Battery pack for a hand-held power tool, hand-held power tool and charger

Abstract

The invention describes a battery pack for a hand-held power tool, having a battery pack housing with an interface for establishing a mechanical and electrical connection of the battery pack with a hand-held power tool and / or a charger, wherein the interface has at least one first contact element and a second contact element for electric and / or mechanical contact with corresponding counter contact elements on the hand-held power tool and / or on the charger. The battery pack according to the invention has at least one battery cell and a battery pack electronics. The battery pack electronics comprises a charging current path and a discharging current path. The charging current path is provided for connecting the first contact element and the second contact element with the at least one battery cell during charging of the at least one battery cell, while the discharging current path is provided for connecting the first contact element and the second contact element with the at least one battery cell during discharging of the at least one battery cell. The charging current path and the discharging current path are at least partially electrically separated from each other. The battery pack further has a first switching element for switching between at least the charging current path and the discharging current path. The invention further describes a hand-held power tool and a charger, which each have a machine-side interface and an appliance-side interface for mechanical and electrical coupling of the hand-held power tool and the charger with the corresponding interface of the aforementioned battery pack.

Description

Technical Field

[0001] The present invention relates to a battery pack for a handheld machine tool according to claim 1, a handheld machine tool according to claim 13, a charger according to claim 14, and a tool system according to claim 15. Background Technology

[0002] Electric handheld power tools are known in principle and are powered via a mains connection. Alternatively, battery-powered devices offer greater flexibility in operation because they are particularly independent of mains current. This method also facilitates outdoor work, for example, and handheld power tools are often configured to use battery packs when in operation.

[0003] Within the scope of this application, a battery pack is therefore understood to preferably comprise a battery pack consisting of multiple electrically connected, energy-storing battery cells, providing the energy required for the operation of a handheld machine tool, and being replaceable and installable in the chamber, interface, or similar of the handheld machine tool and the charger. An interface is particularly understood as a device configured to establish, directly or indirectly, an electrical connection and, in particular, a mechanical connection with the charger and / or the discharge side, i.e., the handheld machine tool.

[0004] Such battery packs are known in principle and generally consist of multiple rechargeable batteries connected in parallel and / or series, such as three cylindrical lithium-ion cells, each with a voltage of 3.6 volts, connected in series, with a total voltage of 10.8 volts. The connected battery cells are interconnected and also connected to the battery pack's electronic components, which include other circuitry in addition to the individual battery cells. The battery pack's electronic components are particularly responsible for controlling the charging and discharging processes of the battery pack based on parameters such as the maximum allowable charging and discharging current, cell temperature, and other parameters.

[0005] A battery pack typically also includes a battery pack housing, in which individual battery cells are received, either wholly or partially, by means of cell retainers. Alternatively, the cell retainers themselves form the battery pack housing element.

[0006] The coupling of the battery pack to the handheld machine tool is accomplished by plugging or pushing the battery pack's interface into a complementary connector on the tool housing. To prevent the battery pack from coming loose, for example, due to vibrations during the operation of the handheld machine tool, the interface is typically equipped with a locking mechanism.

[0007] The interface also features contact seams in which contact elements can be arranged. These contact elements connect to the battery pack's electronic components. If the battery pack's energy is depleted, it can be removed and connected to a charging station with the corresponding contact elements. If multiple battery packs are available, it is possible to remove the depleted battery pack from the handheld power tool and replace it with a fully charged one. Generally, the power and operating time of the handheld power tool are determined based on the nominal voltage and capacity of the battery pack used.

[0008] Battery packs, handheld power tools, chargers, and corresponding interfaces are under development. Typically, additional contact elements and corresponding contact elements should be implemented in the interface to exchange additional information between the devices. The aim is to keep the required structural space for the interface as compact as possible for ease of use and hand operation of the battery packs and handheld power tools. Furthermore, for compatibility with previous models, the geometry of the interface needs to be changed as little as possible relative to previous models. In particular, the handheld power tools, battery packs, and chargers contain mutually matched mechanical or electrical coding elements, through which possible combinations of the battery packs, handheld power tools, and chargers for compatibility reasons are limited.

