Adaptive load management in a vehicle

Abstract

The invention provides adaptive load management in a vehicle. In response to an indication that a magnitude of current associated with power supplied to loads having the same priority from the vehicle is close to or exceeds a predefined threshold and that one of the loads is not coexisting with other of the loads, the load is activated. One or more controllers may switch off or operate the one of the loads at reduced power prior to switching off or operating the other of the loads at reduced power.

Description

Technical Field

[0001] The present disclosure relates to automotive power systems. Background Art

[0002] A motor vehicle may include an energy storage device, such as a battery. This energy may be used for electrical and electronic components of the vehicle and external to the vehicle. For example, aftermarket snow plow equipment may be powered by energy from a battery. Such a connection to a battery may be facilitated by a so-called upfitter module. Summary of the invention

[0003] A power system for a vehicle includes one or more controllers that reduce or interrupt the supply of power to the loads according to priority in response to the magnitude of a current associated with power supplied to the loads from the vehicle exceeding a predefined threshold, so that the loads with the same priority are cut off or operated at reduced power based on an indication of whether one of the loads with the same priority exists simultaneously with other loads with the same priority.

[0004] A method includes, in response to the amplitude of a current associated with power supplied to a load from a vehicle approaching a predefined threshold, reducing or interrupting the supply of power to the load according to a priority defined by conditions, such that the load with the lowest priority among the priorities defined by the conditions is first cut off or operated at a reduced power to keep the amplitude less than the predefined threshold, and the order of the priorities defined by the conditions is different for different conditions.

[0005] A power system for a vehicle includes one or more controllers that disconnect or operate one of the loads at a reduced power before disconnecting or operating the other loads of the loads at a reduced power in response to a magnitude of current associated with power supplied from the vehicle to loads of the same priority approaching or exceeding a predefined threshold and an indication that one of the loads is not present simultaneously with the other loads of the loads. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 and Figure 2 It is a block diagram of the vehicle power system and the modifier module.

[0007] Figure 3 and Figure 4 is a flow chart of an algorithm associated with control of load shedding of modifier loads and vehicle loads. DETAILED DESCRIPTION

[0008] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be enlarged or minimized to show details of particular components. Therefore, the specific structural details and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art.

[0009] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired.

[0010] The use of a retrofit module may affect the power supply system of a motor vehicle. In some examples, a retrofit module is a modular component that can be added to a vehicle to provide additional functionality, such as lighting, power distribution, or power management. For example, a retrofit module that provides lighting and power distribution may be installed in a vehicle, allowing the vehicle to be used as a work vehicle, such as a service truck or a construction vehicle. Additionally, a retrofit module may be designed to meet specific requirements, such as providing power to a specific component or group of components.

[0011] In selecting a retrofit module, several factors may be considered, including the power requirements of the component or group of components that the retrofit module will power, the required voltage level, and the environmental conditions in which the retrofit module will be used.

[0012] Some retrofit modules may not support medium or high current applications, may not be scalable, may not provide feedback to the vehicle to manage the effects of high current loads, and / or may not support added cameras, etc.

[0013] Some modifier modules take the form of switches mounted in the overhead compartment and relays in an additional engine compartment switch box. In some arrangements, wires are fed to the engine compartment switch box but are not connected to the relays. The screen can be used to support touch actuation of the field effect transistors that control the load.

[0014] Here, some examples contemplate that during the setup of the modifier, the vehicle may learn which device is connected to each field effect transistor, and the devices may be cycled on / off to learn their initial load profiles (running and inrush), as well as device priorities for load shedding based on user input or vehicle-to-device communication. To the extent that several devices have the same priority level, certain devices may have their power reduced or cut off based on different factors. For example, if the modifier loads may be pulse width modulated (typical motor control) or may operate at a low speed pulse width modulation (e.g., 10 seconds on and 30 seconds off), they may be interleaved or staggered with other loads at the same priority level. Rather than completely shedding a load (e.g., a light), the system may deliver a lower level of average power. For example, a camper's water pump motor may run slower (i.e., run at a reduced flow rate) while maintaining the overall but potentially reduced functionality of other modifier loads.

