An electric vehicle (EV) charger control device

Abstract

The invention relates to an electric vehicle (EV) charger control device. The device comprises a data communication interface, a memory configured to store a maximum available EV charging current, and a processor configured to couple to load sensors. At least one load sensor measures current used by one or more electronic devices other than an EV vehicle charger. The processor is configured to obtain at least one load current measurement detected by the load sensor, determine a maximum available current remaining in a multi-use circuit, calculate an available EV charging current, and compare the available EV charging current to a previously set maximum available EV charging current stored in the memory. When the available EV charging current does not correspond to the previously set maximum available EV charging current, the processor automatically sets the maximum available EV charging current and sends a command message to the EV charger.

Description

AN ELECTRIC VEHICLE (EV) CHARGER CONTROL DEVICE

[0001] The present invention generally relates to engineering of an electric vehicle (EV) charger control device and more specifically relates to the control device that can adaptively determine the EV charging current.

[0002] To charge an electric vehicle (EV) at home, a large amount of electric current must be drawn through a circuit breaker. A separate electric power network is normally required to support an EV home charger. The separate network has its disadvantage in that it is costly and must match the required current load of a designed EV. Adding one or more EVs, the network may need to be adjusted to meet the new current load.

[0003] EV chargers with dynamic load balancing have been available in markets. They normally require a manual load setting. If the setting is not correct or matched with the current conditions, the charging time may be longer than necessary, or it may cause current overloading when other electrical appliances are being used at the same time.

[0004] U.S. Pat. No. US11186194B2 has disclosed a charging device comprises an optimization module configured to create a charging profile based on power consumption predictions for EV and other equipment items. The profile switches the operation between the charging mode for an EV and for other appliances.

[0005] It is still necessary to have a charger that can simultaneously supply both EV and other equipment at the same time on the same network to reduce the cost of EV charger setup. Moreover, most EV chargers are supplied by EV manufacturers, they cannot be modified or added sensors or other devices onto them. It is thus an aim of the present invention to provide the charger control device that can communicate with an existing EV charger and control its supplied current when other equipment is operating on the same network.

[0006] The present invention relates to an electric vehicle (EV) charger control device comprising a data communication interface, a memory configured to store a maximum available EV charging current, and a processor. The processor is configured to communicatively couple to at least one load sensor via the data communication interface, wherein the at least one load sensor measures current used by one or more electronic devices other than an EV vehicle charger. The processor is further configured to obtain, from the at least one load sensor, at least one load current measurement detected by the at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit. From the at least one load sensor, the processor further determines a maximum available current remaining in a multi-use circuit based on the obtained one or more load current measurement, calculate an available EV charging current based on the maximum available current remaining in the multi-use circuit, and compare the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current. When the available EV charging current does not correspond to the previously set maximum available EV charging current, the processor automatically sets the maximum available EV charging current to correspond to the calculated available EV charging current and automatically sends a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.

[0007] In another embodiment, a computerized method for controlling an electric vehicle (EV) charger is disclosed. The method comprises the steps of obtaining, from at least one load sensor, at least one load current measurement detected by at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit; determining a maximum available current remaining in the multi-use circuit based on the obtained one or more load current measurement; calculating an available EV charging current based on the maximum available current remaining in the multi-use circuit; and comparing the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current. When the maximum available EV charging current does not correspond to the previously set maximum available EV charging current, the method further comprises automatically setting the maximum available EV charging current to correspond to the calculated available EV charging current, and automatically sending a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.

[0008] The objective of the present invention is to provide an electric vehicle (EV) charger control device comprising a data communication interface, a memory, and a processor, wherein the processor is configured to communicatively couple to at least one load sensor that measures current used by one or more electronic devices other than an EV vehicle charger, to obtain at least one load current measurement detected by the load sensor, to determines a maximum available current remaining in a multi-use circuit, to calculate an available EV charging current based on the maximum available current remaining in the multi-use circuit, and to compare the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current. If the available EV charging current does not correspond to the previously set maximum available EV charging current, the processor automatically sets the maximum available EV charging current to correspond to the calculated available EV charging current and automatically sends a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.Fig.1

[0009] shows schematic block diagram of the electric vehicle charger control device of the present invention.Fig.2

[0010] shows a process flow of the method of the present invention.Fig.3

[0011] shows another embodiment of the process flow of the method of the present invention.