[0009] At least two of the contact elements are connected here to the highest and lowest potentials of the interconnected cells, i.e., to the battery (+) and ground, through which current can be drawn from or supplied to the battery pack. For cost reasons and to achieve a compact structural space for the interface, the charging and discharging processes are preferably carried out through the same contact elements, but it is also known to be achieved with separate charging and discharging contacts.

[0010] However, due to the increased safety requirements of battery packs, it is also desirable to be able to cut off both charging and discharging currents. Metal-oxide-semiconductor field-effect transistors (MOSFETs) are used here because of their high current carrying capacity and low resistivity. However, MOSFETs have a parasitic body diode, which means that, depending on the polarity, current can always be cut off in only one direction.

[0011] The aforementioned compatibility requirements of the battery pack and the resulting need to avoid changes in interface geometry raise issues regarding the need for improved safety and the limited possibility of separate current shutdown for charging and discharging currents without modifying the battery pack interface. Summary of the Invention

[0012] The object of the present invention is to improve upon the aforementioned disadvantages and provide an improved battery pack of the type mentioned at the beginning, which achieves an improved level of safety in battery operation while maintaining the same configuration of contact elements for charging and discharging processes at the battery pack interface.

[0013] This task is solved by the battery pack according to claim 1. Advantageous configurations, variations, and extensions of the invention can be derived from the dependent claims.

[0014] A battery pack for a handheld power tool according to the present invention comprises: a battery pack housing having an interface for establishing a mechanical and electrical connection between the battery pack and the handheld power tool and / or a charger, wherein the interface has at least one first contact element and a second contact element for electrical and / or mechanical contact with corresponding corresponding contact elements on the handheld power tool and / or on the charger. The battery pack according to the present invention further comprises at least one battery cell and battery pack electronic components. The battery pack electronic components include a charging current path and a discharging current path. The charging current path is configured to connect the first and second contact elements to the battery cell during charging of the at least one battery cell, while the discharging current path is configured to connect the first and second contact elements to the battery cell during discharging of the at least one battery cell. The charging current path and the discharging current path are at least partially electrically separated from each other. The battery pack also comprises a first switching element for switching between at least the charging current path and the discharging current path.

[0015] This invention enables the charging current path and the discharging current path to be at least partially separated and thus implemented differently while maintaining a minimal interface configuration with consistent contact elements for both the charging and discharging processes. This possibility, in particular, allows for an improved level of safety in the battery pack.

[0016] Another advantage is that current limiters, such as MOSFETs, with advantageous polarities can be coupled separately in the charging and discharging current paths to enable the switching off of the charging and discharging currents, especially independently. By separating the charging and discharging current paths at least partially, it is possible to eliminate the need for anti-series MOSFET circuitry in the discharging current path, which saves costs and minimizes power losses from additional electrical components energized during the operation of the handheld machine tool.

[0017] Additional, unspecified, and individually advantageous circuitry for extended functionality, such as charging and discharging current paths, is also possible.

[0018] The use and expansion of existing mechanical mechanisms also enable compatibility with existing appliances, namely handheld machine tools and chargers, which is beneficial to end customers who wish to expand their combination of existing appliances or battery packs.

[0019] In an embodiment of the invention, the interface has a first mechanism for operating a first switching element. The first mechanism may be a manually operable mechanism by a user, such as a switch at a suitable, but arbitrary location on the battery pack housing. In one embodiment of the invention, the first mechanism is integrated into the interface of the first battery pack such that when the battery pack is connected via the interface to a corresponding interface of a handheld power tool and / or charger, the first mechanism operates the first switching element.

[0020] In this way, the battery pack automatically switches to the desired mode, i.e., charging or discharging, when plugged into a handheld tool or charger, without the user having to consciously perform the switching.

