CHARGING A TRACTION BATTERY

Abstract

In response to a request for DC fast charging of a traction battery at a charging station that offers a variety of DC fast charging rates, each with a cost per unit of time that increases with increasing rate, a controller generates an output indicating the cost of charging the traction battery at that rate only for each rate that corresponds to an aging parameter for the traction battery that is less than a threshold.

Description

FIELD OF TECHNOLOGY

[0001] The present disclosure relates to strategies for charging electric vehicles. GENERAL STATE OF THE ART

[0002] Electric vehicles are equipped with one or more traction batteries for propulsion. The traction batteries can be recharged using a charger. SUMMARY

[0003] A vehicle includes a traction battery and a controller. In response to a request for DC fast charging of a traction battery at a charging station offering a plurality of DC fast charging rates, each with a cost per unit time that increases with increasing rates, the controller generates an output indicating a cost to charge the traction battery at the rate only for each of the rates that corresponds to an aging parameter for the traction battery that is less than a threshold, and charges the traction battery at a selected one of the rates.

[0004] A method includes, upon receiving a request for DC fast charging of a traction battery at a charging station that offers a plurality of DC fast charging rates, each with a cost per unit time that increases with an increase in the rate, charging the traction battery at one of the rates automatically selected according to a total cost that includes portions representing a power cost for charging, a user's time cost for charging, and an aging cost of a traction battery for charging, such that the total cost is less than a threshold cost.

[0005] A vehicle control system includes a controller that charges a traction battery at one of a plurality of DC fast charge rates selected such that the one corresponds to an aging parameter for the traction battery based on a duration of charge less than a threshold. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a diagram of an electrified vehicle illustrating powertrain and energy storage components including an electric machine. Fig. 2 is a block topology of a vehicle charging system. Fig. Figure 3 is a flowchart of an electric vehicle charging process. DETAILED DESCRIPTION

[0006] Embodiments are described in this specification. It should be understood, however, that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features may be exaggerated or reduced to show details of specific components. Therefore, specific structural and functional details disclosed in this specification are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.

[0007] Various features illustrated and described with respect to any of the figures may be combined with features illustrated in one or more other figures to produce embodiments not explicitly illustrated or described. The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure may be desirable for particular applications or implementations.

[0008] The present disclosure proposes, among other things, a system and method for charging an electric vehicle. Traditionally, a total price for charging an electric vehicle may be determined by a total amount of electrical energy consumed by the vehicle. With the introduction of high-power DC chargers, utilities may set the price rate based on the maximum charging power over time. For example, 150 kW of DC fast charging power may correspond to $0.99 / min, while 75 kW of DC fast charging power may correspond to only $0.25 / min. In a variable-power charging process, the charger may adjust the charging power based on real-time feedback from the vehicle battery. The charging process may start with a high charging power when the battery state of charge (SOC) is low and gradually reduce the charging power as the SOC increases.However, the price rate corresponding to the maximum charging power may be applied throughout the entire charging process. Continuing with the current example, if the charging process begins with a charging power of 150 kW, the price rate of the current charging process is set to $0.99 / min throughout the entire process, even if the charging power is subsequently reduced to 75 kW. In other words, the price rate for the charging process is determined by the highest charging power, even though the highest charging power is only used at the beginning of the process. The present disclosure proposes a system for charging the vehicle while allowing the user to save money.

[0009] Fig. 1 illustrates an electrified vehicle 112, which may be referred to as a plug-in hybrid-electric vehicle (PHEV), a battery electric vehicle (BEV), and / or a full hybrid electric vehicle (FHEV). A plug-in hybrid-electric vehicle 112 may include one or more electric machines 114 mechanically coupled to a hybrid transmission 116. The electric machines 114 may be capable of operating as a motor or generator. Additionally, the hybrid transmission 116 is mechanically coupled to an internal combustion engine 118. The hybrid transmission 116 is also mechanically coupled to a driveshaft 120, which is mechanically coupled to the wheels 122. The electric machines 114 may provide propulsion and braking capability when the internal combustion engine 118 is on or off.The electric machines 114 can also function as generators and can provide fuel efficiency benefits by recovering energy that would normally be lost as heat in a friction braking system. The electric machines 114 can also reduce vehicle emissions by enabling the engine 118 to operate at more efficient speeds and by enabling the hybrid electric vehicle 112 to operate in electric mode with the engine 118 off under certain conditions. An electrified vehicle 112 can also be a BEV. In a BEV configuration, the engine 118 may not be present.

