WO2024037862A1

WO2024037862A1 - Method for charging a battery of an electric vehicle, and electric vehicle

Info

Publication number: WO2024037862A1
Application number: PCT/EP2023/071134
Authority: WO
Inventors: Jens Berger
Original assignee: Bayersche Motoren Werke Aktiengesellschaft
Priority date: 2022-08-16
Filing date: 2023-07-31
Publication date: 2024-02-22
Also published as: DE102022120573A1

Abstract

The invention relates to a method (S1-S8) for charging a battery of an electric vehicle (F), in which at least one charging energy value of the charged energy has been recorded during at least one previous charging procedure of the battery (S1); during a current connection of the electric vehicle (F) to a charging point (EVSE) with a bi-directional charging capability, at least one discharge energy value is provided for a possible discharging procedure (S3); based on the charging energy value recorded for the at least one previous charging procedure and the current discharging energy value, it is analysed (S4) whether, during the current connection to the charging point (EVSE), it is worthwhile to have the battery discharged at the time of departure below an initial charge state that exists when the electric vehicle (F) was connected; and, if this is the case, the battery is discharged (S8) below the initial charge state until the time of departure, otherwise, it is charged (S6) until the time of departure.

Description

METHOD FOR CHARGING AN ELECTRIC VEHICLE BATTERY AND ELECTRIC VEHICLE

The invention relates to a method for charging a battery of an electric vehicle, in which at least one charging energy value of the charged energy has been tracked during at least one previous charging process of the battery and at least one during a current coupling of the electric vehicle to a charging point with the possibility of bidirectional charging Discharge energy value is provided for a possible discharge process. The invention also relates to an electric vehicle that is set up to run the method. The invention further relates to a system comprising the electric vehicle and an external data processing instance that can be coupled to the electric vehicle in terms of data technology. The invention is particularly advantageously applicable to fully electrically powered electric vehicles.

DE 11 2015 006 711 T5 discloses a V2G system comprising: a power supply system; a charging/discharging device that includes an electricity storage unit provided in a transportation device, a power conversion unit that converts power transferred between the electricity storage unit and the power supply system, a receiving unit, and a control unit that controls an operation of the power conversion unit based on a received signal controls; and a server device that manages charging and discharging of the electricity storage unit in the charging/discharging device. The server device determines a period of time during which power is discharged from the electricity storage unit of the charging/discharging device to the power system or during which the electricity storage unit is charged using power supplied from the power system, and transmits an instruction specifying the Period of time to the loading/unloading device. The control unit of the loading/unloading device starts or stops based on the time period indicated by the instruction from the server device.

US 8,836,281 B2 discloses that a computer manages a charging transaction for an electric vehicle. A set of principals is identified that is associated with the electric vehicle charging transaction. A principal is an entity that has an interest in a settlement transaction. Electric vehicle charging information comes from one Retrieved from a number of sources. An energy transaction plan is generated during a precharging phase using the charging information of the electric vehicle and based on preferences from one or more principals to control the charging transaction. The computer initiates a charging phase of the electric vehicle charging transaction for an electric vehicle connected to a charging station according to the energy transaction plan. The charging phase includes charging the electric vehicle with electricity, storing electricity in the electric vehicle and drawing electricity to discharge the electric vehicle. The computer settles the financial obligations between principals according to the energy transaction plan.

US 9,964,415 B2 provides methods, devices and systems that track details of power transfers performed between power sources and electric vehicles. The performance tracking system monitors the source of the electrical charge received, how much electrical charge was provided, the rates charged for the charging operation, and other information related to a charging transaction. Tracked energy consumption can be used by the power tracking system's server to anticipate future charging times, preferences or locations, and even determine driving habits and demand for charging in a region or area.

US 11,124,080 B2 discloses vehicle control systems. These may include one or more position sensors, an energy storage device, one or more charging sensors and one or more vehicle computing devices. The location sensor(s) may determine a current location of a vehicle, while the charging sensor(s) may determine a current state of charge of an energy storage device that may be onboard the vehicle to provide operating power to one or more vehicle systems. The vehicle computing device(s) may transmit the current location of the vehicle and the current state of charge of the energy storage device to a remote computing device, receive from the remote computing device a charge control signal that is determined at least in part by the current location of the vehicle and the current state of charge of the energy storage device , and control charging of the energy storage device according to the charging control signal. WO 2011/156776 A2 discloses an expert system that manages a power grid in which charging stations are connected to the power grid, electric vehicles being connected to the charging stations, the expert system selectively receiving power from connected electric vehicles via a grid-coupling inverter within the charging stations (if present). feeds into the power grid. In a more traditional use, the expert system enables electric vehicle charging, coupled with user preferences regarding charging time, charging cost and charging station capabilities, without exceeding grid capacity at any point.

