Vehicle-to-vehicle charging unit and process

Abstract

The invention relates to a vehicle-to-vehicle charging unit and process. A charging unit for use by a charge receiving electrical system ("acceptor") and a charge providing electrical system ("donor") includes a housing and an auxiliary battery. A bi-directional buck-boost high voltage (HV) to HV converter is connected to an HV bus between circuit breaking devices. A bi-directional buck-boost HV to LV converter is connected to an HV bus and a low voltage (LV) bus. A power supply equipment communication controller (SECC) detects a charge port control signal and establishes communication between the SECC and a system controller. Separate donor and acceptor monitoring circuits determine an isolation state of the HV bus and a state of the circuit breaking device. During the charging process, the system controller selectively commands unloading of the charging current from the donor energy storage system through the HV-to-HV converter and then to the acceptor energy storage system.

Description

TECHNICAL FIELD

[0001] Battery electric vehicles, as well as plug-in hybrid electric vehicles and range-extended electric vehicles (for simplicity, collectively referred to herein as EVs) are equipped with electrified powertrain systems. The electrified powertrain systems include one or more electric traction motors. The motors are connected to a set of road wheels of the EV. The battery management system of the EV controls the discharge of the high-voltage traction battery pack during the propulsion mode to energize the phase windings of the motor(s) and produce output torque. The EV is thus propelled along the road surface via electrically driven rotation of the road wheels, with engine-driven rotation remaining possible in the above-mentioned hybrid electric and range-extended configurations. BACKGROUND

[0002] The electrochemical battery cells of the depleted traction battery pack can be selectively recharged using off-board plug-in charging procedures. As understood in the art, off-board charging of the battery electrical system requires the battery pack to be electrically connected to electric vehicle supply equipment (EVSE), i.e., an off-board charging station, via a suitably configured charging cable. The necessary communication and control circuitry of the charging station and the EV, as well as the associated controllers, establish bidirectional communication in accordance with a suitable charging protocol. Thereafter, the charging station off-loads a charging current to the depleted traction battery pack to re-charge the individual battery cells. This exchange is referred to in the art as DC-to-DC charging when the charge-donating and charge-receiving nodes participate in the transmission / reception of a direct current (DC) charging waveform. SUMMARY

[0003] Disclosed herein is a dual-sided charging unit and corresponding computer-based charging procedure. The charging unit, which is portable in some embodiments, is configured to perform direct current-to-direct current (DC-to-DC) charging operations between a charge-donating node ("donor") and a charge-receiving node ("recipient") in the form of respective first and second electrical systems. The disclosed charging architecture, control circuitry, and charging strategy collectively enable energy transfer between the donor and the recipient, for example, when off-board charging stations are not readily available.

[0004] In representative constructions as set forth herein, both the donor and the recipient are configured as electric vehicles (EVs), such as battery electric vehicles, plug-in hybrid electric vehicles, range-extended electric vehicles, or another electrified mobile system capable of performing the disclosed functions. The present teachings can also extend to DC-to-DC charging events performed using stationary or non-vehicle electrical systems within the scope of the present disclosure.

[0005] In particular embodiments, a charging unit for performing a charging process between a donor and a recipient includes a housing, an auxiliary battery or another rechargeable energy storage system (RESS) connected to the housing, a high voltage (HV) bus, and a system controller. The housing includes a donor charging port and a recipient charging port that are selectively connectable to the donor and the recipient, respectively, via corresponding charging cables and connectors. In this embodiment, packaged within the housing is the HV bus with a donor HV circuit breaking device and a recipient HV circuit breaking device, where the HV bus is connectable to the donor and the recipient via the donor HV circuit breaking device and the recipient HV circuit breaking device, respectively. Also packaged within the housing is a low voltage (LV) bus with an auxiliary switch, such as a manually actuated push button device, a smart switch, or a switch device activated by a control signal from a human machine interface (HMI) or another external device or a command from a mobile application. A bidirectional buck-boost HV to HV converter is connected to the HV bus between the donor HV circuit breaking device and the recipient HV circuit breaking device. A bidirectional buck-boost HV to LV converter is connected to the HV bus and the LV bus.

[0006] In one or more embodiments, the system controller is connectable to the LV bus via the auxiliary switch described above. A supply equipment communication controller (SECC) is configured to detect charging port control signals via the donor charging port and the recipient charging port and establish communication between the SECC and the system controller in response to the charging port signals. Respective donor isolation monitoring circuitry and recipient isolation monitoring circuitry are configured to determine an isolation state of the HV bus and an open / closed state of the donor circuit breaking device and the recipient circuit breaking device (e.g., HV contactors). The system controller is connectable to the auxiliary battery and in communication with the HV to HV converter, the HV to LV converter, the donor HV circuit breaking device and the recipient HV circuit breaking device, and the SECC. The system controller selectively commands the DC charging current to be discharged from the donor’s battery pack through the HV buck-boost converter and then to the recipient’s battery pack or other RESS.

[0007] The donor monitoring circuitry and the recipient monitoring circuitry can include first and second electrical sensors, respectively, each configured to measure a corresponding voltage and current on the HV bus.

[0008] The charging unit can also include a thermal management system (TMS) connected to the auxiliary battery, the HV to HV converter, and the HV to LV converter, and a relay that selectively disconnects the TMS from the auxiliary battery in response to a relay control signal from the system controller. In one or more embodiments, the TMS can include an electrically powered fan and / or pump configured to circulate air or coolant to the HV to HV converter and the HV to LV converter when the fan or pump is connected to the auxiliary battery.

[0009] Aspects of the disclosure relate to an HMI connected to a housing. The HMI is configured to receive user input to a system controller and display information related to a charging process.

[0010] Embodiments of the system controller are configured to quantify the charging process, generate a charge summary for the charging process, and communicate the charge summary to a user of the recipient upon completion of the charging process. The system controller can also be configured to execute an adaptive self-learning algorithm to analyze charging behavior from a group of recipients for previous charging processes and adjust performance of the charging unit over time based on the charging behavior.

[0011] The recipient and the donor are optionally configured as electric vehicles (EVs), in which case the charging process is a vehicle-to-vehicle (V2V) charging process. The donor HV circuit breaking device and the recipient HV circuit breaking device can include contactors as described above, or single-pull single-throw switches or solid state relays (SSRs) in representative embodiments.

[0012] Some implementations of the charging unit have a unique identifier (ID) code. The charging unit can remotely enable pairing of the donor and the server in response to the unique ID code matching corresponding ID codes stored in respective memories of the donor and the recipient.