[0010] A traction battery or battery pack 124 stores energy that can be used by the electric machines 114. The vehicle battery pack 124 can provide a high-voltage direct current (DC) output. The traction battery 124 can be electrically coupled to one or more power electronics modules 126 (such as a traction inverter). The power electronics module 126 is also electrically coupled to the electric machines 114 and provides the ability to transfer power bidirectionally between the traction battery 124 and the electric machines 114. For example, a traction battery 124 can provide a DC voltage, while the electric machines 114 can operate using three-phase alternating current (AC).The power electronics module 126 can convert the DC voltage into a three-phase AC current to operate the electric machines 114. In a regeneration mode, the power electronics module 126 can convert the three-phase AC current from the electric machines 114, which act as generators, into the DC voltage compatible with the traction battery 124.

[0011] The vehicle 112 may include a variable-voltage converter (VVC) (not shown) electrically coupled between the traction battery 124 and the power electronics module 126. The VVC may be a DC / DC boost converter configured to increase or boost the voltage provided by the traction battery 124. By increasing the voltage, current requirements may be reduced, resulting in a reduction in wire size for the power electronics module 126 and the electric machines 114. Furthermore, the electric machines 114 may operate with better efficiency and lower losses.

[0012] In addition to providing power for propulsion, the traction battery 124 may provide power to other vehicle electrical systems. The vehicle 112 may include a DC / DC converter module 128 that converts the high-voltage DC output of the traction battery 124 into a low-voltage DC supply compatible with low-voltage loads 129 of the vehicle. An output of the DC / DC converter module 128 may be electrically coupled to an auxiliary battery 130 (e.g., a 12V battery) to charge the auxiliary battery 130. The low-voltage systems may be electrically coupled to the auxiliary battery 130.

[0013] The electrified vehicle 112 may be configured to charge the traction battery 124 from an external power source 136. The external power source 136 may be a connection to an electrical outlet. The external power source 136 may be electrically coupled to a charger or electric vehicle supply equipment (EVSE) 138. The external power source 136 may be an electrical power distribution network or grid, such as provided by a utility company. The EVSE 138 may provide circuitry and controls to manage the transfer of energy between the power source 136 and the vehicle 112. The external power source 136 may provide DC or AC electrical power to the EVSE 138. The EVSE 138 may include a charging plug 140 for plugging into a charging port 142 of the vehicle 112.The charging port 142 may be any type of port configured to transfer power from the EVSE 138 to the vehicle 112. The charging port 142 may be electrically coupled to a charger or an on-board power conversion module 144. The power conversion module 144 may condition the power supplied by the EVSE 138 to provide the proper voltage and current levels to the traction battery 124. The power conversion module 144 may interface with the EVSE 138 to coordinate the delivery of power to the vehicle 112. The EVSE 138 may output a DC fast-charging current to charge the traction battery 124 via the power conversion module 144. The EVSE 138 may adjust the charging power by varying the current (or voltage) output. The EVSE connector 140 may have pins that mate with corresponding recesses of the charging port 142.Alternatively, various components described as electrically coupled or connected may transfer power using wireless inductive coupling. Furthermore, the charging port 142 may be configured to output DC electrical power from the traction battery 124 through the power conversion module 144. One or more contactors 146 may isolate the traction battery 124 from other components when open and connect the traction battery 124 to other components when closed.

