Vehicle electrical system and vehicle with such a vehicle electrical system

Abstract

The invention relates to a vehicle electrical system (12) for an internal combustion engine vehicle with an on-board battery (12) and a charging unit (14) for charging the on-board battery (13), wherein the on-board battery (13) provides a first low-voltage on-board voltage, in particular a 48V on-board voltage, wherein the vehicle electrical system (12) comprises: an energy distribution unit (18); a low-voltage DC voltage source (25 26) which can be connected to or is connected to the energy distribution unit (18) and is configured to provide a second low-voltage on-board voltage, which is in a range below the first low-voltage on-board voltage;and a control unit (28) which is connected to the energy distribution unit (18) and is configured to supply low-voltage consumers (16) of the vehicle electrical system (12) in a first vehicle state by means of the first low-voltage electrical system voltage, and in a second vehicle state to supply the low-voltage consumers (16) only by means of the second low-voltage electrical system voltage.

Description

[0001] The present invention relates to a vehicle electrical system for a vehicle, in particular for an internal combustion engine vehicle, and to a vehicle with such a vehicle electrical system.

[0002] Vehicles typically have an electrical system that supplies the vehicle's electrical components with energy / power. These components are usually low-voltage devices, operating on a low-voltage electrical system voltage ranging from 5V to 16V.

[0003] Supplying power to low-voltage consumers such as lights, turn signals, fans, control units, air conditioning, heating, etc., while a vehicle is in operation is not critical. In combustion engine vehicles, for example, the energy for these low-voltage consumers can come from a dedicated on-board battery. This battery is typically charged by the vehicle's charging unit, which could be, for example, an alternator or a starter-generator. The energy or power supplied by the battery is then usually distributed throughout the vehicle by a power distribution unit.

[0004] The situation is different when the vehicle is in park mode, for example. In park mode, it is best if all non-critical loads and low-voltage consumers are switched off, and only the critical loads (key-off loads) are supplied by the vehicle's electrical system. Critical low-voltage consumers include, for example, the immobilizer, alarm system, GPS tracker, cameras, access control, and the like.

[0005] Document DE 10 2021 117 997 A1 discloses a method for operating an on-board electrical system comprising a first branch of the on-board electrical system in which an energy storage device is provided, and a second branch of the on-board electrical system, wherein the two branches of the on-board electrical system are connected to each other via a DC-DC converter, further comprising a unit that detects a state of the second branch of the on-board electrical system and controls the DC-DC converter depending on the detected state of the second branch of the on-board electrical system, wherein the control of the DC-DC converter is such that the DC-DC converter supplies the second branch of the on-board electrical system with a reduced voltage when the second branch of the on-board electrical system is in the standby state.

[0006] Document DE 10 2009 048 614 A1 discloses a method for operating a dual-voltage electrical system in a vehicle, in particular a hybrid vehicle, fuel cell vehicle, or electric vehicle, wherein the dual-voltage electrical system comprises a low-voltage electrical system for supplying at least one low-voltage consumer with electrical energy and a high-voltage electrical system for supplying at least one high-voltage consumer with electrical energy, as well as a DC-DC converter connected between the electrical systems, and wherein the DC-DC converter is controlled depending on the vehicle's driving state and / or an electrical voltage and / or an electrical current of one of the electrical systems. This allows a low-voltage storage device to be recharged from a high-voltage storage device, thus enabling a significantly smaller and lighter design.

[0007] Document DE 199 159 73 C1 discloses a method for regulating the electrical system voltage of a motor vehicle powered by an engine. According to the invention, a voltage reduction is carried out to reduce the load on a vehicle battery when the engine is off.

[0008] The object of the present invention is therefore to provide a vehicle electrical system and a vehicle, in particular an internal combustion engine vehicle, with such a vehicle electrical system, which can ensure an energy-saving and simple supply of critical loads or critical low-voltage consumers, especially in parking mode.

[0009] This problem is solved by the subject matter of the independent claims. Further advantages of the invention are the subject matter of the dependent claims.