[0013] A V2V charging process is also disclosed herein. Embodiments of such a process include energizing a system controller of a V2V charging unit via a LV bus in response to actuation of an auxiliary switch, and detecting a charge port control signal via a SECC of the V2V charging unit. The charge port signal indicates electrical connection of the donor and the recipient (e.g., EVs). The process includes establishing a handshake / communication between the SECC and the system controller of the V2V unit in response to the charge port control signal, thereby initiating the V2V charging process.

[0014] During the V2V charging process, the process includes commanding the separate donor HV circuit breaking device and the recipient HV circuit breaking device on the HV bus of the V2V charging unit to close via the system controller, thereby connecting a bi-directional step-down- up HV to HV converter to the HV bus; recharging the LV bus via the bi-directional step-down-up HV to LV converter; and monitoring the separate donor monitoring circuit and the recipient monitoring circuit of the V2V charging unit to determine an isolation state of the HV bus and an open / close state of the donor HV circuit breaking device and the recipient HV circuit breaking device. The process also includes selectively commanding an offload of DC charging current from the battery pack of the donor through the HV to HV converter and then to the battery pack of the recipient.

[0015] Aspects of the present disclosure also relate to a vehicle system having a donor EV having a first traction battery pack, a recipient EV having a second traction battery pack, and a V2V charging unit configured as outlined above.

[0016] The present invention provides the following technical solutions.

[0017] Technical Solution 1. A charging unit for performing a charging process between a charge-providing system ("donor") and a charge-receiving system ("recipient"), comprising:

[0018] a housing having a donor charging port and a recipient charging port, the donor charging port and the recipient charging port being selectively connectable to the donor and the recipient, respectively, via corresponding charging cables and connectors;

[0019] an auxiliary battery connected to the housing; and

[0020] encapsulated within the housing are:

[0021] a high voltage (HV) bus having a donor HV circuit breaking device and a recipient HV circuit breaking device, wherein the HV bus is connectable to the donor and the recipient, respectively, via the donor HV circuit breaking device and the recipient HV circuit breaking device;

[0022] a low voltage (LV) bus having an auxiliary switch;

[0023] a bidirectional buck-boost HV-to-HV converter connected to the HV bus between the donor HV circuit breaking device and the recipient HV circuit breaking device;

[0024] a bidirectional buck-boost HV-to-LV converter connected to the HV bus and the LV bus;

[0025] a system controller connectable to the LV bus via the auxiliary switch;

[0026] a supply equipment communication controller (SECC) configured to detect a charging port control signal via the donor charging port and the recipient charging port and to establish communication between the SECC and the system controller in response to the charging port signal;

[0027] respective donor and recipient isolation monitoring circuits configured to determine an isolation state of the HV bus and an open / closed state of the donor and recipient contactors; and

[0028] a system controller connectable to the auxiliary battery and in communication with the HV-to-HV converter, the HV-to-LV converter, the donor HV disconnect device and the recipient HV disconnect device, and the SECC, the system controller configured to selectively command a DC charging current to offload from the donor's battery pack through the HV-buck-boost converter and then to the recipient's battery pack.

[0029] Technical Solution 2. The charging unit of Technical Solution 1, wherein the donor monitoring circuit and the recipient monitoring circuit each include first and second electrical sensors, respectively, each configured to measure a corresponding voltage and current on the HV bus.

[0030] Technical Solution 3. The charging unit of Technical Solution 1, wherein the auxiliary switch is a manually actuated pushbutton device.

[0031] Technical Solution 4. The charging unit of Technical Solution 1, further comprising:

[0032] a thermal management system (TMS) connected to the auxiliary battery, the HV-to-HV converter, and the HV-to-LV converter; and

[0033] a relay responsive to a relay control signal from the system controller to selectively disconnect a fan or pump of the TMS from the auxiliary battery to energize the fan or pump.

[0034] Technical Solution 5. The charging unit of Technical Solution 4, wherein the TMS includes an electrically powered fan or pump configured to circulate air or coolant to the HV-to-HV converter and the HV-to-LV converter.

[0035] Technical Solution 6. The charging unit of Technical Solution 1, further comprising:

[0036] a human-machine interface (HMI) connected to the housing, wherein the HMI is configured to receive user input to the system controller and to display information related to the charging process.

[0037] Technical Solution 7. The charging unit of Technical Solution 1, wherein the system controller is configured to quantify the charging process, generate a cost summary for the charging process, and communicate the cost summary to a user of the recipient upon completion of the charging process.

[0038] Technical Solution 8. The charging unit of Technical Solution 1, wherein the system controller is configured to execute an adaptive self-learning algorithm to analyze charging behavior of a group of recipients from previous charging processes and adjust performance of the charging unit over time based on the charging behavior.

[0039] Technical Solution 9. The charging unit of Technical Solution 1, wherein the recipient and the donor are configured as electric vehicles, and wherein the charging process is a vehicle-to-vehicle charging process.

[0040] Technical Solution 10. The charging unit of Technical Solution 1, further comprising: the charging cable and connector.

[0041] Technical Solution 11. The charging unit of Technical Solution 1, wherein the auxiliary battery is located within the housing.

[0042] Technical Solution 12. The charging unit of Technical Solution 1, wherein the donor HV circuit breaking device and the recipient HV circuit breaking device comprise a contactor, a single-pull single-throw switch, or a solid state relay.

[0043] Technical Solution 13. The charging unit of Technical Solution 1, wherein the HV-to-HV converter has a rating of at least about 50 kW and about 150 V to about 1000 V.

[0044] Technical Solution 14. The charging unit of Technical Solution 1, wherein the charging unit has a unique identifier (ID) code, wherein the charging unit is configured to remotely enable pairing of the donor and the recipient in response to the unique ID code matching a corresponding ID code stored in respective memories of the donor and the recipient.

[0045] Technical Solution 15. A vehicle-to-vehicle (V2V) charging process, comprising:

[0046] in response to actuation of an auxiliary switch, energizing a system controller of the V2V charging unit via a low voltage (LV) bus;

[0047] detecting, via a supply equipment communication controller (SECC) of the V2V charging unit, a charging port control signal, the charging port signal indicating electrical connection of a charge-providing vehicle (“donor”) and a charge-receiving vehicle (“recipient”);

[0048] in response to the charging port control signal, establishing a handshake / communication between the SECC and a system controller of the V2V unit, thereby initiating a V2V charging process; and

[0049] during the V2V charging process:

[0050] commanding, via the system controller, separate donor HV break equipment and recipient HV break equipment on the HV bus of the V2V charging unit to close, thereby connecting a bidirectional buck-boost HV-to-HV converter to the HV bus;

[0051] recharging, via a bidirectional buck-boost HV-to-LV converter, the LV bus;

[0052] monitoring separate donor monitoring circuitry and recipient monitoring circuitry of the V2V charging unit to determine isolation status of the HV bus and open / close status of the donor HV break equipment and the recipient HV break equipment; and

[0053] selectively commanding an offload of DC charging current from the donor's battery pack through the HV-to-HV converter and then to the recipient's battery pack.