It is the object of the present invention to at least partially overcome the disadvantages of the prior art and in particular to provide an improved possibility for a user of an electric vehicle to achieve an advantage by discharging his drive battery at a charging point.

This task is solved according to the features of the independent claims. Preferred embodiments can be found in particular in the dependent claims.

The task is solved by a method for charging a battery of an electric vehicle, in which

- during at least one previous charging process of the battery, at least one charging energy value of the charged energy is or has been maintained,

- when the electric vehicle is currently coupled to a charging point with the possibility of bidirectional charging (i.e. charging and discharging the battery), at least one discharge energy value is provided for a possible discharging process,

- based on the charging energy value recorded for the at least one previous charging process and the current discharging energy value, it is analyzed whether it is worthwhile during the current coupling to the charging point to discharge the battery at the time of departure to an initial state of charge present when the electric vehicle is coupled to have, and

- if this is the case, the battery is discharged below the initial charge level by the time of departure,

- Otherwise it will be charged until the time of departure. This method achieves the advantage that a user of the electric vehicle can utilize different energy values when charging the battery at a specific charging point and during the subsequent discharging at a particularly different charging point in order to achieve an economic and/or ecological advantage. The "worth" therefore refers in particular to the fact that an economic and/or ecological advantage can be achieved by the fact that the electric vehicle is completely discharged through the current coupling, i.e. at the time of departure it has a (final) charging state (also known as SoC, "State -of-Charge") that is lower than the (initial) charge state at the start of coupling.

The recommendation or decision to charge or discharge overall or "net" during the coupling process is determined not only on the basis of the at least one energy value, which may vary during this coupling process, but at least by the difference between the at least one energy value during the current coupling between the coupling process and the at least one energy value during at least one previous charging process.

Charging a battery particularly includes charging and/or discharging the battery. The battery is in particular a drive battery of the electric vehicle. The electric vehicle can in particular be a plug-in hybrid vehicle, PHEV, or a fully electric vehicle, BEV.

The tracking includes, in particular, a retrievable storage of the at least one charging energy value or a time course thereof, which was based on or determined during at least one charging process carried out before the current coupling. The tracking includes in particular a retrievable storage of the at least one charging energy value or a time course thereof of the last charging process carried out before the current coupling.

Bidirectional coupling includes the possibility of discharging the electric vehicle battery into an energy network connected to the charging point. The bidirectional coupling can include, for example, the generally known V2G ("Vehicle-to-Grid") and V2H ("Vehicle-to-Home") concepts. The coupling can, for example, take place via a CCS interface according to Part 3 of IEC 62196 or EN 62196, but is not limited to this. Coupling can also be done via other types of interfaces such as CHAdeMO, GB/T, etc. or inductively.

It is a further development that the user is digitally authenticated at the charging interface of the electric vehicle through digital charging communication, e.g. according to ISO 15118, the charged amounts of energy are measured by calibrated energy measuring devices, verified by the electric vehicle and billed, e.g. via "Plug & Charge" . For example, the ISO 15118-20 standard for charging communication can be used for feedback via the CCS interface.

The charging point can be, for example, a public charging station, a wallbox, an inductive charging parking space, etc.

Furthermore, energy values that vary over time can be exploited in a generally known manner by means of energy management during the current connection period or coupling process of the electric vehicle in order to charge the electric vehicle to the advantage of the user.

The electric vehicle has an initial state of charge (also referred to as "initial SoC") at the beginning of the current coupling or the current coupling process and a departure state of charge (also referred to as "departure SoC") at the end of the current coupling process at the time of departure . The fact that the battery is discharged below the initial state of charge by the time of departure can also be expressed by the relationship initial SoC > departure SoC. Charging can be expressed by the relationship initial SoC < departure SoC.

