Electric vehicle low voltage battery charging system

Abstract

Systems, methods, and computer-readable storage media for charging a low voltage battery using a high voltage battery of electrical vehicles are described. A vehicle includes a first battery having a first nominal voltage, a second battery having a second nominal voltage that is less than the first nominal voltage, a battery control system, a control unit, and a DC-to-DC converter. The battery control system includes a first battery management system that controls the first battery, and a second battery management system that controls the second battery. The vehicle operates between a standby mode during which the second battery control system monitors a voltage of the second battery, and an active mode during which the battery control system charges the second battery. The control unit switches the vehicle from the standby mode to the active mode and outputs a control signal to charge the second battery via the first battery.

Description

213742-00195ELECTRIC VEHICLE LOW VOLTAGE BATTERY CHARGING SYSTEMTECHNICAL FIELD

[0001] The present application is generally directed to electrical vehicles and charging batteries of electrical vehicles.BACKGROUND OF THE INVENTION

[0002] Electrical vehicles (EV) and hybrid vehicles may include a high voltage (HV) battery as well as a low voltage (LV) battery for powering the vehicle or components of the vehicle. For example, the LV battery may be a 12 voltage (V) battery (e.g., often between 12V to 48V, below 100V) that is used for the electronics, lights, entertainment system, windows, and other electrical equipment or accessories of the vehicle. The HV battery may be at least a 100V battery (e.g., often between 200V and 800V).

[0003] In some cases, the LV battery of the vehicle, which may be an EV, may discharge such that it no longer provides the expected voltage. As an example, the LV battery may discharge when then the vehicle is parked, especially when parked for an extended period. In particular, the LV battery may discharge because an electric control unit (ECU) of the vehicle may consume current when the vehicle is in a sleep state (e.g., vehicle-off mode when the vehicle is parked). The current may be a quiescent current, which may be the current to maintain quiescent functions after the vehicle enters the sleep state. In such cases, to recharge the LV battery back to an original charge or an acceptable charge above a threshold charge, a power source external to the LV battery (e.g., external power source) may be used.

[0004] However, using an external power source to charge the LV battery may result in various inefficiencies as well as battery degradation (e.g., decreased lifespan of the LV battery), particularly after frequent use of the external power source to re-charge the LV battery. For example, using the external power source to charge the LV battery may be time-consuming (e.g., especially with multiple attempts to re-charge), as well as result in connection issues between the external power source and the LV battery and a reliance on the external power source to be readily available (e.g., reliance on a battery charger or another vehicle to charge the LV battery). Moreover, frequent charging using the external power source may lead to wear of the battery and reduce the lifespan of the battery.213742-00195BRIEF SUMMARY OF THE INVENTION

[0005] The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

[0006] In some cases, a low voltage (LV) battery of an electric vehicle (EV) may discharge when then the vehicle is parked, especially when parked for an extended period. To recharge the LV battery, a power source external to the vehicle (e.g., a battery charger or another vehicle) may be used. However, using an external power source to charge the LV battery may result in various inefficiencies as well as battery degradation (e.g., decreased lifespan of the LV battery). For example, using the external power source to charge the LV battery may be timeconsuming, connection issues between the external power source and the LV battery may occur, and a reliance on the external power source to be readily available may be formed. Moreover, frequent re-charging using the external power source may lead to wear of the battery and reduce the lifespan of the battery.

[0007] To efficiently charge the LV battery and without reducing the lifespan of the LV battery (e.g., that may otherwise occur with charging the LV battery using the external power source), the techniques described herein include a high voltage (HV) battery of the EV that charges the LV battery. For example, an LV battery management system associated with the LV battery may monitor a state of charge (SoC) of the LV battery. If the SoC falls below a threshold charge, then the LV battery management system may wake up one or more electric control units (ECUs), as well as the HV battery management system to initiate the charging of the LV battery. Charging safety measures for the LV battery and / or the HV battery may be in place, and a user of the EV (e.g., the driver) may receive charging-related notifications, such as notifications indicating that the LV battery is charging or has stopped charging.

[0008] In some embodiments, a vehicle (e.g., an EV) may include a first battery (e.g., an HV battery) having a first nominal voltage, a second battery (e.g., an LV battery) having a second nominal voltage that is less than the first nominal voltage, a battery control system, a control unit, and a DC-to-DC converter. The battery control system may include a first battery213742-00195management system (e.g., HV battery management system) that controls the first battery and a second battery management system (e.g., LV battery management system) that controls the second battery. The vehicle may operate between a standby mode during which the second battery control system monitors a voltage of the second battery and an active mode during which the battery control system charges the second battery.

[0009] The control unit may switch the vehicle from a standby mode to the active mode and output a control signal to the battery control system causing, via the first battery management system, the first battery to output power (e.g., control signal to cause HV battery to charge the LV battery). The DC-to-DC converter may receive the power output by the first battery at a third voltage and output the power output by the first battery at a fourth voltage to charge the second battery (e.g., cause the HV battery to charge the LV battery), the fourth voltage being less than the third voltage.

[0010] Using the HV battery to charge the LV battery, that are both internal to the vehicle, may reduce time latencies and other inefficiencies associated with charging the LV battery using an external power source. Additionally, monitoring the SoC of the LV battery and automatically charging the battery using the HV battery may further reduce these latencies, as well as reduce the likelihood of decreasing the lifespan of the LV battery (e.g., that may otherwise occur when letting the LV battery discharge to the extent use of the external power source is required).

[0011] Although aspects of this disclosure are described with reference to charging the LV battery, aspects of this disclosure may likewise be applied to other batteries or components within the EV that may benefit from charging.