[0054] Technical Solution 16. The V2V charging process of Technical Solution 15, wherein the V2V charging unit includes a thermal management system (TMS), further comprising:

[0055] regulating, via the TMS, respective temperatures of the HV-to-HV converter and the HV-to-LV converter during the V2V charging process.

[0056] Technical Solution 17. The V2V charging process of Technical Solution 15, further comprising:

[0057] generating, via the system controller, a fare summary for the V2V charging process; and

[0058] communicating, via a wireless communication link, the fare summary to the recipient.

[0059] Technical Solution 18. A vehicle system, comprising:

[0060] a charge-providing ("donor") electric vehicle (EV) having a first traction battery pack;

[0061] a charge-receiving ("recipient") EV having a second traction battery pack; and

[0062] a vehicle-to-vehicle (V2V) charging unit configured to perform, by the donor EV, a V2V charging process of the recipient EV, the V2V charging unit comprising:

[0063] a housing having a donor charging port and a recipient charging port, the donor charging port and the recipient charging port being selectively connectable to the donor and the recipient, respectively, via corresponding charging cables and connectors;

[0064] an auxiliary battery connected to the housing; and

[0065] encapsulated within the housing are:

[0066] a high voltage (HV) bus having a donor HV circuit breaking device and a recipient HV circuit breaking device, wherein the HV bus is connectable to the donor and the recipient, respectively, via the donor HV circuit breaking device and the recipient HV circuit breaking device;

[0067] a low voltage (LV) bus having an auxiliary switch;

[0068] a bidirectional buck-boost HV-to-HV buck-boost converter connected to the HV bus between the donor HV circuit breaking device and the recipient HV circuit breaking device;

[0069] a bidirectional buck-boost HV-to-LV buck-boost converter connected to the HV bus and the LV bus;

[0070] a system controller connectable to the LV bus via the auxiliary switch;

[0071] a supply equipment communication controller (SECC) configured to detect charge port control signals via the donor charge port and the recipient charge port and to establish communication between the SECC and the system controller;

[0072] donor and recipient monitoring circuits configured to determine isolation status of the HV bus and open / closed status of the donor HV circuit breaking device and the recipient HV circuit breaking device; and

[0073] a system controller connectable to the auxiliary battery and in communication with the HV-to-HV converter, the HV-to-LV converter, the donor HV circuit breaking device and the recipient HV circuit breaking device, and the SECC, and configured to selectively command DC charge current unloading from the donor's battery pack through the HV converter and then to the recipient's battery pack during the V2V charging process.

[0074] Technical Solution 19. The vehicle system of Technical Solution 18, wherein the V2V charging unit comprises:

[0075] a thermal management system (TMS) connected to the auxiliary battery, the HV-to-HV converter, and the HV-to-LV converter; and

[0076] a relay selectively disconnecting a fan or pump of the TMS from the auxiliary battery to power the fan or pump in response to a relay control signal from the system controller.

[0077] Technical Solution 20. The vehicle system of Technical Solution 18, wherein the system controller is configured to execute an adaptive self-learning algorithm to analyze charging behavior of a group of recipients from previous charging processes and adjust performance of the V2V charging unit over time based on the charging behavior.

[0078] The above features and advantages and other features and attendant advantages of the present disclosure will become more readily apparent from the following detailed description, when taken in conjunction with the drawings in which: BRIEF DESCRIPTION OF DRAWINGS

[0079] Figure 1 is an illustration of a direct current to direct current (DC-DC) charging process in the form of a representative vehicle-to-vehicle (V2V) charging process in accordance with aspects of the present disclosure, wherein the V2V charging process is performed between an electric vehicle providing charge (“donor”) and an electric vehicle receiving charge (“recipient”) using a V2V charging unit.

[0080] Figure 2 ILLUSTRATION Figure 1 of a representative embodiment of a V2V charging unit.

[0081] Figure 3A , Figure 3B and Figure 3C collectively form a flowchart depicting a process for using a V2V charging unit of Figure 1 and Figure 2 during a representative V2V charging process.

[0082] The present disclosure can be modified or implemented in alternative forms, with representative embodiments shown in the drawings and described in detail below. The inventive aspects of the present disclosure are not limited to the disclosed embodiments. Rather, the present disclosure is intended to cover all alternatives, modifications, and equivalents falling within the scope of the disclosure as defined by the appended claims. DETAILED DESCRIPTION

[0083] Reference is made to the drawings, wherein identical reference numerals are used to designate identical elements throughout the several views, Figure 1Direct current to direct current (DC-DC) charging is depicted via a representative vehicle to vehicle (V2V) charging process 10 involving a vehicle system 11 having a charge-providing battery electrical system 12D and a charge-receiving battery electrical system 12R. During the illustrated V2V charging process 10, the charge-providing battery electrical system 12D (hereinafter referred to as the donor 12D for clarity) offloads a high voltage direct current (DC) charging current (DC-1) to a portable V2V charging unit 14. The V2V charging unit 14 in turn delivers a DC charging current (DC-2) to the charge-receiving battery electrical system 12R (hereinafter referred to as the recipient 12R). From the perspective of the recipient 12R, the donor 12D and the V2V charging unit 14 appear as electric vehicle supply equipment (EVSE), i.e., a non- on-board charging station. However, as described below, the optional portability and configured functionality of the V2V charging unit 14 provide benefits of enhanced charging mobility and reduced range anxiety for the owner / operator of the electrified system, among other attendant benefits, as compared to fixed non-on-board charging stations capable of providing direct current (DC) charging functionality.

[0084] As Figure 1 illustrated in Figure 1 , the donor 12D and the recipient 12R can optionally be configured as electric vehicles EV1 and EV2, respectively. As used herein, an “electric vehicle” can encompass a broad range of mobile electrified systems, including but not limited to battery electric vehicles, hybrid electric vehicles, extended range electric vehicles, and the like. Although motor vehicles are shown in Figure 1 , the skilled person will appreciate that the present teachings can be extended to many electrified systems, including rail vehicles, aircraft, boats, agricultural vehicles, delivery or transport vehicles, and the like. Thus, unless otherwise indicated, the illustrated motor vehicle scenarios of are merely illustrative of one possible approach and are non-limiting.