[0014] Electronic modules / controllers within the vehicle 112 may communicate over one or more vehicle networks (described in detail below). The vehicle network may include a plurality of channels for communication. Vehicle network channels may include discrete connections between modules and may include power signals from the auxiliary battery 130. Different signals may be transmitted over different vehicle network channels. For example, video signals may be transmitted over a high-speed channel, while control signals may be transmitted over a low-speed channel. The vehicle network may include any hardware and software components that assist in transmitting signals and data between modules. A computing platform 148 may be present to perform and coordinate various operations of the vehicle 112.

[0015] Fig. 2 is a block topology 200 of the vehicle charging system. A computing platform 148 of the vehicle 112 may include one or more processors 204 configured to execute instructions, commands, and other routines to support the processes described herein. For example, the computing platform 148 may be configured to execute instructions from vehicle applications 206 to provide features such as communications and charging controls. Such instructions and other data may be maintained in a non-transitory manner using a variety of types of computer-readable storage media 208.Computer-readable medium 208 (also referred to as processor-readable medium or processor-readable memory) includes any non-transitory medium (physical medium) involved in providing instructions or other data readable by processor 204 of computing platform 148. Computer-executable instructions may be compiled or interpreted by computer programs prepared using a variety of programming languages ​​and / or technologies, including, without limitation, Java, C, C++, C#, Objective C, Fortran, Pascal, Java Script, Python, Perl, and SQL, either alone or in combination.

[0016] Computing platform 148 may be provided with various features that enable vehicle occupants / users to interface with computing platform 148. For example, computing platform 148 may receive inputs from controls 210 of a human-machine interface (HMI) configured to provide interaction between occupants and vehicle 112. As one example, computing platform 148 may interface with one or more buttons (not shown) or other HMI controls (e.g., audio buttons on the steering wheel, a talk button, dashboard controls, etc.) configured to invoke functions on computing platform 148 as well as other components of vehicle 112.

[0017] The computing platform 148 may also drive or otherwise communicate with one or more displays 212 configured to provide visual output to vehicle occupants via a video controller 214. In some cases, the display 212 may be a touchscreen further configured to receive touch input from users via the video controller 214, whereas in other cases, the display 212 may simply be a display without touch input capabilities. The computing platform 148 may further drive or otherwise communicate with one or more speakers 218 configured to provide audio output to the vehicle occupants via an audio controller 220.

[0018] Computing platform 148 may be configured to communicate with a vehicle user's mobile device 222 via a wireless connection 224. Mobile device 222 may be any of various types of portable computing devices, such as mobile phones, tablet computers, smartwatches, laptop computers, portable music players, key fobs, or other devices capable of communicating with computing platform 148.In many examples, the computing platform 148 may include a wireless transceiver 226 in communication with a Wi-Fi controller 228, a near-field communication (NFC) controller 229, a Bluetooth controller 230, and other controllers, such as a ZigBee transceiver, an IrDA transceiver (not shown), a radio-frequency identification (RFID) transceiver (not shown), and configured to communicate with a compatible wireless transceiver 232 of the mobile device 222. The computing platform 148 may be further provided with location services via a global navigation satellite system (GNSS) controller 234 configured to determine the location of the vehicle 112 and plan navigation routes.For example, the GNSS controller 234 may be configured to support the global positioning system (GPS), as one example. Navigation software may be stored on the non-volatile memory 208 as part of the vehicle applications 206. The map data used for route planning may be stored on the non-volatile memory 208 as part of the vehicle data 236.

[0019] The mobile device 222 may be provided with a processor 238 configured to execute instructions, commands, and other routines to support processes such as calls, wireless communications, multimedia processing, and digital authentication. The wireless transceiver 232 of the mobile device 222 may be in communication with a Wi-Fi controller 240, a Bluetooth controller 242, an NFC controller 244, and other controllers configured to communicate with the compatible wireless transceiver 226 of the computing platform 148. The mobile device 222 may be provided with a non-volatile memory 246 configured to store various software and data. For example, the non-volatile memory 246 may store mobile applications 248 and mobile data 250 to enable various features of the mobile device 222.

