WO2011107119A1

WO2011107119A1 - Battery powered product

Info

Publication number: WO2011107119A1
Application number: PCT/EP2010/001372
Authority: WO
Inventors: Mikael Racov
Original assignee: Husqvarna Ab
Priority date: 2010-03-05
Filing date: 2010-03-05
Publication date: 2011-09-09

Abstract

A battery powered system (100, 500) comprising a battery powered device (200, 600) and a battery pack (300,700), in which the battery pack (300,700) includes a means for storing a first lock part and the battery powered device (200, 600) includes a means for storing a second lock part, the system being inoperable until it is unlocked by a combination of a first lock part and second lock part stored in the respective storage means upon connection of the battery pack to the device (200, 600), and in which the battery powered system includes a lock part modifying means which in use of the system enables at least one of the battery pack (300,700) and the powered device (200, 600) at least one of the battery pack and the powered device to be modified by assigning a lock part to it, or by unlocking a lock part already assigned to it so as to enable the system to be unlocked.

Description

A BATTERY POWERED PRODUCT

This invention relates to battery powered products, especially battery powered handheld semi- or professional hand tools. It also relates to batteries for use with such devices.

Hand-held semi or professional battery powered tools, including but not limited to chainsaws, strimmers, leaf blowers, hedge trimmers and electric saws are today relatively expensive to purchase as they are highly sophisticated products which offer high levels of performance to the end user. In many cases the product comprises the device itself together with a "smart" battery pack, which includes electronics to aid with optimised charging and discharging of the battery pack. The battery packs themselves often account for a high proportion of the overall cost of the product.

As with any readily portable high cost product these products are liable to be stolen. This is especially the case for products intended primarily for outdoor use. It is also not unknown for the battery alone to be stolen from the product for use with other products.

We are aware of various proposals for providing batteries with unique key codes which unlock corresponding unique locks provided in a hand held device. An example of such an arrangement is known from US2006/0204004 which proposes locking a battery to a mobile telephone device. A further example is known from 2007/0192877 in which after installation of a battery to a mobile phone, and prior to use, an exchange of text messages between phone and battery must occur to authenticate the battery. If the exchange does not show that it is authentic the phone can not be operated by the battery.

The purpose of the lock and key code is to ensure that only authenticated batteries can be used to power the device. This solves the problem of a user attempting to use a counterfeit or incorrect battery with the device. However, these locks do not help prevent theft of the product or the battery they merely ensure that the device cannot be used with unauthenticated batteries. Generally a battery is linked to a whole class of devices, such as a particular brand or model of phone, so it can still be used with other phones of the same model if stolen.

According to a first aspect the invention provides a battery powered system comprising a battery powered device and a battery pack, in which the battery pack includes a means for storing a first lock part and the battery powered device includes a means for storing a second lock part, the system being inoperable until it is unlocked by a combination of a first lock part and second lock part stored in the respective storage means upon connection of the battery pack to the device , and in which the battery powered system includes a lock part modifying means which in use of the system enables at least one of the battery pack and the powered device to be modified by assigning a lock part to it, or by unlocking a lock part already assigned to it so as to enable the system to be unlocked. The battery powered device may comprise a power tool, a semi- or professional hand held, portable, device for use by a householder or workman to perform a manual work task, such as sawing, shearing, cutting, trimming, strimming, mowing or drilling. By modifying lock parts, either by assigning new ones to the device and/or battery pack, or unlocking ones that are already stored, the battery pack is able to arrange for the right first and second lock parts to the stored which work together to unlock the product and enable it to operate. Only with the correct matching/complimentary first and second lock parts can the device operate, so unless the correct parts have been assigned and or the parts unlocked the device cannot be used. Because the first lock part must correctly compliment/match the second lock part the battery is prevented from being used with other products which do not have the correct second lock part assigned to them. The device and battery pack are therefore linked (coded) together by the provision of the two lock parts to allow them to be used together but not with other devices or battery packs which are not so linked: Unlike the prior art the battery is not preassigned with a code but is assigned a code that links it to the battery operated device when the system is in use.

The first and second lock parts may comprise first and second keys, and the system may further include a third lock part comprising a lock which enables the battery operated device to operate only when unlocked, and in which the lock is arranged so that in use it can be unlocked by the correct combination of the first and second keys. It may be arranged so it cannot be unlocked by any other combination of first and second keys. It may, for instance unlock if two first and second lock parts which are "unlocked" by appropriate pin codes from the modifying means have been used, or if two correct codes are present.