[0085] Figure 1 In a representative configuration of HVThe charging port 16 of the traction battery pack 18 (or another rechargeable energy storage system, such as a capacitor bank) is connected to the power inverter module (PIM) 22, i.e., the inverter circuit. During the discharge mode of the battery pack 18, the battery pack 18 delivers a DC voltage (VDC) to the DC side of the PIM 22. The PIM 22 is driven by pulse width modulation or another suitable switching control technique using the on / off conduction state control of multiple solid-state semiconductor switches (not shown) (such as insulated gate bipolar transistors (IGBTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), thyristors, etc.) to convert the DC voltage waveform to an alternating current (AC) voltage waveform and vice versa, as understood in the art. That is, the switching control of the PIM 22 ultimately converts the DC input voltage from the battery pack 18 into a voltage suitable for driving the electric traction motor (M E The AC voltage (VAC) of the phase winding of the electric traction motor 24 causes the machine to rotate. The output torque from the electric traction motor 24 (arrow T) O One or more load wheels 15 of donor 12D can be delivered without performing the charging process illustrated.

[0086] Figure 1 The receptor 12R shown can be similarly or identically configured to include a corresponding charging port 116, traction battery pack 118, DCFC contactor 120, PIM 122, and electric traction motor 124. Therefore, in addition to being equipped to perform... Figure 1 In addition to the V2V charging process 10 shown, the corresponding electric powertrain systems 50D and 50R are also configured to electrically propel the corresponding donor 12D and acceptor 12R during the separate discharge modes of the battery packs 18 and 118. In other words, Figure 2 In the illustrated embodiment, both the donor 12D and the recipient 12R are mobile systems capable of performing propulsion functions in addition to the V2V charging process 10 described herein.

[0087] refer to Figure 1 The illustration shows a representative structure of the V2V charging unit 14, and the traction battery pack 118 of the receiver 12R. Figure 2) can become sufficiently charge-depleted during operation of the recipient 12R such that the owner / operator of the recipient 12R needs to be charged. When this occurs, the owner / operator can request performance of the V2V charging process 10 as a mobile DCFC charging session, in accordance with the present teachings. During this event, the portable V2V charging unit 14 can be transported to the location of the recipient 12R, for example, by the donor 12D, the recipient 12R, or another vehicle such as a third-party roadside service provider. The aforementioned charging ports 16, 116 can receive SAE J1772, National Alternative Fuel Vehicle Charging Station (NAFCVCS), Combined Charging System (CCS), CHAdeMO, or other suitable charging connectors that are connected to or integrated with the charging cables. An electric power take-off (ePTO) port, commonly found on donor 12D / recipient 12R for mobile machinery, can be used in one or more embodiments that enable the DC power discharge contemplated herein.

[0088] The donor 12D and the recipient 12R are each equipped with an on-board electric vehicle (EV) controller 25, 125 having one or more processors (P) and a non-transitory computer readable storage medium (memory) (M). In cooperation with the circuitry of the intervening V2V charging unit 14, the donor 12D and the recipient 12R are equipped to communicate, manage and coordinate power flow, monitor proper connection and other conditions / error states of the charging cables / connectors, regulate the temperature of the V2V charging unit 14, and perform other related functions as described below, via exchange of data during the V2V charging process 10.

[0089] V2V charging unit (14): The V2V charging unit 14, as a sufficiently robust and optionally portable device, includes a housing 23 having a donor charging port 26 and a recipient charging port 126. The housing 23 can be constructed of a lightweight weatherproof material such as aluminum or a robust plastic. In some implementations, the charging cables and connectors 21 can be connected to the donor charging port 26 and the recipient charging port 126 as part of the V2V charging unit 14, or the charging cables and connectors 21 can be provided by the owner / operator of the respective donor 12D and recipient 12R. The donor charging port 26 and the recipient charging port 126 are thus capable of being selectively connected to the donor 12D and the recipient 12R, respectively, via the corresponding charging cables and connectors 21.

[0090] In Figure 2In the illustrated configuration, an auxiliary battery 28 (e.g., a 12V lead-acid or lithium-ion battery) is connected to the housing 23. The auxiliary battery 28 may be part of the V2V charging unit 14 shown, or externally connected, for example, via a corresponding auxiliary port (not shown) on the housing 23. Various electrical components are packaged within the volume of the housing 23. These components include a high-voltage (HV) bus 29 having a donor HV disconnect device 30 and a receiver HV disconnect device 130, such as a high-voltage electrical contactor, a single-push / single-throw (SPST) switch, or a solid-state relay (SSR) as understood in the art, having possible ratings of at least 1000V and 300A to cover the current full range of EV charging voltages and expected currents. The HV bus 29 is capable of being connected to donor 12D and receiver 12R via the respective donor HV disconnect device 30 and receiver HV disconnect device 130.

[0091] The housing 23 also encapsulates a low-voltage (LV) bus 31 having an auxiliary switch 32, which is implemented as, for example, a manually actuated push-button device, a smart switch, or a switching device activated via a control signal from an HMI or another external device or a command from a mobile application. A bidirectional buck-boost HV to HV converter 34 is connected to the HV bus 29 between the donor HV circuit breaker 30 and the recipient HV circuit breaker 130, and a bidirectional buck-boost HV to LV converter 35 is connected to the HV bus 29 and the LV bus 31. In one or more non-limiting embodiments, the converter 34 may be isolated or non-isolated, single-phase or multi-phase, and rated at least 50 kilowatts (kW), wherein “high voltage” is, for example, a voltage level of 150V to 1000V or higher. In other embodiments, the converter 34 may consist of a plurality of connected converters 34, each having a power rating of, for example, 25kW, 50kW, 75kW, 100kW, or another higher or lower rating depending on the embodiment.

[0092] Still referencing Figure 1 The V2V charging unit 14 also includes a system controller 36 that can be connected to the LV bus 31 via an auxiliary switch 32. For example, the system controller 36 can remain unpowered until the owner / operator of the donor 12D and the receiver 12R decides to activate it. Figure 2V2V charging process 10. In this case, auxiliary switch 32 can be closed to connect system controller 36 to LV bus 31 to initiate V2V charging process 10. In a“smart” system, initiation can be performed using a mobile application to enable auxiliary battery 28 to provide the necessary battery current for turning on system controller 36 or other loads. System controller 36 is configured to communicate internally and with other components of donor 12D and recipient 12R using, for example, controller area network (CAN) signals, analog / discrete signals, ISO / SPI, etc.

[0093] Figure 2 Also housed within housing 23 of FIG. 1 is a supply equipment communication controller (SECC) 40D and 40R for the respective donor 12D and recipient 12R. As contemplated herein, SECC 40D, 40R is configured to detect charging port control signals via donor charging port 26 and recipient charging port 126 and establish communication between SECC 40D, 40R and system controller 36 when performing V2V charging process 10. Thus, SECC 40D, 40R (either separate components or one component as shown) performs the necessary“handshaking” with EV controller 25, 125 of the respective donor 12D and recipient 12R.

