Method for charging an electric vehicle battery at an electric vehicle charging station, data processing device, computer program product and electric vehicle

Abstract

A method for charging a battery (5) of an electric vehicle (1) at an electric vehicle charging station (9) is disclosed, wherein the method comprises connecting (S21, S31) the electric vehicle (1) to the electric vehicle charging station (9) via a connection (10) in order to charge the battery (5) with an electrical charge from the electric vehicle charging station (9) via the connection (10), and charging (S23, S34) the battery (5) of the electric vehicle (1) by the electric vehicle charging station (9) with an electrical charge via the connection (10) after the connection. The method further provides for discharging (S22, S33) the battery (5) of the electric vehicle (1) into the electric vehicle charging station (9) via the connection (10) after the connection in order to increase the operating temperature of the battery (5). Furthermore, a device (2) for data processing, a computer program product (3) and an electric vehicle (1) related to the method are disclosed.

Description

[0001] The invention relates to a method for charging a battery of an electric vehicle at an electric charging station, wherein the method comprises connecting the electric vehicle to the electric charging station via a connection in order to charge the battery with electrical charge from the electric charging station via the connection, and charging the battery of the electric vehicle by the electric charging station via the connection with electrical charge after the connection.

[0002] The invention further relates to a device for data processing, comprising a processor configured to execute the method.

[0003] Furthermore, the invention relates to a computer program product comprising instructions which, when the program is executed by a processor, cause it to execute the method.

[0004] Furthermore, the invention relates to an electric vehicle that includes the device for data processing.

[0005] Charging a battery or battery cell takes longer if the battery temperature is too low. Especially at very low temperatures, charging times can be significantly extended. The lower the temperature, the lower the permissible charging current and therefore the longer the charging time.

[0006] To address this problem, one known method is to heat a coolant using a PTC heater and then supply the coolant to a cooling plate in the battery. Another known method is drive-based heating, where the coolant is heated by the electric vehicle's drive motor rather than by the PTC heater. Coolant can also be heated by other electrical components that emit heat. Furthermore, heating strips or films can be provided inside the battery or on the outside of the battery housing, allowing for direct heating of the battery cells rather than via the coolant. Preconditioning is also a known method. Combinations of the aforementioned solutions, as well as more robust implementations of these known solutions, have also been considered.

[0007] WO 2023 / 213147 A1 shows and describes a battery heating control method and a corresponding device, as well as an electric vehicle. The battery can be brought to a normal operating temperature by heating. It is proposed that the battery be heated as soon as a driver takes a seat in the electric vehicle. A pre-sensing logic makes the necessary preparations for heating beforehand.

[0008] A self-heating method for a battery is known from WO 2023 / 207324 A1. This method prevents impermissible self-heating of the battery by maintaining the battery voltage within a preset safe voltage range.

[0009] From WO 2022 / 2247836 A1, a method and a system for providing a trigger for battery temperature regulation of a vehicle are known. When it is detected that the vehicle is approaching an electric vehicle charging station, a message is transmitted to the vehicle's user, containing a trigger to initiate battery heating. The message can be a visual and / or audio message. The user can respond to the message by activating the battery temperature trigger.

[0010] The object of the invention is to provide a method for charging a battery of an electric vehicle at an electric charging station, a device for data processing, a computer program product and an electric vehicle of the type mentioned at the outset, which are improved compared to the prior art.

[0011] The foregoing problem is solved by a method for charging a battery of an electric vehicle at an electric charging station with the features of independent claim 1, by a device for data processing with the features of independent claim 8, by a computer program product with the features of independent claim 9, and by an electric vehicle with the features of independent claim 10.

[0012] Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the data processing device, the computer program product, and the electric vehicle according to the invention, and vice versa, so that the disclosure regarding the individual aspects of the invention always makes, or can make, reciprocal references.

[0013] According to the invention, the method comprises the following step: - Discharging the electric vehicle's battery into the electric charging station via the connection after connecting, in order to increase the battery's operating temperature.