[0015] After setup, the vehicle can continue to learn and update its table. During operation, the vehicle can monitor all modifier FETs via sensors to maintain accurate data about which loads are typically turned on together (in case it has to choose between loads of equal priority) and how each load varies with parameters such as time of day, outside ambient temperature, device temperature (if a corresponding sensor exists), gear position, operating hours, etc.

[0016] In some examples of dynamic load shedding, the vehicle determines if enough current is available to power all loads. If not, a lookup table of priority loads to shelve from lowest priority to highest priority may be consulted. The lowest priority load may then be shelved until the current demand is no longer greater than the current supply. If multiple loads have the same priority level, it may be checked which devices are typically on at the same time.

[0017] As mentioned above, the vehicle can learn from sensor data which loads tend to be present at the same time. This information can be used to select which loads with the same priority level should be cut off. For example, during plowing, the plow motor, plow lights, and salt spreader motor may be turned on together. If the salt box light is inadvertently left on and has the same priority as the plow motor, plow lights, and salt spreader motor, the salt box light may be cut off because it is not usually turned on in conjunction with the other components. Even if the modifier mistakenly defines the salt box light as having the same priority as the plow motor, plow lights, and salt spreader motor, the salt box light may still be cut off first.

[0018] Certain architectures can provide the modifier with the opportunity to enable both low-power loads and high-power loads controlled by the vehicle through feedback. In some examples, the basic modifier module is associated to the vehicle via Ethernet and acts as a gateway to connect downstream expansion modules. Multiple additional modifier modules can be connected to the first modifier module. Each expansion module can identify whether it is a master module and is connected to the previous module via a daisy chain. This allows the number of expansion modules. Therefore, each of these modules can be plug-and-play, sending a signal back to the controller to report its functionality. For example, all expansion modules can receive power from a 100A output, a 200A output, or other rated output of a distribution center. When the current usage approaches the limit (for example, within 10% or 5%), the operator will be notified: the basic module reports the load to the controller.

[0019] If multiple devices have the same priority level, it can be determined whether the devices are permitted to operate with pulse width modulated power. If so, the device power can be reduced via a low speed cycle to spin up. The system can wait for the charge margin to increase before returning the load to full power.

[0020] For each circuit using the proposed load shedding strategy, the vehicle can map the capabilities of each branch of the circuit based on user input and / or installation specifications from the modifier / manufacturer. Each branch of the circuit can be connected to a different load / device, and each branch can include a circuit breaker, relay, or field effect transistor rated to a specific current that can be capable of pulse width modulation control. The vehicle can learn / store which devices are connected to each branch of the circuit based on user input or vehicle-to-device communication. The maximum or continuous current rating of each branch and the entire circuit can be programmed into the vehicle based on hardware specifications, so the vehicle can program how much "overhead" to keep and / or generate based on which device / branch of the circuit has priority.

[0021] During use of the powered devices / loads, the vehicle may monitor via sensors the current output with respect to maximum continuous current, inrush current, time average current of varying durations, and / or the variation in current required to operate each device / branch of the circuit during normal use.

[0022] This arrangement permits automatic load shedding of other vehicle loads and / or retrofit loads and is user programmable, can utilize the DC / DC converter to consume power from the auxiliary charger trailer, and permits shut-off operation of various loads. Additionally, high current can be associated with the battery to prevent transients from occurring to the expansion module power, and permits the battery to act as a transient suppression intermediary for the high current modules.

[0023] As mentioned above, relative importance (e.g., user-specified priority) can be defined by the user with respect to each device on each circuit. This priority rating can be used to coordinate the order of load shedding when the device approaches the current limit of the circuit. The user can also specify requirements for the type of derating / load shedding that may occur with respect to each branch of the circuit. The type of load shedding that may occur can include turning each device on / off (e.g., circuit breaker type operation) or pulse width modulation based on two types of control of the device: operating the device at a certain percentage of duty cycle for a short period of time (e.g., 10Hz to 10kHz, turning the device on very quickly so that the effective voltage is a certain percentage of the maximum voltage); or operating the device at a certain percentage of duty cycle for a longer period of time (e.g., 10s to 600s, operating the device at a 16.6% duty cycle, turning it on for 10s and then turning it off for 50s). The user can program or the device can communicate how the load should be shelved to prevent device problems. The relative importance of load shedding can also be specific to the location of the vehicle (e.g., geo-fencing), based on the operation of the vehicle (e.g., parked vs. driving vs. in gear), or based on the mode of the vehicle (e.g., "work mode" or "drive mode"; for recharging the vehicle vs. for shoveling snow, etc.).