[0012] An electric vehicle (EV) charger control device of the present invention according to many embodiments is shown in. The device100comprises a data communication interface10, a memory20, and a processor30. The processor30is configured to communicatively couple to at least one load sensor40via the data communication interface10. The interface10allows data transfer between the load sensor40and processor30. The memory20is configured to store a value indicating maximum available EV charging current that a charger200can supply. The maximum available EV charging current may be supplied to one or more electric vehicles300. If only one EV is connected to the charging network, the current amount that can be supplied to the EV is less than or equal to the maximum available EV charging current. If more than one EVs are connected to the network, the current amount supplied for each EV may be reduced proportionally from the maximum available current. But the sum cannot be more than the indicated maximum available EV charging current.

[0013] Normally, the maximum available EV charging current is determined by an electric power distribution network which allows a particular current load to be drawn from the network to consumer products and / or electric vehicles. A multi-use circuit or a circuit breaker is normally installed to protect the network from current overloading. An EV charger installed to the grid must comply with this current limit to prevent electric short circuits or fire hazards due to current overloading.

[0014] It is emphasized that the purpose of the multi-use circuit and circuit breaker is the same as to provide a protection to the network from current overloading. Multi-use circuits, however, may be used to provide other functionalities and indicators such as safety mechanisms or couplers, etc. Thus, multi-use circuits are more generic than circuit breakers in views of the present invention.

[0015] The processor30is configured to communicatively couple to at least one load sensor40via the data communication interface10allowing data transfer between the processor and the load sensor. The interface can be either wired or wireless. The data may include sensor data and a control protocol allowing the processor to control the sensor operations and read back a measurement from the sensor for further processing.

[0016] The load sensor40measures current, voltage, or both that is consumed by one or more electronic devices400and one or more EV chargers200. The purpose of the load sensor40is to measure the electric power consumed by electronic devices or other electrical equipment in the network. The measurement values from the sensor are used to determine the current available for EV charging so that when one or more EV chargers200operate, the total current drawn from the network does not exceed the network current limit. Example of the electronic devices400include, but are not limited to, air conditioners, heaters, refrigerators, laundry machines, dishwashers, televisions, or lighting devices.

[0017] The processor30is further configured to obtain, from the at least one load sensor40, at least one load current measurement detected by the at least one load sensor40. The load current measurement corresponding to a load current used by one or more electronic devices400and one or more EV chargers200on a multi-use circuit or a circuit breaker. When there is more than one load sensors, the processor30may read their current measurement sequentially and store the measurement values onto the memory20for further processing. The memory20can be an embedded memory in the processor30or an external memory disposed on the same electrical circuit or other external memory that the processor30can access its data. The memory20can be either volatile or non-volatile.

[0018] The processor30is further configured to determine a maximum available current remaining in a multi-use circuit based on the obtained one or more load current measurement. In general, a multi-use circuit can handle a limited amount of load current supplied through it. For example, a dual function circuit breaker Siemens B120DFH can operate at 120VAC with the maximum current 20A. By knowing the maximum current limit of a multi-use circuit, one can either use it to configure the processor30or store it in the memory20and configure the processor30to read it for processing. The maximum available current remaining in a multi-use circuit is the amount of load current that is available in the current state while other equipment on the same network is operating. For example, the Siemens B120DFH will have the maximum of 15A current available when the processor30obtains a 5-A reading of load current measurement from load sensor40. It means that at the current state, the EV charging current supplied to an EV cannot be more than 15A, preferrable less for safety purposes.

