DE102021212943A1 - Method for charging a starter battery and device for carrying out the method - Google Patents

Abstract

The present invention relates to a method and a device for charging a starter battery of a motor vehicle, which can be connected to a charging device external to the vehicle at a coupling point in order to maintain the charging capacity. In order to propose a method for charging a starter battery of a motor vehicle, which optimally prepares the starter battery for the forthcoming load scenario, the invention provides that the starter battery is charged with a needs-based charging profile, with the settings of the charging profile depending on parameters that can be specified manually and/or can be determined automatically he follows.

Description

The present invention relates to a method and a device for charging a starter battery of a motor vehicle, which can be connected to a vehicle-external charging device at a coupling point in order to maintain the charging capacity.

Motor vehicles of the type mentioned have an internal combustion engine that is started by means of a starter battery. While driving, the electrical energy consumed during the starting process and when supplying the vehicle's peripheral devices, such as the infotainment system or the heater, is fed back into the starter battery by means of an alternator. In conventional vehicles, the starter battery is no longer charged after the vehicle has been switched off until the vehicle and thus the internal combustion engine are started again. After a journey, the starter battery usually has sufficient charging capacity to ensure a subsequent starting process even weeks after the vehicle has been switched off, because during this time there are usually no consumers in operation that draw electrical energy from the starter battery and thereby reduce the charging capacity.

Modern vehicles have extensive software, which regulates and/or controls internal vehicle processes, both as part of the vehicle control system and as part of the vehicle's own peripheral devices. The increasing computer-aided control of the vehicle and its peripherals requires regular software updates to replace outdated elements of the software with revised versions or to add new software packages if, for example, the vehicle owner has purchased additional functions. Software updates are carried out wirelessly via suitably set up radio interfaces. Information about an upcoming update is displayed visually to the customer after the vehicle has started and the infotainment system has started up. For safety and accident prevention reasons, the details of the forthcoming update and the required confirmation are not displayed while driving. The period from the start of the vehicle to the point at which the journey is usually started is regularly not suitable for informing the driver about the forthcoming update and for obtaining its confirmation. After completing the journey, the driver would have to leave the vehicle ignition switched on, contrary to normal practice, and call up and confirm the update notification manually in the menu. In this case, the downloading of the software package and the subsequent installation only begin afterwards - and therefore when the engine is usually switched off. The electrical energy required for this is drawn from the starter battery and is therefore no longer available for a later starting process. In particular with extensive software updates and a comparatively long downtime of the motor vehicle, there is a risk that the charging capacity of the starter battery does not have enough energy for restarting the motor vehicle, so that restarting is only possible using a complex jump starter. Even in the event that it is possible to restart the combustion engine using a starter battery despite the update-related reduction in charging capacity, the reduction in charging capacity is disadvantageous because the energy loss after the combustion engine has started must first be compensated for by the alternator, so that on-board peripherals with a comparatively high energy requirement, such as the seat heating, can only be switched on later and several minutes after the start of the journey. In this respect, an update-related reduction in the charging capacity of the starter battery is also associated with a noticeable loss of comfort.

A comparable problem also exists with demonstration vehicles from car dealerships, which are started comparatively infrequently and nevertheless have a not insignificant power consumption for the purpose of demonstrating the vehicle's peripheral devices. The starter battery of such a vehicle is connected directly to a vehicle-external charging device, which, however, requires free access to the starter battery and therefore an open bonnet. The charging capacity of a starter battery of the motor vehicle can therefore not be maintained in a comparable manner outside the secured area of a car dealership, which is why motor vehicles have been proposed for this purpose that have a suitable coupling point for a vehicle-external charging device on the outside of the vehicle, which also locks the rest of the way vehicle is accessible.

Regardless of the positioning and arrangement of a coupling point, known methods for maintaining the charge capacity of a starter battery have proven to be in need of improvement. Known charging methods for starter batteries are reduced to applying a substantially constant charging current to the starter battery until the starter battery is fully charged. Future loads on the starter battery are not taken into account here. For the user, it is also not readily apparent whether the starter battery during the impending standstill of the motor vehicle with the fahrzeugex external charging device must be connected or not. As a result, starter batteries are not optimally prepared for starting the motor vehicle, especially after a long standstill.