[0024] The vehicle may also elect to shut off certain devices / branches of the circuit based on identifying the user's position relative to the devices / loads associated with the branch of the circuit. Examples may include turning off interior climate components (e.g., heated steering wheel, etc.) if it is determined via interior radar / interior camera that no one is in the car; the vehicle need not be able to operate an attached snow plow if no one is in the vehicle.

[0025] Priorities may also be assigned during the initial startup of each device so that startup of each device is performed in stages to prevent inrush current from increasing beyond circuit capabilities.

[0026] During use, the capacity of the circuit will be monitored relative to the actual use of the circuit, and based on the defined priorities and specified load shedding requirements, the vehicle may derate various parts of the circuit to remain within the capacity (e.g., current or temperature-based capacity) as previously suggested. The maximum current capacity may be defined at various time intervals (e.g., 500A for 10s; 300A for 60s; 250A continuous or based on the maximum design temperature of various components in the circuit). A specific threshold for the desired current headroom may be maintained by the circuit, and the device may be derated / shut down to maintain the headroom. The margin target may be based on the maximum, time-averaged, or expected current from the highest priority load and / or circuit, such as 10% of the total 90th percentile average current of the X highest priority components on the circuit. The margin may be adjusted up or down to ensure that the X highest priority devices remain at full capacity. For devices / loads with less input current variation, the margin may not need to be as large, and vice versa. Historical / real-time data of loads / devices may be monitored and recorded to provide a reasonable estimate of the required margin. Control of load shedding may also be based on the temperature of the devices and / or field effect transistors of each circuit branch to prevent problems during operation.

[0027] Based on which circuits are derated, the customer can be notified as to which circuit is derated and the amount each circuit is derated by. When a user replaces a device on a particular circuit, user input or vehicle-to-device communication can be used to identify that this event occurred and reprogram the vehicle stored data on the branch of the circuit that was changed.

[0028] Features may also be prioritized when the vehicle is deactivated (e.g., key off) or when the user is not present. Given a basic or known weighting (priority) scheme defined by the user or based on learned usage that prioritizes certain features over others in terms of load shedding, a dynamic situational priority may be incorporated that takes into account various factors (e.g., ambient temperature, distance from home, location familiarity, etc.) and changes the priority scheme based on the situation. The dynamic options may take into account i) ambient temperature, which may affect both starting (amount of energy required to crank) and charging (ability of the battery to accept a charge), ii) opportunity to pull the engine up to charge the battery, which may vary based on location (e.g., inside vs. outside, idle limit, etc.), fuel level, distance to the nearest open gas station, etc., iii) distance to home or charging location, iv) nearby people outside the vehicle or movement around the vehicle, v) occupancy (e.g., possible driver or passenger presence, potentially moving windows up / down for active heating / cooling, etc.), vi) last driver of the vehicle, vii) device charging in the vehicle (e.g., via USB charging, etc.), viii) strength of battery or other wireless signal (strategy for performing over-the-air updates), ix) time of day or night, and / or until daytime, and / or x) safety or rescue vehicle prioritization.

[0029] Opportunistic use cases can only run if resources are already being used for other features, which means they do not cause additional power consumption. A feature's flexible use case specifies the latest possible time to run, and the virtual power state manager can try to schedule it to run when other feature use cases (using the same or at least overlapping resources) are also running, in order to reduce or eliminate the power consumption caused by that use case.

[0030] In some examples, the controller of the vehicle can learn through sensors monitoring how features of the vehicle consume battery power and how the features are used when the vehicle is deactivated. A priority scheme can be created based on this learning or via user specification by ranking the list of features used by the amount of energy consumed when the vehicle is active and when the vehicle is deactivated. The priority scheme can be modified taking into account vehicle conditions as described above (e.g., occupancy, devices charged in the vehicle, etc.). Opportunities and flexible use cases can then be considered. The driver can then be notified via an alert what will be prioritized and why. As the state of charge decreases, features can be modified to use less power: put certain control units to sleep; dial climate control to a level that is still comfortable but not quite as cold or not quite as warm but still able to keep the windshield clear; deactivate the heated steering wheel (allowing reactivation if the customer requests); deactivate rear-seat entertainment; limit the peak volume of the audio system (recommending turning it off if not used for road information or news); ask if phone / computer charging can be paused, or if the phone state of charge exceeds a predefined threshold, turn off the phone charger; ask if the cabin wireless hotspot can be deactivated; deactivate tire pressure monitoring; reduce screen brightness until someone touches the screen; and / or deactivate certain lights.