[0020] The computing platform 148 may be further configured to communicate with a charging controller 252 via one or more in-vehicle networks 254. The in-vehicle network 254 may include, among others, one or more of a controller area network (CAN), an Ethernet network, an ultra-wideband (UWB), and a media-oriented system transport (MOST), as some examples.

[0021] The charging controller 252 of the vehicle 112 may be configured to control the charging of the vehicle battery 124. The charging controller 252 may be configured to communicate with the EVSE 138 (the charger) to coordinate the charging of the vehicle via a charging cable 256 to support data communication. Alternatively, the charging controller 252 may be configured to communicate with the EVSE 138 via a wireless connection (not shown). Additionally or alternatively, the system may be configured to communicate the vehicle information to the EVSE 138 using the mobile device 222 through a wireless connection 258 with or without involvement of the vehicle charging controller 252. The vehicle 112 and the mobile device 222 may be further configured to communicate with a remote server 259 via their respective wireless transceivers to obtain various information.

[0022] The EVSE 138 may include one or more processors 260 configured to execute instructions, commands, and other routines to support the processes described herein. As an example, the EVSE 138 may be configured to execute instructions from station software 262 stored on memory 264 to provide functions such as enabling / disabling charging, price selection, payment processing, and wireless communication with various digital entities. The EVSE 138 may be provided with HMI controllers 266 configured to provide user interaction.

[0023] The EVSE 138 may include a wireless transceiver 268 in communication with an NFC controller 270, a radio-frequency identification (RFID) controller 272, a Bluetooth controller 274, a Wi-Fi controller 276, and other controllers configured to communicate with the compatible wireless transceiver 226 of the vehicle 112 and / or the compatible wireless transceiver 232 of the mobile device 222.

[0024] With reference to Fig. 3 illustrates an exemplary flow diagram of a process 300 for charging the vehicle of one embodiment of the present disclosure. The process 300 provides a method for more economical and flexible vehicle charging by allowing the vehicle user to adjust charging preferences while taking into account battery aging caused by DC fast charging. With further reference to Fig. 1 and Fig.2, process 300 may be implemented individually or jointly by one or more of the EVSE 138, the charging controller 252 of the vehicle 112, and / or the server 259. For simplicity, the following description will be made with reference to the EVSE 138. At operation 302, in response to detecting that the vehicle 112 is connected to the EVSE plug 140 via the charging port 142, the EVSE 138 establishes data communication with the vehicle 112 in preparation for the upcoming charging event. As discussed above, the charging cable 256 may be configured to support data communication protocols and therefore enables wired communication between the EVSE 138 and the charging controller 252 of the vehicle 112. Additionally or alternatively, data communication between the EVSE 138 and the vehicle 112 may be established via a wireless connection through the wireless transceivers 268, 226 of each respective device.Additionally or alternatively, the EVSE 138 may establish wireless data communication with the mobile device 222 associated with the vehicle 112.

[0025] At operation 304, the EVSE 138 receives vehicle information via the previously established data communication. The vehicle information may include various information / data related to the vehicle 112 that may be used to evaluate the charging of the vehicle. For example, the vehicle information may include a SOC of the traction battery 124, which may be used to determine the amount of energy the vehicle requires. The vehicle information may further include a vehicle make / model and charging power configurations (e.g., charging wattage) supported by the vehicle 112, which may be used to determine one or more charging powers applicable to the vehicle 112. The vehicle information may further include information regarding the battery health and temperature of the traction battery 124, which may be used to adjust the charging power.

[0026] As discussed above, the present disclosure enables the vehicle user to customize the charging experience based on user preference. At operation 306, the EVSE 138 receives a charging request for the current user-specified charging event. The charging request may be received from the vehicle 112 and / or the mobile device 112 associated with the vehicle 112. The charging request may specify a desired outcome for the charging event defined by the user. For example, the charging request may include a desired target SOC at the end of the user-specified charging event. The charging request may further include a maximum duration of the charging event that the user is willing to wait. The charging request may further include a maximum budget that the user is willing to spend.For example, the charging request may include a target SOC of 80% (from the current 30%) with a maximum duration of 20 minutes and a maximum budget of $20.