An energy value is a quantitative quantity that reflects an ecological and/or economic value of the amount of energy charged (i.e. charged or discharged).

The energy value can be a value averaged over a certain number of previous charging processes. The energy value can correspond to the energy value of the last charging process. It is a further development that the battery is only discharged if a user query has previously given permission for discharging. In this training, the (net) unloading must be specifically enabled by a user. In this way, a user can advantageously be protected from finding a lower departure SoC than desired.

As an alternative to charging until the time of departure, a user can also decide to disconnect the electric vehicle from the charging point again without charging.

It is an embodiment that the battery is not discharged further than a predetermined minimum state of charge ("minimum SoC") until the time of departure. The minimum state of charge as the lower limit of the discharge advantageously means that the battery cannot be discharged to such an extent that the user's mobility requirements can no longer be met. This can also be described by the relationship Departure SoC > Minimum SoC.

It is a further development that the minimum charge level is a fixed value, e.g. 20% or 30% of a full battery (100%).

It is an embodiment that the predetermined minimum state of charge is a state of charge that is sufficient to reach a next destination, in particular plus a certain state of charge safety margin. This makes it particularly reliable to meet the user's mobility requirements. The next destination can be specified by the user, for example via a route planner, suggested by the route planner, for example a charging station on a route to a destination, and/or can be derived from history data, for example a place of residence given the current location at a workplace. The next destination is in particular a charging point.

It is an embodiment that the departure SoC is sized to be no less than the initial SoC minus the amount of energy charged at the last charge, that is, the initial SoC at the last charge. This advantageously ensures that the currently discharged amount of energy is not greater than the ("cheaper") amount of energy charged during the last charging process. It is an embodiment that the energy value of the electrical energy includes at least one economic value, in particular a price. As a result, a pecuniary advantage for the user can be achieved using the method. It is a further development that the charging energy value includes a price for charging the battery and the discharging energy value includes a profit for discharging the battery. If the charging point is, for example, a public charging point, for example a charging station, the charging energy value can correspond, for example, to a price for charging billed by the operator of the charging point, for example in ct/kWh. The discharge energy value can then correspond, for example, to the feed-in amount that is paid by the operator of the charging point when discharging, for example in ct/kWh. This can be extended analogously to a local home energy network. In addition or as an alternative to the price or profit, the economic value may include, for example, the consumption and/or crediting of CO2 equivalents such as carbon credits etc.

It is an embodiment that the energy value of the electrical energy includes an ecological value, in particular a CO2 emission required for provision. This means that an ecological advantage can be achieved using the process. It is a further development that the charging energy value includes an amount of CO2 emissions for generating the charged amount of electrical energy and the discharging energy value includes an amount of CO2 emissions that can be saved during discharging, for example in g/kWh. Additionally or alternatively, the ecological value may include, for example, the consumption and/or crediting of CO2 equivalents such as carbon credits, etc. It is also possible to determine the ecological value based on a measure of ecological sustainability.

It is an embodiment that analyzing includes calculating a difference between the charging energy value and the discharging energy value and discharging the battery below the initial state of charge by the departure time if the difference is negative. In this way, it can advantageously be automatically determined whether an economic and/or ecological advantage can be achieved through unloading, i.e. whether unloading is worthwhile. For example, if the energy value is a price per kWh, the difference becomes negative if the charging price was lower than the current discharging price. If the battery is discharged net during the current pairing process, The (absolute) economic profit for the user results from the product of this difference and the amount of energy discharged. For example, if the energy value is a CO2 emission, e.g. in g/kWh, the difference becomes negative if the CC>2 emission for charging was lower than the CCh emission, which can be saved when discharging during the current coupling process, since the Discharged amount of energy does not need to be generated. If the battery is discharged net during the current coupling process, the product of the difference and the amount of energy discharged results in a reduction in CCh emissions as an ecological gain for the user. Consuming and/or accounting for CO2 equivalents can be viewed as a combination of ecological and economic energy value.

It is a further development that the user can select which energy value or values should be considered for deciding whether the battery should be discharged. This means the user can advantageously set their own economic and/or ecological goals. It is also possible for the user to specify boundary conditions regarding one or more types of energy values, e.g. discharging should be carried out if this can save a CO2 emission of X g/kWh, but only up to a monetary loss of €5, etc .

