GB2548961A

GB2548961A - Apparatus and method for indicating vehicle charging status

Info

Publication number: GB2548961A
Application number: GB1701769.0A
Authority: GB
Inventors: Holloway Katy; Suffield Iain
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2013-05-01
Filing date: 2015-07-08
Publication date: 2017-10-04
Anticipated expiration: 2035-07-08
Also published as: GB2513610B; GB201307863D0; GB201511940D0; GB2548961B; GB2530848B; GB2530848A; GB2513610A; GB201701769D0

Abstract

An apparatus for a vehicle 100 driven by an electric motor 123, powered by an energy storage means 150 such as a battery, generates an audible sound dependent on whether the electric vehicle, which may be a hybrid electric vehicle (HEV) 100 is charging. The sound or sonic signature is generated upon detecting the proximity of a portable user identification device 190, such as an electronic key or wireless key. Whether charging is occurring may depend on a charging current, or a current and target state of charge (SOC). The audible alert may also depend on a determination that a user or driver wishes to unlock the vehicle. The apparatus may provide different sounds or noises depending on charge state. The charging may be inductive or non-contact.

Description

APPARATUS AND METHOD FOR INDICATING VEHICLE CHARGING STATUS

TECHNICAL FIELD

The present invention relates to an apparatus for a motor vehicle, a motor vehicle control system, a vehicle and a method of controlling a vehicle. In particular, embodiments of the invention relate to apparatus or a control system for a vehicle having an electric propulsion motor powered by charge from an energy storage device that may be recharged. In particular, but not exclusively, embodiments of the invention relate to apparatus or a control system for a vehicle having an electric propulsion motor powered by charge from an energy storage device that may be recharged when the vehicle is connected to a recharging facility.

BACKGROUND

It is known to provide a plug-in electric vehicle and a plug-in hybrid electric vehicle each having an electric propulsion motor and a battery for storing charge for powering the motor. The battery may be recharged by connecting the vehicle to a recharging facility. Connection to a recharging facility is typically by means of a charging cable although inductive charging systems may also be employed.

It is an aim of embodiments of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

Embodiments of the invention may be understood with reference to the appended claims.

Aspects of the present invention provide an apparatus, a vehicle and a method.

In one aspect of the invention for which protection is sought there is provided apparatus for a vehicle having an electric propulsion motor and energy storage means for powering the motor, the apparatus being configured to: generate an audible sonic signature in dependence on whether charging of the energy storage means is in progress and upon detecting the presence of a portable user identification device.

Embodiments of the present invention have the advantage that a user may be informed of the charging state of the vehicle without having to enter the vehicle or inspect a vehicle instrument panel.

The apparatus may form part of a motor vehicle control system, or be provided substantially separate therefrom. The apparatus may be arranged to communicate with a motor vehicle control system. For example, the apparatus may be arranged to be connected to a controller area network (CAN) bus or other onboard communications network, or directly to a controller or other computing device.

The charging facility may be any facility by means of which the energy storage means of the vehicle may be supplied with charge. The charging facility may be one allowing a charging connection to be established by wireless (cableless) means such as by inductive coupling between the vehicle and charging facility.

Embodiments of the present invention are useful in enabling the provision of apparatus that can provide feedback to a user as to whether charging is still in progress.

The apparatus may be operable to determine whether charging of the energy storage means is in progress in dependence at least in part on a status of a signal received by the apparatus indicative of whether charging of the energy storage means is in progress.

Alternatively or in addition the apparatus may be operable to determine whether charging of the energy storage means is in progress in dependence at least in part on a value of a charging current.

It is to be understood that if the value of charging current exceeds a prescribed value, the apparatus may determine that the energy storage means is in a process of being charged. The prescribed value may be a value that is higher than a nominal trickle charge value, being a value supplied to the energy storage means in order to maintain a given state of charge once the state of charge has been attained.

In an example of the disclosure the apparatus may be operable to determine whether charging of the energy storage means is in progress in further dependence at least in part on a value of a state of charge of the energy storage means.

If the energy storage means is substantially full and the value of charging current is below a prescribed value, the apparatus may be configured to determine that charging is not taking place.

Advantageously the apparatus may be operable to determine a value of target state of charge being a state of charge that the energy storage means is required to achieve.

The determination may be made directly by reference to an input signal corresponding to target state of charge, by reference to a user input, such as a user input of a required state of charge, or by any other suitable means.