[0012] Some embodiments of the present vehicle include a first battery having a first nominal voltage, a second battery having a second nominal voltage that is less than the first nominal voltage, a battery control system, a control unit, and a DC-to-DC converter. The battery system includes a first battery management system configured to control the first battery and a second battery management system configured to control the second battery. The vehicle is configured to operate between a standby mode during which the second battery control system monitors a charge of the second battery and an active mode during which the battery control system charges the second battery. The control unit is configured to switch the vehicle from the standby mode to the active mode and output a control signal to the battery control system, where the control signal causes, via the first battery management system, the first battery to output power. The DC¬' S -213742-00195to-DC converter is configured to receive the power output by the first battery at a third voltage and output the power output by the first battery at a fourth voltage to charge the second battery, where the fourth voltage being less than the third voltage.

[0013] In some embodiments, the second battery management system is configured to output a wakeup signal to the control unit.

[0014] In some embodiments, the second battery management system is configured to output the wakeup signal in response to one or more wakeup events, and the one or more wakeup event(s) comprises a state of charge of the second battery being at or below a threshold charge.

[0015] In some embodiments, the threshold charge is at least 20% of a charge capacity of the second battery.

[0016] In some embodiments, control unit is configured to identify at least one of the one or more wakeup event(s) as a triggering event to switch the vehicle from the standby mode to the active mode and output the control signal, and where the triggering event comprises the state of charge of the second battery being at or below the threshold charge.

[0017] In some embodiments, the control signal comprises a request to the first battery management system to charge the second battery, a wakeup signal to wake up the first battery management system, a request to authenticate the first battery management system, or any combination thereof.

[0018] In some embodiments, the control unit is configured to receive, from the second battery management system, a signal indicating the threshold charge, and output, to the first battery management system, a signal indicating the threshold charge.

[0019] In some embodiments, the control unit is configured to stop charging the second battery based on the second battery having a state of charge that is at least the threshold charge.

[0020] In some embodiments, the control unit is configured to output a second control signal causing the first battery to stop outputting power.

[0021] In some embodiments, the control unit outputs the second control signal based at least in part on a system error associated with the vehicle, a temperature associated with the213742-00195vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof.

[0022] In some embodiments, the vehicles comprises a communication interface configured to receive a charging start notification and a charging stop notification associated with the first battery charging the second battery.

[0023] Some embodiments of the present method include monitoring for a wakeup signal indicating that a second battery associated with a vehicle has a state of charge below a threshold charge, where a first battery of the vehicle has a first nominal voltage, and the second battery has a second nominal voltage that is less than the first nominal voltage. The method includes switching from operating in a standby mode of the vehicle to an active mode of the vehicle based at least in part on the wakeup signal, where the standby mode comprises monitoring the state of charge of the second battery, and where the active mode comprises charging the second battery using power output from the first battery. The method includes outputting a control signal causing the vehicle to switch from the standby mode to the active mode.

[0024] In some embodiments, the wakeup signal is received from a second battery management system configured to control the second battery.

[0025] In some embodiments, the wakeup signal is received in response to one or more wakeup events, and the method comprises identifying at least one event of the one or more wakeup event(s) as a triggering event for switching from the standby mode to the active mode.

[0026] In some embodiments, outputting the control signal comprises authenticating a first battery management system that controls the first battery prior to the first battery outputting power.

[0027] In some embodiments, when the vehicle is in the active mode, the method comprises receiving, from a second battery management system that controls the second battery, a signal indicating a threshold charge, and outputting, to a first battery management system that controls the first battery, a signal indicating the threshold charge.

[0028] In some embodiments, the threshold charge is at least 20% of a charge capacity of the second battery.213742-00195

[0029] In some embodiments, outputting a second control signal causes the first battery to stop outputting power.

[0030] In some embodiments, outputting the second control signal is based at least in part on the second battery having a charge of at least the threshold charge, a system error associated with the vehicle, a temperature associated with the vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof.

[0031] In some embodiments, outputting, to a communication interface of the vehicle, a charging start notification and a charging stop notification associated with the first battery outputting power.

[0032] As discussed herein, the term “standby mode” refers to when the vehicle remains partially active by performing low-power consumption tasks, for example, using the LV battery rather than the HV battery, allowing for a quick wake-up and resumption of tasks. As an example, the low-power consumption tasks may include providing power to security systems, remote key functions, and telematics. In the standby mode, the HV battery and / or the HV battery management system may be in a low-power state (e.g., sleep), such that the vehicle is not using or only partially using the HV battery for low-power consumption tasks. As discussed herein, the term “active mode” refers to when the vehicle is no longer in the low-power state and is in a greater power consumption state than the low-power state. The HV battery and / or the HV battery management system may be active and used in the active mode.

[0033] The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be unitary with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially” and “approximately” are each defined as largely but not necessarily wholly what is specified — and include what is specified, e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel — as understood by a person of ordinary skill in the art. In any disclosed embodiment, the term “approximately” may be substituted with “within [a percentage] of’ what is specified, where the percentage includes 0.1, 1, 5, and 10 percent.

[0034] The terms “comprise” and any form thereof such as “comprises” and “comprising,” “have” and any form thereof such as “has” and “having,” and “include” and any213742-00195form thereof such as “includes” and “including” are open-ended linking verbs. As a result, an apparatus or system that “comprises,” “has,” or “includes” one or more elements possesses those one or more elements but is not limited to possessing only those elements. Likewise, a method that “comprises,” “has,” or “includes” one or more steps possesses those one or more steps but is not limited to possessing only those one or more steps.