It is an embodiment that the battery is only discharged below the initial SoC by the time of departure if a minimum energy value for the electric vehicle is also exceeded as a result of the discharging, e.g. a minimum gain set by the user. This means that discharging, which reduces the remaining range of the electric vehicle, can be dispensed with if there is no sufficient profit, e.g. if at least a profit of €5 cannot be achieved.

It is an embodiment that at least one charging process has been carried out on a local energy network, which is carried out via an energy measuring device (e.g. via a conventional electricity meter and then possibly via a private electricity meter attached topologically in series or via a so-called "smart meter") a public energy network is connected and additionally has at least one energy generating device (e.g., a photovoltaic system, a private wind turbine, etc.). This has the advantage that CO2-free forms of energy such as sun and/or wind can be converted into electrical energy and used to charge the electric vehicle. she is In addition, it is usually cheaper than purchasing electrical energy from the public power grid. The local energy network is therefore particularly suitable for charging electric vehicles economically and ecologically, for example using a wallbox as a charging point. This is particularly advantageous if a stationary electrical energy storage device is connected to the local energy network.

It is an embodiment that an energy value of the electrical energy fed into the local energy network by the at least one energy generating device is determined based on at least costs, in particular electricity production costs, of the at least one energy generating device. This reflects that there are costs associated with the at least one energy generation device, e.g. comprehensive consideration of the purchase price, maintenance, depreciation, etc. Such costs must be determined individually for many local energy networks.

Further influencing variables of the energy value of a charging point connected to the local energy network, in particular a wall box, can be, for example, an electrical power fed into the local network by the at least one energy generation device, an energy value (e.g. price) of an energy purchase from the public energy network, a feed-in energy value (e.g. a feed-in tariff) from the public network, energy consumption in the local energy network, etc., whereby in particular the electrical power fed into the local energy network by the at least one energy generation device can fluctuate greatly over time, for example depending on a time of day, solar radiation, the presence of an energy source. cache, etc.

Especially in small local energy networks with at least one energy generation device, it is particularly advantageous to note that the energy value at the charging point varies greatly over time depending on an electrical power fed into the local energy network by the at least one energy generation device, an energy consumption in the local energy network and tariffs of the public energy network can.

In particular, the charging process itself can have a major influence on the energy value at the charging point, for example in the event that a surplus at the transition point to the public energy network can result in an energy consumption. In order to be able to take this into account particularly reliably during the charging process of the electric vehicle and then to be able to control the charging process in such a way that a particularly partial energy value for charging on the local energy network, it is, for example, advantageous to have historical data on electricity consumption in the local energy network and / or prediction data or predictions for the power fed in by the at least one energy generating device (for example based on a weather forecast) as well as tariff data from the public energy network to be kept, especially over time. It then becomes possible to determine the energy value or its time course during charging particularly reliably.

It is a further development that the local energy network is a home or house energy network of a private house, especially a single-family home.

The task is also solved by an electric vehicle, the electric vehicle being set up to run the method as described above. The electric vehicle can be designed analogously to the method and vice versa, and has the same advantages.

It is an embodiment that the electric vehicle has:

- an analysis module that is set up - e.g. programmed - to analyze, on the basis of the charging energy value recorded for the at least one previous charging process and the current discharging energy value, whether it is worth using the battery at the time of departure during a current connection to the charging point to discharge below an initial charge state that exists when the electric vehicle is coupled,

- and a control module that is set up - e.g. programmed - for this purpose, in the event that the analysis module has come to the conclusion that it is worth discharging the battery at the time of departure below an initial state of charge that exists when the electric vehicle is coupled Discharge the battery below the initial charge level by the time of departure, and otherwise charge it until the time of departure.

This configuration has the advantage that recommending and/or carrying out a discharge during the current coupling process can be carried out independently by the electric vehicle. The object is also achieved by a system comprising an electric vehicle as described above and an external data processing instance that can be coupled to the electric vehicle in terms of data technology, the data processing instance being set up to do so on the basis of the charging energy value tracked for the at least one previous charging process and the current discharging energy value to analyze whether, during a current connection to the charging point, it is worthwhile to discharge the battery at the time of departure below an initial state of charge when the electric vehicle is connected, and to transmit the result of the analysis to the electric vehicle.