The apparatus may be operable to determine whether charging of the energy storage means is taking place in dependence at least in part on a current state of charge of the energy storage means and the target state of charge of the energy storage means.

The apparatus may be operable to determine whether a state of charge of the energy storage means has achieved the target state of charge, which may be less than a maximum allowable value of state of charge. For example, the target state of charge may be set in dependence on a length of a journey a user wishes to make following the charging operation, so as to allow adequate charge to complete the journey.

If the state of charge of the energy storage means is substantially equal to the target value and the rate of flow of charge into the energy storage means is below a prescribed value the apparatus may be operable to determine that the vehicle is no longer charging. If the state of charge of the energy storage means is less than the target value and the rate of flow of charge into the energy storage means is above a prescribed value the apparatus may be operable to determine that the vehicle is in the process of charging the energy storage means.

The target state of charge may be determined in dependence on a user input.

The target state of charge may be a value determined by a user by means of a human machine interface (HMI). The HMI may take the form of a touch screen, one or more soft keys, hard keys or any other suitable means.

The value of target state of charge may be supplied to the apparatus via another controller, computing device or the like. The value of target state of charge may be determined in dependence on a journey a user wishes or may wish subsequently to make.

The portable user identification device may for example be a key, a key fob or other starter device or starting means.

The apparatus may be operable to generate the sonic signature in response to a signal received from the portable user identification device.

The apparatus may be operable to generate the sonic signature in response to a determination that a user wishes to unlock the vehicle.

Thus, if the user signals to the control system, for example by means of the portable user identification device, that they wish to unlock the vehicle the control system may generate the sonic signature and unlock the vehicle.

In some embodiments the control system may recognise that the user wishes to unlock the vehicle when a particular one or more user identification devices are recognised by the control system. In some embodiments, the control system may recognise that the user wishes to unlock the vehicle when a particular one or more user identification devices are recognised by the control system and at the same time the system detects that a user is sufficiently close to door opening means such as handle means. The handle means may be retractable handle means, the control system being operable to deploy the handle means to allow the user to open a door of the vehicle when the user’s hand is sufficiently close to the handle means and an authorised user identification device is determined to be present. By authorised device is meant a device corresponding to an authorised user of that particular vehicle, for example a device programmed with a unique identification codes such as the vehicle identification number (VIN).

The apparatus may be operable to generate a first sonic signature if charging of the energy storage means is in progress.

The apparatus may be operable to generate a second sonic signature different from the first if charging of the energy storage means is not in progress.

This feature has the advantage that a user may be provided with positive confirmation as to whether the energy storage means is still being charged.

The apparatus may be operable to generate the second sonic signature if charging of the energy storage means is not in progress and the energy storage means has achieved the target state of charge.

The apparatus may be operable to generate a third sonic signature if charging of the energy storage means is not in progress and the energy storage means has not achieved the target state of charge.

This feature has the advantage that a user may be alerted to a potential problem with the vehicle or a charging station.

The apparatus may be operable to generate the audible sonic signature whereby the signature may be heard from outside the vehicle.

The apparatus may be operable to generate the audible sonic signature by means of audio transducer means external to a cabin of the vehicle.

The apparatus may be operable to generate the audible sonic signature whereby the signature may be heard from inside the vehicle.

Alternatively or in addition the apparatus may be operable to generate the audible sonic signature by means of audio transducer means internal to the cabin of the vehicle.

In a further aspect of the invention for which protection is sought there is provided a motor vehicle system comprising apparatus according to a preceding aspect.

In one aspect of the invention for which protection is sought there is provided a motor vehicle comprising apparatus or a system according to a preceding aspect.

The vehicle may be operable to charge the energy storage means by means of an inductive charging system.

The vehicle may be operable to charge the energy storage means without requiring a cable connection between the vehicle and a charging facility, for example by means of inductive charging.

The vehicle may be an electric vehicle.

The vehicle may be a hybrid electric vehicle.

In one aspect of the invention for which protection is sought there is provided a method of providing feedback to a user of a motor vehicle having an electric propulsion motor and energy storage means for powering the motor, the method comprising generating an audible sonic signature in dependence on a result of a determination whether charging of the energy storage means is in progress and upon detecting the presence of a portable user identification device.

By determination is included determining that charging is in progress by reference substantially solely to an input signal indicating whether or not charging of the energy storage means is in progress.