It is therefore the object of the present invention to propose a method for charging a starter battery of a motor vehicle which optimally prepares the starter battery for the forthcoming load scenario. In addition, the object of the invention is to specify a device for carrying out the method.

This object is achieved by the method according to claim 1 and by the device according to claim 10. According to the invention, it is provided that the starter battery is charged with a needs-based charging profile, with the charging profile being set as a function of parameters that can be specified manually and/or can be determined automatically. The method according to the invention applies a charging current to the starter battery which is based on the forthcoming load scenario, so that the starter battery is optimally prepared for restarting the motor vehicle.

Preferred embodiments of the method are given below and in the subclaims.

According to a first advantageous embodiment of the method, it is provided that the demand-dependent charging profiles are designed to carry out quick charging, trickle charging, service charging or a separate charging request. The specifically specified charging profiles differ in particular by their respective settings, which, however, are not fixed in an unchangeable manner, but are dependent on the parameters that can be specified manually and/or can be determined automatically.

The parameters that can be determined automatically include in particular the battery type of the starter battery, the open-circuit voltage of the starter battery, the battery state of charge (SOC), a location determination, a vehicle idle time detection, the outside temperature and/or a start-up detection.

In contrast, the parameters that can be determined manually include, in particular, a calendar entry for the next planned departure time and/or a separate charging request for operating selectable on-board peripheral devices.

A selection of different charging profiles is discussed in detail below as an example.

The charging profiles available are typically dependent on the battery type of the existing starter battery. A distinction must be made between lead-acid batteries, AGM batteries and lithium batteries. To set the charging profile, the battery type can be recognized by a typical discharge curve and/or by readable information within a memory unit in the battery control unit.

A required quick charge is determined in particular by measuring the off-load voltage of the starter battery, because there is usually a clear assignment rule between the off-load voltage and the battery state of charge (SOC). Fast charging preferably takes place if, when the vehicle-external charging device is connected, it is determined that the battery state of charge is less than a limit value of preferably 80%. With fast charging, the maximum available charging current is applied until the starter battery is fully charged and the maximum battery state of charge (SOC) is reached.

A trickle charge is preferably carried out if no short-term departure time is known. After connecting the starter battery to the vehicle-external charging device, the battery state of charge is determined. If this is greater than or equal to an upper limit value of preferably 80%, the battery state of charge is monitored until the battery state of charge has reached a lower limit value of preferably 60%. The starter battery is then charged with a preferably low charging current until a battery charge state of preferably 80% is reached. In addition to reading out the battery state of charge, a location is preferably identified, in particular a GPS location is identified, from which information can be derived that no short-term departure is planned. Such information is correct, for example, with a sufficient probability if the location detection shows that the vehicle is in an airport parking lot or in a showroom of a car dealership.

If no short-term departure time is known, it may be necessary to carry out a service charge in addition to the trickle charge. Provision is preferably made for service charging to take place when the vehicle's idle time exceeds a limit value, with the limit value preferably being preset manually is negotiable and/or is 28 days. Consequently, as part of an advantageous development of the method, the idle time of the motor vehicle is also recorded. After about four weeks of idle time, a battery check is carried out, during which the off-load voltage of the starter battery is measured in particular. If this is lower than a battery-specific limit value, typically 11.6 V, a defective battery can be concluded, so that the starter battery must be replaced with a new starter battery. If necessary, the order is placed automatically online, for which purpose the device is connected to suitable communication channels.

However, if the time of the next departure and/or another significant load on the starter battery is known, the starter battery will be charged after a separate charging request. A significant load on the starter battery results, for example, from heating or cooling air conditioning in the vehicle cabin, the operation of seat heating or the operation of heated windows while the vehicle is stationary, for example to remove ice or snow from the windows. The separate charging request can be specified manually or automatically, for example based on a calendar entry that is actively entered in the vehicle's infotainment system or a connected app on the vehicle owner's mobile device. Automatic recognition of a separate charging request is preferably achieved by automatically recognizing the behavior of the vehicle owner, for which purpose a network between the vehicle, vehicle-external charging device and a suitable evaluation unit is set up, which recognizes regularities in the vehicle owner's behavior and extrapolates them to future situations.