[0019] The processor30is further configured to calculate an available EV charging current based on the maximum available current remaining in the multi-use circuit. The available EV charging current is the actual current that the charger is allowed to supply to one or more EVs. The available EV charging current may be configured to be the same as the maximum available current or a proportion of it. For example, the available EV charging current is 80% of the maximum available current in order to have a level of spare current available in the circuit network.

[0020] The processor30is further configured to compare the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current. If the available EV charging current does not correspond to the previously set maximum available EV charging current, the processor30is configured to automatically set the maximum available EV charging current to correspond to the calculated available EV charging current and automatically send a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn. In particular, the processor30creates a new control pilot (CP) signal to control the charging current of the EV charger. Preferably, the format of the CP signal follows SAE J1772 standard allowing the current invention to be compatible with other AC chargers available in the markets.

[0021] The load current used by one or more electronic devices400other than an EV charger200may be changing from time to time. The processor30monitors and compares the available EV charging current to the maximum available EV charging current to ensure that the EV charger200does not supply overloaded current to one or more electric vehicles300that may cause the multi-use circuit or the circuit breaker to trip or burn.

[0022] In a particular embodiment, the processor30is further configured to determine the maximum available current remaining in the multi-use circuit or the circuit breaker by subtracting the obtained one or more load current measurement from the maximum current of the multi-use circuit. For example, if the maximum current of the multi-use circuit is 100A and the load current measurement reads 60A, the maximum available current remaining in the multi-use circuit is calculated from 100A-60A, which is equal to 40A. This allows one or more electric vehicles300to draw a maximum of 40A current from the EV charger200. When the load current measurement changes; for example, when an air conditioner is turned on, the corresponding maximum available current changes accordingly to prevent the current from exceeding 100A. Preferably, the maximum current of the multi-use circuit is configurable so that the EV charger control device according to this invention can be configured to operate with different load limitations.

[0023] In a particular embodiment, the processor30may be further configured to calculate the available EV charging current to be a proportion of the maximum available current remaining in the multi-use circuit and the proportion of the maximum available current remaining is less than one hundred percent of the maximum available current remaining and more than zero percent of the maximum available current remaining.

[0024] In a particular embodiment, an additional load sensor may be disposed to measure the EV charging current (denoted as Icharge_sensor). The EV load current is measured so that the processor30can monitor the current supplied to one or more electric vehicles. With the additional load sensor, the processor30determines the load current used by one or more electronic devices400and measures the current used by the EV charger200. The current supplied (denoted as Iuse) to one or more electronic devices400other than an EV charger200may be determined by subtracting the load current measurement from load sensor40(denoted as Isensor) by the EV charging current (Icharge_sensor). Therefore, the available EV charging current can be determined by the difference between the maximum available current (denoted as Imax) and the current supplied (Iuse).

[0025] shows an embodiment of the process flow that the processor30can be configured to create CP signals to control an EV charger according to this embodiment. Firstly, the processor30obtains load current measurement from load sensor (Isensor) and adds an initial charging current (Ilow) to 6A to the measurement value. This initial charging current (Ilow) is intended to be used as the EV charging current if the total current does not exceed the maximum available current (Imax) of the multi-use circuit. If the added value does not exceed the maximum available current, the processor30sets the initial EV charging current to Ilow (6A) and sets charging current limit (Ic_limit). The processor30, then, calculates the current supplied (Iuse) to one or more electronic devices400other than an EV charger200by subtracting the load current measurement from load sensor (Isensor) by the EV charging current (Icharge_sensor). The available EV charging current (Icharge) can be determined by the difference between the maximum available current (Imax) and the current supplied (Iuse). If the determined available EV charging current (Icharge) exceeds the maximum charging current (Ic_max), the processor30limits the available EV charging current (Icharge) to the maximum charging current (Ic_max). If the determined available EV charging current (Icharge) is less than initial charging current (Ilow), the processor30stops the charging process. Otherwise, the processor30checks the charging current limit (Ic_limit). If the charging current limit (Ic_limit) is less than the available EV charging current (Icharge), the processor30increases the charging current limit (Ic_limit) by an increasing step INC. If the charging current limit (Ic_limit) exceeds the available EV charging current (Icharge), the processor30decreases the charging current limit (Ic_limit) by a decreasing step DEC. Then, the processor30sets the EV charging current to the charging current limit (Ic_limit). The processor30continues the charging process until the EV battery is fully charged or a stop charging signal is received. Whenever the load current exceeds the maximum available current, due to the increasing of the load current measurement, the processor30stops the charging process by sending a command message to the EV charger200to stop its charging operation. In between the process, the processor30keeps monitoring the load current and compares the total current with the maximum available current to prevent an overloaded current. The increasing step INC and decreasing step DEC may be set the same value such as 1A. However, the different values between increasing step INC and decreasing step DEC may be set.