[0094] Additionally, separate donor isolation monitoring circuit 42D and recipient isolation monitoring circuit 42R are configured to determine the isolation state of HV bus 29 and the open / closed state of donor HV circuit breaking device 30 and recipient HV circuit breaking device 130. Similarly, separate donor voltage / current monitoring circuit 44D and recipient voltage / current monitoring circuit 44R are configured as respective first and second electrical sensors or sensor suites that measure and monitor the corresponding voltage and current levels on HV bus 29 and that ensure proper fault-free operation of V2V charging unit 14. Also included on HV bus 29 and LV bus 31 are fuses (F) for overcurrent protection, where the fuses (F) are variously configured as, for example, thermal fuses, electronic fuses, or pyrotechnic fuses in different embodiments.

[0095] Figure 1 System controller 36 illustrated in FIG. 1 is capable of connecting to auxiliary battery 28 and communicating with HV-to-HV converter 34, HV-to-LV converter 35, donor HV circuit breaking device 30 and recipient HV circuit breaking device 130, and SECC 40D and 40R. In Figure 1 During V2V charging process 10 of FIG. 1, system controller 36 selectively commands DC charging current from battery pack 18 Figure 1 of donor 12D through HV-to-HV converter 34 to then unload to Figure 2 battery pack 180 of recipient 12R as shown in FIG. 1.

[0096] In one or more embodiments, Figure 2 The V2V charging unit 14 of the V2V charging system 10 includes a thermal management system (TMS) 43. Portions of the V2V charging unit 14 can be placed inside and / or integrated with the donor 12D and / or recipient 12R according to component size. This will enable the V2V charging unit 14 to share some of its components with portions of the donor 12D / recipient 12R, such as custom cooling lines or port connections, 12V / 24V / 48V auxiliary power via auxiliary power outlets, etc. Thus, Figure 2 The TMS 43 and other components of the V2V charging unit 14 are shown in the possible standalone portable configuration in the V2V charging system 10 without limiting the present teachings to such embodiments.

[0097] In the illustrated configuration, the TMS 43 can be connected to the HV-to-LV converter 35, the HV-to-HV converter 34, where the TMS 43 includes electrically powered fans and / or pumps 53F configured to circulate air or coolant (e.g., from a tank 57) to the HV-to-HV converter 34 and the HV-to-LV converter 35. A heat exchanger or evaporator 55 can be used as part of the process to facilitate heat extraction from the converters 34 and 35. In such embodiments, a relay 52 (connections omitted for clarity) can be selectively disconnected from the auxiliary battery 28 via the system controller 36 in response to a relay control signal from the relay 52. That is, the TMS 43 is used for thermal management of the converters 34 and 35, where auxiliary power from the auxiliary battery 28 is used to turn on and keep the fan / pump 53F running for as long as needed. Similarly, the V2V charging unit 14 can include an emergency stop (ES) button 45 located in or near the housing 23, where a press of the emergency stop button 45 is used to initiate an immediate termination of the V2V charging process 10.

[0098] Figure 1 Additional components of the V2V charging unit 14 can include a human-machine interface (HMI) 46, such as a touchscreen display, connected to the portable housing 23. The HMI 46 can be configured to accept user input (CC U) receiving system controller 36 and displaying information related to the process. For example, in one or more embodiments, system controller 36 can be configured to quantify the V2V charging process 10 when it is completed, generate a summary of the charges for the V2V charging process 10 and transmit the summary of charges to the owner / operator or other user of recipient 12R, e.g., wirelessly. System controller 36 can also be configured to perform an adaptive self-learning algorithm to analyze the charging behavior of a group of recipients 12R from previous V2V charging processes 10 and adjust the performance of V2V charging unit 14 over time based on such past charging behavior.

[0099] V2V charging unit 14 can optionally be equipped with a unique identifier (ID) code, e.g., a unique string of numbers and / or letters that uniquely identifies V2V charging unit 14 from a larger population of similarly equipped V2V charging units 14. Such ID code will facilitate such process quantification as well as security / verification. To this end, the wireless interface can be configured to remotely enable the pairing of donor 12D and recipient 12R in response to the unique ID code matching the corresponding ID code stored in the respective memories (M) of donor 12D and recipient 12R.

[0100] System controller (36): located Figure 3A at the core of V2V charging process 10, system controller 36 is configured to oversee, monitor and control the various functions required to execute process 10. System controller 36 works in conjunction with SECCs 40D and 40R throughout process 10. Via the flowcharts in Figure 3B , Figure 3C and Figure 2 describing the functions of V2V charging unit 14 in exemplary embodiments, the flowcharts collectively describe the process of V2V charging process 10 via the corresponding processes 100A, 100B and 100C. That is, for clarity of illustration, V2V charging process 10 is broken down into V2V charging processes 100A, 100B and 100C, which together form charging process 10 as described herein. Figure 1 Figure 2 With regard to

[0101] Figure 2 ​​The component control units can be equipped with electrical connectors and / or wireless connections to communicate with the various other control devices or sensor devices described above. Although omitted for clarity and simplicity, the functions of the system controller 36 and other control devices occur by execution of computer-readable instructions from a tangible, non-transitory computer-readable storage medium similar to the memory (M) of the EV controllers 25 and 125. Such memory can include magnetic or optical media, CD-ROMs, and / or solid state / semiconductor memory (e.g., various types of RAM or ROM).

[0102] Although shown schematically in Figure 1 the system controller 36 and other depicted control devices can be implemented as control modules, control units, processors, and similar terms can refer to one or various combinations of application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), electronic circuit(s), central processing unit(s) (e.g., microprocessor(s)), and associated non-transitory memory components in the form of memory and storage devices (read only, programmable read only, random access, hard drives, etc.). The non-transitory components of memory used herein are capable of storing machine-readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuits, input / output circuit(s) and devices, signal conditioning and buffering circuitry, and other components.

[0103] The mobile insertion functionality as contemplated herein involves coordinated bidirectional data communication between the donor 12D and the recipient 12R. The data exchange regulated by the SECCs 40D, 40R requires transmission of low voltage control pilot or communication (Comm) signals typically in the range of 0-12V and a proximity voltage signal of 0-5V. Electrical ground is also provided. For example, an established J1772 connection allows the respective processors of the donor 12D and the recipient 12R to communicate with each other using power line communication (PLC) for the communication signals, which in turn proceed via coordinated exchange of data messages in accordance with an established communication protocol. The communication signals are typically used to verify the connection between the off-board EVSE charging station and the charging EV, which are respectively the donor 12D and the V2V charging unit 14 (together functioning as such EVSE charging station) and the recipient 12R herein, to communicate the state of charge. This can occur, for example, using a fixed duty cycle during the contemplated DC charging. The same signals can be used to adjust the charging rate as needed. Other standards such as the aforementioned NACS, CCS, CHAdeMO, etc. can be used in a similar manner, and thus the particular charging standard can vary with the desired end use.