The first and second keys may differ or may in fact be the same key. Where they differ the further lock may in fact comprise two locks, one opened by each key, and both needing to open for the device to be operated.

By enabling the device to be operated, we mean allowing at least one function of the device to be enabled which is otherwise not enabled. In the case of a hedge trimmer, for instance, the blades may only be driven which enabled. However, other functions may be operable whether or not the device is unlocked. For instance, a power light may be illuminated when locked or unlocked, and various mechanical parts such as latches for securing the battery may be opened and closed even if it is not operable.

In an alternative, the first and second lock parts may comprise locks, and the system may also include a third lock part comprising a key, the device only being operable if the key opens both locks. The first and second lock parts may be the same, or may differ in which case the third lock part may comprise two keys. The modifying means may assign the locks to the parts, or may unlock the using one or more pin codes.

Other combinations of locks and keys may be provided for the first, second and third lock parts.

A lock part may be a lock or key, which in turn may be an electronic lock or key, and most likely the lock is a software algorithm which when provided with the first and second keys which comprise codes is arranged to determine whether the codes are the correct ones to "unlock" the lock. A lock part which is to be unlocked may comprise an encrypted lock which is unlocked when supplied with a suitable decryption key or code.

The third lock part comprising either a lock or key opened by, or opening, the first and second lock parts may be a part of the battery powered device or part of the battery, or a separate part from either the battery pack of the battery powered device.

The modifying means may be operable to assign a first lock part to the battery pack between manufacture of the product and battery pack and their first use so that they can only be used together. Once assigned it may not be reassigned. In this case the first and second lock parts should be unique to the combination of product and device so that they can only be used together.

Alternatively, and preferably, the modifying means may be operable by a user or upon connection of a battery pack to a device to assign a correct ' lock part to a battery pack at a time after manufacture. This allows devices and batteries to be sold separately, or for replacement or spare battery packs to be correctly coded. It may assign both the first lock part and the second lock part to the battery pack and device respectively. These lock parts may be determined by the modifying means based on a suitable algorithm for example, or based upon the value of a third lock part. For instance, where the third lock part is a lock it may assign keys that fit the lock.

The modifying means may instead be operable to unlock first and or second lock means previously stored in the battery pack and or power tool. For instance, the lock parts may be encrypted and the modifying means may decrypt them to enable them to be used to operate the power tool. This decryption can be achieved using pin codes.

The modifying means may form an integral part of the battery operated device such that upon connection of a battery to the device the correct first lock part may be allocated to the battery and so the battery and device are coded together. This provides security because the battery cannot then be removed and used with other devices which have different locks. Alternatively the battery powered system may include a charger which may include charging circuitry enabling it to be used to recharge the battery pack, and in which the modifying means forms a part of the charger. By this we mean that it is separate from the battery powered device and from the battery. The charger may be adapted to assign the first lock part to the battery, or to unlock a lock part of the battery pack using a code.

It is preferred that the modifying means is separate from the battery device and battery pack in this manner because the charger will often be stored away in a secure place, and also because it conveniently allows a user with a range of different battery powered devices and battery packs to code them together to be used in different combinations. Only one modifying means is needed to do this, associated with the charger, rather than one in each device or each battery pack. Also, the charger is the one common part that connects to all of the batteries and perhaps all of the devices during their use, for instance during charging of the battery. In some cases where the batteries can be charged in situ (connected to the battery powered device) the charger is also effectively able to connect to the device as well as the battery.

The first lock part, or a code for unlocking the lock part, may be stored permanently (or temporarily) within the charger along with the modifying means and it may be arranged to assign the first lock part to the battery whenever the battery is connected to the charger, or perhaps only when it is first connected. As soon as this process has been carried out the battery can be used with the device associated with the charger but not with any other device which will have a different lock (even if the same make, model or type of device).

The first lock part, or its unlock code, may be derived form the second lock part (in a simple example it may be the same as the first lock part) and the charger may include means for receiving the second lock part from the battery powered device in order to achieve this. This can be achieved whenever the device is connected to the charger. The charger may derive the first lock part from the second lock part.