[0010] According to one aspect of the present invention, a vehicle electrical system for an internal combustion engine vehicle is provided, comprising an on-board battery and a charging unit for charging the on-board battery, wherein the on-board battery provides a first low-voltage on-board voltage, in particular a 48V on-board voltage. The vehicle electrical system includes: a power distribution unit for distributing electrical energy or electrical power within the vehicle electrical system; a low-voltage DC power supply that can be connected to or is connected to the power distribution unit, wherein the low-voltage DC power supply is configured to provide a second low-voltage on-board voltage, which is in a range below the first low-voltage on-board voltage and in particular in a range of 5V to 16V;a control unit connected to the energy distribution unit and designed to provide, in a first vehicle state, in particular when the vehicle is in operation, the first low-voltage on-board voltage supplied by the on-board battery to low-voltage consumers such as turn signals, tailgate, A / C, ECUs, steering, lights, and fans of the vehicle's on-board electrical system, and, in a second vehicle state, in particular when the vehicle is parked, to provide only the second low-voltage on-board voltage supplied by the low-voltage DC power source to the low-voltage consumers.

[0011] The present invention is based, at least in part, on the understanding that supplying power to key-off loads in park mode is resource-intensive. To ensure power supply in park mode, it is proposed to use a low-voltage DC power source that provides a second low-voltage on-board voltage, which is below the first low-voltage on-board voltage provided by the vehicle's battery. The low-voltage DC power source is designed to supply energy / power only to the critical low-voltage consumers in the second vehicle state. A control unit detects whether the vehicle is in a first vehicle state, which may be, in particular, the vehicle being driven, or in a second vehicle state, which may be, in particular, the vehicle being parked.When the vehicle is in the first vehicle state, the control unit ensures that the low-voltage consumers are supplied with the (first) low-voltage electrical system voltage as usual. However, when the vehicle is in the second vehicle state, the low-voltage consumers, and in particular the key-off loads of the vehicle's electrical system, are supplied only by the second low-voltage electrical system voltage provided by the low-voltage DC power source.

[0012] Preferably, the low-voltage DC power source is a DC-DC converter that is connected or connectable to the vehicle's electrical system battery and is designed to convert the first low-voltage system voltage provided by the battery into a second low-voltage system voltage. The DC-DC converter can also be referred to as a micro-DC-DC converter. This DC-DC converter takes over the function of the separate battery. The DC-DC converter is connected or connectable to the vehicle's electrical system battery and provides a low-voltage system voltage sufficient to power the key-off loads.

[0013] Another preferred embodiment provides that the DC-DC converter is designed for a maximum power output of 15 watts, preferably a maximum of 10 watts, and even more preferably a maximum of 5 watts. This preferred embodiment is based on the understanding that the DC-DC converter needs to provide significantly less power because it only has to supply the key-off loads. The micro-DC-DC converter requires little installation space, is easy to control, and is cost-effective.

[0014] According to the invention, the low-voltage DC voltage source is connected to the power distributor via a diode and provides the second low-voltage on-board voltage in both the first and second vehicle states, wherein the diode is designed such that in the first vehicle state the first low-voltage on-board voltage provided by the on-board battery is not present at the low-voltage DC voltage source or no current can flow into the low-voltage DC voltage source.

[0015] In vehicles with a zonal electrical system architecture, each low-voltage consumer can be connected to a converter, for example, a converter located in a zone control unit or zone controller of the vehicle's electrical system. This converter typically comprises a half-bridge with a high-side transistor circuit and a low-side transistor circuit. This converter, which is usually already present in zonal electrical system architectures, can selectively provide either the first or the second low-voltage electrical system voltage to supply the low-voltage consumers.The preferred embodiment now provides that the control unit is controllably connected to such converters in such a way that, in the first vehicle state, i.e., the vehicle state in which the low-voltage consumers are supplied with the first low-voltage on-board voltage, the high-side transistor circuit and the low-side transistor circuit are controlled in such a way that the low-voltage consumers can only be supplied with the first low-voltage on-board voltage, and that, in the second vehicle state, i.e., the vehicle state in which the low-voltage consumers are to be supplied with the second low-voltage on-board voltage (namely from the micro-DCDC), the low-side transistor circuit is opened and the high-side transistor circuit is closed, so that the low-voltage consumers can only be supplied with the second low-voltage on-board voltage.In other words, the design envisages that in the first vehicle state, the (zone) converters operate as usual as (buck) DC-DC converters, i.e., converting, for example, a 48V vehicle electrical system voltage, supplied by a 48V vehicle battery, into 12V or 5V. In the second vehicle state, the (zone) converters are operated not as converters but as "pass-through" converters, by opening the low-side transistor circuit and closing the high-side transistor circuit. While the (zone) converters typically have a coil that exhibits a certain inductance when current flows, this inductance has little or no effect because the coil is supplied with a constant voltage / power. In other words, the loss through the (converter) coil is negligible in the second vehicle state. The preferred embodiment therefore provides for the (zone) converters to be used not as converters but as (pass-through) switches in the second vehicle state.This allows the (zone) converter to be used in both the first and second low-voltage on-board voltage ranges.