Within the scope of the claims it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying figures in which: FIGURE 1 is a schematic illustration of a hybrid electric vehicle according to an embodiment of the present invention; and FIGURE 2 is a flow chart illustrating a method according to an embodiment of the present invention.

DETAILED DESCRIPTION FIG. 1 shows a hybrid electric vehicle (HEV) 100 according to an embodiment of the present invention. The vehicle 100 has an internal combustion engine 121 releasably coupled to a crankshaft integrated motor/generator (CIMG) 123 by means of a clutch 122. The CIMG 123 is in turn coupled to an automatic transmission 124. The vehicle 100 is operable to provide drive torque to the transmission 124 by means of the engine 121 alone, the CIMG 123 alone or the engine 121 and CIMG 123 in parallel.

It is to be understood that in some embodiments the transmission 124 may be a manual transmission instead of an automatic transmission

It is to be understood that embodiments of the present invention are not limited to hybrid vehicles. Embodiments of the invention may also be provided in the form of electric-only vehicles.

The vehicle 100 has a battery 150 connected to an inverter 151 that generates a three-phase electrical current supply. The current is supplied to the CIMG 123 when the CIMG 123 is operated as a motor. The battery 150 is arranged to receive charge from the CIMG 123 when the CIMG 123 is operated as a generator.

The battery 150 is also connectable to an inductive charging element 150C that allows the battery 150 to be coupled inductively to a charging port 160P of a charging station 160 without a requirement to connect a charging cable to the vehicle 100. Because the vehicle 100 is operable to recharge the battery 150 from an external power source, the vehicle 100 may be described as a HEV of ‘rechargeable’ or ‘plug-in’ type. The vehicle 100 may be described as a ‘plug-in’ vehicle even though the vehicle 100 shown does not physically connect to a charging station.

The vehicle 100 has a controller 140 configured to control the vehicle 100 to operate in an EV mode in which the engine 121 is prevented from being switched on and a hybrid mode in which engine operation is permitted.

When it is required to charge the battery 150 of the vehicle 100 by means of the charging station 160, the vehicle 100 is positioned such that the inductive charging element 150C is sufficiently close to a corresponding charging port 160P of the charging station 160 to allow charging to take place. In some embodiments the inductive charging element 150C is positioned on an underside of the vehicle 100, and the charging port 160P of the station 160 is positioned to allow coupling between the charging element 150C and charging station 160 by positioning the charging element 150C above the charging station 160.

The vehicle 100 has a vehicle control unit (VCU) 145 operable to place the vehicle in one of a plurality of power modes. The power modes include a parked mode (power mode 1, or ‘PMT) in which the controller 140 is prevented from allowing the engine 121 or CIMG 123 to be operated. The parked mode may be assumed only when the transmission is placed in the park mode.

If a user exits the vehicle 100 and locks the vehicle, the VCU 145 is operable to place the vehicle in a ‘parked and locked’ condition in which vehicle systems are placed in a low power consumption mode. This mode is referred to as ‘power mode 0’ or PMO.

The VCU 145 is configured to check that each of four doors and each of two rear payload doors (not shown) of the vehicle 100 are closed before allowing the vehicle to assume mode PMO. Other checks may also be made before mode PMO may be assumed, for example that one or more controllers such as controller 140 have shut down. A user may place the vehicle 100 in PMO by means of a key fob 190. The fob 190 has first and second control buttons 191, 192. The first control button 191 is operable to unlock the vehicle 100 whilst the second control button 192 is operable to lock the vehicle 100.

With the vehicle in mode PMO, if the VCU 145 detects that a user has pressed the first control button 191 of the fob 190, the VCU 145 is configured to control the vehicle 100 to assume power mode PM1 and unlocks the vehicle 100.

The VCU 145 then checks whether a charging operation is in progress. The VCU 145 does this by communicating with inverter 151 to determine the magnitude of any current flowing from the charging element 150C to the battery 150, and the state of charge (SOC) of the battery 150. If the magnitude of this current is less than a prescribed minimum threshold value, the VCU 145 determines that a charging operation is no longer in progress. Furthermore, if the magnitude of the charging current is less than the prescribed minimum threshold value and the battery state of charge (SOC) exceeds a prescribed maximum threshold value, the VCU 145 determines that a charging operation is no longer in progress and that the battery 150 is substantially full, and generates an audible ‘charging not in progress battery full’ sonic signature (sonic signature A).