[0031] Alarms (e.g., audio alarms, visual alarms, etc.) can be used to indicate that load shedding is expected (e.g., approaching a power limit at which load shedding will occur) or is actually occurring. Such alarms can be calibrated based on background noise, distance to others, and / or location. For example, cameras, radars, etc. can be used to detect whether there are people nearby, whether the vehicle is indoors or outdoors, etc. If the vehicle is indoors and someone is nearby, an audio alarm can be generated at a lower volume to reduce the impact of ambient noise. Alarms can also be used to indicate the type of load shedding that is about to occur. For example, an expected shedding of a vehicle load can be associated with a user-defined sound that is different from an expected shedding of a modifier load. Graphic displays associated therewith can also be different in a similar manner. When the current amplitude limit is exceeded, the system can generate a notification using a sound exciter, a window projector, etc.

[0032] Prior to the Adapter being connected, the user may provide the vehicle with an expected load profile which will be incorporated into a corresponding profile. Use case details (e.g. identification data, expected duration, severity, required resources, current consumption, etc.) may be incorporated into a profile which may be read as a lookup table upon receiving a Adapter request. When communication is established through the appropriate interface, the Adapter will be able to communicate the expected demand based on the "Use Case" system. Alternatively, when communication is established with the Adapter, the user may be able to input / upload the expected load profile via a touch screen along with custom or pre-configured selections for review.

[0033] When the modifier's use case is sent, the system can determine whether the request is valid or invalid based on the available power capabilities. When the modifier exceeds the allowable current draw threshold of the connected field effect transistor (e.g., 100A or 200A, depending on the rating of the corresponding field effect transistor), the field effect transistor may trip and the user is notified about the threshold being exceeded and the option of automatic retry or manual retry.

[0034] Thus, there is more user control and feedback on modifier usage rather than no notification. And before switching to meet modifier energy needs, the system can provide the user with the option to cut off loads based on various factors including load type (e.g., radio, air conditioner, modifier load, etc.)

[0035] refer to Figure 1 , an example automotive power system 10 for a vehicle 12 includes a power distribution center 14 , a retrofit module 16 , a retrofit current booster module 18 , a 12V battery 20 , and a controller 21 .

[0036] The power distribution center 14 includes a 12V modifier output 22 (e.g., a 100A field effect transistor control output) and a 12V interconnector distribution box 24 (e.g., a 200A field effect transistor control output). Therefore, the respective ratings of these field effect transistors define their limits for the current flowing therethrough. The 12V modifier output 22 is connected to the modifier module 16. The interconnector distribution box 24 is connected to the 12V battery 20.

[0037] The retrofit module 16 is grounded and includes a network connection 26 to which a plurality of user devices 32, 34, 36, 38 are connected. In this example, the retrofit module 16 is configured to receive digital inputs 40, 42 and analog inputs 44, and to provide current to loads 46, 48, 50, 52, 54, 56, 58, 60. The retrofit module 16 is also configured to provide current to a relay output 62. Multiple such retrofit modules may be so connected (e.g., daisy-chained) to obtain as many inputs / outputs as desired as mentioned above.

[0038] The retrofit current booster module 18 is grounded and includes a relay 66, a fuse 68, a connector 70, and a plurality of relays 72. The connector 70 is connected between the relay 66, the fuse 68, and the relay 72. The relay 66 is connected to the interconnector distribution box 24. The fuse 68 is connected to an auxiliary 12V battery 74. The relay 72 is configured to provide current to a plurality of large loads 76, 78, 80.