[0016] Another preferred embodiment provides that the power distribution unit typically includes a switching device that acts as an electrical safety device (such as an eFuse), wherein the switching device typically has a first switching state (e.g., "off" or "closed") and a second switching state (e.g., "on" or "open"), and wherein the first switching state is typically assumed in the first vehicle state and the second switching state is typically assumed in the second vehicle state (as a safety function). The preferred embodiment provides that the control unit is configured such that the first switching state of the switching device is set in the first vehicle state, and the second switching state of the switching device is set in the second vehicle state.In other words, the preferred embodiment provides that the eFuse, which is normally inactive in the first vehicle state, remains in the first switching state, whereas the eFuse, which is normally active in the second vehicle state, is actively switched from the second switching state to the first switching state. The preferred embodiment is based on the understanding that an eFuse, such as those commonly used as a safety device in power distribution units, can be actively deactivated by the control unit, or actively switched from the second (open) switching state to the first (closed) switching state, when the vehicle is in the second vehicle state and key-off loads still need to be supplied with power.

[0017] It is further preferred that the DC-DC converter is connected to the vehicle's battery in such a way that it provides the second low-voltage system voltage in both the first and second vehicle states. In other words, the micro-DC-DC converter is always active and always provides the second low-voltage system voltage, both in the first and second vehicle states (even though it would not be needed in the first state). The micro-DC-DC converter's low power consumption allows for continuous operation without significant losses.

[0018] Another aspect of the present invention provides for a vehicle that has such a vehicle electrical system. The vehicle can, in particular, be an internal combustion engine vehicle that has a vehicle electrical system battery and a charging unit for charging the vehicle electrical system battery.

[0019] Further features and functions of the present invention will become apparent to the person skilled in the art by carrying out the teaching presented here and by examining the accompanying drawings. These show: Fig. 1 a schematic view of an embodiment of a vehicle electrical system according to the invention, Fig. 2 a schematic view of a further embodiment of a vehicle electrical system according to the invention, Fig. 3 a schematic view of a further embodiment of a vehicle electrical system according to the invention, Fig. 4 a schematic view of a further embodiment of a vehicle electrical system according to the invention, Fig. 5 a schematic view of a possible control of a half-bridge, where the half-bridge is operated as a converter, and Fig. 6 a schematic view of another possible control of the half-bridge of Fig. 5.

[0020] Elements of the same construction or function are provided with the same reference symbols across all figures.

[0021] It should first be on Fig. Reference is made to Figure 1, which shows a schematic view of a vehicle 10 with a vehicle electrical system 12. In the specific example of Fig. In Figure 1, vehicle 10 is an internal combustion engine vehicle, i.e., a vehicle with an internal combustion engine (not shown). Vehicle 10 has an on-board battery 13 and a charging unit 14 for charging the on-board battery 13. The charging unit 14 can be an alternator, a starter-generator, or another type of charging unit.

[0022] The vehicle electrical system 12 has several low-voltage consumers 16, which can also be referred to as low-voltage loads or simply loads. Low-voltage consumers 16 are required in the vehicle electrical system 12 to ensure various functions and / or operations, as is well known to experts. Examples of low-voltage consumers 16 include: immobilizer, alarm system, GPS tracker, cameras, access control, turn signals, tailgate, A / C, ECUs, steering, lights, fans, etc.

[0023] To supply the low-voltage consumers 16 with energy / power, the vehicle electrical system 12 also includes a power distribution unit 18. This unit 18 typically serves to distribute energy / power within the vehicle electrical system 12. In the specific example of Fig. The vehicle electrical system 12 also includes so-called zone controllers 32. The zone controllers 32 are connected to the power distribution unit 18 and in turn distribute the power to the low-voltage consumers 16 connected to the respective zone controller 32. In other embodiments not shown, zone controllers 32 may not be present.