[0021] In one embodiment of the invention, the first switching element and the first mechanism are configured such that, in a base state where the interface of the battery pack is not connected to the corresponding interface of the handheld machine tool and / or charger, the discharge current path or the charging current path is connected. As will be explained in detail later, this method allows for particularly simple switching between the discharge current path and the charging current path.

[0022] In one embodiment of the invention, the first mechanism is configured such that when the battery pack is connected to a handheld machine tool via an interface, the first switching element connects the discharge current path.

[0023] In one embodiment of the invention, the first mechanism is configured such that when the battery pack is connected to the charger via an interface, the first switching element turns on the charging current path.

[0024] Preferably, the charging current path and the discharging current path include a common section, wherein the common section includes at least one first current limiter configured to turn off the discharge current when limits, particularly discharge current limits and / or temperature limits, are exceeded. The at least one first current limiter may, in embodiments of the invention, comprise an n-type MOSFET whose current carrying capacity is configured for the expected discharge current. Regarding its polarity, the at least one first current limiter is advantageously configured in the common section such that parasitic elements present in some cases, depending on the configuration of the current limiter, such as the body diode already mentioned in the MOSFET case, do not prevent the discharge current from being turned off.

[0025] In one embodiment, the charging current path has at least one second current limiter, wherein the at least one second current limiter is configured to shut off the charging current when limits are exceeded, particularly charging current limits and / or temperature limits and / or individual cell voltage limits. Like the at least one first current limiter, the at least one second current limiter in embodiments of the invention may include an n-type MOSFET.

[0026] In one embodiment, a first switching element is arranged in the discharge current path, wherein the first switching element and the second current limiter are connected in parallel.

[0027] In one embodiment, the first switching element is configured to bridge the at least one second current limiter when the first switching element connects the discharge current path. This prevents the second current limiter from being energized with power loss during battery pack discharge.

[0028] In one embodiment, the first switching element is configured to switch between a charging current path, a discharging current path, and a neutral state, wherein, in the neutral state, the at least one battery cell is electrically separated from the first and / or second contact elements. By separating both the charging and discharging current paths from the contact elements in the neutral state, a particularly high level of safety for the battery pack is achieved, such as safety against unintentional discharge.

[0029] In one embodiment, the at least one first current limiter and / or the at least one second current limiter are electrical components from the group consisting of bipolar transistors (BJTs), field-effect transistors (FETs), and metal-oxide-semiconductor field-effect transistors (MOSFETs), particularly n-type MOSFETs.

[0030] According to another aspect, the present invention includes a handheld machine tool, comprising: an electric motor; a machine-side interface for mechanical and electrical coupling between the handheld machine tool and a corresponding interface of a battery pack; and the aforementioned battery pack. Here, the machine-side interface is configured such that when the battery pack is connected to the machine-side interface of the handheld machine tool, a first mechanism of the battery pack connects a discharge current path via a first switching element.

[0031] The present invention also includes a charger for charging the aforementioned battery pack. The charger includes an appliance-side interface for mechanical and electrical coupling between the charger and the corresponding interface of the battery pack. The appliance-side interface is configured such that when the battery pack is coupled to the appliance-side interface, a first mechanism of the battery pack connects the charging current path through a first switching element.

[0032] According to another aspect, the present invention includes a tool system comprising the aforementioned battery pack, the aforementioned handheld power tool, and the aforementioned charger.