In one arrangement there may be provided means for manually entering the first lock part, or its unlock code, or the second lock part or its unlock code, into the charger prior to connection of a battery pack to a battery powered device, the first lock part being associated with the second lock part (or perhaps being the same as the second lock part) allowing different batteries to be locked to a product. All the user has to do in manually enter the lock part for the device to the charger, and this then assigns the first lock part to the battery pack when the battery pack is placed in communication with the charger. Where the modifying means is adapted to unlock lock parts using a code, the appropriate codes to be entered to the charger may be printed on the device or battery to be unlocked, or supplied on a printed document along with the device to be stored in a safe place. The device and battery may each be provided with a code to unlock them. This provides a simple means of creating a single lock part which uniquely links the battery pack to the battery powered device. The modifying means, whether part of the device or the charger may include a user interface which enables the user to enter the required code or lock part. This may comprise a keypad or other interface. The code may, therefore, not be stored in the charger itself which increases security. To increase security, at least one of the first lock part and second lock part or the codes to unlock them should be unique to the battery powered device, or at least should be selected from a very large range of possible lock parts to minimise the chances of a battery pack working with a different device and so render it useless. Where a third lock part is provided which forms part of the system, this should be unique (or from a large range) to enable groups of devices and batteries to be linked together through the first and second lock parts in such a way they cannot be used with other devices or batteries. The modifying means may store details of any first, or second, or third lock parts or codes it has assigned, or that it has been presented with during coding of batteries. The modifying means may assign additional first lock parts to a battery pack provided that any other first lock part stored in the battery pack is also stored previously in the modifying means. This can be enabled by providing a memory associated with the charger which stores any previously assigned lock parts, or any keys entered into the charger for use in enabling previous assignment of lock parts. In this way, it is possible for a battery to be coded to many different devices, and/or many devices to be coded to one battery. But if the battery is then stolen and an attempt is made to recode it to another device using an alternative charger the attempt will fail as that charger would not have in its memory the required earlier codes or lock parts.

A similar result can be achieved by providing the battery pack with interrogating means which enables it to interrogate lock parts or codes stored in the charger, and only accepts a new lock part or code if the existing first lock part stored in its memory is recorded in the charger. The interrogation means may comprise a software function and may access information in the charger via the usual power terminals or in any other suitable manner. This, however, is not as preferred as it may be easier to copy the first lock parts to a charger in order to get around this security feature.

In all of the arrangements above, the battery when connected to the device will unlock it to allow it to be used. The applicant has appreciated that in some cases this may lead to the device being started on accident. For example, if a child picks up a device and presses a start button when the battery is connected it will start, which could surprise the child.

Therefore, in an alternative arrangement or modification a further user operable key may be required to operate the device even when the battery is provided with the correct key of the battery operated device. Only when this further key is used will the tool be ready to be operated.

The further key may comprise a pass code, perhaps one or more letters or digits or symbols or a combination thereof, or an electronically readable fob which is encoded with the pass code. The battery operated device may become operable only when the key is present and the first and second lock parts link the battery and device together.

Where a charger is provided and used to perform coding of the battery pack, it may connect to the battery pack by a direct electrical connection or an indirect connection such as Infra red link, Bluetooth, Wifi etc. It may connect to the battery pack through the conventional battery terminals associated with the battery pack and the corresponding charging terminals of the charger.

According to a second aspect the invention provides a charger for use in combination with a battery pack and a battery powered, the battery pack being operable to provide power for the device, in which the charger include modifying means for unlocking at least one lock part associated with one or both of the device and the battery pack using one or more associated pin codes or assigning at least one appropriate lock part to at least one of the battery pack and the battery powered device.

The charger may include means for verifying the authenticity of the pin codes used, and/or the lock parts already stored in the battery pack or device.

The charger may include a user interface through which the user can enter information required to unlock the battery pack, or verify a code stored in the battery pack, or assign a lock part, such as the first lock part, or information from which it can be derived, or information about the device to which the battery pack is to be linked.

The charger may include a means for verifying a code stored in a battery pack or device. It may include means for updating the means for verifying, perhaps by obtaining updated information using a connection to a suitable site hosted on an internet or intranet or extranet. Of course, the receipt of information through the user interface where provided can be construed also as means for updating verification information.

The charger may store a plurality of codes corresponding to a plurality of battery packs.

The charger may be arranged so that it does not provide charge to a battery pack which does not include a verified code or lock part, or perhaps a code that corresponds to one already stored in the charger. It may only assign a new code to a battery pack if the battery pack does not already contain an existing code.