[0039] In the high current architecture described above, the revamp current booster module 18, which may be a ram track relay controlled by the revamp module 16, is powered from a different distribution center output than the revamp module 16. All expansion modules receive power from the 100A output of the distribution center 14. When current usage approaches the 100A limit, the operator may be notified (e.g., via a screen, cell phone i.e. key, speaker, etc.) via an alarm generated and forwarded by the controller 21, for example. The revamp module 16 tracks the load and reports the load to the controller 21, which may facilitate notifying the operator.

[0040] The modifier module 16 allows / facilitates reduced power operation or automatic load shedding (interruption of the power being supplied) of vehicle loads prioritized by the operator or automatically prioritized via learned data and / or modifier loads (e.g., snow plow equipment, power tools, auxiliary lighting, etc.) to remain within the 100A limit at the output of the corresponding distribution center. If 100A (or 200A, depending on the output port) from the distribution center 14 is not available (as assessed using standard techniques such as current sensors, etc.), the controller 21 notifies the modifier module 16. The modifier module 16 can then request to operate at reduced power or to shelve the vehicle load (e.g., radio, heating, ventilation, air conditioning, etc.). In response to such a request, the controller 21 can then generate a command to reduce or interrupt the flow of power to the lowest priority vehicle load defined by the user. This allows the modifier feature to be prioritized in certain situations. As explained in more detail below, the opposite situation and other situations are also possible.

[0041] The user may input a desired priority scheme for the cut-off or reduced power operation of the modifier loads and vehicle loads via an interface (e.g., a phone screen, a vehicle screen, a button, etc.). For example, the user may prioritize all modifier loads over vehicle loads such that the vehicle loads will be cut off in order from lowest priority to highest priority before any modifier load is cut off. Alternatively, the user may prioritize all vehicle loads over modifier loads such that the modifier loads will be cut off in order from lowest priority to highest priority before any vehicle load is cut off. In other cases, the user may prioritize vehicle loads and modifier loads in a mixed manner such that some of the vehicle loads have a higher or lower priority than some of the modifier loads, etc. This information may reside within the modifier module 16, the controller 21, and / or other controllers / modules. When the magnitude of the current associated with the power supplied to the modifier loads approaches a limit, the controller 21 may generate a command to interrupt the power supply to the lowest priority modifier loads and / or vehicle loads in an attempt to keep the magnitude less than the limit. That is, if assembler load 1 and vehicle load 1 have the highest priority, vehicle load 2 has a medium priority, and assembler load 2 has the lowest priority, then assembler load 2 will be cut off first in an attempt to keep the current magnitude below the limit of the corresponding output terminal. If shedding assembler load 2 is not sufficient to maintain the current magnitude below the limit, then vehicle load 2 will be shedding next, and so on.

[0042] An optional connection to a charging trailer is shown for a 200A output. Communication with the charging trailer can be done, for example, via a controller area network or Ethernet. This allows the retrofitter to exceed the 200A continuous distribution center limit.

[0043] refer to Figure 2 , the distribution center 14 also includes a plurality of bidirectional field effect transistors 82, a 100A-capable field effect transistor 84 (in series), and a 200A-capable field effect transistor 86 (in series). The 100A-capable field effect transistor 84 is connected between the bidirectional field effect transistor 82 and the 12V converter output 22. The 200A-capable field effect transistor 86 is connected between the bidirectional field effect transistor 82 and the interconnector distribution box 24. The distribution center 14 also includes other field effect transistors connected between the bidirectional field effect transistor 82 and other vehicle components (e.g., DC / DC converters, supercapacitors, other power supplies, etc.).

[0044] The vehicle power system 10 may also include a distribution box 88. The distribution box 88 may be packaged on top of or beside the 12V battery 20. It may serve as the interconnection point for the modifier current booster module 18, the 12V battery 20, the interconnector distribution box 24, and any jump-start posts.

[0045] The modifier current booster module 18 also includes a plurality of field effect transistors 90, 92, 94, 96. The field effect transistor 90 is connected between the distribution box 88 and the field effect transistors 92, 94, 96. The field effect transistor 92 is connected between the large load 76 and the field effect transistor 90. The field effect transistor 94 is connected between the auxiliary 12V battery 74, the large load 78 and the field effect transistor 90. The field effect transistor 96 is connected between the large load 80 and the field effect transistor 90. The field effect transistor 90 is thus arranged to isolate the large loads 76, 78, 90 from negative transient loads. These loads may be some of the loads that are assigned priority in the event of a need to be cut off as described above.