The system can be designed analogously to the method and the electric vehicle, and vice versa, and has the same advantages. The system has the particular advantage that computing power can be outsourced from the electric vehicle to the external data processing instance. The external data processing instance can be, for example, a network server or a cloud computer. The data connection between the electric vehicle and the external data processing instance can be established, for example, via the charging point or directly through, for example, radio communication.

The characteristics, features and advantages of this invention described above, as well as the manner in which these are achieved, will be more clearly and clearly understood in connection with the following schematic description of an exemplary embodiment, which will be explained in more detail in connection with the drawing.

Fig.1 shows a possible sequence of the method; and

Fig.2 shows a sketch of an infrastructure used by an electric vehicle to carry out the method.

Fig.1 shows a possible sequence of the method. Fig.2 shows a sketch of an infrastructure used by an electric vehicle F to carry out the method.

In a step S1, the electric vehicle F is charged at a charging point in the form of a wallbox WB of a private home energy network LEN. The house energy network LEN is equipped with its own photovoltaic system PV as a local energy generation facility, if necessary with electricity storage (not shown). The home energy network LEN is via one Power connection point, at which a smart meter SM is arranged, is connected to a public energy supply network EVN-1 or power grid. The electric vehicle F and the wallbox WB are set up in particular for bidirectional charging, for example in the manner of the V2H concept, and can communicate with one another bidirectionally. A charging process can be planned and, if necessary, carried out in a generally known manner by an energy management system of the home energy network LEN. The energy management system is implemented here purely as an example in an IT system IT-1 in the form of a cloud computer. The IT system IT-1 can, for example, communicate with the wallbox WB, the electric vehicle F and/or a user terminal CE of a user of the home energy network LEN and/or the electric vehicle F.

In particular, the energy management system can track the temporal behavior of at least the electrical consumers (not shown) of the home energy network LEN, such as kitchen appliances, entertainment electronics, laundry appliances, boilers, etc., for which, for example, data from the smart meter SM can be used. The energy management system can also track and/or predict the temporal behavior of the electrical power fed in by the photovoltaic system PV. In this way, with tariff information from the public energy supply network EVN-1 as well as with the costs for providing and maintaining the photovoltaic system PV, the energy management system can determine an economic energy value in the form of a price and/or a price per kilowatt hour of charging. If the CO2 emissions from the public energy supply network EVN-1 required for charging are also known, an ecological energy value can be determined in the form of a CCh emission and/or a CO2 emission per kilowatt hour of charging. This at least one energy value is stored in particular together with the amount of energy charged during this charging process at the end of the charging process or at the time of departure and / or transmitted to the electric vehicle F and stored there. The at least one energy value can be calculated by the wallbox WB or by the electric vehicle F instead of by the energy management system.

In a second step S2, at the time of departure, the electric vehicle F is uncoupled from the wallbox WB and driven to another charging point, for example to a charging station EVSE, possibly with several intermediate stops and/or noticeably later. In a third step S3, the electric vehicle F is coupled to the charging station EVSE, for example connected via a charging cable. The EVSE charging station can, for example, be a component of a group of charging stations of a specific charging area, charging park, public parking lot, private parking lot, etc. The EVSE charging station can be a public EVSE charging station. The EVSE charging station is connected to a public energy supply network or EVN-2 power network via a power connection point at which a smart meter SM is arranged. The electric vehicle F and the charging station EVSE are set up for bidirectional charging, for example in the manner of the V2G concept, and can communicate with each other bidirectionally. A charging process can be planned and, if necessary, carried out in a generally known manner by an energy management system assigned to the EVSE charging station. The energy management system is implemented here purely as an example in an IT system IT-2 in the form of a cloud computer. The IT system IT-2 can, for example, communicate with the charging station EVSE, the electric vehicle F and/or a user terminal CE of a user of the electric vehicle F. Alternatively or additionally, a charging process can be planned and carried out by the EVSE charging station and/or the electric vehicle F.

The public energy supply network EVN-2 provides tariff information for charging and discharging, as well as information about CO2 emissions that occur when electricity is generated.