[0027] The charging request may further include a battery degradation threshold within which battery degradation caused by the current charging event is acceptable. As discussed above, DC fast charging may cause battery health to degrade due to the heat generated by the high current. Battery degradation may be quantified in various ways. For example, battery degradation may be quantified as a percentage of the battery's total capacity loss (e.g., 0.01% of the maximum capacity per charge). Additionally or alternatively, battery degradation may be quantified as a monetary value calculated based on the extent of capacity loss. Continuing with the above example, if the total value of the traction battery 124 is considered to be 10,For a power budget defined as $0.000, a capacity loss of 0.01% can be converted into the equivalent of a monetary depreciation of the traction battery 124 of approximately $1.00. Battery aging (especially in monetary depreciation form) can be considered as a proportion of the maximum price offered by the vehicle. For example, if the user pays $30 for fast charging and a battery depreciation of $2.00 is incurred during fast charging, the actual total expenditure allocated to the fast charging event is $32 instead of $30. Therefore, the user's maximum budget is at least $32 for the current charging event to qualify.

[0028] At operation 308, the EVSE 138 determines the one or more candidate charging options using both the vehicle information and the previously received charging request. Depending on the specific situation, more than one candidate charging option may be determined. Each candidate charging option may include a variety of characteristics associated with the scheduled charging event that qualifies the user-specified charging request. For example, the charging option may include one or more charging power levels at different phases of the charging event that have met both the user's time and budget requirements. In general, the charging event may begin with a higher charging power level at the beginning of the charging event and gradually reduce the charging power level over the duration of the charging event depending on the expected and real-time feedback from the traction battery 124.Varying charging power can affect charging duration, which in turn can lead to different total prices. Additionally, different charging powers can also cause different battery aging. At operation 310, the EVSE 138 determines the battery aging of each candidate charging option and assigns the battery aging to the corresponding charging option. Therefore, each charging option can be associated with a price, a charging duration, and a battery aging value (aging parameter). Battery aging can be determined and calculated by considering various factors. As some non-limiting examples, battery aging can be determined using factors such as an expected amount of heat and / or temperature predicted using the charging powers and their corresponding durations.Battery aging may be further determined using a current and / or expected ambient temperature during the charging event, measured locally or received from the server 259. Battery aging may be further determined using the current health of the traction battery 124. As a general rule, a lower charging power may be associated with a reduced amount of battery aging, while a higher charging power may be associated with an increased amount of battery aging. In one example, a charging power of 75 kW may be associated with almost $0.00 of battery aging, whereas 125 kW and 150 kW may be associated with $1.00 and $1.25 of battery aging, respectively, over a given period.

[0029] At operation 312, the EVSE 138 determines whether the aging value is within the aging threshold specified in the user request. If the answer is no, indicating that the aging associated with one or more candidate charging options is unacceptable, the process proceeds to operation 314, where the EVSE 138 reduces the scheduled charging power and re-determines one or more new charging options. Generally, a reduced charging power can reduce the heat generated during charging and thus reduce battery aging. If the answer to operation 312 is yes, the process proceeds to operation 316, where the EVSE 138 presents the options to the user for selection. The EVSE 138 may present the options via the HMI controls 266. Additionally or alternatively, the EVSE 138 may output the charging options to the vehicle 112 and / or the mobile device 222 for presentation to the user.The charging option may include various information associated with each option. For example, the charging option may be presented to the user, including a total price, charging time, and battery aging value associated with each option, and the user may be prompted to select from one of the options. In response to receiving user input indicating a user selection of one of the candidate charging options, the process proceeds to operation 318, and the EVSE 138 charges the vehicle based on the selected charging option.