[0035] Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of — rather than comprise / have / include — any of the described steps, elements, and / or features. Thus, in any of the claims, the term “consisting of’ or “consisting essentially of’ can be substituted for any of the open-ended linking verbs recited above to change the scope of a given claim from what it would otherwise be using the open-ended linking verb.

[0036] Further, an apparatus or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.

[0037] The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

[0038] Some details associated with the embodiments described above and others are described below.BRIEF DESCRIPTION OF THE DRAWINGS

[0039] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:

[0040] FIG. 1 is schematic of a vehicle that includes a system for charging a low voltage battery using a high voltage battery of the vehicle in accordance with an embodiment of the present invention.

[0041] FIG. 2A is a first portion of a process flow of a method for charging the low voltage battery of the vehicle using the high voltage battery of the vehicle in accordance with an embodiment of the present invention.213742-00195

[0042] FIG. 2B is a second portion of a process flow of a method for charging the low voltage battery of the vehicle using the high voltage battery of the vehicle in accordance with an embodiment of the present invention.

[0043] FIG. 3 is another process flow of a method for charging the low voltage battery of the vehicle using the high voltage battery of the vehicle in accordance with an embodiment of the present invention.

[0044] It should be understood that the drawings are not to scale and that the disclosed embodiments are illustrated diagrammatically and in partial views. It should also be understood that this disclosure is not limited to the particular embodiments illustrated herein.DETAILED DESCRIPTION OF THE INVENTION

[0045] The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

[0046] The present disclosure provides systems, apparatuses, methods, and computer-readable media that support data processing and charging a battery, including techniques for charging a low voltage (LV) battery of a vehicle using a high voltage (HV) battery of the vehicle. Although the techniques described herein are discussed with respect to an electric vehicle (EV), the techniques described herein may apply to any vehicle that uses a battery for powering the vehicle or components of the vehicle and includes an LV battery and an HV battery. For example, the techniques described herein may apply to a hybrid vehicle.

[0047] Aspects of this disclosure provide for operations and EV components used in those operations for charging the LV battery using the HV battery. For example, an LV battery management system associated with the LV battery may monitor a state of charge (SoC) of the LV battery. If the SoC falls below a threshold charge, then the LV battery management system may wake up one or more electric control units (ECUs), as well as the HV system, to initiate the charging of the LV battery. Charging safety measures for the LV battery and / or the HV battery213742-00195may be in place, and a user of the EV (e.g., the driver) may receive charging-related notifications, such as notifications indicating that the LV battery is charging or has stopped charging.

[0048] Particular implementations of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages or benefits. In some aspects, the present disclosure provides techniques for reducing latencies and other inefficiencies associated with charging the LV battery using an external power source (e.g., timeconsuming, connection issues between the external power source and the LV battery, dependency on availability of the external power source, etc.). Additionally, monitoring the SoC of the LV battery and automatically charging the battery using the HV battery may reduce these latencies, as well as reduce the likelihood of decreasing the lifespan of the LV battery (e.g., that may otherwise occur when using the external power source to repeatedly re-charge the LV battery).

[0049] FIG. 1 illustrates a system 100 that may be included in a vehicle with batteries (e.g., an electric vehicle (EV) or a hybrid vehicle), according to one or more aspects of the disclosure. A system 100 may include a control unit 102 that may bidirectionally communicate with an HV battery management system 104 and an LV battery management system 108. The HV battery management system 104 may control an HV battery 106 and the LV management system may control an LV battery 110.

[0050] The HV battery management system 104 may monitor for safety and efficient operation of the HV battery 106 (e.g., maintain lifespan of the HV battery 106). For example, the HV battery management system 104 may balance performance and safety, given the high voltages involved in the vehicle, often ranging from 400V to over 800V. The HV battery management system 104 may monitor the HV battery 106 and current levels, adjusting to stay within safe operating limits and prevent overcharging or deep discharging. In some examples, the HV battery management system 104 may monitor critical parameters associated with the such as voltage, current, temperature, and SoC of the HV battery 106. As an example, during charging, the HV battery management system 104 may monitor power entering the HV battery 106. The HV battery management system 104 may monitor to adjust the power entering the HV battery 106 based on the SoC and temperature of the HV battery 106, for example, to increase charging speed while protecting the battery from stress and overheating. Moreover, the HV battery management system 104 may monitor for a wakeup frame from the LV battery management system 108 (e.g., relayed via the control unit 102) for when the charge of the LV battery 110 falls below a threshold charge.213742-00195

[0051] The HV battery management system 104 may also communicate with a DC-to-DC converter 112, which may communicate with the HV battery 106 and the LV battery 110, as discussed with respect to FIGs. 2A, 2B, and 3. For example, one or more inputs of the DC-to-DC converter 112 may receive power from the HV battery 106 (e.g., via signaling from the HV battery management system 104 or the control unit 102) at a first voltage (e.g., high voltage). The DC-to-DC converter 112 may output power through one or more outputs of the DC-to-DC converter 112 at a second voltage (e.g., low voltage) that is less than the first voltage when the one or more inputs of the DC-to-DC converter 112 receives power from the HV battery 106 at the first voltage.

[0052] For example, the first voltage at which input of DC-to-DC converter 112 may receive power from HV battery 106 may be approximately the same as the first nominal battery voltage of the HV battery 106, such as greater than or equal to any one of, or between two of: 100V, 200V, 500V, 800V, and 1000V (e.g., 400V to 800V). The second voltage at which the DC-to-DC converter 112 may output power from any of the one or more outputs may be less than or equal to any one or, or between two of: 10V, 15V, 20V, 50V, 75V, and 100V (e.g., 12V to 48V). In this manner, the DC-to-DC converter 112 may reduce the voltage of power received from HV battery 106 to a voltage suitable for the LV battery 110. Additionally, the DC-to-DC converter 112 may output an adequate amount of power (e.g., power above a threshold) for the system 100.