[0046] refer to Figure 3 , at operation 98, it is determined whether the magnitude of the current supplied to the load exceeds a predefined threshold. If not, the algorithm returns to operation 98. If yes, it is determined whether there are multiple loads of the same lowest priority. If not, the lowest priority load is cut off at operation 102, and the algorithm returns to operation 98. For the sake of brevity, the reference to the cut-off can be replaced with a reference to the reduced power operation. If yes, it is determined at operation 104 whether any of the multiple loads of the same lowest priority does not usually exist with other loads. If not, the lowest priority load is cut off at operation 102, and the algorithm returns to operation 98. If yes, only the loads that are not usually present with other loads among the multiple loads of the same lowest priority are cut off at operation 106. Then, the algorithm returns to operation 98.

[0047] refer to Figure 4 , at operation 108, it is determined whether the magnitude of the current supplied to the load is about to exceed a predefined threshold. If not, the algorithm returns to operation 108. If yes, it is determined at operation 110 whether there is a condition that affects the priority order. If yes, the priority order is redefined (reordered) at operation 112 according to which condition exists. Then, at operation 114, one or more lowest priority loads are disconnected according to the priority order. Then, the algorithm returns to operation 108. Returning to operation 110, if no, the algorithm proceeds to operation 114.

[0048] The algorithm, method or process disclosed herein can be delivered to or implemented by a computer, controller or processing device, which can include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithm, method or process can be stored in various forms as data and instructions that can be executed by a computer or controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disk, a random access memory device or other magnetic and optical media. The algorithm, method or process can also be implemented by a software executable object. Alternatively, a suitable hardware component (such as an application-specific integrated circuit, a field programmable gate array, a state machine or other hardware component or device) or a combination of firmware, hardware and software components can be used to embody the algorithm, method or process in whole or in part.

[0049] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are descriptive rather than limiting, and it should be understood that various changes can be made without departing from the spirit and scope of these disclosed materials. For example, the terms "controller" and "multiple controllers" can be used interchangeably herein because the functionality of a controller can be distributed across several controllers / modules, which can all communicate via standard technologies.

[0050] As previously mentioned, the features of the various embodiments may be combined to form additional embodiments of the present invention that may not be explicitly described or shown. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be appreciated by those of ordinary skill in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, and the like. Therefore, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of the present disclosure and may be desirable for a particular application.

[0051] According to the present invention, a power system for a vehicle is provided, the power system having: one or more controllers, the one or more controllers being programmed to reduce or interrupt the supply of power to the loads according to priority in response to the amplitude of the current associated with the power supplied to the loads from the vehicle exceeding a predefined threshold, so that the loads with the same priority are cut off or operated at reduced power according to an indication of whether one of the loads with the same priority exists simultaneously with other loads with the same priority.

[0052] According to an embodiment, the one or more controllers are also programmed to shut off or operate the one of the loads at a reduced power before shutting off or operating the other of the loads at a reduced power in response to the indication that the one of the loads having the same priority does not exist simultaneously with the other of the loads having the same priority.

[0053] According to an embodiment, the priorities are condition-dependent, such that the order of the priorities is different for different conditions.

[0054] According to an embodiment, the one or more controllers are further programmed to receive an input defining the sequence.

[0055] According to an embodiment, the predefined threshold is based on historical data.

[0056] According to an embodiment, the conditions include temperature, time of day, location of the vehicle, gear position of the vehicle or presence of occupants in the vehicle.

[0057] According to an embodiment, the load is a retrofitter load, a vehicle load or both.

[0058] According to the present invention, a method includes: in response to the amplitude of the current associated with the power supplied to the load from the vehicle approaching a predefined threshold, reducing or interrupting the supply of power to the load according to the priority defined by the conditions, so that the load with the lowest priority among the priorities defined by the conditions is first cut off or operated at reduced power to keep the amplitude less than the predefined threshold, and the order of the priorities defined by the conditions is different for different conditions.

[0059] In one aspect of the invention, the method includes switching off or operating the loads of lowest priority at reduced power based on an indication of whether one of the loads of lowest priority exists concurrently with other loads of the loads of lowest priority.