In order to specify the departure time, an advantageous development of the invention provides for an automatic query to be made after the end of the journey as to when the next departure is planned. The query is preferably made via a suitably set up display and control unit inside the vehicle, by voice control or via a connection to the vehicle owner's mobile terminal device. A corresponding entry is saved and taken into account as a manual parameter when selecting the charging profile. Specifications can also be made here, such as setting a comfortable climate 1½ hours before the planned start of the journey. If the input is made via a mobile device, an advantageous development of the invention provides that the mobile device recognizes the disconnection of the wireless connection to the vehicle when the journey is completed, whereupon the query is made by means of a push message on the mobile device .

• 1a-f Kraftfahrzeuge in perspektivischen und teilgeschnittenen Ansichten,
• 2a-e fahrzeugexterne Ladevorrichtungen, jeweils mit einer Ladekontakteinrichtung,
• 3a eine Seitenansicht eines Kraftfahrzeugs mit verschiedenen Kopplungsstellen, die jeweils mit einer fahrzeugexternen Ladevorrichtung verbunden sind,
• 3b eine perspektivische Ansicht einer herausgeschwenkten Tankklappe mit einer darunter angeordneten Kopplungsstelle und
• 4 ein Ablaufdiagramm eines Ladeverfahrens.

Concrete embodiments of the present invention are explained below with reference to the figures. Show it:

• 1a-f Motor vehicles in perspective and partially sectioned views,
• 2a-e vehicle-external charging devices, each with a charging contact device,
• 3a a side view of a motor vehicle with various coupling points, which are each connected to a vehicle-external charging device,
• 3b a perspective view of a pivoted-out tank flap with a coupling point arranged underneath and
• 4 a flow chart of a charging method.

The 1a-f show different embodiments of motor vehicles 1 with an internal combustion engine 2 and a starter battery 3, each shown in a perspective and partially sectional view, such motor vehicles can be charged using the method according to the invention.

To start an internal combustion engine 2, electrical energy is required, which is made available by the starter battery 3 in the illustrated exemplary embodiments. To ensure that the starter battery 3 has sufficient electrical energy to ensure that the internal combustion engine 2 can be restarted after performing sometimes energy-intensive software updates, a connection to a 1a-f not shown) vehicle-external charging device provided, which causes the maintenance of the charging capacity. A coupling point 4 , which is arranged on the outside of the vehicle body 5 , is provided for connecting the starter battery 3 to the vehicle-external charging device. In concrete terms, the coupling points 4 can be arranged on protruding elements 10 , elements 20 that can be extended or swung out, or surface elements 30 of the vehicle body 5 .

1a shows an embodiment with a coupling point 4 on the left exterior mirror 11 as a protruding element 10 of the vehicle body 5. It is provided that the coupling point 4 is arranged in the roadway of the exterior mirror 11, in particular on the side of the roadway that is opposite to the direction of travel.

1b shows an alternative embodiment with a coupling point 4 on an antenna 12, which also forms a protruding element 10 of the vehicle body 5.

The coupling point 4 can also be arranged on a wiper linkage 13 of the windshield wiper system on the front or rear window, as shown in the exemplary embodiment in 1c is shown.

Also is after 1d provided that the coupling point 4 is formed on the tank flap 21, which forms a swing-out element 20 of the vehicle body 5. Specifically, the coupling point 4 is arranged on the upper side of the hinge 6, which allows a simple connection to the charging contact device of the vehicle-external charging device and which, due to the tank flap 21, prevents the charging contact device from accidentally slipping off, especially when the charging contact device is designed as a loop or hook.

1e 1 shows a motor vehicle 1 with a headlight wiper system 22 in the form of a nozzle that can be moved out of the vehicle body 5 . This retractable headlight wiper system 22 also has a coupling point 4 for the current-transmitted connection to a charging device external to the vehicle. Coupling points can be formed on the right-hand and/or left-hand headlight wiper system 22 . Due to their design, the headlight wiper systems 22 also have a power supply, so that the wiring harness that is already present there only has to be supplemented by the current-carrying connection between the coupling point 4 and the starter battery 3, which simplifies assembly. Furthermore, the headlight wiper system 22 is retracted while driving and the coupling point 4 is thus protected from contamination. Any soiling caused by the cleaning fluid in the headlight wiper system 22 can also be easily cleaned.