In a step S4, it is analyzed whether it is even worth discharging the battery of the electric vehicle F at the time of departure below an initial SoC present when the electric vehicle F is coupled. In order to analyze or check whether it is worthwhile from an economic point of view, the difference between the price per kWh during the charging process in step S1 and the price when feeding in during the current coupling process is calculated here as an example.

Assume that in step S1 an amount of energy of 20 kWh was charged for a price of €2.10, which corresponds to a kWh price of 10.5 ct/kWh, and currently in step S4 a feed-in tariff for discharging of 9, If 5 ct / kWh is paid, there would be a difference in the (absolute) amounts of 10.5 - 9.5 = 1 ct / kWh, so that it would basically not be worth discharging ("N"). In this case, a usual charging process could be carried out in step S5. In a subsequent step S6, the electric vehicle F is uncoupled from the EVSE charging station at the time of departure, possibly under automatic billing, for example "Plug &Pay".

However, if a feed-in tariff is paid in step S4 that is higher in amount than the charging price in step S1, e.g. 60 ct / kWh, the difference in the (absolute) amounts would be 10.5 - 60 = 49.5 ct / kWh, so that it would generally be worthwhile to discharge ("J"), especially if it is known that the electric vehicle F is to be reconnected to the wallbox WB.

Step S4 can take place in an analysis module of the electric vehicle F, which is present here as an example as a combined analysis and control module MOD, for example in the form of a controller.

In step S7, the user is asked, for example via the electric vehicle F or via a query on his terminal CE, whether he would like to agree to a discharging process or not. If this is not the case ("N"), the system branches to step S5 and a usual charging process is carried out.

However, if the user agrees (individually or via a default setting) ("Y"), a discharging process is carried out in step S8, in which the battery is not discharged further than a predetermined minimum charge state. The exact amount of energy discharged can also depend, among other things, on the duration of the coupling process, the discharge power enabled by the EVSE charging station, etc. The specified minimum charge level can, for example, be a charge level that is sufficient to reach a next destination, e.g. the Wallbox WB, in particular plus a charge level safety margin.

The state of charge at the time of departure can also be dimensioned such that it is not less than an initial state of charge minus the amount of energy charged during the last charging process, for example 20 kWh in the example above. In a further development, it is therefore possible to discharge the battery until (a) the minimum charge level is reached or 20 kWh have been discharged, whichever comes first.

The following branches to step S6.

Step S8 can take place in a control module of the electric vehicle F, which is present here as an example as a combined analysis and control module MOD, for example in the form of a controller.

Of course, the present invention is not limited to the exemplary embodiment shown.

This means that a CO2 emission can be used as an energy value instead of the price. Then in step S4, for example, the difference can be formed between the CO2 emissions per kWh during the charging process in step S1 and the CO2 emissions saved by discharging or feeding in during the current coupling process. Assume that a CO2 emission of 400 g was generated during charging in step S1, which corresponds to a CO2 emission per kWh hour of 20 g / kWh, and currently in step S4 a CO2 emission per kWh of 10 g / kWh could be saved, there would be a difference in the (absolute) amounts of 10 g / kWh, so that in principle it would not be worthwhile to discharge ("N").

In step S7, information about the size of the achievable advantage or profit can also be displayed to the user in order to decide whether he wants to agree to the unloading process or not. For example, if the amount of energy that could be discharged during the coupling process is known (e.g. from the expected departure time, the remaining amount of energy until the minimum SoC is reached, the amount of energy charged in step S1, etc.), this can be multiplied by the difference in energy values to determine the economic or ecological gain. For example, if the amount of energy charged in step S1 of 20 kWh were discharged earlier than the minimum SoC would be reached, a monetary profit of 49.5 ct / kWh * 20 kWh = € 9.90 could result. The user can then decide whether he wants to get the €9.90 or whether it is not worth it for him to accept a lower remaining range.

If the energy value under consideration is a CC>2 emission, in the example above a CC>2 emission saved by discharging at the EVSE charging station of X g / kWh with X > 20 would result in an ecological gain of (X - 20) g / kWh * 20 kWh, at X = 400 g / kWh e.g. of 7.6 kg.

Alternatively, a threshold value can be preset, e.g. €5, which must be exceeded in order for a discharging process to be considered at all. Such a check could then be inserted between step S4 and step S7, which branches to step S5 if the result is negative.

