some embodiments include certain features, elements, and / or steps, while others do not. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are in some form for an embodiment, nor is it intended to imply that an embodiment necessarily includes logic for determining whether these features, elements, and / or steps should be included in or performed in any particular embodiment, with or without user input or input request.

[0101] Disjunctive phrases such as "at least one of X, Y, or Z" are generally understood, unless otherwise specified, to be used from the context to indicate that an item, term, etc., could be any one of X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z). Therefore, such disjunctive phrases are generally not intended, nor should they be, to imply that some embodiments require the presence of at least one X, at least one Y, or at least one Z, respectively.

[0102] Any process description, element, or block in a flowchart described herein and / or depicted in the accompanying drawings should also be understood to represent a module, segment, or portion of code containing execution instructions for implementing a particular logical function or element in the process. Within the scope of the embodiments described herein, alternative embodiments may be included in which, depending on the function in question, elements or functions may be omitted, executed in an order different from the order illustrated or described, substantially simultaneously or in reverse order, as will be understood by those skilled in the art.

[0103] It should be emphasized that many variations and modifications can be made to the above examples, and that the elements of these variations should be understood to be found in other acceptable embodiments. All such modifications and variations are intended to be incorporated herein within the scope of this disclosure.

[0104] Any process description, element, or block in a flowchart described herein and / or depicted in the accompanying drawings should also be understood to represent a module, segment, or portion of code containing execution instructions for implementing a particular logical function or element in the process. Within the scope of the embodiments described herein, alternative implementations are included in which, depending on the function in question, elements or functions may be omitted, executed in an order different from that shown or described, substantially simultaneously or in reverse order, as will be understood by those skilled in the art.

[0105] Unless otherwise specified, articles such as "a" or "an" should generally be interpreted as including one or more described items. Therefore, phrases such as "devices configured to do ~" are intended to include one or more enumerated devices. Such one or more enumerated devices may also be collectively configured to perform the stated enumeration. For example, "processors configured to perform enumerations A, B, and C" may include a first processor configured to perform enumeration A, which works in conjunction with a second processor configured to perform enumerations B and C.

[0106] It should also be understood that one or more of the elements shown in the drawings / figures may be implemented in a more separated or integrated manner to be useful for a particular application, or may be removed or rendered as non-functional in certain cases.

Claims

1. A system for protecting a battery pack during a submersion event related to the battery pack, The system includes a first recovery, the first recovery being, The pressure inside the battery pack is detected, and a first signal indicating the pressure inside the battery pack is generated. The first signal is configured to be transmitted to the pressure controller. The pressure controller is configured to adjust the pressure inside the battery pack within a range based on the first signal in order to prevent liquid from entering the battery pack during the submersion event.

2. The system according to claim 1, wherein the pressure controller causes a valve connected to the pressure source to adjust the pressure inside the battery pack toward the upper limit of the range.

3. The system according to claim 2, wherein the pressure controller closes the valve connected to the pressure source when the first signal indicates that the pressure inside the battery pack has reached the upper limit of the range.

4. The system according to claim 3, wherein the upper limit is within a pressure range of 0.8 to 1 psi above the reference pressure value.

5. The system according to claim 4, wherein the pressure controller opens the valve connected to the pressure source when the first signal indicates that the pressure inside the battery pack has reached the lower limit of the range.

6. The system according to claim 5, wherein the lower limit is within a pressure range of 0.65 to 0.7 psi above the value of the reference pressure.

7. The system according to claim 2, wherein the pressure source is a standalone reservoir or part of the vehicle's air suspension system.

8. The system according to claim 1, further comprising a second sensor configured to detect the submersion event related to the battery pack.

9. The system according to claim 8, wherein, in response to detecting the submersion event related to the battery pack, the second sensor generates a second signal to enable the pressure controller to adjust the pressure inside the battery pack within the range.

10. The system according to claim 1, wherein adjusting the pressure inside the battery pack includes positively pressurizing the battery pack such that the pressure inside the battery pack is higher than the ambient pressure by a predetermined value or range.

11. The system according to claim 10, wherein the predetermined value or range is adjustable according to the degree of submersion.

12. The system according to claim 1, wherein the pressure controller is further configured to adjust the pressure inside the battery pack based on the detected ambient pressure so that the pressure inside the battery pack is maintained at a predetermined value that exceeds the detected ambient pressure.

13. The system according to claim 1, further comprising a valve that is normally closed and requires power to be supplied to open.

14. The system according to claim 13, wherein the valve is configured to provide a double seal when closed.

15. The system according to claim 1, further comprising a pressure relief valve.

16. The system according to claim 15, wherein the pressure release valve is biased by a spring to prevent overpressure of the battery pack by releasing air when the pressure inside the battery pack exceeds a predetermined pressure threshold.

17. The system according to claim 1, wherein the system is configured to determine the integrity of the sealing of the battery pack and to perform a pack check to set an error flag if a leak is detected.

18. The system according to claim 2, wherein the system includes a hose connecting the valve to the auxiliary volume and enclosure volume within the battery pack.

19. The system according to claim 1, wherein the system is configured to operate within a pressure range inside the battery pack of approximately 80 kPa to 115 kPa.

20. The system according to claim 1, wherein the system is configured to adjust the pressure inside the battery pack in response to environmental conditions, including changes in altitude and temperature.

21. The system according to claim 1, further comprising a function for detecting thermal changes within the battery pack in order to determine the degree of damage in the sealing of the battery pack.

22. The system according to claim 21, wherein the function for detecting the thermal change utilizes a pressure change related to the heat generated during charging of the battery pack.

23. The system according to claim 1, further comprising a user interface element that enables a user to manually initiate the positive voltage conversion of the battery pack.

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