1f shows a motor vehicle 1 with a coupling point 4, which is integrated into the left side door 31 as a surface element 30 of the vehicle body 5.

The in the 1a-f coupling points 4 shown have charging contact devices that can be connected to corresponding charging contact devices of vehicle-external charging devices. The 2a-e show different embodiments of vehicle-external charging devices 7, each with different charging contact devices 81, which can be connected to the corresponding charging contact devices 82 at the coupling points 4.

2a shows a first embodiment of such a vehicle-external charging device 7 in the form of a loop 71 whose charging contact device 81 has a transmitting coil 9 (primary coil) and a cable 40 connected thereto for connection to a stationary or portable power source 41 . The loop 71 also has magnetic elements 42 and/or a counterweight 43 opposite the transmission coil 9 , which allows the transmission coil 9 to be connected to a vehicle-side receiver coil 47 of the charging contact device 82 and therefore to the coupling point 4 in a precisely positioned manner. To prevent damage to the paintwork, the loop 71 (shown only by way of example in the area framed by dashed lines) has a scratch protection 44 in the form of a fabric covering. Such a charging device 7 can be connected to the charging contact device 82 of the motor vehicle at the coupling point 4 by hanging the loop 71 over the exterior mirror 11, the antenna 12, the tank flap 21 or over the headlight wiper system 22, for example. In this case, the current is transmitted inductively via the receiver coil 47 of the vehicle-side charging contact device 82 at the coupling point 4.

An alternative embodiment of such an on-board charging device 7 is in 2 B shown in the form of a hook 72, which can be connected to a coupling point 4 of the motor vehicle 1 in an otherwise analogous manner.

2c shows a vehicle-external charging device 7 with a plug 73 as a charging contact device 81, which can be inserted into a coupling 48 of the vehicle-side charging contact device 82, so that a current-conducting contact is formed.

2d shows one to 2c Comparable embodiment with a terminal 74 as a charging contact device 81 of the vehicle-external charging device 7. This terminal 74 can be connected to a vehicle-side clamping surface 49 in a clamping and therefore contact-closing manner, so that the charging current can flow from the power source 41 to the starter battery 3.

Finally shows 2d a charging device 7 with a magnetic contact 75 as a charging contact device 81, wherein the magnetic contact 75 can be connected to a corresponding or corresponding magnetic contact of the charging contact device 82 of the coupling point.

3a shows a side view of a motor vehicle 1, which shows, by way of example, several positioning points of coupling points 4, at which, by way of example, a vehicle-external charging device 7 is arranged in each case.

A first coupling point 4 is arranged on the left exterior mirror 11, around which a loop 71 of the charging device 7 can be hung in the manner already described, which loop has, for example, a charging contact device with a transmitting coil. Such a loop 71 is also designed in a comparable manner in order to establish a current-transmitted connection with an extendable door handle 23, the antenna 12, the tank flap 21 pivoted out or the headlight wiper system 22 extended. A charging contact device 7 is also arranged on the wiper linkage 13, for example, with a charging contact there preferably being connected via a plug or a terminal (both in 3a not shown in detail) is produced.

3b shows an open tank flap 21, ie pivoted in the direction of arrow 45, which in the closed position not only covers the tank filler neck and the tank cap 46, but also the coupling point 4, so that the coupling point 4 is protected from dirt. In the exemplary embodiment shown, the coupling point 4 is a magnetic contact 75 which only releases the power supply when the magnetic contact 75 is correctly positioned, so that the coupling point 4 is otherwise short-circuit-proof.

4 shows a specific embodiment of the invention and thus a method for charging a starter battery of a motor vehicle, which is connected to a vehicle-external charging device at a coupling point to produce and/or maintain the charging capacity, for example as described above. First, there is a needs-based charging profile selection 50 and a determination 51 of the battery state of charge (SOC) of the starter battery and the idle time of the motor vehicle. If the battery state of charge of the starter battery is less than 80%, rapid charging 52 takes place with a maximum charging current. If the battery state of charge is greater than or equal to 80%, the battery state of charge is monitored until the battery state of charge has reached 60%. A trickle charge 53 then takes place with a comparatively low charging current until the battery state of charge has again reached 80%. If the determination of the idle time shows that the motor vehicle has not been started for more than 4 weeks, a service charge 54 takes place, during which a battery check 541 and/or, if necessary, a new battery is ordered 542 .