[0024] During vehicle operation 10, the low-voltage consumers 16 are typically supplied with energy / power from the vehicle battery 13, with the power provided by the vehicle battery 13 being supplied by the charging unit 14. Depending on the architecture and vehicle battery used, the vehicle battery 13 can, for example, provide an initial low-voltage system voltage of 24V, 48V, or even 60V. Currently, 24V or 48V vehicle batteries are used.

[0025] The on-board battery 13 is connected to a switching device 24 of the power distribution unit 18. The switching device 24 functions as a safety device and is, for example, an eFuse. The switching device 24 can have a first switching state and a second switching state, and it can be switched between these two states. In the first switching state, an electrical connection is typically established between the on-board battery 13 and the power distribution unit 18. In other words, in the first switching state, the low-voltage consumers 16 can be supplied with electrical energy / power from the on-board battery 13. In the second switching state, an electrical connection between the on-board battery 13 and the power distribution unit 18 is typically interrupted. The second switching state can be understood as a safety shutdown in the sense of an eFuse functionality.For example, in park mode, not all low-voltage consumers 16 should be supplied with electrical power. The interruption of the supply to these low-voltage consumers 16 is ensured by the eFuse functionality.

[0026] In a driving mode of the vehicle 10, which is an example of a first vehicle state, the low-voltage consumers 16 are typically supplied with electrical power provided by the vehicle battery 13. In the first vehicle state, the switching device is therefore typically in its first (closed) switching state, so that the electrical connection between the vehicle battery 13 and the low-voltage consumers 16 exists.

[0027] However, if the vehicle is in a parking mode, which is an example of a second vehicle state, the switching device 24 typically switches to the second (open) switching state according to its eFuse functionality. In this state, the low-voltage consumers 16 would not be supplied with electrical power.

[0028] For safety and other reasons, it is necessary that some low-voltage consumers, such as immobilizers, alarm systems, GPS trackers, cameras, access controllers, etc., continue to receive power even in parked mode. These so-called key-off loads must be supplied with power.

[0029] As in Fig. As shown in Figure 1, the vehicle electrical system 12 has a low-voltage DC voltage source 25 for this purpose. In the example of Fig. 1. This is a battery. The low-voltage DC power supply 25 provides a second low-voltage on-board voltage, which is in a range below the first low-voltage on-board voltage, and in particular in a range of 5V to 16V, preferably 12V. The second low-voltage on-board voltage is suitable for supplying energy / power to the critical low-voltage consumers 16.

[0030] The vehicle electrical system 12 also includes a control unit 28, which is connected, among other things, to the power distribution unit 18. The control unit 28 is designed such that, in the first vehicle state, the low-voltage consumers 16 are supplied with the first low-voltage electrical system voltage or power, and in the second vehicle state, the low-voltage consumers 16 are supplied only with the second low-voltage electrical system voltage or power.

[0031] If, for example, it has been determined that the first vehicle state exists, the switching device 24 will typically be in the first (closed) switching state and the low-voltage consumers 16 will be supplied with the power provided by a DC-DC converter 33. In such a case, the control unit 28 will not change the switching state of the switching device 24.

[0032] However, if, for example, it is determined that the second vehicle state exists because the vehicle 10 is in parking mode, the switching device 24 will typically be in the second (open) switching state, and the low-voltage consumers 16 will typically not be supplied with power. In such a case, however, the control unit 28 will control the switching device 24 in such a way that the switching device 24 changes from the second (open) state to the first (closed) state. The low-voltage consumers 16 can then be supplied with power, specifically with the power provided by the low-voltage DC power source 25.

[0033] The control unit 28 can be a separate control unit or it can be a functional unit within a control unit already existing in the vehicle architecture. For example, a typical vehicle electrical system architecture usually has a master controller, which is schematically represented in Fig. 1 is indicated by the reference numeral 30. It is conceivable that the control unit 28 could be integrated into the master controller 30. Other configurations of the control unit 28 are of course also possible.

[0034] As already indicated, modern vehicle electrical system architectures may exhibit zonal structures. For example, in Fig. One different zone control unit 32 is indicated. These control units, also referred to as zone controllers, supply power to several low-voltage consumers 16. These zone control units 32 are connected to the power distribution unit 18 and can, for example, themselves include further converters 33, such as DC-DC converters 33. These converters 33 convert the vehicle electrical system voltage provided by the power distribution unit 18 into the low-voltage voltage relevant / necessary for the low-voltage consumers 16. If, for example, a typical low-voltage vehicle electrical system voltage 10 is 48V (because, for example, the vehicle electrical system battery 13 is a 48V battery), then the converters 33 of the zone control units 32 would convert this 48V into, for example, 16V, 12V, or 5V, depending on the voltages for which the low-voltage consumers 16 are designed.