[0030] Additionally or alternatively, the EVSE 138 may be configured to perform automated decision-making when multiple charging options are available, without having to present each option to the user. In particular, the user may predefine a cost threshold that allows the EVSE 138 and / or the vehicle 112 to automatically select one of the qualifying options without requiring user input each time the vehicle 112 is connected to the EVSE 138. The cost threshold may consider not only the price to be paid for charging, but also battery aging costs and any additional time spent waiting for the user to pay the charging costs. For example, the total cost for each charging option may be determined using the following equation: Costtotal=t*p+cbatt+u*a

[0031] The above equation considers three factors to evaluate the total cost. The first factor, t*p, represents the price to be paid for charging for the corresponding option (the power cost of charging). t denotes the time required to charge the vehicle for the option, and p denotes the charging rate (e.g., the price per minute) for the option. The second factor, c battrepresents a monetary devaluation of the traction battery 124 associated with the charging option (the traction battery aging cost). The third factor u*a represents the time cost associated with the user waiting for the vehicle to complete charging. The time cost can be represented and evaluated in several ways. In the present example, the time cost can be evaluated in terms of additional time over the fastest charging option, which is used as a reference. u denotes a user-defined value ($20 per hour) representative of the user's time rate, and a denotes additional time of the corresponding option compared to the fastest charging time. For example, if the EVSE 138 determines that the fastest charging time is 30 minutes and the present option requires 45 minutes to complete, the additional 15 minutes results in a time cost of $5 (e.g.,$20 per hour * 0.25 hours). Once the total cost for each option is determined, the EVSE 138 can be configured to automatically select the charging option with the lowest cost without requiring user input each time.

[0032] The algorithms, methods, or processes disclosed in this document may be executable by or implemented by a computer, controller, or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Furthermore, the algorithms, methods, or processes may be stored in many forms as computer- or controller-executable data and instructions, including, but not limited to, information permanently stored on non-writable storage media, such as read-only memory devices, and information modifiably stored on writable storage media, such as compact discs, random access memory devices, or other magnetic and optical media. The algorithms, methods, or processes may also be implemented in software-executable objects.Alternatively, the algorithms, methods, or processes may be implemented in whole or in part using suitable hardware components, such as application-specific integrated circuits, field-programmable gate arrays, state machines, or other hardware components or devices, or a combination of firmware, hardware, and software components.

[0033] While exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. For example, the terms processor and processors may be interchanged throughout this specification, as may the terms controller and controllers.

[0034] As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments may have been described as providing advantages or being preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, one of ordinary skill in the art will understand that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the specific application and implementation. These attributes may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc.Thus, embodiments that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.

[0035] According to the present invention, a vehicle is provided comprising: a traction battery; and a controller programmed, in response to a request for DC fast charging of a traction battery at a charging station offering a plurality of DC fast charging rates, each having a cost per unit time that increases with increasing rate, to generate an output indicative of a cost to charge the traction battery at the rate only for each of the rates that corresponds to an aging parameter for the traction battery that is less than a threshold, and to charge the traction battery at a selected one of the rates.

[0036] According to one embodiment, the controller is further programmed to automatically select one of the rates according to a user-defined criterion to identify the selected one of the rates.

[0037] According to one embodiment, the output further indicates a duration for charging the traction battery at the rate.

[0038] According to one embodiment, the cost includes a portion representing a user value per unit of time.

[0039] According to one embodiment, the controller is further programmed to receive an input defining the user value per unit of time.

[0040] According to one embodiment, the cost includes a portion representing a product of a user value per unit time and a difference between a charging time at the rate and a charging time at a maximum value of the rates corresponding to the aging parameters that are less than the threshold.

[0041] According to one embodiment, the controller is further programmed to receive an input defining the threshold.

[0042] According to the present invention, a method includes, upon receiving a request for DC fast charging of a traction battery at a charging station that offers a plurality of DC fast charging rates, each with a cost per unit time that increases with an increase in the rate, charging the traction battery at one of the rates that is automatically selected according to a total cost that includes portions representing a power cost for charging, a user's time cost for charging, and an aging cost of a traction battery for charging, such that the total cost is less than a threshold cost.