If the magnitude of the charging current is less than the prescribed minimum threshold value and the battery state of charge (SOC) is less than the prescribed maximum threshold value. the VCU 145 determines that a charging operation is no longer in progress and that the battery 150 is not yet full, and generates an audible ‘charging not in progress battery not full’ sonic signature (sonic signature B).

If the magnitude of the charging current is greater than the prescribed minimum threshold value, the VCU 145 determines that a charging operation is in progress and generates an audible ‘charging in progress’ sonic signature (sonic signature C). In some embodiments, sonic signature C is generated only if the further condition is met that the battery SOC is less than the prescribed maximum threshold value.

The sonic signatures are generated by means of an audio transducer 145S in the form of an audio speaker 145S. The sonic signatures are stored in a memory of the VCU 145 as .wav file although other formats are also useful.

In the present embodiment the audio transducer 145S is in the form of a dynamic loudspeaker having a cone-shaped diaphragm and electromagnetic coil driver. Other forms of audio transducer such as contact transducers and bending wave radiators are also useful. Other audio transducers are also useful.

It is to be understood that embodiments of the present invention are also suitable for implementation when a vehicle 100 is in power mode PM1, as well as when a vehicle 100 is in mode PMO. Thus, if a user parks the vehicle but does not lock the vehicle, and the vehicle remains in mode PM1, the VCU 145 may still be operable to generate an audible sonic signature as described above if a user returns to the vehicle 100 and presses the first control button 191 to unlock the vehicle. In some embodiments, a user may trigger the generation of a sonic signature by other means in addition or instead. In some embodiments, a separate ‘charging status’ control button or the like may be provided. Other arrangements are also useful for generating an audible sonic signature to check charging status, such as simultaneous depression of more than one button 191, 192. FIG. 2 illustrates a method according to an embodiment of the present invention implemented by the VCU 145.

At step SI 01 the vehicle 100 is parked in power mode PMO, i.e. in a locked condition.

At step S103 the VCU 145 checks whether a request has been received to unlock the vehicle 100 via fob 190. If a request has not been received, the VCU 145 repeats step SI 03.

If a request to unlock the vehicle 100 is received the VCU 145 continues to step SI 05. At step SI 05 the VCU 145 unlocks the vehicle 100 and continues at step SI 07.

At step SI07 the VCU 145 interrogates the inverter 151 to determine whether the charging current being fed to the battery 150 from the charging station 160 is less than a threshold value. The threshold value is set to a value corresponding substantially to the maximum charging current that might be expected for a battery 150 that is substantially full in order to maintain the battery 150 substantially full. This current may be referred to as a ‘trickle current’. The threshold value of trickle current may take into account a maximum amount of current drained from the battery 150 due to one or more loads that may be present even when a vehicle is parked in power mode PMO. Provision of a trickle current even when charging is complete may be useful in ensuring that the battery state of charge is not depleted by such loads.

If at step SI 07 it is determined that the charging current is less than the threshold value, i.e. the charging current corresponds to a value consistent with trickle charging, the VCU 145 continues at step SI 09.

At step SI09 the VCU 145 determines whether the state of charge of the battery 150 is less than a prescribed maximum threshold value corresponding to a substantially fully charged battery 150. If the VCU 145 determines that the state of charge is not less than the prescribed maximum threshold value, the VCU 145 continues at step Sill. At step Sill the VCU 145 causes the ‘charging not in progress battery full’ sonic signature (sonic signature A) to be generated.

If at step SI 09 the VCU 145 determines that the state of charge is less than the prescribed maximum threshold value, the VCU 145 continues at step S113. At step S113 the VCU 145 causes the ‘charging not in progress battery not full’ sonic signature (sonic signature B) to be generated.

If at step S107 it is determined that the charging current is not less than the threshold value, the VCU 145 continues at step S115. At step S115 the ‘charging in progress’ sonic signature (sonic signature C) is generated.

Embodiments of the present invention have the advantage that a user may be made aware of a charging condition of a vehicle 100 before the user enters the vehicle 100. Thus if the user does not know whether charging of the battery 150 of the vehicle 100 is still in progress, the user may tell, from the audible sonic signature generated when the vehicle 100 is unlocked, whether or not this is the case. Thus, the user does not have to perform a visual inspection of an indicator provided on the charging station 160 or in the vehicle 100, to determine whether charging is in progress. For example, a user wishing to know whether the battery 150 is fully charged as he or she approaches the vehicle 100 is not required to enter the vehicle 100 and check the state of charge of the battery 150 by reference to an instrument panel of the vehicle 100.