[0053] The LV battery management system 108 (e.g., a smart battery management (SBM) system) may provide a safe and efficient operation of the LV battery 110. For example, the LV battery management system 108 may track the health of the LV battery 110 and / or individual cells within the LV battery 110, monitoring for battery -related issues like over-voltage, undervoltage, and temperature fluctuations. The LV battery management system 108 may optimize energy use of the LV battery 110 by controlling the charging and discharging processes to extend battery life and efficiency (e.g., to extend longevity of the LV battery 110). The LV battery management system 108 may provide a particular battery temperature by monitoring heat levels and, if necessary, activating cooling or heating systems to prevent overheating or undercooling.

[0054] Additionally, the LV battery management system 108 may estimate battery states like the SoC and State of Health (SoH), giving the vehicle user accurate expected battery life of the LV battery 110. By determining the SoC of the LV battery 110, and when the SoC falls below a threshold charge, the LV battery management system 108 may send a wakeup signal to213742-00195the control unit 102 and / or the HV battery management system 104 to facilitate charging the LV battery 110 using the HV battery 106, as discussed with respect to FIGs. 2A, 2B, and 3. Additionally, the LV battery management system 108 may also collect data on battery performance, and the data may be used for diagnostics, maintenance, and, in some cases, communicated to the vehicle’s management system, such as the control unit 102 and / or the HV battery management system 104.

[0055] The control unit 102 may switch and / or monitor the status of the vehicle, for example, when the vehicle is in the standby mode and the active mode. The control unit 102 may cause the vehicle to be in the standby mode and based on one or more conditions, the control unit 102 may cause the vehicle to switch to the active mode. For example, as discussed with respect to FIGs. 2A, 2B, and 3, the vehicle may be in a standby mode and switch to the active mode when the SoC of the LV battery 110 is below a threshold charge to charge the LV battery 110 via the HV battery 106. For example, the control unit 102 may bidirectionally communicate with the HV battery management system 104 and the LV battery management system 108 and operate as a relay between the HV battery management system 104 and an LV battery management system 108. For example, the control unit 102 may relay information provided from the LV battery management system 108 to the HV battery management system 104 to control charging the LV battery 110. Additionally, or alternatively, the HV battery management system 104 and the LV battery management system 108 may communicate directly.

[0056] As an example, the control unit 102 may monitor for a wakeup signal and / or a wakeup reason from the LV battery management system 108, relay the wakeup signal to the HV battery management system 104, as well as send an HV ON request (e.g., to charge the LV battery 110) to the HV battery management system 104. The control unit 102 may switch from a standby mode to the active mode upon an indication that the HV battery 106 is in condition (e.g., ready and passes system authentication) to charge the LV battery 110. In such examples, the control unit 102 may switch from the standby mode to the active mode for the HV battery management system 104 to control the HV battery 106, for example, to charge the LV battery 110.

[0057] The user interface 114 (UI) may include one or more displays, set of controls, and / or systems that allow the vehicle user to communicate with the user interface 114, for example, to communicate with the control unit 102, the HV battery management system 104, and / or the LV battery management system 108. The user interface 114 may communicate user input, receive213742-00195notifications related to the vehicle, and so forth. The notifications to the user may include notifications related to the control unit 102, the HV battery management system 104, and / or the LV battery management system 108. For example, the notifications displayed may indicate that the HV battery 106 is starting to charge the LV battery 110, stopping charging of the LV battery 110, the vehicle is in the active mode, the vehicle is in the standby mode, and so forth.

[0058] In some examples, the user interface 114 may be an embedded system within the vehicle, such as a telematics or a similar system, that facilitates bidirectional communication between the vehicle and external systems, often over cellular or satellite networks. For example, the user interface 114 may facilitate in operating, monitoring, and controlling aspects like navigation, climate control, media, and vehicle settings, associated with the vehicle. The user interface 114 may process and transmit data related to the vehicle’s location, performance, and other operational parameters, to a cloud or telematics platform, enabling a wide range of connected services.

[0059] In some examples, the control unit 102, the HV battery management system 104, and / or the LV battery management system 108 may include one or more processors and / or one or more memories. Although some descriptions herein are provided with respect to the control unit 102, the techniques performed herein may be performed by any one of, or a combination of, the control unit 102, the HV battery management system 104, and / or the LV battery management system 108.

[0060] The control unit 102 may include a processing system. A processing system may include one or more components (or subcomponents) that are directly or communicatively coupled. For example, the one or more components may be, be similar to, include, or be included in, at least one memory, at least one communication interface, or at least one processor. A processing system may generally be a system of one or more components that may perform one or more functions, such as any function or combination of functions described herein. For example, one or more components may receive input (e.g., any information that is an input, such as a signal, any digital information, or any other information), one or more components may process the input to generate an output (e.g., any information that is an output, such as a signal or any other information), one or more components may perform any function as described herein, or any combination thereof.213742-00195

[0061] As an example, the control unit 102 may receive a wakeup signal from the LV battery management system 108 as an input, and the control unit 102 may output a wakeup signal to the HV battery management system 104 as an output. Any information generated by any component may be provided to one or more other systems or components. For example, a processing system may include a first component that may receive or obtain information, a second component that may process the information to generate an output, and / or a third component that may provide an output to other systems or components. In this example, the first component may be a communication interface (e.g., a first communication interface), the second component may be at least one processor (e.g., that is coupled to the communication interface and / or at least one memory), and the third component may be a communication interface (e.g., the first communication interface or a second communication interface).