Regardless of the specific implementation of the charging process, a check 55 is carried out to determine whether the time of the next start of the journey is known, for example due to a calendar entry, a recognition of regularities in the vehicle owner's behavior or a query when the vehicle is parked. In this case, the starter battery is charged 56 immediately before the imminent departure. However, if the time of the next start of the journey is unknown, a check 57 is carried out to determine whether there is a separate charging request. If there is a separate charging request, charging 56 takes place. If, on the other hand, there is no separate charging request, the need-based charging profile selection 50 is checked again, with which the method starts again.

Reference List

1

motor vehicle

2

combustion engine

3

starter battery

4

coupling point

5

vehicle body

6

hinge

9

transmitter coil (primary coil)

40

Cable

41

power source

42

magnetic element

43

counterweight

44

scratch protection

45

arrow direction

46

gas cap

47

receiver coil (secondary coil)

48

coupling

49

clamping surface

7

off-board charging device

71

loop

72

Hook

73

Plug

74

clamp

75

magnetic contact

81

Charging contact device of the charging device

82

Charging contact device of the motor vehicle

10

protruding element

11

exterior mirrors

12

antenna

13

wiper linkage

20

extendable element

21

tank flap

22

headlight wiper system

23

door handle

30

surface element

31

side door

50

Load profile selection

51

Determination of the battery state of charge

52

fast charge

53

trickle charge

54

service charge

541

battery control

542

Order a new battery

55

Check next start of journey

56

charging

57

Checking separate charging requests

Claims (10)

Method for charging a starter battery (3) of a motor vehicle (1), which can be connected to a vehicle-external charging device (7) at a coupling point (5) in order to establish and/or maintain the charging capacity, characterized in that the starter battery (3) is equipped with a demand-dependent charging profile is charged, the settings of the charging profile being dependent on manually specifiable and/or automatically ascertainable parameters. procedure after claim 1 , characterized in that the demand-dependent charging profiles are designed to carry out quick charging (52), trickle charging (53), service charging (54) or a separate charging request (57). Procedure according to one of Claims 1 or 2 , characterized in that the automatically ascertainable parameters - the battery type of the starter battery and/or - the off-load voltage of the starter battery and/or - the battery state of charge (SOC) and/or - a location determination and/or - a standstill time detection of the vehicle and/or - the Outside temperature and/or - a start-up detection is concerned. Procedure according to one of Claims 1 until 3 , characterized in that the parameters that can be specified manually relate to a calendar entry for the next planned departure time and/or a separate charging request for operating selectable on-board peripherals. procedure after claim 2 , characterized in that a quick charge (52) is carried out if it is determined when connecting the vehicle-external charging device (7) that the battery state of charge (SOC) is less than a limit value of preferably 80%. Procedure according to one of claims 2 until 5 , characterized in that in the quick charge (52) the maximum available charging current is applied until the starter battery (3) is fully charged and the maximum battery state of charge (SOC) is reached. procedure after claim 2 , characterized in that a trickle charge (53) is carried out if no short-term departure time is known and after connecting the starter battery (3) to the vehicle-external charging device (7) it is determined that the battery state of charge (SOC) exceeds an upper limit value of preferably 80 % is not fallen below. procedure after claim 7 , characterized in that the battery state of charge (SOC) is monitored until the battery state of charge (SOC) has reached a lower limit value of preferably 60%, and the starter battery (3) is then charged until the battery state of charge (SOC) reaches an upper limit value of preferably 80% is reached. procedure after claim 2 , characterized in that a service charge (54) takes place when the idle time of the motor vehicle (1) exceeds a limit value, the limit value preferably being able to be specified manually and/or being 28 days. Device for charging a starter battery (3) of a motor vehicle (1) with a vehicle-external charging device (7) which can be connected to the starter battery (3) at a coupling point (4) in order to establish and/or maintain the charging capacity, and a control unit which for carrying out the method according to one of Claims 1 until 9 is set up.

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