[0035] Another idea of ​​the present invention is therefore to use these converters 33 by means of clever control of the control unit 28 in such a way that the low-voltage consumers 16 can be supplied with electrical power in both the first and second vehicle states. One possibility of control is described in Fig. 5 and Fig. 6 explained.

[0036] First, however, let us focus on Fig. Reference is made to Figure 2, which shows a further embodiment of the vehicle electrical system 12 according to the invention.

[0037] Compared to the design according to Fig. 1 is in the design according to Fig. 2. A blocking diode 34 is provided between the output of the low-voltage DC power supply 25 and the input of the power distribution unit 18 or the switching device 24. The blocking diode 34 prevents electrical power or current from flowing from the vehicle battery 13 into the low-voltage DC power supply 25 in the first vehicle state. In other words, the diode 34 blocks the electrical path towards the low-voltage DC power supply 25.

[0038] It is now on Fig. Reference is made to Figure 3, which shows a further embodiment of the vehicle 10 according to the invention and of the vehicle electrical system 12.

[0039] In the design of Fig. 3. The low-voltage DC power source is not a battery, but a DC-DC converter 26. The DC-DC converter 26 is connectable to, or already connected to, the vehicle battery 13 and converts the voltage of the vehicle battery 13 into a second low-voltage vehicle system voltage, which is in a range below the first low-voltage vehicle system voltage of the vehicle battery 13, and in particular in a range of 5V to 16V, preferably 12V. The second low-voltage vehicle system voltage is suitable for supplying energy / power to the critical low-voltage consumers 16.

[0040] The DC-DC converter 26 is designed only for key-off loads. For example, the DC-DC converter 26 is designed for a maximum power output of 15 watts, preferably a maximum of 10 watts, and preferably a maximum of 5 watts. The DC-DC converter 26 has a simple design, is easy to control, is cost-effective, lightweight, and requires little installation space. The DC-DC converter 26 can also be referred to as a micro-DC-DC converter. The DC-DC converter 26 can be connected to the vehicle's electrical system battery 13, so that it always provides power, i.e., in both the first and second vehicle states; the resulting losses are negligible.

[0041] It was now on Fig. Reference is made to Figure 4, which shows a further embodiment of the vehicle electrical system 12 according to the invention.

[0042] Compared to the design according to Fig. 3 is in its design according to Fig. 4. A blocking diode 34 is again provided between the output of the DC-DC converter 26 and the input of the power distribution unit 18 or the switching device 24. The blocking diode 34 prevents electrical power or current from flowing from the vehicle battery 13 into the DC-DC converter 26 in the first vehicle state. In other words, the diode 34 blocks the electrical path towards the DC-DC converter 26.

[0043] In Fig. 5 and Fig. Section 6 now schematically depicts parts of the previously mentioned converter 33.

[0044] The converter 33 typically comprises a half-bridge 36 with a high-side transistor circuit 38 and a low-side transistor circuit 40. An inductor 42 is arranged between the transistor circuits 38 and 40, as is well known to those skilled in the art of such converters.

[0045] As in Fig. As shown in Figure 5, in the first vehicle state the converter operates as usual, i.e., as a converter that transforms a low-voltage on-board voltage Vin into a low-voltage on-board voltage Vout. Fig. Figure 5 shows the typical case of the first vehicle state, in which the initial low-voltage electrical system voltage Vin is 48V in this example. The converter would convert this voltage to the voltage Vout required for the low-voltage consumers, which is 12V in this example.

[0046] In the second vehicle state, for example in park mode, the control unit would control the converter differently. An example is in Fig. Figure 6 illustrates this. The control unit would, for example, control the converter such that the low-side transistor circuit 40 is open or interrupted, and the high-side transistor circuit 38 is closed. In such a case, the converter would not be used as a converter, but as a switch, so that the second low-voltage on-board voltage provided in the second vehicle state by the low-voltage voltage source 25 or the DC-DC converter 26 can be supplied directly (i.e., without conversion) to the low-voltage consumers. The control unit essentially repurposes the existing converter as a switch, so that the low-voltage consumers can be supplied with the required power even in park mode. In this specific example, the low-voltage DC voltage source would consist of Fig. 1 and Fig. 2 or the DC / DC converter from Fig. 3 and Fig.4 12V are available and the converters would be able to pass this 12V on to the low-voltage consumers without conversion, so that a supply to the key-off loads is ensured even in park mode.