[0062] FIG. 2A is a first portion of a process flow of a method 200A for charging the LV battery of the vehicle using the HV battery of the vehicle in accordance with an embodiment of the present invention. This portion of the process flow describes the method with respect to the vehicle being in a standby mode (e.g., a vehicle passive mode). In an aspect, the method 200A may be performed by the control unit 102, the LV battery management system 108, the HV battery management system 104, and the user interface 114 (one or more collectively referred to as “charging system components”), as described herein. In an aspect, steps of the method 200A may be stored as instructions that, when executed by one or more processors (e.g., of the charging system components), cause the one or more processors to perform operations of the method 200A and the concepts described herein. In the following description of the method 200A, the operations performed by the charging system components may be performed in different orders or at different times than the exemplary order shown. Some operations may also be omitted from the method 200A, or other operations may be added to the method 200A. Further, while operations in the method 200A are illustrated as being performed by the charging system components, the examples herein are not to be construed as limiting, as the described features may be associated with any quantity of different devices.

[0063] At step 120, the LV battery management system 108 may be a in a low-power state and wake up at intervals to perform maintenance, monitoring, or processing of tasks. As an example, the LV battery management system 108 may perform health checks related to the LV battery management system 108, such as monitoring and measuring the SoC of the LV battery. The LV battery management system 108 may perform the health checks at set intervals (e.g.,213742-00195periodically), which may be changed (e.g., increase or decrease intervals). For example, the intervals may be fixed for scheduled system health checks, random, continuous for providing or processing real-time data, and / or triggered by an event (e.g., an alert or if a health parameter falls below a permitted threshold).

[0064] At step 122, the LV battery management system 108 may check to see if the SoC of the LV battery is below a threshold charge. For example, the threshold charge may be less than or equal to any one of, or between two of 5%, 10%, 20%, 30%, 40%, and 50%, of the charge capacity of the LV battery. In other examples, the threshold charge may be any percent of the charge capacity, for example, based on other vehicle parameters or the health of the LV battery (e.g., applications using the LV battery, preferred lifespan for the LV battery, type of battery, the LV battery’s discharge curve, and so forth).

[0065] When the SoC of the LV battery is below the threshold charge, at step 124, the LV battery management system 108 may send a wakeup frame or wakeup signal to the control unit 102. At step 126, the control unit 102, which is in communication with other systems of the vehicle, such as the HV battery management system 104, may send a wakeup frame or wakeup signal to the HV battery management system 104. That is, the control unit 102 may operate as a relay for communication between the LV battery management system 108 and the HV battery management system 104. At step 128, the HV battery management system 104 may send a wakeup frame or a wakeup signal to the user interface 114. The control unit 102, the HV battery management system 104, and the user interface 114 may be in a low-power state or a battery saving state (e.g., to conserve energy) prior to receiving the wakeup frame or the wakeup signal. Upon receiving the wakeup signal, the control unit 102, the HV battery management system 104, and the user interface 114 may wakeup and no longer be in a low-power state (e.g., not sleeping), and may actively monitor for upcoming signals.

[0066] According, at step 130, upon receiving the wakeup signal, the control unit 102 may establish or reestablish connection to the network (e.g., network wakeup), for example, to receive forthcoming signals, collect data, receive updates, receive instructions, and so forth. Similarly, upon receiving the wakeup signal at the HV battery management system 104, at step 132, the HV battery management system 104 may establish or reestablish connection to the network, for example, to monitor for forthcoming signals. At step 134, upon receiving the wakeup signal at the user interface 114, the user interface 114 may establish or reestablish connection to213742-00195the network, for example, to monitor for forthcoming signals (e.g., notifications related to charging and vehicle state).

[0067] At step 136, the LV battery management system 108 may send a signal to the control unit 102 indicating a wakeup reason for the wakeup frame (e.g., at step 124). The wakeup reason may include one or more reasons, such as the SoC of the LV battery falling below a threshold charge. Accordingly, at step 138, the control unit 102 may check the wakeup reason. In some examples, some wakeup reasons may be considered a triggering event that cause the vehicle to switch from the standby mode to the active mode. As an example, the SoC of the LV battery falling below the threshold charge may be a triggering event and trigger the vehicle to switch from the standby mode to the active mode. In particular, the control unit 102 may output a signal to trigger the switch from the standby mode to the active mode at the vehicle.

[0068] At step 140, the control unit 102 may send a signal to the HV battery management system 104 indicating an HV ON request. The HV ON request may be a command that allows HV components, such as components related to HV battery used for charging, to be activated when requested, rather than remaining constantly powered (e.g., to conserve energy when HV components are not being used for operations). Additionally, at step 140, the control unit 102 may cause the vehicle to switch from the standby mode to the active mode upon determining that the wakeup reason is a valid reason for triggering the vehicle to switch from the standby mode state (e.g., passive mode) to the active mode.

[0069] At step 142, the HV battery management system 104 may perform an HV status check, and in some examples, an authentication check. The HV status check may include the HV battery management system 104 checking that the components related to the HV battery are functioning correctly or as expected, and that the components related to the HV battery are safe to use. As an example, the HV battery management system 104 may send a signal to the control unit 102 indicating a “HV status OK,” which may indicate that the HV battery system is ready for use without faults. In some examples, the HV battery management system 104 may perform the check without sending a status update to the control unit 102. In some examples, the HV battery management system 104 may also authenticate that the request for HV components to be ON, for example, based on the request received from an approved system or device (e.g., the LV battery management system 108 and / or the control unit 102), or that the HV components will be used for an approved system or device (e.g., the HV battery for charging the LV battery).213742-00195

[0070] At step 144, the control unit 102 may switch the vehicle status from the standby mode to the active mode (e.g., vehicle active (VA) state). For example, the vehicle that is in a standby mode is triggered to switch to the active mode based on a wakeup reason (e.g., SoC of the LV battery is below the threshold charge) that constitutes a triggering event and the HV battery management system 104 HV passing the status check. The status check may include assessing and confirming that the HV battery and / or related components of the HV battery management system are operating as expected.