Furthermore, if charging is not in progress, the user may be informed whether or not the vehicle battery 150 is full. This may be useful in informing a user that a charging operation may have failed, since a user may be confident that the vehicle 100 has been left for a sufficiently long period to enable the battery state of charge to be restored to a fully charged state.

Embodiments of the present invention are useful in battery charging arrangements in which a vehicle may be coupled electrically to a charging facility without a requirement for the connection or disconnection of a charging cable to the vehicle, as well as in situations where a cable is required to be connected between the vehicle and charging station in order to facilitate charging of a battery. This is because the sonic signatures are generated in dependence on charging current and battery state of charge, independently of any physical connection between the vehicle and charging station. Embodiments of the invention have the advantage that they may reduce user workload by providing a convenient audible sonic signature providing useful information to a user as they approach the vehicle. The sonic signature provides information that may be directly useful to a user, and save the user from potentially inconvenient inspection of gauges or other indicators on a vehicle instrument panel or charging station panel.

It is to be understood that some embodiments of the invention provide a user feedback system for a vehicle having an electric propulsion motor and an energy storage device for powering the motor. In an embodiment, a system is provided that is operable to generate an audible sonic signature in dependence on a result of a determination whether charging of the energy storage device is in progress when a user approaches the vehicle. The sonic signature may be generated in response to a door unlock signal. The unlock signal may be received from a keyfob when a user presses an unlock button. Alternatively the unlock signal may be generated by the vehicle automatically upon detecting the presence of an authorised user, for example by detecting the presence of an authorised keyfob having radio frequency identification (RFID) capability. Other arrangements are also useful. Embodiments of the present invention may be particularly useful where charging systems are employed which do not require a user to disconnect a charging cable before driving away from a charging station. For example, embodiments of the present invention may be useful in vehicles employing cable-free charging systems such as inductive (inductively coupled) charging systems. This is because the sonic signature is generated independently of the method by which charge is supplied to the vehicle from a charging system.

Embodiments of the present invention may be understood by reference to the following numbered paragraphs: 1. An apparatus for a vehicle having an electric propulsion motor and an energy storage device for powering the motor, the apparatus being operable to: generate an audible sonic signature in dependence on a result of a determination whether charging of the energy storage device is in progress and upon detecting the presence of a portable user identification device. 2. An apparatus according to paragraph 1 operable to determine whether charging of the energy storage device is in progress in dependence at least in part on a status of a signal received by the apparatus indicative of whether charging of the energy storage device is in progress. 3. An apparatus according to paragraph 1 operable to determine whether charging of the energy storage device is in progress in dependence at least in part on a value of a charging current. 4. An apparatus according to paragraph 1 operable to determine a value of target state of charge being a state of charge that the energy storage device is required to achieve. 5. An apparatus according to paragraph 4 operable to determine whether charging of the energy storage device is taking place in dependence at least in part on a current state of charge of the energy storage device and the target state of charge of the energy storage device. 6. An apparatus according to paragraph 4 wherein the target state of charge is determined in dependence on a user input. 7. An apparatus according to paragraph 1 operable to generate the sonic signature in response to a signal received from the portable user identification device. 8. An apparatus according to paragraph 1 operable to generate the sonic signature in response to a determination that a user wishes to unlock the vehicle. 9. An apparatus according to paragraph 1 operable to generate a first sonic signature if charging of the energy storage device is in progress. 10. An apparatus according to paragraph 9 operable to generate a second sonic signature different from the first if charging of the energy storage device is not in progress. 11. An apparatus according to paragraph 10 operable to determine a value of target state of charge being a state of charge that the energy storage device is required to achieve, the apparatus being operable to generate the second sonic signature if charging of the energy storage device is not in progress and the energy storage device has achieved the target state of charge. 12. An apparatus according to paragraph 10 operable to determine a value of target state of charge being a state of charge that the energy storage device is required to achieve, the apparatus being operable to generate a third sonic signature if charging of the energy storage device is not in progress and the energy storage device has not achieved the target state of charge. 13. An apparatus according to paragraph 1 operable to generate the audible sonic signature whereby the signature may be heard from outside the vehicle. 14. An apparatus according to paragraph 1 operable to generate the audible sonic signature by means of an audio transducer external to a cabin of the vehicle. 15. An apparatus according to paragraph 1 operable to generate the audible sonic signature whereby the signature may be heard from inside the vehicle. 16. An apparatus according to paragraph 1 operable to generate the audible sonic signature by means of an audio transducer internal to the cabin of the vehicle. 17. A motor vehicle system comprising apparatus according to paragraph 1. 18. A motor vehicle comprising apparatus according to paragraph 1 or a system according to paragraph 17. 19. A vehicle according to paragraph 18 operable to charge the energy storage device by means of an inductive charging system. 20. A vehicle according to paragraph 19 operable to charge the energy storage device without requiring a cable connection between the vehicle and a charging facility. 21. A vehicle according to paragraph 18 wherein the vehicle is an electric vehicle. 22. A vehicle according to paragraph 18 wherein the vehicle is a hybrid electric vehicle. 23. A method of providing feedback to a user of a motor vehicle having an electric propulsion motor and energy storage device for powering the motor, the method comprising generating an audible sonic signature in dependence on a result of a determination whether charging of the energy storage device is in progress and upon detecting the presence of a portable user identification device..