[0026] Another embodiment of the process flow is shown in. In this embodiment, a load sensor is disposed to measure the EV charging current (Icharge_sensor). The EV load current is measured so that the processor30can monitor the current supplied to one or more electric vehicles. With the additional load sensor, the processor30determines the current supplied (Iuse) from the multi-use circuit by subtracting the load current measurement from load sensor (Isensor) by the EV charging current (Icharge_sensor). Then processor30then calculates the EV charging current to be the difference between the maximum available current and the current supplied. Once the charging current is set and the load current does not exceed the maximum available current, the charging process continues. If, however, the load current exceeds the maximum available current, the processor30stops the charging process. The process continues until the EV battery is fully charged or a stop charging signal is received. In between the process, the processor30keeps monitoring the load current and compares the load current with the maximum available current to prevent an overloaded current.

[0027] A person skilled in the art may recognize the modifications of the process flows previously mentioned to allow the EV charger to maintain its current supply at its maximum capacity while maintaining the load current at its limitation.

[0028] In another embodiment, the processor30may be further configured to determine the maximum available current remaining in the multi-use circuit by predicting a load current of all of the one or more electronic devices400other than the EV charger200on the multi-use circuit and subtracting the predicted load current from the maximum current of the multi-use circuit. The prediction capability can be added to the processor30when a history of load current measurements is available. Instead of using only the latest load current, the processor30may utilize the history of the load current measurement to predict the load current used by other electronic devices400. This can be done via a regression or machine learning model. The examples of the models include, but are not limited to, linear regression, logistic regression, polynomial regression, neural network regression, decision tree regression, and random forest.

[0029] In a particular embodiment, the processor30predicts the load current to be an average of the load current of all of the one or more electronic devices400other than the EV charger200on the multi-use circuit during a predetermined period of time. For example, an average of load current over a day or a week may be used as a baseline of electrical consumption for the multi-use circuit under consideration. The processor30, thus, utilizes the baseline as the predicted load current when calculating the available EV charging current for the EV charger200.

[0030] In another embodiment, the memory20may be configured to store a database. The processor30is further configured to record, in the database, measurements of individual load currents associated with each of the one or more electronic devices400other than the EV charger200with an associated time of measurement. Storing the measurement data in the database locally allows the processor30to access the data whenever it needs. The processor30may adaptively recalculate the available EV charging current over time based on the recorded measurements. This is particularly useful when load current varies on an hourly basis. The time of measurement provides time reference for the processor30when predicting the load current.

[0031] In another embodiment, the processor30may be further configured to communicate with a server via another data communication interface10, and update the database based on the communication with the server50. The server50provides a larger data storage media and a higher processing capacity compared to the local memory20and processor30. The server50may be configured to have one or more databases for storing the load current measurements allowing the server50to accurately determine load current of all of the one or more electronic devices400other than the EV charger200on the multi-use circuit. The server50may determine the pattern of load current from its previous measurements. More sophisticated prediction models, such as machine learning models, can be realized by the server50capabilities. It is understood that the server50may be configured to perform some operations that the processor30can do to off-load the processor30.