[0104] Figure 3AThe V2V charging process 10 is coordinated via the exchange of data / messages between the EV controller 25 of the donor 12D, the system controller 36 of the V2V charging unit 14, and the SECCs 40D, 40R, and the corresponding EV controller 125 (e.g., a battery management system or another battery controller) of the recipient 12R. The above-mentioned communication signals and proximity signals are exchanged according to a predetermined protocol, wherein the general process of DC charging is conducted according to DIN 70121 or other related protocols well known in the art, such as international protocols / standards like ISO 15118-20, ISO 15118-2, etc. Such protocols proceed according to a defined multi-step electronic “handshake” process before allowing energy transfer, wherein this process is also mentioned in the following description of the charging process 10. Wireless communication can be facilitated via one or more communication modules connected to or usable with, e.g., BLE / WiFi / LTE.

[0105] For the sake of clarity, Figure 3B , Figure 3C and Figure 2 collectively represent embodiments of the charging process 10 using discrete process steps, segments, or logical blocks. Each constituent block of the charging process 10 can be implemented in the sequence set forth herein to conduct the V2V charging process 10 using representative hardware of Figure 1 . Figure 3A

[0106] Referring first to Figure 1 , the charging process 100A begins at block B102, wherein an emergency charge is requested for the recipient 12R of Figure 2 and Figure 3A . For example, the owner / operator of the recipient 12R can transmit a request to the owner / operator of the donor 12D, request the V2V charging process 10 via an SMS text message or a phone call using , or otherwise signal a need or desire for the V2V charging process 10. The charging process 100A then proceeds to block B104.

[0107] At block B104, the donor 12D arrives at the location and parks near the recipient 12R. In this case, the donor 12D can park in front of or alongside the recipient 12R such that the charging ports 16 and 116 are easily accessible to one another. Thereafter, the charging process 100A proceeds to block B106.

[0108] Figure 1 Block B106 includes connecting the charging cable 23 to Figure 2 and Figure 3A ​The donor 12D and V2V charging unit 14. For example, the charging cable 23 can be a CCS / NACS charging cable as described above, in which case one end of the cable 23 can be inserted into the charging port 16 on the donor 12D. Once the charging cable 23 has been securely connected to the donor 12D, the charging process 100A proceeds from block B106 to block B108.

[0109] At block B108, similar to block B106, another charging cable 23 is connected between the charging port 116 of the V2V charging unit 14 and the charging port 116 of the recipient 12R. Upon completion of block B108, the donor 12D is electrically connected to the recipient 12R via the intermediary V2V charging unit 14. Thereafter, the charging process 100A proceeds to block B110.

[0110] Figure 2 Block B110 includes powering the V2V charging unit 14. This includes powering the system controller 36 of the V2V charging unit 14 via low-voltage power from the LV bus 31. For example, Figure 3A The auxiliary switch 32 can be manually activated or manually actuated to connect the LV bus 31 to the system controller 36. Afterward, the charging process 100A continues to block B112.

[0111] At block B112, system controller 36 is powered on and woken up. When LV bus 31 is powered on, one or more 12V loads can also be powered on and woken up during this 100A charging phase. The power-on / wake-up state of system controller 36 corresponds to... Figure 3B Point A in the illustrated processing flow.

[0112] Now for reference Figure 3A The charging process is 100B, and from Figure 2 Starting at point A, the charging process 100B proceeds to blocks B128 and B129 to begin the function of donor 12D, and then to block B129 to begin the function of recipient 12R. For example, using Figure 3B In HMI 46, the user can request charging via donor 12D, which will then initiate the remaining charging sequence. Charging process 100B proceeds to blocks B130 and B131 after completing blocks B128 and B129, respectively.

[0113] like Figure 3B As illustrated, block B128 is similar to block B129, block B130 is similar to block B132, block B132 is similar to block B133, and so on. Block B139, described below, relates to the pre-charging of the acceptor 12R, which occurs once the pre-charging of the donor 12D is complete and the contactor of the donor 12D is closed, i.e., after blocks B138 and 140 are completed.

[0114] Blocks B130 and B131 need to detect the charging port control signal via SECC 40D, 40R. The charging port signal indicates the electrical connection between donor 12D and acceptor 12R. As understood in the art, this may require checking the CP voltage, duty cycle, and resistance via the respective donor 12D and acceptor 12R's SECC 40D, 40R, and initiating bidirectional communication between EV controllers 25 and 125.

[0115] Blocks B132 and B133 may include authentication of the donor 12D and the recipient 12R, for example by determining whether the donor 12D has received an electronic handshake signal such as a transport layer security (TLS) handshake from the recipient 12R (block B132) and vice versa (block B133).

[0116] Therefore, a handshake / communication is established between SECC 40D, 40R and system controller 36 in response to the charging port control signal to initiate the V2V charging process 10. As understood in the art, such a handshake signal is typically used to establish an encrypted bidirectional communication session between the charge provider and charge acceptor during EV charging. This is extended to the current V2V charging process 10. After authentication is complete, the charging process 100B proceeds to blocks B134 and B135.

[0117] exist Figure 2 At blocks B134 and B135, donor 12D and recipient 12R transmit their respective voltage, current, power, and state of charge (SOC) limits to V2V charging unit 14 over the established connection via intermediary charging cable 23. Through intermediary V2V charging unit 14 and its resident system controller 36 and SECC 40D, 40R, the respective EV controllers 25 and 125 of donor 12D and recipient 12R are aware of each other's capabilities. V2V charging unit 14 responds to a successful handshake by pre-charging DC bus 56 of FIG3. Thereafter, charging process 100B proceeds to blocks B136 and B137.

[0118] Blocks B136 and B137 require the inspection and isolation of cable 23, the latter using the aforementioned... Figure 2 Isolation monitors 42D and 42R. Afterwards, the charging process 100B proceeds to blocks B138 and B139.

[0119] Continuing the discussion of charging process 100B, blocks B138 and B139 include pre-charging the HV bus 29 on the donor 12D side (block B138), and subsequently pre-charging the HV bus 29 on the acceptor 12R side (block B139). For this purpose, Figure 2HV-to-LV converter 38 can operate in a boost mode such that the internal switches and power conversion of HV-to-LV converter 35 are operated to increase the voltage level of LV energy storage device 28 to match the higher voltage level of donor 12D. Thereafter, charging process 100B proceeds to blocks B140 and B145.