[0071] FIG. 2B is a second portion of a process flow of a method 200B for charging the LV battery of the vehicle using the HV battery of the vehicle in accordance with an embodiment of the present invention. This portion of the process flow describes the method with respect to the vehicle being in the active mode (e.g., VA state). In an aspect, the method 200B may be performed by the charging system components, as described herein. In an aspect, steps of the method 200B may be stored as instructions that, when executed by one or more processors, cause the one or more processors (e.g., of the control unit 102) to perform operations of the method 200B and the concepts described herein. In the following description of the method 200B, the operations performed by the charging system components may be performed in different orders or at different times than the exemplary order shown. Some operations may also be omitted from the method 200B, or other operations may be added to the method 200B. Further, while operations in the method 200B are illustrated as being performed by the components, the examples herein are not to be construed as limiting, as the described features may be associated with any quantity of different device.

[0072] In some examples (as indicated by the dashed line arrow), at step 148, the HV battery management system 104 may send a signal to the control unit 102 indicating that that the components of the HV system are ready for use without faults (e.g., “HV ON OK” status). At step 150, the LV battery management system 108 may send a signal to the control unit 102 indicating the LV battery parameters and error status, and the LV battery parameters and error status may trigger the vehicle to send an HV to LV charging request, at step 152. For example, the LV battery parameters may indicate that the SoC of the LV battery is below a threshold charge. At step 154, the LV battery management system 108 may send a signal to the HV battery management system 104 indicating a target charging voltage for the LV battery, for example, based on the HV battery management system 104 receiving the HV to LV charging request. The target charging voltage may be a voltage to be applied to the LV battery during the charging process and / or a voltage to213742-00195which the LV battery is to be charged during the charging process. The target charging voltage may be a voltage that corresponds to a charge of the LV battery that is at least threshold charge (e.g., greater than or equal to any one of, or between any two of, 1.00, 1.05, 1.10, 1.20, 1.30, 1.40, 1.50, or 2.00 times the threshold charge, the charge capacity of the LV battery, or the like).

[0073] After receiving the target charging voltage, at step 156, the HV battery management system 104 may start charging the LV battery (e.g., via DC-to-DC converter 112). Prior to charging the LV battery, the HV battery management system 104 may ensure that the components associated with the HV battery management system 104 and the HV battery are operating as expected (e.g., no errors or faults) to facilitate charging without issues that may otherwise result. In some examples (as indicated by the dashed line bidirectional arrow), at step 158, the HV battery management system 104 may send a signal to the control unit 102 and / or the user interface 114 indicating a confirmation that the HV battery is charging the LV battery (e.g., the HV to LV charging request has been processed). In this manner, the control unit 102 may perform any additional actions (e.g., monitoring or requesting a charge status of the HV battery) and a user may also be aware that the LV battery is charging while the vehicle is in the active mode.

[0074] Accordingly, at step 160, the LV battery management system 108 may send a signal to the control unit 102, indicating, for example, the present LV battery voltage, SoC, and / or the like. To further illustrate, as the LV battery is charged via the HV battery, the LV battery management system 108 may indicate the charging current, power (e.g., indicating charging speed), SoC of the LV battery, charging duration, LV battery capacity, LV battery temperature, cooling system status associated with the LV battery, charge efficiency, and / or other parameters related to ensuring safe and efficient charging of the LV battery. The control unit 102 may also relay the same information or some of the information to the HV battery management system 104. For example, the HV battery management system 104 may adjust charging parameters based on the information received (e.g., use more or less power to charge the LV battery, stop charging if the LV battery has a temperature above a threshold temperature, etc.).

[0075] At step 162, the user interface 114 may display to the user the status of the HV battery charging the LV battery. The user interface 114 may also indicate additional parameters associated with the charging, for example, the expected duration for the LV battery to charge, the status of the charge (e.g., 50% of the charging has been completed), and the like.213742-00195

[0076] In some examples (as indicated by the dashed line box), if intelligent target conditions are achieved or a critical system error is present, then steps 164, 166, 168, 170, 172, 174, and / or 176 may occur. For example, at step 164, the control unit 102 may send a signal to the HV battery management system 104 indicating a request to stop charging the LV battery via the HV battery based on conditions met. In some examples, sending the request may be automated. Intelligent target conditions may include optimized parameters or goals associated with the LV battery and / or the HV battery. The parameters may be ones that are associated with increasing battery health, improving charging efficiency, and enhancing overall driving performance. In particular, the parameters may consider operational and charging characteristics associated with the vehicle, ensuring safety of the user, longevity of the batteries, and ability to adapt to external factors (e.g., increased environmental temperatures). The critical system error may include one that compromises operability, functionality, and / or safety of the vehicle. As an example, a critical system error may include an error associated with the HV battery management system 104 and / or the LV battery management system 108 that manage the respective batteries, SoC miscalculations, overcurrent or overvoltage during charging, and so forth.