[0032] In a particular embodiment, the predicted load may be determined based on an output of a predictive or a machine learning model. The model may be trained based on load current measurements recorded in a time series fashion; for example, the load current recorded at every 1, 5, or 10 minutes, etc. The load current measurements recorded in the time series fashion include measurements of individual load currents associated with each of the one or more electronic devices400other than the EV charger200with an associated time of measurement.

[0033] In some embodiments, the data communication interface10is a wireless network communication interface that allows the load sensor data to be transferred from at least one load sensor40to the processor30. The wireless network communication interface includes Wi-Fi, Bluetooth, ZigBee, LTE, etc.

[0034] The EV charger control device of the present invention may be realized by a computerized method. The method for controlling an EV charger200comprising the steps of: obtaining, from at least one load sensor, at least one load current measurement detected by at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit; determining a maximum available current remaining in the multi-use circuit based on the obtained one or more load current measurement; calculating an available EV charging current based on the maximum available current remaining in the multi-use circuit; and comparing the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current. When the maximum available EV charging current does not correspond to the previously set maximum available EV charging current, the method performs the following: automatically setting the maximum available EV charging current to correspond to the calculated available EV charging current; and automatically sending a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.

[0035] In another embodiment, the method further comprises determining the maximum available current remaining in the multi-use circuit by subtracting the obtained one or more load current measurement from the maximum current of the multi-use circuit.

[0036] In another embodiment, the method further comprises calculating the available EV charging current to be a proportion of the maximum available current remaining in the multi-use circuit and the proportion of the maximum available current remaining is less than one hundred percent of the maximum available current remaining and more than zero percent of the maximum available current remaining.

[0037] In another embodiment, when a history of load current measurements is available, the method may further comprise determining the maximum available current remaining in the multi-use circuit by predicting a load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit and subtracting the predicted load current from the maximum current of the multi-use circuit. The prediction capability may be added to the method when a history of load current measurements is available. The method utilizes the history of the load current to predict the load current used by other electronic devices. This prediction can be done by using a regression or machine learning model. The examples of the models include, but are not limited to, linear regression, logistic regression, polynomial regression, neural network regression, decision tree regression, and random forest. In some embodiment, the predicted load is an average of the load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit during a predetermined period of time.

[0038] In another embodiment, the method further comprises determining the predicted load based on an output of a predictive model, wherein the predictive model is trained based on load current measurements recorded in a time series fashion, and the load current measurements recorded in the time series fashion include measurements of individual load currents associated with each of the one or more electronic devices other than the EV charger with an associated time of measurement.

[0039] The method for controlling an EV charger can be programmed into a non-transitory computer readable medium comprising computer-executable instructions that when executed, cause a processor to perform the operations representing the method for controlling an EV charger previously mentioned.