[0120] Part of V2V charging process 10 includes commanding donor HV disconnect device 30 and recipient HV disconnect device 130 on HV bus 29 to close via system controller 36, thereby connecting HV-to-HV converter 34 to HV bus 29; recharging LV bus 31 via HV-to-LV converter 45; and using Figure 3B Separate donor monitoring circuit 44D and recipient monitoring circuit 44R of V2V charging unit 14 are used to determine the isolation state of HV bus 29 and the open / close state of donor HV disconnect device 30 and recipient HV disconnect device 130. This occurs prior to selectively commanding the DC charging current to be offloaded from traction battery pack 18 of donor 18D through HV-to-HV converter 45 to traction battery pack 118 of recipient 12R.

[0121] To this end, Figure 2 Block B140 includes determining via system controller 36 of V2V charging unit 14 whether DCFC contactor 20 Figure 2 ) on donor 12D is closed, and Figure 3B whether first set of disconnect devices 30 of V2V charging unit 14 are likewise closed. Once DCFC contactor 20 and first set of disconnect devices 30 of V2V charging unit 14 are closed, charging process 100B proceeds to Figure 3C block B142, and in the alternative when DCFC contactor 20 or disconnect devices 30 are in an open state, charging process 100B returns to Figure 3B block B121.

[0122] Block B142 includes completing a handshake between donor 12D and recipient 12R, and recording a bit flag or suitable code in memory of system controller 36 indicating the handshake. Thereafter, charging process 100B proceeds to block B144.

[0123] At block B144, system controller 36 transitions HV-to-LV converter 35 into a voltage-reducing "buck" mode to maintain auxiliary battery 28 or other low voltage energy storage system at a calibrated low voltage level, nominally about 12-15V. Once the buck mode has taken effect, charging process 100B proceeds to block B145.

[0124] At block B145, system controller 36 commands HV-to-LV converter 38 to operate in a boost mode to increase the voltage level of auxiliary battery 28 to match the higher voltage level of donor 12D. Thereafter, charging process 100B proceeds to block B150. Figure 3CAt block B145, system controller 36 next verifies that HV disconnect device 130 of V2V charging unit 14 and DCFC contactor 120 of recipient 12R are closed. When closed, charging process 100B proceeds to block B147. Charging process 100B proceeds in the alternative to block B121 (point D). Figure 3C

[0125] Block B147 includes determining completion of the handshake with donor 12D and recording a bit flag or suitable code in memory of system controller 36 indicating the handshake. Thereafter, charging process 100B proceeds to block B149 or to block B121 (point D) when system controller 36 is unable to determine that the handshake has been completed.

[0126] Block B149 includes requesting delivery of charging power from donor 12D. Block B149 can require communication of such a request by SECC 40R to system controller 36, where system controller 36 thereafter communicates with EV controller 25 on donor 12D via SECC 40D. Charging process 100B then proceeds to blocks B151 and B153.

[0127] At blocks B151 and B153, donor 12D and recipient 12R respectively discharge and receive suitable charging current / voltage. The magnitude of either can be dynamically changed by system controller 36, for example via commands to various control nodes of V2V charging unit 14, to charge battery pack 118 on recipient 12R. Charging process 100B thus completes at point B of FIG. 3, which proceeds to Figure 3C block B114.

[0128] Referring now to Figure 2 and beginning at block B114, charging process 100C proceeds by controlling operation of V2V charging unit 14 to control power flow from donor 12D to recipient 12R. As this step continues, charging process 100C proceeds to block B116.

[0129] Block B116 includes scanning for cable / disconnection errors. If Figure 2 Such errors can occur if either of charging cables 23 becomes loose or disconnected. In the event that such an error is detected, charging process 100C proceeds to block B118. In the absence of such an error, charging process 100C proceeds in the alternative to block B117.

[0130] At block B117, Figure 2 ​The system controller 36 verifies whether the corresponding state of charge (SOC) of the donor 12D and the acceptor 12R has reached the predetermined SOC limit. If so, the charging process 100C proceeds to block B121; otherwise, the charging process 100C continues to block B119.

[0131] Block B118 includes stopping energy transfer through V2V charging unit 14. Block B118 may need to set bit codes to record this change in state, where the setting of the bit codes triggers subsequent blocks B120, B122, B124, and B126.

[0132] At block B119, system controller 36 next determines whether the user has requested to terminate V2V charging process 10. For example, the owner / operator of donor 12D or recipient 12R can do so via wireless or HMI-based communication with system controller 36 (e.g., via...). Figure 1 The user requests that the V2V charging process 10 be stopped via the HMI 46 and / or via an application on a cellular phone or tablet. When the user requests that the V2V charging process 10 should be stopped, the charging process 100C proceeds to block B121.

[0133] At block B120, the DCFC contactor 120 of receptor 12R can be commanded to disconnect, which occurs before the DCFC contactor 20 of receptor 12D is commanded to disconnect. Then, the charging process 100C proceeds to block B122.

[0134] Block B121 includes terminating the V2V charging process 10. This may require transmitting the necessary signal from the EV controller 125 of the receiver 12R to the system controller 36 of the V2V charging unit 14, indicating that the receiver 12R no longer needs charging. As part of block B121, the system controller 36 may command the circuit breaker 130 to disconnect, thereby interrupting the high-voltage connection between the V2V charging unit 14 and the receiver 12R. On the receiver 12R, Figure 2 The DCFC contactor 120 is also commanded to disconnect. Then, the charging process 100C proceeds to block B120.

[0135] At block B122, system controller 36 can command TMS 43 to stop operating. This can include commands. Figure 3C The fan and pump 53F stop. Then, the charging process 100C proceeds to block B124.

[0136] Block B124 needs to terminate the V2V charging process 10 before proceeding to block B126.

[0137] exist Figure 1At block B126, the system controller 26 can optionally generate a summary of the charging time, kilowatt hours (kWhr), and possibly associated financial costs for the V2V charging process 10. This allows the system controller 26 to quantify the DCFC charging process upon completion, generate a cost summary for the DCFC charging process, and communicate the cost summary to the user of the recipient, e.g., via a smart phone, email, electronic funds transfer, etc. Once block B126 has been performed, the charging process 100C is complete.

[0138] Accordingly, the above-described mobile DCFC-related hardware and software solutions provide an electrical architecture that enables energy transfer between two EVs or other battery electrical systems equipped with high-voltage rechargeable energy storage systems (illustrated herein as traction battery packs 18 and 118) to occur. The portability of the V2V charging unit 14 and its ability to be configured together enable faster, more flexible, and user-convenient mobile charging in a V2V environment relative to such alternative approaches. In view of the foregoing disclosure, those skilled in the art will readily understand the benefits and other attendant benefits of these advantages. ​

[0139] The present disclosure allows for many different forms of embodiments. Representative examples of the present disclosure are shown in the drawings and described in detail herein as non-limiting examples of the disclosed principles. To this end, elements and limitations described in the Abstract, Introduction, Summary, and Detailed Description sections are not to be construed as limitations on the scope of the claims unless expressly recited in a claim.