[0014] This method has the advantage that the battery utilizes its own heat generation during discharge into the charging station to increase its operating temperature. The higher the discharge current, the greater the heat generation. The charging process is particularly problematic in cold conditions. A permissible charging current depends not only on the battery's state of charge (SOC) but also on the temperature. Exceeding this maximum current can lead to damage or premature aging of the battery cells. This problem is either absent or significantly less pronounced during discharge. Therefore, considerably higher currents are possible during discharge than during charging, allowing the battery to be heated much more effectively and rapidly than with previously known methods.

[0015] In other words, the method allows the battery's operating temperature to be raised towards its optimal operating temperature range by discharging it into the charging station. This is achieved more quickly with the proposed method than would be possible solely through the heat generated during charging, and is even possible if the electric vehicle does not have an auxiliary battery heater, although one may be provided as an add-on. The optimal operating temperature range is the one in which the maximum technically possible charging currents for the battery can be achieved. This can be approximately between 30°C and 50°C, depending on the battery and its state of charge (SOC). However, to save charging time, a narrower optimal operating temperature range may be used, depending on the SOC, starting temperature, battery type, etc. For example, it might not be practical to discharge a battery with a 50% SOC at -7°C to, say, 50%.The battery has reached an operating temperature of 40 °C. At this temperature, too much state of charge (SOC) could be lost, and the overall charging time would be longer than if the battery's operating temperature were only increased to, say, 15 °C or 25 °C. A possible target operating temperature within the optimal operating temperature range is 23 °C, but this usually depends on the type of battery and can therefore be higher or lower.

[0016] A preferred battery is the electric vehicle's traction battery. The traction battery can supply power to the electric vehicle's drive system to power its wheels and is typically charged via electric vehicle charging stations. Alternatively, the battery could be an auxiliary battery or any other type of battery that can be charged and discharged via the charging station. The auxiliary battery can supply power to auxiliary systems such as the vehicle's electrical system, lighting, or general vehicle electronics that are not directly related to the electric vehicle's drive system.

[0017] In some embodiments, the method, particularly the discharging step, involves continuously discharging the battery of the electric vehicle into the charging station. This allows chemical processes and / or internal resistance within the battery cells to generate heat, thereby increasing the battery's operating temperature. In other words, the temperature increase can be caused by internal cell resistance in addition to or as an alternative to chemical processes. The heat generation thus occurs within the battery itself. Ideally, this eliminates the need for external heating elements, such as an auxiliary heater.

[0018] The continuous discharge period may include interruptions, which can be either discharge pauses or charging cycles. It is important that any interruptions be timed so that the goal of warming the battery by increasing its operating temperature is still achieved. The discharge, particularly between two interruptions, can last one or more seconds. Preferably, the discharge lasts between 10 and 20 seconds, particularly 15 seconds, especially between two interruptions. However, some embodiments provide for considerably longer durations. For a discharge from 10% to 3% state of charge (SOC), the continuous period can last between 50 and 200 seconds. This can depend on many factors. At a SOC of 20%, the continuous period can also exceed 200 seconds.The unloading process can therefore take several minutes, such as between 1 and 10 minutes, especially between two interruptions. Continuous discharge can be achieved in such a way that the battery's state of charge changes. With each discharge cycle, the state of charge will decrease.

[0019] This distinguishes the present method from other methods that, for example, provide for rapid electrical sinusoidal oscillations via the connection between the battery and the electric charging station, which switch from charging to discharging in fractions of a second, but do not change the state of charge of the battery.

[0020] In some embodiments, particularly during the discharging step, the battery is discharged to a lower state-of-charge threshold, which is above a complete discharge of the battery, and then the battery is subsequently charged by the charging station. The lower state-of-charge threshold can be between 3% and 10% of the battery's maximum state of charge, particularly 3% or 5%. This ensures that a minimum charge remains in the battery to prevent damage. However, some embodiments may stipulate that the lower state-of-charge threshold is a complete discharge of the battery. Once the battery has reached its optimal operating temperature range, the process preferably switches to charging.This means that the discharge into the electric charging station can preferably be stopped automatically by the electric vehicle, the electric charging station or manually by a user, such as via the dashboard of the electric vehicle or a mobile phone, as soon as the optimal operating temperature range is reached, even if the lower charge level threshold has not yet been reached by the discharge.