Claims

An electric vehicle (EV) charger control device comprising: a data communication interface; a memory configured to store a maximum available EV charging current; and a processor configured to communicatively couple to at least one load sensor via the data communication interface, wherein the at least one load sensor measures current used by one or more electronic devices other than an EV vehicle charger, and the processor is further configured to: obtain, from the at least one load sensor, at least one load current measurement detected by the at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit; from the at least one load sensor; determine a maximum available current remaining in a multi-use circuit based on the obtained one or more load current measurement; calculate an available EV charging current based on the maximum available current remaining in the multi-use circuit; compare the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current; when the available EV charging current does not correspond to the previously set maximum available EV charging current: automatically set the maximum available EV charging current to correspond to the calculated available EV charging current; and automatically send a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.The EV charger control device as in claim 1, wherein the processor is further configured to: determine the maximum available current remaining in the multi-use circuit by subtracting the obtained one or more load current measurement from the maximum current of the multi-use circuit.The EV charger control device as in claim 2, wherein a maximum current of the multi-use circuit is configurable.The EV charger control device as in claim 1, wherein the processor is further configured to: calculate the available EV charging current to be a proportion of the maximum available current remaining in the multi-use circuit and the proportion of the maximum available current remaining is less than one hundred percent of the maximum available current remaining and more than zero percent of the maximum available current remaining.The EV charger control device as in claim 1, wherein the processor is further configured to determine the maximum available current remaining in the multi-use circuit by: predicting a load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit; and subtracting the predicted load current from the maximum current of the multi-use circuit.The EV charger control device as in claim 5, wherein the predicted load is an average of the load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit during a predetermined period of time.The EV charger control device as in claim 6, wherein the memory stores a database, and the processor is further configured to record, in the database, measurements of individual load currents associated with each of the one or more electronic devices other than the EV charger with an associated time of measurement.The EV charger control device as in claim 7, wherein the processor is further configured to communicate with a server via the data communication interface, and update the database based on the communication with the server.The EV charger control device as in claim 1, wherein the predicted load is determined based on an output of a predictive model, the predictive model is trained based on load current measurements recorded in a time series fashion, and the load current measurements recorded in the time series fashion include measurements of individual load currents associated with each of the one or more electronic devices other than the EV charger with an associated time of measurement.The EV charger control device as in claim 1, wherein the data communication interface includes a wireless network communication interface.A computerized method for controlling an electric vehicle (EV) charger comprising the steps of: obtaining, from at least one load sensor, at least one load current measurement detected by at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit; determining a maximum available current remaining in the multi-use circuit based on the obtained one or more load current measurement; calculating an available EV charging current based on the maximum available current remaining in the multi-use circuit; comparing the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current; when the maximum available EV charging current does not correspond to the previously set maximum available EV charging current: automatically setting the maximum available EV charging current to correspond to the calculated available EV charging current; and automatically sending a command message indicating the automatically set maximum available EV charging current to the EV charger so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.The computerized method as in claim 11, further comprising: determining the maximum available current remaining in the multi-use circuit by subtracting the obtained one or more load current measurement from the maximum current of the multi-use circuit.The computerized method as in claim 11, further comprising calculating the available EV charging current to be a proportion of the maximum available current remaining in the multi-use circuit and the proportion of the maximum available current remaining is less than one hundred percent of the maximum available current remaining and more than zero percent of the maximum available current remaining.The computerized method as in claim 11, further comprising: determining the maximum available current remaining in the multi-use circuit by: predicting a load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit; and subtracting the predicted load current from the maximum current of the multi-use circuit.The computerized method as in claim 14, wherein the predicted load is an average of the load current of all of the one or more electronic devices other than the EV charger on the multi-use circuit during a predetermined period of time.The computerized method as in claim 11, further comprising: determining the predicted load based on an output of a predictive model, wherein the predictive model is trained based on load current measurements recorded in a time series fashion, and the load current measurements recorded in the time series fashion include measurements of individual load currents associated with each of the one or more electronic devices other than the EV charger with an associated time of measurement.A non-transitory computer readable medium comprising computer-executable instructions that when executed, cause a processor to perform the following operations: obtaining, from at least one load sensor, at least one load current measurement detected by at least one load sensor, the detected load current measurement corresponding to a load current used by one or more electronic devices other than an EV charger on a multi-use circuit; determining a maximum available current remaining in the multi-use circuit based on the obtained one or more load current measurement; calculating an available EV charging current based on the maximum available current remaining in the multi-use circuit; comparing the available EV charging current to a previously set maximum available EV charging current stored in the memory to determine whether the available EV charging current corresponds to the previously set maximum available EV charging current; when the maximum available EV charging current does not correspond to the previously set maximum available EV charging current: automatically setting the maximum available EV charging current to correspond to the calculated available EV charging current; and automatically sending a command message indicating the automatically set maximum available EV charging current to the EV charger so that so that the EV charger sends a signal to electric vehicle indicating the available charging current to be drawn.

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