[0043] In one aspect of the invention, the method includes receiving an input defining the threshold cost.

[0044] In one aspect of the invention, the user's time cost is a product of a user value per unit time and a duration of the charge.

[0045] In one aspect of the invention, the traction battery aging cost is a function of a duration of charge and one of the rates.

[0046] In one aspect of the invention, the method further comprises generating an output indicating a recommendation to switch to non-DC fast charging in response to a state of charge of the traction battery exceeding a threshold state of charge.

[0047] According to the present invention, a vehicle control system is provided, comprising: a controller programmed to charge a traction battery at one of a plurality of DC fast charge rates selected such that the one corresponds to an aging parameter for the traction battery based on a duration of charge less than a threshold.

[0048] According to one embodiment, the controller is further programmed to perform a charge with the selected one such that a total cost of the charge is less than a threshold cost, and wherein the total cost includes portions including a power cost for the charge, a user's time cost for the charge, and a traction battery aging cost for the charge.

[0049] According to one embodiment, the user's time cost is a product of a user value per unit of time and the duration.

[0050] According to one embodiment, the aging cost of the traction battery is a function of the duration and one of the rates.

[0051] According to one embodiment, the total cost is user-defined.

Claims

[1] Vehicle comprising: a traction battery; and a controller that is programmed to in response to a request for DC fast charging of a traction battery at a charging station that offers a plurality of DC fast charging rates, each with a cost per unit time that increases with increasing rate, to generate an output indicating a cost to charge the traction battery at the rate only for each of the rates that corresponds to an aging parameter for the traction battery that is less than a threshold, and to charge the traction battery at a selected rate. [2] The vehicle of claim 1, wherein the controller is further programmed to automatically select one of the rates according to a user-defined criterion to identify the selected one of the rates. [3] The vehicle of claim 1, wherein the output further indicates a duration for charging the traction battery at the rate. [4] The vehicle of claim 1, wherein the cost includes a portion representing a user value per unit time. [5] The vehicle of claim 4, wherein the controller is further programmed to receive an input defining the user value per unit time. [6] The vehicle of claim 1, wherein the cost includes a proportion that is a product of a user value per unit time and a difference between a charging time at the rate and a charging time at a maximum value of the rates corresponding to the aging parameters that are less than the threshold. [7] The vehicle of claim 1, wherein the controller is further programmed to receive an input defining the threshold. [8] Method comprising: upon receiving a request for DC fast charging of a traction battery at a charging station that offers a plurality of DC fast charging rates, each with a cost per unit time that increases with an increase in the rate, charging the traction battery at one of the rates that is automatically selected according to a total cost that includes components representing power costs for charging, time costs of a user for charging, and aging costs of a traction battery for charging, such that the total cost is less than a threshold cost. [9] The method of claim 8, further comprising receiving an input defining the threshold cost. [10] The method of claim 8, wherein the user's time cost is a product of a user value per unit time and a duration of the charge. [11] The method of claim 8, wherein the traction battery aging cost is a function of a duration of charge and the one of the rates. [12] The method of claim 8, generating an output indicating a recommendation to switch to non-DC fast charging in response to a state of charge of the traction battery exceeding a threshold state of charge. [13] Vehicle control system comprising: a controller programmed to charge a traction battery at one of a plurality of DC fast charge rates selected such that the one corresponds to an aging parameter for the traction battery based on a duration of charge less than a threshold. [14] The vehicle control system of claim 13, wherein the controller is further programmed to perform a charge with the selected one such that a total cost of the charge is less than a threshold cost, and wherein the total cost includes portions including a power cost for the charge, a user's time cost for the charge, and a traction battery aging cost for the charge. [15] The vehicle of claim 14, wherein the user's time cost is a product of a user value per unit time and the duration.

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