[0021] Some embodiments include charging the battery to an upper state-of-charge threshold, which is below a full charge, after connection. This shortens the overall process compared to cases where the battery is fully charged. Some embodiments, preferably during the charging step, include charging the battery to an upper state-of-charge threshold, which is below a full charge, after the electric vehicle's battery has been discharged into the charging station. This increases the battery's state of charge, which also heats the battery, without requiring the maximum charging time. In some embodiments, however, the upper state-of-charge threshold corresponds to a full charge. This can be advantageous, for example, if the expected driving distance for the electric vehicle necessitates charging to a full charge.

[0022] Some embodiments include, preferably in the charging step, charging the battery to an upper charge level threshold that is below a full charge of the battery, before discharging the battery of the electric vehicle into the electric charging station.

[0023] This option can be advantageous if the battery charge level is very low upon connection, such as 5% or less of the maximum charge level. The upper charge threshold can be set between 7% and 15% of the battery's maximum charge level, for example, approximately 10%. Even at this level, some heat is generated within the battery, allowing for sufficient initial charge to be added before the battery is subsequently discharged into the charging station, further increasing its operating temperature.

[0024] One possible embodiment includes, particularly immediately after connection, discharging the battery to 5% of its maximum state of charge, followed by charging to 10% of its maximum state of charge, followed by another discharge to 5% of its maximum state of charge. The discharge-charge cycle outlined above can be repeated once or several times until the battery's optimal operating temperature range is reached or at least nearly reached. Finally, the battery can be charged to more than the upper state-of-charge threshold, for example, to between 80% and 100% of its maximum state of charge, such as 100%. Some embodiments also provide for a charge-discharge cycle in which charging to the upper state-of-charge threshold is performed first, followed by discharging to the lower state-of-charge threshold. In some embodiments, this process is repeated cyclically to gradually increase the battery's operating temperature.Charge-discharge cycles, in which charging begins and discharging then takes place in the electric charging station, are particularly useful when there is only a small charge left on the battery when connecting, so that a partial charging of the battery by the electric charging station is first required in order to make discharging into the electric charging station possible at all.

[0025] In some cases, the discharge-charge cycles or charge-discharge cycles can increase the operating temperature by, for example, 0.5 K per minute at an ambient temperature of -7 °C, especially if the electric vehicle has an auxiliary heater for the battery. This can improve the increase in battery operating temperature by several factors, such as a factor of 5 to 10, compared to known techniques. Two specific scenarios for charge-discharge cycles or discharge-charge cycles that can be implemented in embodiments of the method are the following: - The battery's state of charge (SOC) is 5% when connected to the electric charging station. This is too low to heat the battery by discharging it into the charging station.

[0026] Therefore, due to the low operating temperature, the battery is initially charged very slowly to, for example, 10% state of charge (SOC) by the charging station, and then very quickly discharged back into the charging station to 5% SOC. This is followed by a significantly faster charge of the battery back to 10% SOC, or further to a target SOC value if the battery is sufficiently warm. This is a concrete example of a charge-discharge cycle.

[0027] - The battery's state of charge (SOC) is 20% when connected to the charging station. It is then rapidly discharged to 5% SOC. In this example, the battery's operating temperature has already reached its target operating temperature. The charging station then recharges the battery to, for example, 80% SOC. This is a concrete example of a discharge-charge cycle.

[0028] As illustrated, there are many degrees of freedom for different configurations in how charging and discharging can be combined to optimize the overall charging process, for example, in terms of total charging time. The discharge / heating strategy might look different, for instance, if the target state of charge (SOC) were 70% or 90% instead of 80%.