[0140] For purposes of this specification, unless specifically stated otherwise, the use of the singular includes the plural and vice versa, the use of "and" and "or" means "and / or", "any" means "any and all", and the use of "including" means "including but not limited to". In addition, the words "approximately", "about", "substantially", "generally", "almost", and the like, can be used in this disclosure in the sense of "within 0-5% of", or "within acceptable manufacturing tolerances" or "within a range that is acceptable for the ordinary skill in the art", or their logical equivalents.

[0141] The detailed description and accompanying drawings or diagrams are support and description of the present teachings, but the scope of the present teachings is only limited by the claims. While there has been described herein the best mode and other embodiments for the practice of the present teachings, the teachings are to cover all alternatives, modifications, equivalents, and equivalents falling within the scope of the appended claims. In addition, the disclosure explicitly includes combinations and sub-combinations of the elements and features presented above and below.​

Claims

1. A charging unit for performing a charging process between a charge providing system ("donor") and a charge receiving system ("acceptor"), comprising: The housing has a donor charging port and a receiver charging port, which can be selectively connected to the donor and the receiver respectively via corresponding charging cables and connectors; An auxiliary battery is connected to the housing; and The following are encapsulated within the housing: A high-voltage (HV) bus having a donor HV disconnect device and a recipient HV disconnect device, wherein the HV bus can be connected to the donor and the recipient respectively via the donor HV disconnect device and the recipient HV disconnect device; Low voltage (LV) bus with auxiliary switches; A bidirectional buck-boost HV to HV converter connected to the HV bus between the donor HV disconnect device and the recipient HV disconnect device; A bidirectional buck-boost HV to LV converter, which is connected to the HV bus and the LV bus; The system controller is connected to the LV bus via the auxiliary switch; A power supply equipment communication controller (SECC) is configured to detect a charging port control signal via the donor charging port and the receiver charging port and to establish communication between the SECC and the system controller in response to the charging port signal. Corresponding donor isolation monitoring circuits and recipient isolation monitoring circuits are configured to determine the isolation status of the HV bus and the open / closed status of the donor contactor and the recipient contactor; and A system controller, which is connected to the auxiliary battery and communicates with the HV-to-HV converter, the HV-to-LV converter, the donor HV disconnect device, the recipient HV disconnect device, and the SECC, is configured to selectively command the DC charging current to be unloaded from the donor's battery pack through the HV buck-boost converter and then to the recipient's battery pack.

2. The charging unit according to claim 1, wherein, The donor monitoring circuit and the recipient monitoring circuit each include a first electrical sensor and a second electrical sensor, which are each configured to measure the corresponding voltage and current on the HV bus.

3. The charging unit according to claim 1, wherein, The auxiliary switch is a manually actuated button device.

4. The charging unit according to claim 1 further includes: A thermal management system (TMS) is connected to the auxiliary battery, the HV to HV converter, and the HV to LV converter; and A relay, in response to a relay control signal from the system controller, selectively disconnects the fan or pump of the TMS from the auxiliary battery to energize the fan or pump.

5. The charging unit according to claim 4, wherein, The TMS includes an electric fan or pump configured to circulate air or coolant to the HV-to-HV converter and the HV-to-LV converter.

6. The charging unit according to claim 1, further comprising: A human-machine interface (HMI) is connected to the housing, wherein the HMI is configured to receive user input from the system controller and display information related to the charging process.

7. The charging unit according to claim 1, wherein, The system controller is configured to quantify the charging process upon completion, generate a cost summary for the charging process, and transmit the cost summary to the recipient's user.

8. The charging unit according to claim 1, wherein, The system controller is configured to execute an adaptive self-learning algorithm to analyze the charging behavior of a set of receptors from previous charging processes, and adjust the performance of the charging unit over time based on the charging behavior.

9. A vehicle-to-vehicle (V2V) charging process, comprising: In response to the actuation of the auxiliary switch, the system controller of the V2V charging unit is powered on via the low voltage (LV) bus; The power supply equipment communication controller (SECC) of the V2V charging unit detects the charging port control signal, which indicates the electrical connection between the charge providing vehicle ("donor") and the charge receiving vehicle ("receiver"); In response to the charging port control signal, a handshake / communication is established between the system controller of the SECC and the V2V unit, thereby initiating the V2V charging process; and During the V2V charging process: The system controller commands the individual donor HV disconnect device and acceptor HV disconnect device on the HV bus of the V2V charging unit to close, thereby connecting the bidirectional buck-boost HV to HV converter to the HV bus; The LV bus is recharged via a bidirectional buck-boost HV-LV converter; The individual donor monitoring circuit and acceptor monitoring circuit of the V2V charging unit are monitored to determine the isolation status of the HV bus and the open / closed status of the donor HV circuit breaker and the acceptor HV circuit breaker. and Selectively, DC charging current is directed from the donor's battery pack through the HV-to-HV converter and then to the recipient's battery pack for unloading.

10. A transportation system, comprising: A charge-providing ("donor") electric vehicle (EV) having a first traction battery pack; Charge receiving ("receptor") EV, which has a second traction battery pack; and A vehicle-to-vehicle (V2V) charging unit configured to perform a V2V charging process for the recipient EV by the donor EV, the V2V charging unit comprising: The housing has a donor charging port and a receiver charging port, which can be selectively connected to the donor and the receiver respectively via corresponding charging cables and connectors; An auxiliary battery is connected to the housing; and Encapsulated within the housing are: A high-voltage (HV) bus having a donor HV disconnect device and a recipient HV disconnect device, wherein the HV bus can be connected to the donor and the recipient respectively via the donor HV disconnect device and the recipient HV disconnect device; Low voltage (LV) bus with auxiliary switches; A bidirectional buck-boost HV to HV buck-boost converter is connected to the HV bus between the donor HV disconnect device and the recipient HV disconnect device; A bidirectional buck-boost HV to LV buck-boost converter, which is connected to the HV bus and the LV bus; The system controller is connected to the LV bus via the auxiliary switch; A power supply equipment communication controller (SECC) is configured to detect charging port control signals via the donor charging port and the receiver charging port and establish communication between the SECC and the system controller; Donor monitoring circuitry and recipient monitoring circuitry are configured to determine the isolation state of the HV bus and the open / closed state of the donor HV disconnect device and the recipient HV disconnect device; and A system controller, which is connected to the auxiliary battery and communicates with the HV-to-HV converter, the HV-to-LV converter, the donor HV disconnect device, the recipient HV disconnect device, and the SECC, and is configured to selectively command the DC charging current to be unloaded from the donor's battery pack through the HV converter and then to the recipient's battery pack during the V2V charging process.

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