[0060] In one aspect of the invention, the method includes shutting off or operating the one of the loads at a reduced power before shutting off or operating the other of the loads at a reduced power in response to the indication that the one of the loads does not exist simultaneously with the other of the loads.

[0061] In one aspect of the invention, the method includes receiving an input defining the sequence.

[0062] In one aspect of the invention, the predefined threshold is based on historical data.

[0063] In one aspect of the invention, the conditions include temperature, time of day, location of the vehicle, gear position of the vehicle, or presence of an occupant in the vehicle.

[0064] In one aspect of the invention, the load is a retrofitter load, a vehicle load, or both.

[0065] According to the present invention, a power system for a vehicle is provided, the power system having: one or more controllers, the one or more controllers being programmed to disconnect or operate one of the loads at a reduced power before disconnecting or operating the other loads of the loads at a reduced power in response to an indication that the magnitude of a current associated with power supplied from the vehicle to loads having the same priority is approaching or exceeding a predefined threshold and that one of the loads is not present simultaneously with the other loads of the loads.

[0066] According to an embodiment, the priorities are condition-dependent, such that the order of the priorities is different for different conditions.

[0067] According to an embodiment, the one or more controllers are further programmed to receive an input defining the sequence.

[0068] According to an embodiment, the predefined threshold is based on historical data.

[0069] According to an embodiment, the conditions include temperature, time of day, location of the vehicle, gear position of the vehicle or presence of occupants in the vehicle.

[0070] According to an embodiment, the load is a retrofitter load, a vehicle load or both.

Claims

1. A vehicle power system, the power system comprising: One or more controllers programmed to reduce or interrupt the supply of power to the loads according to priority in response to the magnitude of the current associated with the power supplied to the loads from the vehicle exceeding a predefined threshold, so that the loads with the same priority are cut off or operated at reduced power according to an indication of whether one of the loads with the same priority exists simultaneously with other loads with the same priority.

2. The power system of claim 1 , wherein the one or more controllers are further programmed to shut off or operate the one of the loads at a reduced power before shutting off or operating the other of the loads at a reduced power in response to the indication that the one of the loads having the same priority level is not present simultaneously with the other of the loads having the same priority level. 3 . The power system of claim 1 , wherein the priorities are condition-dependent such that the order of the priorities is different for different conditions.

4. The power system of claim 3, wherein the one or more controllers are further programmed to receive input defining the sequence.

5. The power system of claim 4, wherein the input is user defined.

6. The power system of claim 3, wherein the conditions include temperature, time of day, location of the vehicle, gear position of the vehicle, or presence of an occupant in the vehicle.

7. The power system of claim 1, wherein the load is a retrofit load, a vehicle load, or both.

8. A method comprising: In response to the amplitude of the current associated with the power supplied to the load from the vehicle approaching a predefined threshold, the supply of power to the load is reduced or interrupted according to the priority defined by the conditions, so that the load with the lowest priority among the priorities defined by the conditions is first cut off or operated at reduced power to keep the amplitude less than the predefined threshold, and the order of the priorities defined by the conditions is different for different conditions.

9. The method of claim 8, further comprising shutting off or operating the loads of the lowest priority at a reduced power based on an indication of whether one of the loads of the lowest priority exists simultaneously with other loads of the loads of the lowest priority.

10. The method of claim 9, further comprising shutting off or operating the one of the loads at a reduced power before shutting off or operating the other of the loads at a reduced power in response to the indication that the one of the loads is not present simultaneously with the other of the loads.

11. The method of claim 8, further comprising receiving input defining the sequence. The method of claim 11 , wherein the input is user defined.

13. The method of claim 8, wherein the conditions include temperature, time of day, location of the vehicle, gear of the vehicle, or presence of an occupant in the vehicle.

14. The method of claim 8, wherein the load is a retrofit load, a vehicle load, or both.

15. A power system for a vehicle, the power system comprising: One or more controllers programmed to shut off or operate one of the loads at a reduced power before shutting off or operating the other of the loads at a reduced power in response to a magnitude of current associated with power supplied from the vehicle to loads having the same priority approaching or exceeding a predefined threshold and an indication that one of the loads is not present simultaneously with the other of the loads.

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