[0029] In some embodiments, the amount of charge discharged from the battery during charging at the charging station is determined. This allows the vehicle owner to be financially compensated for the amount of charge discharged during charging. For example, the determined amount of charge discharged can be offset against the amount of charge subsequently charged, so that the owner is only billed for the portion of the charge that was additionally fed into the battery. This determination can be performed on the electric vehicle side and / or on the charging station side, for example, by a charge meter, which may be integrated into a data processing device. If the determination is performed on both the electric vehicle and the charging station side, the determined charge amounts can be compared to identify any errors in the determination.The electric vehicle charging station can absorb the discharged power from the battery and store it in the power grid, buffer it in the charging station's own battery, or use it to charge another electric vehicle connected to the charging station at the same time. The charging station can then bill the customer for the absorbed discharged power, either by paying out the equivalent value or crediting it towards future charging sessions.

[0030] Embodiments of the method involve issuing a notification regarding the battery's discharge into the charging station prior to the discharge process. The notification can be visual or audio. It can be issued by the electric vehicle, a mobile phone, and / or the charging station. Alternatively, it can be issued by a notification unit, such as a display or a speaker. The notification unit can be integrated into the electric vehicle, the mobile phone, and / or the charging station. The notification informs the electric vehicle user of the impending discharge. It can also initiate an interaction with the user related to the discharge process.The user can be notified that the battery is about to be heated, or is currently being heated, and is therefore being discharged. The state of charge (SOC) initially drops during this process, which may be surprising or even undesirable for the user. However, this method can ultimately shorten the charging time.

[0031] The notification can include a request to confirm that the vehicle should be discharged into the charging station. It is advantageous to offer the customer a choice of charging methods, such as via a menu. Alternatively, the electric vehicle itself can decide on the charging process. The notification can be issued before or after the vehicle is connected to the charging station. If a notification is provided, it should preferably be issued before discharge begins, but no later than the start of the discharge process. The vehicle user may not agree to discharge because they do not have enough time, or because the current operating temperature is only slightly below the optimal operating temperature range.By providing feedback in response to the request, the electric vehicle user can, for example, indicate whether or not they agree to discharge the battery to increase its operating temperature. The notification can also allow the user to modify parameters related to discharge and potentially charging, such as discharge power, lower state-of-charge threshold, upper state-of-charge threshold, charging power, and the battery's optimal operating temperature range. The notification may include suggestions for advantageous parameter values. An input device can be provided to receive user feedback on the notification. This input device can be the electric vehicle charging station, the electric vehicle itself, and / or the user's smartphone.The input device may include a touchscreen, a keypad, a microphone, and the like.

[0032] Some embodiments, particularly during the discharging step, involve discharging the battery into the electric vehicle charging station, especially at least temporarily, with a discharge power during discharge that is above 50% of the battery's maximum possible discharge power. Preferably, the discharge power into the electric vehicle charging station is at least temporarily 50–90% of the maximum possible discharge power, particularly 70–80% or approximately 80%. However, in some embodiments, only 30% of the maximum possible discharge power or less may be released.

[0033] In some embodiments, the discharge power during discharge to the electric charging station is at least temporarily 100% of the battery's maximum possible discharge power. The maximum possible discharge power can be defined as a peak discharge power achievable under optimal conditions, such as a standard temperature of approximately 30–50 °C, for example, 40 °C. There may be a maximum limit imposed by the battery or its cells and a maximum limit imposed by the electric vehicle. In some cases, the electric vehicle will be the limiting factor, in others, the battery.

[0034] Electric vehicles often allow for very high discharge currents, which can be advantageously used to increase the battery's operating temperature when discharging at a charging station. These discharge currents can exceed charging currents many times over. In other words, the highest possible current is preferably used to discharge the battery into the charging station. This high discharge current generates maximum heat within the battery, allowing the operating temperature to be quickly raised to the target operating temperature or within its optimal operating temperature range.

[0035] Furthermore, the task of providing a data processing device that is improved compared to the prior art is solved by the data processing device according to claim 8, as described below.

[0036] According to the invention, the data processing device comprises a processor configured to perform the method described above. This enables it to achieve the advantages of the method. The data processing device can be embodied as a charging control unit for the electric vehicle. The charging control unit can be configured to discharge the electric vehicle's battery into the charging station as soon as the electric vehicle is connected to the charging station. This allows the battery's operating temperature to be increased.