According to a third aspect there is provided a battery pack or battery powered device which includes a means for storing a lock part and a connection means for connecting the storage means to a code modifying means which is arranged in use to provide a code, said code being required to unlock the lock part to enable operation of the battery pack or device.

The storage means may comprise an area of memory in which the code, once supplied, is stored. It may be permanently stored in a tamper proof manner.

The battery pack or device may be supplied with the code to be stored separate from the device, for instance by way of a printed document. Alternatively the device or battery may be provided with means for obtaining a code, such as an address indicating the location of the code.

According to a fourth aspect there is provided a battery powered device suitable for use with a battery pack and a charger to provide the apparatus of the first aspect of the invention. There will now be described two examples of the present invention with reference to the accompanying drawings of which:

Figure 1 shows a first embodiment of a battery powered hand held device according to a first aspect of the invention; and

Figure 2 shows a second embodiment of a battery powered hand held device according to a first aspect of the invention which includes a charger. Figure 1 shows a semi or professional hand held battery powered system 100. The system comprises a battery powered power tool- in the example it is a hedge trimmer 200 with reciprocating cutting blades 510,51 1 driven from an electric motor 220, but it could be any one of a wide range of power tools such as a chainsaw, leaf blower, saw, lawnmower etc which requires a relatively high capacity battery to drive an electric motor which forms a part of the tool. The system also include a battery pack 300 which is compatible with the power tool 200. The battery pack and power tool 200 can be separated to permit recharging or repair or replacement of the battery pack. For instance, a user may keep two battery packs with one charging ready for use when the battery pack that is in use runs low on power.

The battery pack 300 includes a battery 310 and an electronic circuit 320. The electronic circuit provides the functionality required to enable the battery to be safely and optimally discharge and also recharged, and provides identification about the type of battery and its operational requirements for use by a battery charger. The battery includes a male docking part 330 adjacent positive and negative battery terminals 331 ,332. The battery powered device 200 include a battery port which includes both a female docking part 230 that is arranged to receive the male docking part 330 of the battery pack 300, and negative and positive power terminals 231 ,232. When docked the positive power terminal is electrically connected to the positive power terminal of the battery and the negative terminal to the negative terminal of the battery. When so connected the device may draw power from the battery.

The battery pack 300 and power tool 200 include respective first and second lock parts 240, 340. These comprise electronic key codes, each one or more digits in length, which are stored in non-volatile memory 250,350 in the respective device and battery pack. The device also includes a third lock part 260 which comprises a lock that is only opened with the correct combination of first and second lock parts. Until it is opened the power tool 200 will not operate, meaning in this example that the motor will not drive the blades. The third lock part in this example comprises a software function stored in an area of memory of the device. This passes both the first and second lock parts through an appropriate algorithm and the output of the algorithm provides a signal indicative of whether the lock is opened or remains closed. This signal controls an electrical switch that is provided in series in a path between the battery and motor. In a more sophisticated arrangement the state of this signal may be passed to a motor control circuit which is used to drive the motor. This arrangement may be preferred as it does not require the provision of the additional switch, reducing complexity of the device.

The codes 240,340 in the battery pack and power tool are assigned by an assignment means (not shown) which is part of the power tool. Typically this will be embodied as a suitable software routine stored in the memory of the power tool along with the code. This may operate in a variety of manners but in this example the assignment means assigns linked key codes to the battery pack and device when they are first connected together. The software checks that the battery pack is not already coded, and if it is already coded does not assign a new code. Unless the code in the battery is already the correct one for the power tool this means the battery pack cannot be used to operate the power tool. In some cases, the battery pack itself may be arranged so that it can only be coded once, so even if the power tool tries to add the new code it will fail. The codes are unique to the combination of device and battery, and may be produced using a random function held in the software function of the device. Thereafter the codes cannot be changed so that the battery can not be used with any other device, because it is unlikely to have the correct first lock code.

In a modification, the third lock part can be omitted and at least one of first and second lock parts may comprise encrypted locks which must be decrypted using a suitable key before they can be used together to unlock the battery and tool. Until they are decrypted the tool and battery will not operate. The first lock part may be the only part that has to be decrypted, and a code to decrypt (i.e. unlock it) may be provided within the tool. Thus, when a tool with the correct code is connected to a suitable battery pack it will automatically decrypt the lock and the tool can be used. If the wrong battery is used the code will not decrypt the first lock part so the tool will not operate.