Furthermore, for example, at least step S4 can be carried out by the external IT system IT-1, IT-2.

In general, "a", "an", etc. can be understood to mean a singular or a plural, in particular in the sense of "at least one" or "one or more", etc., as long as this is not explicitly excluded, for example by the expression "exactly a" etc.

A numerical statement can also include exactly the number specified as well as a usual tolerance range, as long as this is not explicitly excluded.

Reference symbol list

CE user terminal

EVN-1 energy supply network EVN-2 energy supply network

EVSE charging station

F electric vehicle

IT-1 IT system

IT-2 IT system LEN home energy network

MOD analysis and control module

PV photovoltaic system

S1-S8 procedural steps

SM Smart Meter WB Wall box

Claims

Claims Method (S1-S8) for charging a battery of an electric vehicle (F), in which

- during at least one previous charging process of the battery, at least one charging energy value of the charged energy was maintained (S1),

- When the electric vehicle (F) is currently coupled to a charging point (EVSE) with the possibility of bidirectional charging, at least one discharge energy value is provided for a possible discharging process

(S3),

- is analyzed on the basis of the charging energy value recorded for the at least one previous charging process and the current discharging energy value

(S4), whether it is worthwhile, during the current coupling to the charging point (EVSE), to have the battery discharged below an initial charge state present when the electric vehicle (F) is coupled at the time of departure, and

- if this is the case, the battery is discharged below the initial charge level by the time of departure (S8),

- Otherwise it is charged until the time of departure (S6). Method (S1-S8) according to claim 1, in which the battery is not discharged further than a predetermined minimum state of charge until the time of departure (S8). Method (S1-S8) according to claim 2, in which the predetermined minimum state of charge is a state of charge that is sufficient to reach a next destination, in particular plus a state of charge safety margin. Method (S1-S8) according to one of the preceding claims, in which the state of charge at the time of departure is dimensioned such that it is not less than an initial state of charge minus the amount of energy charged during the last charging process.

5. Method (S1-S8) according to one of the preceding claims, in which the energy value of the electrical energy comprises at least one economic value, in particular a price.

6. Method (S1-S8) according to one of the preceding claims, in which the energy value of the electrical energy comprises an ecological value, in particular a CC>2 emission required for provision.

7. Method (S1-S8) according to one of the preceding claims, in which the analyzing (S4) includes calculating a difference between the charging energy value and the discharging energy value and discharging the battery below the initial charge state by the time of departure will or can be if the difference is negative and, in particular, a minimum energy value for the electric vehicle is exceeded due to discharging.

8. Method (S1-S8) according to one of the preceding claims, in which at least one charging process has been carried out on a local energy network (LEN), which is connected to a public energy distribution network (EVN-1) via an energy measuring device (SM) and additionally has at least one energy generating device (PV), wherein an energy value of the electrical energy fed into the local energy network (LEN) by the at least one energy generating device (PV) is determined based on at least costs, in particular electricity production costs, of the at least one energy generating device (PV).

9. Electric vehicle (F), wherein the electric vehicle (F) is set up to run the method (S1-S8) according to one of the preceding claims.

10. Electric vehicle (F), comprising:

- an analysis module (MOD), which is set up to analyze, based on the charging energy value recorded for the at least one previous charging process and the current discharging energy value, whether the battery is worth using during a current coupling to the charging point (EVSE). to discharge at the time of departure below an initial charge state present when the electric vehicle (F) is coupled,

- and a control module (MOD), which is set up in the event that the analysis module has come to the conclusion that it is worthwhile to discharge the battery at the time of departure below an initial charge state present when the electric vehicle (F) is coupled to discharge the battery below the initial charge level by the time of departure and otherwise charge it until the time of departure.

11. System (F, IT-1, IT-2), comprising the electric vehicle (F) according to one of claims 9 to 10 and an external data processing instance (IT-1, IT-2) that can be linked to the electric vehicle (F), wherein the data processing instance (IT-1, IT-2) is set up to analyze, based on the charging energy value tracked for the at least one previous charging process and the current discharging energy value, whether it is worthwhile during a current coupling to the charging point , to discharge the battery at the time of departure to an initial state of charge present when the electric vehicle (F) is coupled, and to transmit the result of the analysis to the electric vehicle (F).