[0037] The charging control unit can be further configured to continuously discharge the battery into the electric vehicle charging station. Specifically, it can be configured to discharge the battery into the charging station to a lower charge level threshold that is above a complete discharge and then charge the battery via the charging station. The charging control unit can be configured to at least partially discharge the battery into the charging station before charging it. The charging control unit can be configured to at least partially discharge the battery into the charging station after charging it. The charging control unit can be configured to alternately charge the battery at least partially and discharge it at least partially into the charging station.The charging control unit can be configured to alternately charge the battery to the upper state-of-charge threshold and discharge it to the lower state-of-charge threshold into the electric vehicle charging station. Charging can occur before discharging, or vice versa. The charging control unit can be configured to discharge the battery into the electric vehicle charging station with a discharge current greater than the charging current. The charging control unit can be configured to discharge the battery with a discharge current above 50% of the maximum possible discharge current. The charging control unit can be configured to issue a notification regarding the battery discharge into the electric vehicle charging station, particularly before the battery discharges. The charging control unit can be configured to receive user feedback related to the notification.

[0038] In general, the charging control unit can be configured to execute all or at least some of the aforementioned procedure features. The charging control unit can have a memory. A program containing commands for the charging control unit, enabling it to execute the procedure, can be stored in the memory. The memory can contain the parameters mentioned above in relation to the procedure. The memory can contain a target operating temperature or an optimal operating temperature range for the battery. The memory can also contain, preset but possibly modifiable, the lower state-of-charge threshold or the upper state-of-charge threshold. The memory can be configured to store the amount of discharged charge, determined by the charging control unit during the discharge process.The charging control unit can incorporate a self-learning algorithm to continuously optimize the process. This self-learning algorithm can be based on artificial intelligence. The charging control unit can be configured to receive updates wirelessly or via a wired network, such as the internet.

[0039] Furthermore, the problem of providing a computer program product that is improved over the prior art is solved by the computer program product according to claim 9, which comprises instructions which, when the program is executed by a processor, cause it to execute the method described above, as described below.

[0040] The computer program product can be an electronic or optical data storage device, such as a memory chip, magnetic storage, or optical storage. The electric vehicle can incorporate the computer program product. Instructions stored on the computer program product can cause the processor to discharge the battery of an electric vehicle in such a way as to achieve the advantages described in connection with the method. The computer program product can be part of the charging control unit of the electric vehicle. The memory can be embodied by the computer program product.

[0041] Furthermore, the object of the invention, to provide an electric vehicle of the type mentioned above which is improved compared to the prior art, is solved by the electric vehicle according to claim 10, as described below.

[0042] The term "electric vehicle" here encompasses all types of vehicles, such as land, water, and / or air electric vehicles. This includes, in principle, electric trucks, electric cars, electric airplanes, electric helicopters, electric boats, and the like. All electric vehicles that have a battery requiring rapid heating for charging are eligible. The invention can therefore be particularly advantageous for battery-electric vehicles.

[0043] According to the invention, the electric vehicle comprises the aforementioned data processing device. This enables it to execute the method described above and to realize its advantages for the electric vehicle. A preferred electric vehicle is a wheeled electric vehicle. It can be an electric vehicle with a fully electric or hybrid drive for driving operation. In principle, the invention can be particularly relevant for all types of electric vehicles that can be charged at electric charging stations. The electric vehicle can include a battery temperature sensor. The battery temperature sensor can communicate with the charging control unit. The electric vehicle can have a charging port that can be connected to the electric charging station via a charging cable, which is one possible embodiment of such a connection.The charging port can include a communication contact, enabling a communication link between the charging control sensor and the electric vehicle charging station via the charging cable. Alternatively, a wireless communication link between the charging control sensor and the electric vehicle charging station can be provided, such as via a mobile network, infrared connection, Wi-Fi, or Bluetooth. Charging and discharging are preferably carried out via the charging cable, i.e., via a wired connection; however, in some embodiments, charging and discharging can be wireless, i.e., via a wireless connection such as a changing electromagnetic field.

[0044] This application refers to maximum or optimal values, such as those for power, current, or battery capacity. These values ​​are achieved at standard or normal temperatures known in the electric vehicle industry. For example, this could be a temperature of 23 °C. However, this can vary depending on the vehicle or battery type. Therefore, the description should be interpreted in light of the specific individual case.