It has been appreciated that in some instances additional flexibility may be desired, rather than limiting a tool and battery to only work together as sold.

A second embodiment is illustrated in Figure 2 of the accompanying drawings. In this example the system 500 comprises a power tool in the form of a leaf blower 600, a battery pack 700 and a charger 800. The leaf blower includes a motor 610 which powers a fan 620 when supplied with power from the battery pack. Connection between the battery pack and the tool is achieved in the same manner as the first embodiment and so will not be described here in detail. The dedicated battery charger 800 includes a charging circuit 810 suitable for charging the battery pack. Such circuits are well known in the art and typically include a transformer 820 for connection to a source of power such as a mains voltage source, a female docking part 830 that receives the male docking part of the battery, and two connector terminals which respectively connect to the positive and negative terminals of the battery when it is docked to the charger 800. The charger 800 also includes a circuit 840 for modifying at least a first lock part of the battery pack, and optionally a second lock part of the power tool. This may be provided using a software program stored in an area of electronic memory 850 which runs on a microprocessor that forms part of the charging circuit 810.

The battery pack 700 and tool 600 each include means for storing a respective first and second lock which together are required for unlocking the combined tool and battery pack to operate the tool in the same way as the first embodiment of the invention includes such lock parts. The second lock part in the tool is pre-stored in an area of tamperproof memory.

The charger performs the centralised function of assigning lock parts and/or unlocking them using appropriate codes. To assign the first lock part or to unlock it, the charger 800 first requires information about the lock part that is to be assigned or code needed to unlock it. This must be the lock part that will work with the second lock part stored in the tool to cause the tool to operate. Once the charger has the information, and the battery pack 700 is docked to the charger 800, the charger 800 assigns the first lock part to the battery pack. It is then stored in the memory of the battery pack.

The advantage to this arrangement compared with that of the first embodiment becomes apparent where it is desired to use one battery pack with more than one device. The charger can assign the required first lock parts to many batteries and unlock them so they can all be used with the same tool. The charger can be modified in many different ways to provide different levels of functionality, and different forms of security can be achieved in such a manner. For instance, the first lock parts may be supplied along with the tool, so that batteries can easily be coded, if the lock part is unique to the tool, the batteries can only be used with that tool once coded. If stolen they will not work with any other tool.

In another arrangement, the charger may be used as a central store of information about multiple tools. This enables it to assign multiple cods to a battery pack so that the pack can be used with more than one tool.

Also, if desired, the charger can be used as a means for verifying that any codes are authentic to ensure that counterfeit power tools or batteries are not charged. To achieve this the charger may store a set of authentic codes against which a check can be made, or a means for checking codes such as a checking algorithm, or even that it may be web enabled so it can obtain verification of a code from a remote web location or update the store verification algorithm or codes.

In the example of Figure 2 the charger 800 includes a keypad 860 which enables a user to enter the first lock part or second lock part or some other information such as a seed from which the lock parts can be derived into the charger. Alternatively the keypad could be used to enter a first code which is provided with the device, the charger merely providing a convenient means for modifying that code to the battery.

Claims

1. A battery powered system (100,500) comprising a battery powered device (200,600)and a battery pack (300,700), in which the battery pack(300,700) includes a means for storing a first lock part and the battery powered device(200,600) includes a means for storing a second lock part, the system being inoperable until it is unlocked by a combination of a first lock part and second lock part stored in the respective storage means upon connection of the battery pack to the device(200,600) , and in which the battery powered system includes a lock part modifying means which in use of the system enables at least one of the battery pack(300,700) and the powered device(200,600) at least one of the battery pack and the powered device to be modified by assigning a lock part to it, or by unlocking a lock part already assigned to it so as to enable the system to be unlocked.

2. A battery powered system according to claim 1 in which the battery powered device (200,600) comprises a power tool for use by a householder or workman to perform a work task.

3. A battery powered system according to claim 1 or claim 2 in which the first and second lock parts comprise first and second keys, and the system further includes a third lock part comprising a lock which enables the battery operated device (200,600) to operate only when unlocked, and in which the lock is arranged so that in use it can be unlocked by the correct combination of the first and second keys.