Claims

[1] Vehicle electrical system (12) for an internal combustion vehicle (10) comprising an on-board battery (13) and a charging unit (14) for charging the on-board battery (13), wherein the on-board battery provides a first low-voltage on-board voltage, in particular a 48V on-board voltage, comprising: - an energy distribution unit (18) for distributing electrical energy within the vehicle's electrical system (12), - a low-voltage DC voltage source (25, 26) that can be connected to or is connected to the power distribution unit (18), wherein the low-voltage DC voltage source (25, 26) is configured to provide a second low-voltage on-board voltage, which is in a range below the first low-voltage on-board voltage and in particular in a range of 5V to 16V, and - a control unit (28) which is connected to the energy distribution unit (18) and is designed to, - in an initial vehicle state, in particular during vehicle operation (10), to make the initial low-voltage vehicle electrical system voltage provided by the vehicle electrical system battery (13) available to low-voltage consumers (16) of the vehicle electrical system (12), and - in a second vehicle state, in particular a parking mode of the vehicle (10), only the second low-voltage on-board voltage provided by the low-voltage DC voltage source (25, 26) is made available to the low-voltage consumers (16), wherein the low-voltage DC voltage source (25, 26) is connected to the energy distribution unit (18) via a diode (34), the low-voltage DC voltage source (25, 26) provides the second low-voltage on-board voltage in both the first and second vehicle states, and the diode (34) is designed such that in the first vehicle state the first low-voltage on-board voltage provided by the on-board battery (13) is not present at the low-voltage DC voltage source (25, 26) or no current flows into the low-voltage DC voltage source (25, 26). [2] Vehicle electrical system (12) according to claim 1, wherein the low-voltage DC voltage source is a DC voltage converter (26) which can be connected to the vehicle electrical system battery (13) and is designed to convert the first low-voltage vehicle electrical system voltage provided by the vehicle electrical system battery (13) into the second low-voltage vehicle electrical system voltage. [3] Vehicle electrical system (12) according to claim 2, wherein the DC voltage converter (26) is designed for a maximum power of 15 watts, preferably a maximum of 10 watts, and more preferably a maximum of 5 watts. [4] Vehicle electrical system (12) according to one of claims 1 to 3, wherein the low-voltage consumers (16) are each connected to a converter which has a half-bridge (36) with a high-side transistor circuit (38) and a low-side transistor circuit (40), wherein the converter, by appropriate control by the control unit (28), selectively provides either the first low-voltage vehicle electrical system voltage or the second low-voltage vehicle electrical system voltage for supplying the low-voltage consumers (16), and wherein the control unit (28) is further configured to - in the first vehicle state, to control the high-side transistor circuit (38) and the low-side transistor circuit (40) in such a way that the low-voltage consumers (16) can only be supplied with the first low-voltage on-board network voltage, and - in the second vehicle state to open the low-side transistor circuit (40) and to close the high-side transistor circuit (38) so that the low-voltage consumers (16) can only be supplied with the second low-voltage on-board network voltage. [5] Vehicle electrical system (12) according to one of claims 1 to 4, wherein the power distribution unit (18) has a switching device (24) which is designed as an electrical safety device and has a first, closed switching state and a second, open switching state, and wherein the control unit (28) is further configured to - that in the first vehicle state the first switching state of the switching device (24) is set, and - that in the second vehicle state the second switching state of the switching device (24) is set. [6] Vehicle electrical system (12) according to one of claims 2 to 5, wherein the DC voltage converter (26) is connected to the vehicle electrical system battery (13) in such a way that the DC voltage converter (26) provides the second low-voltage vehicle electrical system voltage in both the first and second vehicle states. [7] Internal combustion vehicle (10) with an on-board battery (13) and a charging unit (14) for charging the on-board battery (13), wherein the on-board battery (13) provides a first low-voltage on-board voltage and wherein the vehicle (10) has an on-board electrical system (12) according to one of the preceding claims.

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