[0045] Embodiments of the invention are explained in more detail with reference to the drawings and the following description. The drawings show: Fig. 1 an embodiment of an electric vehicle according to the invention, comprising a device for data processing and a computer program product according to the invention; Fig. 2 a first embodiment of a method according to the invention and Fig. 3 a second embodiment of the method according to the invention.

[0046] Fig. Figure 1 shows an embodiment of an electric vehicle 1 according to the invention. The electric vehicle 1 has a data processing device 2. The data processing device 2 is a charging control unit 2 of the electric vehicle 1. The charging control unit 2 comprises a processor (not shown) configured to process the two embodiments of the method according to the invention, which are based on the Fig. 2 and Fig. 3, illustrated below. To enable this, the charging control unit 2 includes a computer program product 3. The computer program product 3 is, by way of example, a non-volatile memory chip 3, which is arranged in the charging control unit 2 and electrically connected to the processor to enable data transfer between the non-volatile memory chip 3 and the processor. The non-volatile memory chip 3 comprises instructions which, when the program is executed by the processor, cause it to execute the embodiments of the method, which are illustrated below. Fig. 2 and Fig. The following are illustrated below. For illustrative purposes only, the electric vehicle 1 is a fully electric vehicle. It therefore does not include an internal combustion engine as a drive unit, but rather an electric motor 4 located in the front of the electric vehicle 1. During operation, the electric motor 4 is powered by a battery 5, which, for illustrative purposes only, is located in an underbody area of ​​the electric vehicle 1. The battery 5 is connected to the electric motor 4 via an electrical system 6.

[0047] The charging control unit 2 is configured to control the charging process of battery 5. The charging control unit 2 is configured to control the discharging process of battery 5. The charging control unit 2 is configured to determine the battery temperature of battery 5. For this purpose, the electric vehicle 1 has a battery temperature sensor 7 on battery 5. This is shown only as an example, and more than one battery temperature sensor 7 may be provided on or in battery 5. Battery 5 and battery temperature sensor 7 are connected to the charging control unit 2 via the vehicle electrical system 6 to enable communication with the charging control unit 2. The electric vehicle 1 has a charging port 8 at the rear. The charging port 8 is configured for both charging and discharging battery 5 and for communication with an electric vehicle charging station 9.

[0048] Standing at the rear of electric vehicle 1 is in Fig. Figure 1 illustrates the electric charging station 9. The electric charging station 9 is connected via a connection 10, here a charging cable, to the electric charging station 9. Fig. 1 is connected to the charging port 8 of the electric vehicle 1 in order to charge the battery 5 of the electric vehicle 1 via the connection with electrical charge from the electric charging station 9. The charging control unit 2 is configured to carry out the method for charging the battery 5 of the electric vehicle 1 at the electric charging station 9 according to the invention. A first embodiment of the method is described in Fig. 2 illustrated.

[0049] According to the first embodiment, the method comprises Fig. Step S21 involves connecting the electric vehicle 1 to the charging station 9 via connection 10 to charge the battery 5 with electrical charge from the charging station 9. This is followed by step S22, in which the battery 5 of the electric vehicle 1 is discharged into the charging station 9 via connection 10 after connection, in order to raise the operating temperature of the battery 5. During discharge, electrical charge is transferred from the battery 5 to the charging station 9. Finally, step S23 involves charging the battery 5 of the electric vehicle 1 by the charging station 9 via connection 10 after connection.

[0050] The discharge process in step S22 can heat up battery 5 more than the charging process in step S23, since the discharge power into the charging station 9 can be significantly higher than the charging power from the charging station 9. Thus, the operating temperature of battery 5 can be increased by discharging before charging, in order to preheat battery 5 for charging, for example to 23 °C.