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

Claims

CLAIMS:

1. An apparatus for a vehicle having an electric propulsion motor and energy storage means for powering the motor, the apparatus being configured to: generate an audible sonic signature in dependence on whether charging of the energy storage means is in progress and upon detecting the presence of a portable user identification device.

2. An apparatus according to claim 1 operable to determine whether charging of the energy storage means is in progress in dependence at least in part on a status of a signal received by the apparatus indicative of whether charging of the energy storage means is in progress.

3. An apparatus according to claim 1 or claim 2 operable to determine whether charging of the energy storage means is in progress in dependence at least in part on a value of a charging current.

4. An apparatus according to any preceding claim operable to determine a value of target state of charge being a state of charge that the energy storage means is required to achieve.

5. An apparatus according to claim 4 operable to determine whether charging of the energy storage means is taking place in dependence at least in part on a current state of charge of the energy storage means and the target state of charge of the energy storage means.

6. An apparatus according to claim 4 or claim 5 wherein the target state of charge is determined in dependence on a user input.

7. An apparatus according to any preceding claim operable to generate the sonic signature in response to a signal received from the portable user identification device.

8. An apparatus according to any preceding claim operable to generate the sonic signature in response to a determination that a user wishes to unlock the vehicle.

9. An apparatus according to any preceding claim operable to generate a first sonic signature if charging of the energy storage means is in progress.

10. An apparatus according to claim 9 operable to generate a second sonic signature different from the first if charging of the energy storage means is not in progress.

11. An apparatus according to claim 10 as depending through claim 4 operable to generate the second sonic signature if charging of the energy storage means is not in progress and the energy storage means has achieved the target state of charge.

12. An apparatus according to claim 10 as depending through claim 4 or according to claim 11 operable to generate a third sonic signature if charging of the energy storage means is not in progress and the energy storage means has not achieved the target state of charge.

13. An apparatus according to any preceding claim operable to generate the audible sonic signature whereby the signature may be heard from outside the vehicle.

14. An apparatus according to any preceding claim operable to generate the audible sonic signature by means of audio transducer means external to a cabin of the vehicle.

15. An apparatus according to any preceding claim operable to generate the audible sonic signature whereby the signature may be heard from inside the vehicle.

16. An apparatus according to any preceding claim operable to generate the audible sonic signature by means of audio transducer means internal to the cabin of the vehicle.

17. A motor vehicle system comprising apparatus according to any preceding claim.

18. A motor vehicle comprising apparatus according to any one of claims 1 to 16 or a system according to claim 17.

19. A vehicle according to claim 18 operable to charge the energy storage means by means of an inductive charging system.

20. A vehicle according to claim 19 operable to charge the energy storage means without requiring a cable connection between the vehicle and a charging facility.

21. A vehicle according to any one of claims 18 to 20 wherein the vehicle is an electric vehicle.

22. A vehicle according to any one of claims 18 to 20 wherein the vehicle is a hybrid electric vehicle.

23. A method of providing feedback to a user of a motor vehicle having an electric propulsion motor and energy storage means for powering the motor, the method comprising generating an audible sonic signature in dependence on a result of a determination whether charging of the energy storage means is in progress and upon detecting the presence of a portable user identification device.