[0077] Accordingly, once intelligent charging conditions have been met (e.g., SoC of the LV battery is at or above a target charge above the threshold charge) or a critical system error occurs, at step 166, the HV battery management system 104 may stop the HV battery from charging the LV battery (based on receiving the request from the control unit 102). In some examples (as indicated by the dashed line arrow), at step 168, the HV battery management system 104 may send a signal to the control unit 102 indicating a confirmation that the HV battery is no longer charging the LV battery. For example, if the SoC of the LV battery is at a target charge (e.g., at or above the threshold charge), the HV battery may no longer charge the LV battery. Accordingly, since the HV battery is no longer actively charging the LV battery, and if no wakeup reason is present, the control unit 102 may cause the vehicle to return to the standby mode from the active mode, for example, to conserve energy.

[0078] At step 170, the control unit 102 may cause the vehicle to return to the standby mode from the active mode if no wakeup reason is present, for example, to conserve energy. At step 172, the control unit 102 may send a signal to the HV battery management system 104 indicating that the vehicle has switched from the active mode back to the standby mode and may send an HV OFF request. The HV OFF request may include a request to deactivate the HV battery or other components related to the HV battery. At step 174, the HV battery management system213742-00195104 may deactivate the HV battery and / or related components based on the request, and / or if no HV ON reason exists. At step 176, the user interface 114 may display a notification to the user, indicating that the HV battery has stopped charging the LV battery. Additionally, or alternatively, the user interface 114 may indicate the vehicle status (e.g., switched back to standby mode) and / or charging-related parameters (e.g., that have changed since the HV battery was charging the LV battery).

[0079] Accordingly, using the techniques discussed herein, and as described in detail with respect to methods 200A and 200B, the SoC of the LV battery may be monitored via the vehicle (e.g., via the control unit 102 of the vehicle), systems may be triggered to wake up from a low-power consumption state (e.g., the LV battery management system 108, the control unit 102, and / or the HV battery management system 104) when conditions are met (e.g., SoC of the LV battery is below a threshold charge), the LV battery may be charged via the HV battery, the vehicle may alternate between the standby mode and the active mode based on charging the LV battery via the HV battery, and the vehicle user may be notified of the charging statuses, all while ensuring that vehicle and charging occur in safe conditions (e.g., safety measures and safety specifications are met).

[0080] FIG. 3 is another process flow of a method 300 for charging the LV battery of the vehicle using the HV battery of the vehicle in accordance with an embodiment of the present invention. In an aspect, the method 300 may be performed by a computing device, such as the system 100 (e.g., the control unit 102 of the system 100, the HV battery management system 104, and / or the LV battery management system 108) in accordance with aspects of the present disclosure. In an aspect, steps of the method 300 may be stored as instructions that, when executed by one or more processors, cause the one or more processors (e.g., of the control unit 102) to perform operations of the method 300 and the concepts described herein.

[0081] In the following description of the method 300, the operations performed by the computing device may be performed in different orders or at different times than the exemplary order shown. Some operations may also be omitted from the method 300, or other operations may be added to the method 300. Further, while operations in the method 300 are illustrated as being performed by the component (e.g., the control unit 102), the examples herein are not to be construed as limiting, as the described features may be associated with any quantity of different devices.213742-00195

[0082] At step 305, the method 300 may include monitoring for a wakeup signal indicating that a second battery associated with a vehicle has SoC below a threshold charge. A first battery of the vehicle may have a first nominal voltage, and the second battery may have a second nominal voltage that is less than the first nominal voltage. In some examples, the wakeup signal may be received from a second battery management system that may control the second battery. The wakeup signal may be received in response to one or more wakeup events (e.g., the SoC of the LV battery is below a threshold charge). In some examples (as indicated by the dashed line box), at 310, the method may include identifying at least one event of the wakeup event(s) as a triggering event for switching from the standby mode to the active mode.

[0083] At 315, the method 300 may include switching from operating in a standby mode of the vehicle to an active mode of the vehicle based on the wakeup signal. The standby mode may include monitoring a SoC of the second battery. The active mode may include charging the second battery using power output from the first battery.

[0084] When the vehicle is in the active mode, the method 300 may include receiving from a second battery management system that controls the second battery, a signal indicating a target voltage. The method 300 may include outputting, to a first battery management system that controls the first battery, a signal indicating the SoC with respect to a threshold charge. The threshold charge may be a charge portion of the charge capacity of the second battery. In some examples, the threshold charge may be 20% of the charge capacity.

[0085] In some examples (as indicated by the dashed line box), at 320, the method may include outputting a first control signal causing the first battery to start outputting power to charge the second battery. Outputting the control signal may include authenticating a first battery management system that controls the first battery prior to the first battery outputting power. In some examples, the method 300 includes outputting, to a communication interface of the vehicle (e.g., user interface), a charging start notification and a charging stop notification associated with the first battery outputting power.

[0086] In some examples (as indicated by the dashed line box), at 325, the method 300 may include outputting a second control signal causing the first battery to stop outputting power. For example, the method 300 may include outputting the second control signal based on the second battery having an SoC of at least the threshold charge, a system error associated with213742-00195the vehicle, a temperature associated with the vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof.

[0087] In some examples, a vehicle may include a first battery having a first nominal voltage, a second battery having a second nominal voltage that is less than the first nominal voltage, a battery control system, a control unit, and a DC-to-DC converter. The battery control system may include a first battery management system that may control the first battery, and a second battery management system that may control the second battery. The vehicle may operate between a standby mode during which the second battery control system monitors a charge of the second battery, and an active mode during which the battery control system charges the second battery. The control unit may switch the vehicle from the standby mode to the active mode and output a control signal to the battery control system, the control signal causing, via the first battery management system, the first battery to output power.