[0051] Based on Fig. Figure 2 illustrates that discharging occurs before charging. However, this is not necessarily the case. For example, if battery 5 has a state of charge (SOC) that is too low immediately after connection to allow discharging to raise its operating temperature, charging can also occur first, preferably to an upper state of charge threshold below a full charge of battery 5, such as 10%, followed by discharging, optionally in the charge-discharge or discharge-charge cycles described above. In such an example, steps S22 and S23 would be reversed, which is not explained or illustrated further here for the sake of simplicity.

[0052] Fig. Figure 3 shows a second embodiment of the method according to the invention. The state of charge (SOC) of battery 5 is, for example, 20% immediately before connection to the electric charging station 9. The operating temperature of battery 5, as determined by the battery temperature sensor 7, is -7 °C. An optimal operating temperature of battery 5 for charging would, for example, be 23 °C.

[0053] The procedure from Fig.Step 3 comprises step S31 of connecting the electric vehicle 1 to the electric charging station 9 via a connection 10 in order to charge the battery 5 with electrical charge from the electric charging station 9 via connection 10. This is followed by step S32 of issuing a notification concerning the discharge of the battery 5 into the electric charging station 9, prior to the discharge of the battery 5 into the electric charging station 9. The notification is displayed on a screen in the electric vehicle 1. The notification includes a query as to whether the user of the electric vehicle 1 consents to the discharge of the battery 5 into the electric charging station 9 in order to increase the operating temperature of the battery 5. By way of example, the notification also includes a recommendation by the charging control unit 2 to discharge the battery 5 into the electric charging station 9 to increase the operating temperature because the current operating temperature is below 0 °C.Here, the user agrees to the request by activating the unloading on the screen through a touch input on the screen.

[0054] Step S33, following step S32, involves discharging the battery 5 of the electric vehicle 1 into the charging station 9 via connection 10 to increase the operating temperature of the battery 5. This discharge into the charging station 9 occurs continuously, allowing chemical processes in the cells of the battery 5 to generate heat and raise its operating temperature. This continuous period is approximately 5 minutes. For example, the battery 5 discharges continuously into the charging station 9 for 5 minutes. During this discharge, the battery 5 discharges at a power output above 50% of its maximum possible discharge power, in this example, 80% of the maximum possible discharge power.More precisely, the discharge process begins with the battery 5 being discharged to a lower state-of-charge (SOC) threshold, which is above the point of complete discharge, at the charging station 9. This lower SOC threshold is set to 5% of the maximum SOC for this example. During the discharge process, the amount of charge discharged from the battery 5 to the charging station 9 is determined. This amount is stored by the charging control unit 2. The discharged charge is then fed into the public power grid by the charging station 9.

[0055] In step S34, which follows step S33, the battery is finally charged by the electric charging station 9 via connection 10. By way of example, in the second embodiment, the battery 5 is charged to an upper state-of-charge threshold that is below a full charge, i.e., after connection and after discharge. Here, the upper state-of-charge threshold is, for example, 80% of a full charge, in order to shorten the time the electric vehicle 1 spends at the electric charging station 9 under the given cold weather conditions.During charging, the amount of charge discharged into charging station 9 is subtracted from the amount of charge added to battery 5 from charging station 9. This ensures that the user of the electric vehicle 1 is only billed for the actual amount of charge added – the total amount charged minus the amount of charge fed into charging station 9 to heat battery 5. Thus, discharged and charged electrical charges are offset against each other. This is merely an example; other embodiments allow for different procedures.

[0056] In embodiments not shown, battery 5 can also be initially charged to 10% of its maximum state of charge (SOC) in step S34 and then discharged again to 5% of its maximum SOC. This process can be repeated until an optimal operating temperature range or a target operating temperature of battery 5 is reached. The charge-discharge and discharge-charge cycles described in this document can also be used for this purpose. Due to the high discharge power of battery 5 compared to its charging power, the optimal operating temperature range of battery 5 can be reached much faster than by the heat generated in battery 5 during charging at a relatively lower power.