4. A battery powered system according to claim 3 in which the first and second keys differ.

5. A battery powered system according to claim 1 or 2 in which the first and second lock parts comprise first and second locks, and the system further includes a third lock part comprising a key which enables the battery operated device to operate only when unlocked, and in which the locks are arranged so that in use they can be unlocked by the key.

6. A battery powered system according to any preceding claim in which at least one lock part comprises an electronic lock or key code.

7. A battery powered system according to nay one of claims 3 to 6 in which the third lock part is a part of the battery powered device (200,600) or part of the battery (300,700), or a separate part from both the battery pack and the battery powered device.

8. A battery powered system according to any preceding claim in which the modifying means is operable to assign a first lock part to the battery pack (300,700) between manufacture of the product and battery pack and their first use so that they can only be used together.

9. A battery powered system according to any preceding claim in which the modifying means is operable by a user or upon connection of a battery pack to a device to assign a correct lock part to a battery pack at a time after manufacture or to unlock a previously stored lock part using a code.

10. A battery powered system according to claim 8 or claim 9 which is arranged in use to assign both the first lock part and the second lock part to the battery pack (300,700) and device (200,600) respectively, or to unlock lock parts of both the battery and the device.

1 1. A battery powered system according to any preceding claim in which the modifying means forms an integral part of the battery operated device (200,600) such that upon connection of a battery to the device the correct first lock part is allocated to the battery pack, or unlocked by the device and so the battery pack (300,700) and device (200,600) may be used together.

12. A battery powered system according to any one of claims 1 to 10 which includes a separate charger (800) which include charging circuitry (810) enabling it to be used to recharge the battery pack, and in which the modifying means forms a part of the charger.

13. A battery powered system according to claim 12 in which the first lock part or a code suitable for unlocking it is stored permanently (or temporarily) within the charger (800) along with the modifying means and in which the charger (800) is arranged so as to assign the first lock part to the battery pack, or unlock the lock part, whenever the battery pack is connected to the charger.

14. A battery powered system according to claim 13 in which the modifying means includes input means (860) for manually entering the first lock part or the second lock part, or entering codes required to unlock the lock parts.

15. A battery powered system according to claim 14 in which the first and/or second lock part to be entered to the charger, or the unlock codes

(800) is printed on the device, or supplied on a printed document along with the device to be stored in a safe place.

16. A battery powered system according to any preceding claim in which at least one of the first lock part and second lock part or a third lock part is uniquely associated with the battery powered device (200,600).

17. A battery powered system according to any preceding claim in which the modifying means stores details of any first, or second, or third lock parts or unlock codes it has assigned or of a range of lock parts that it is able to assign.

18 A battery powered system according to any preceding claim in which the modifying means is adapted to assign additional first lock parts to a battery pack (300,700) provided that any other first lock part stored in the battery pack (300,700) is also stored previously in the modifying means.

19. A battery powered system according to any preceding claim which further includes an additional user operable key which is required to operate the device even when the battery is provided with the correct lock part for the battery operated device, the additional key being required to make the device ready to be operated.

20. A charger (800) for use in combination with a battery pack and a battery powered, the battery pack being operable to provide power for the device, in which the charger include modifying means for unlocking at least one lock part associated with one or both of the device and the battery pack using one or more associated pin codes or assigning at least one appropriate lock part to at least one of the battery pack and the battery powered device.

21. A charger (800) according to claim 20 which includes means for verifying the authenticity of an unlock code or a lock part already stored in the battery pack (300,700) or device (200,600).

22. A charger (800) according to claim 21 which includes means for updating the means for verifying the code.

23. A charger (800) according to claim 20, 21 or 22 which includes a user interface through which the user can enter information required to assign the code to the battery pack, or verify a code stored in the battery pack, such as the first lock code, or information from which it can be derived, or information about the device to which the battery pack is to be linked or enter codes required to unlock lock parts.

24. A charger (800) according to any one of claims 20 to 23 which is arranged so that it does not provide charge to a battery pack which does not include a verified code, and/or include a code that corresponds to one already stored in the charger.

25. A battery pack or battery powered device semi- or professional hand held device which includes a means for storing a lock part and a connection means for connecting the storage means to a lock part modifying means which is arranged in use to provide a code, said code being required to unlock the lock part for operation of the battery pack or device.

26. A battery pack or battery powered device according to claim 25 in which the storage means comprises an area of memory in which the code, once supplied, is stored.