[0088] The DC-to-DC converter may receive the power output by the first battery at a third voltage, and outputs the power output by the first battery at a fourth voltage to charge the second battery, the fourth voltage being less than the third voltage. The second battery management system may output a wakeup signal to the control unit. The second battery management system may output the wakeup signal in response to one or more wakeup events. The wakeup event(s) may include an SoC of the second battery being at or below a threshold charge. The threshold charge may be at least 20% of the charge capacity of the second battery.

[0089] The control unit may identify at least one of the wakeup event(s) as a triggering event to switch the vehicle from the standby mode to the active mode and output the control signal. The triggering event may include the SoC of the second battery being at or below the threshold SoC. The control signal may include a request to the first battery management system to charge the second battery, a wakeup signal to wake up the first battery management system, a request to authenticate the first battery management system, or any combination thereof.

[0090] The control unit may receive, from the second battery management system, a signal indicating the threshold charge, and may output, to the first battery management system, a signal indicating the threshold charge. The control unit may stop charging the second battery based on the second battery having an SoC that is at least the threshold charge. The control unit may output a second control signal causing the first battery to stop outputting power. The control unit may output the second control signal based on a system error associated with the vehicle, a213742-00195temperature associated with the vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof. In some examples, the vehicle may include a communication interface that receives a charging start notification and a charging stop notification associated with the first battery charging the second battery.

[0091] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps. The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.

[0092] Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification.- 1 -

Claims

213742-00195CLAIMSWhat is claimed is:

1. A vehicle comprising:a first battery having a first nominal voltage;a second battery having a second nominal voltage that is less than the first nominal voltage;a battery control system comprising:a first battery management system configured to control the first battery; and a second battery management system configured to control the second battery; wherein the vehicle is configured to operate between:a standby mode during which the second battery control system monitors a charge of the second battery; andan active mode during which the battery control system charges the second battery;a control unit configured to switch the vehicle from the standby mode to the active mode and output a control signal to the battery control system, the control signal causing, via the first battery management system, the first battery to output power; anda DC-to-DC converter configured to:receive the power output by the first battery at a third voltage; and output the power output by the first battery at a fourth voltage to charge the second battery, the fourth voltage being less than the third voltage.

2. The vehicle of claim 1, wherein the second battery management system is configured to output a wakeup signal to the control unit.

3. The vehicle of claim 2, wherein:the second battery management system is configured to output the wakeup signal in response to one or more wakeup events; andthe one or more wakeup event(s) comprising a state of charge of the second battery being at or below a threshold charge.

4. The vehicle of claim 3, wherein the threshold charge is at least 20% of a charge capacity of the second battery.213742-001955. The vehicle of claim 3 or 4, wherein the control unit is configured to: identify at least one of the one or more wakeup event(s) as a triggering event to switch the vehicle from the standby mode to the active mode and output the control signal; and wherein the triggering event comprises the state of charge of the second battery being at or below the threshold charge.

6. The vehicle of any of claims 1-5, wherein the control signal comprises a request to the first battery management system to charge the second battery, a wakeup signal to wake up the first battery management system, a request to authenticate the first battery management system, or any combination thereof.

7. The vehicle of any of claims 1-6, wherein the control unit is configured to: receive, from the second battery management system, a signal indicating the threshold charge; andoutput, to the first battery management system, a signal indicating the threshold charge.

8. The vehicle of any of claims 1-7, wherein the control unit is configured to stop charging the second battery based at least in part on the second battery having a state of charge that is at least the threshold charge.

9. The vehicle of claim 8, wherein the control unit is configured to output a second control signal causing the first battery to stop outputting power.

10. The vehicle of claim 9, wherein the control unit outputs the second control signal based at least in part on a system error associated with the vehicle, a temperature associated with the vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof.

11. The vehicle of any of claims 1-10, comprising a communication interface configured to receive a charging start notification and a charging stop notification associated with the first battery charging the second battery.213742-0019512. A method comprising:monitoring for a wakeup signal indicating that a second battery associated with a vehicle has a state of charge below a threshold charge, wherein a first battery of the vehicle has a first nominal voltage, and the second battery has a second nominal voltage that is less than the first nominal voltage;switching from operating in a standby mode of the vehicle to an active mode of the vehicle based at least in part on the wakeup signal, wherein the standby mode comprises monitoring the state of charge of the second battery, and wherein the active mode comprises charging the second battery using power output from the first battery; andoutputting a control signal causing the vehicle to switch from the standby mode to the active mode.

13. The method of claim 12, wherein the wakeup signal is received from a second battery management system configured to control the second battery.

14. The method of claim 13, wherein:the wakeup signal is received in response to one or more wakeup events; andthe method comprises identifying at least one event of the one or more wakeup event(s) as a triggering event for switching from the standby mode to the active mode.

15. The method of any of claims 12-14, wherein outputting the control signal comprises authenticating a first battery management system that controls the first battery prior to the first battery outputting power.

16. The method of any of claims 12-15, wherein, when the vehicle is in the active mode, the method comprises:receiving, from a second battery management system that controls the second battery, a signal indicating a threshold charge; andoutputting, to a first battery management system that controls the first battery, a signal indicating the threshold charge.

17. The method of any of claims 12-16, wherein the threshold charge is at least 20% of a charge capacity of the second battery.213742-0019518. The method of any of claims 12-17, comprising outputting a second control signal causing the first battery to stop outputting power.

19. The method of claim 18, wherein outputting the second control signal is based at least in part on the second battery having a charge of at least the threshold charge, a system error associated with the vehicle, a temperature associated with the vehicle, a voltage condition associated with the first battery or the second battery, or any combination thereof.

20. The method of any of claims 12-19, comprising outputting, to a communication interface of the vehicle, a charging start notification and a charging stop notification associated with the first battery outputting power.

Images