[0057] In light of the foregoing description, the invention enables battery heating of a battery 5 by discharging it into a charging station, such as an electric vehicle charging station 9. A partial discharge of the battery 5 can be carried out at the highest possible current into the electric vehicle charging station 9. The charging station receives the power and can feed it into the power grid, buffer it in a charging station battery, or use it to charge another vehicle that is simultaneously connected to the electric vehicle charging station 9. The amount of charge fed back into the grid, i.e., the amount of charge discharged from the battery 5, can be billed to the customer accordingly. As soon as the battery 5 has reached a target temperature, for example, charging of the battery 5 via the electric vehicle charging station 9 can be switched to the other method.

[0058] Compared to known approaches, significantly faster warm-up of the battery 5 is possible, even several times faster. Furthermore, there are fewer heat losses than with approaches where heat is generated externally to warm the battery 5 and then transferred to the cells of the battery 5. A particular advantage over previous approaches is that very rapid warm-up of the battery 5 at the electric charging station 9 is possible without the need to install additional components in the electric vehicle 1. The invention can, however, be combined with other existing heating methods such as PTC heating, drive heating, heating mats, etc. Whether charging or discharging should occur can be determined by the electric vehicle 1 itself at any given time. A combination of the present invention with previously common approaches may also be possible and advantageous.Furthermore, warming up the cells of battery 5 can be advantageous not only in cold conditions, but also at higher temperatures, such as during best-case charging (preferably at 23 °C), in order to further reduce charging times.

[0059] This method can reduce the effort, costs, and required installation space in the design of electric vehicles, as components can be eliminated, for example. Charging time can also be saved because no preconditioning is required, which would otherwise need to be planned or started before connecting the charging cable. However, depending on the specific circumstances, additional preconditioning may be beneficial and could further reduce charging time. Reference symbol list 1 electric vehicle 2 Data processing device / charging control unit 3 Computer program product / non-volatile memory chip 4 electric motor 5 batteries 6 On-board electrical system 7 Battery temperature sensor 8 charging ports 9 electric charging stations 10 connection S21 - S23 procedural steps S31 - S34 Procedure steps QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2023 / 213147 A1

[0007] WO 2023 / 207324 A1

[0008] WO 2022 / 2247836 A1

[0009]

Claims

[1] Method for charging a battery (5) of an electric vehicle (1) at an electric vehicle charging station (9), the method comprising: - Connect (S21, S31) the electric vehicle (1) to the electric charging station (9) via a connection (10) in order to charge the battery (5) via the connection (10) with electrical charge from the electric charging station (9); and - Charging (S23, S34) the battery (5) of the electric vehicle (1) by the electric charging station (9) via the connection (10) with electrical charge after connecting, characterized by - Discharging (S22, S33) of the battery (5) of the electric vehicle (1) into the electric charging station (9) via the connection (10) after connecting, in order to increase the operating temperature of the battery (5). [2] Method according to claim 1, characterized by - Discharging the battery of the electric charging vehicle (1) into the electric charging station (9) over a continuous period of time, such that in particular chemical processes and / or an internal resistance in cells of the battery (5) generate heat to increase the operating temperature of the battery (5). [3] Method according to claim 1 or 2, characterized by - Discharging the battery (5) to a lower charge level threshold that is above a complete discharge of the battery (5) in the electric charging station (9) and subsequently charging the battery (5) by the electric charging station (9). [4] Method according to any of the preceding claims, characterized by - Charging the battery (5) to an upper charge level threshold that is below a full charge of the battery (5) after connection. [5] Method according to any of the foregoing claims, characterized by - Determining the amount of charge discharged from the battery (5) during discharge into the electric charging station (9). [6] Method according to any of the foregoing claims, characterized by - Issuing (S32) a notification concerning the discharge of the battery (5) into the electric charging station (9) prior to the discharge of the battery (5) into the electric charging station (9). [7] Method according to any of the foregoing claims, characterized by - Discharging the battery (5) into the electric charging station (9) with a discharge power of the battery (5) during the discharge process that is above 50% of a maximum possible discharge power of the battery (5). [8] Device (2) for data processing, comprising a processor configured to perform the method according to any one of claims 1 to 7. [9] Computer program product (3) comprising instructions which, when the program is executed by a processor, cause the processor to execute the method according to any one of claims 1 to 7. [10] Electric vehicle (1) comprising a device (2) for data processing according to claim 8.

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