[0033] Other features, applications, and advantages of the invention will become apparent from the following description of embodiments of the invention, which are illustrated in the accompanying drawings. It should be noted that the features shown are merely descriptive and may be used in combination with features of other extensions described above, and should not be construed as limiting the invention in any way. Attached Figure Description

[0034] The invention will be described more clearly below in conjunction with the accompanying drawings, wherein the same reference numerals are used for the same features. The drawings are schematic and illustrate:

[0035] Figure 1 An exemplary view of a handheld machine tool with a battery pack according to one embodiment of the present invention is shown;

[0036] Figure 2 This is an exploded perspective view of a battery pack according to one embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of a circuit in a battery pack according to one embodiment of the present invention, the circuit including a charging current path and a discharging current path;

[0038] Figure 4 This is a schematic diagram of the current in a battery pack according to another embodiment of the present invention, the circuit including a charging current path and a discharging current path. Detailed Implementation

[0039] Figure 1A handheld power tool 300 according to one embodiment of the invention is shown, exemplarily configured as a battery-powered drill screwdriver. Accordingly, in the illustrated embodiment, the handheld power tool 300 is mechanically and electrically connected to a battery pack 100 for independent power supply from the mains. However, it should be noted that the invention is not limited to battery-powered drill screwdrivers, but can be used with various handheld power tools 300. The handheld power tool 300 has a transmission 330 arranged in a housing 305 and a handle 315. The transmission 330 is used to transmit torque generated by a drive motor 335 to a drive shaft that rotates about an axis x. A tool receiver 320 for a tool (not shown) is fastened to the drive shaft. An electronic component 370 is arranged within the housing 305, and the electronic component 370 is in electronic and / or mechanical contact with the drive motor 335 and / or the transmission 330. The handle 315 serves as a place for the operator's hand to rest on the hand of the handheld machine tool 300 and generally has a longitudinal axis y, a front 317 (which faces the tool receiver 320 along the axis x), a back 316, and two sides 318.

[0040] A first operating element 310 for supplying energy to the drive motor 335 is arranged in the area of ​​the handle 315. The first operating element 310 protrudes from the housing 305 in a manner manually accessible to the user, such that the drive motor can preferably be controlled and / or adjusted according to the adjustment displacement of the first operating element 310 by pressing it in a known manner, and the voltage supply to the drive motor 335 can also be turned on and / or off. The handheld tool 300 also has a second operating element 312 in the form of a push switch for adjusting the rotation direction of the drive motor 335 of the handheld tool 300. The second operating element 312 is movably arranged perpendicular to the rotation axis x of the drive shaft, particularly the tool receiving portion 320 of the handheld tool 300, such that the second operating element 312 can move back and forth between a first position, a second position, and a third position during operation. Here, the first and second positions respectively determine a rotation direction of the drive motor. Therefore, the user of the handheld power tool 300 has identified the operating mode of the handheld power tool 300 based on the position of the second operating element 312. Additionally, the second switching element has a third position, such as an intermediate state, between the first and second positions, in which an electrical, electromechanical, and / or mechanical interruption of the motor current is performed. For example, the operation of the first switching element 310 can be mechanically locked, wherein the second operating element 312 locks onto the first switching element 310 when it is moved to the third position. Here, the second operating element 312 can be implemented as a push switch as shown or alternatively as a rocker switch.

[0041] The first operating element 310 and the second operating element 312 are arranged along the rotation axis x such that they can be operated with the index or middle finger. The spacing between the first operating element 310 and the second operating element 312 is chosen to enable one-handed operation of the handheld machine tool 300. Furthermore, the two operating elements 310 and 312 are located in the area below the rotation axis x and protrude from the housing 305.

[0042] exist Figure 1 In the indicated position, the battery pack 100 is secured to the handle 315 of the handheld power tool 300 and locked by a locking device. By positioning the battery pack 100 below the handle 315, operation of the handheld power tool 300 is not interfered with. The locking device, not shown in detail, includes a locking element and an operating element 220. The battery pack 100 can be detached from the handle 315 of the handheld power tool 300 by operating the operating element 220. The handheld power tool 300 also has an interface 380.

[0043] According to one embodiment of the present invention, in Figure 1 and 2 The battery pack 100 shown is implemented as a push-mounted battery pack and has an interface 180 corresponding to the interface 380 of the handheld power tool 300. Alternatively, it may be implemented as a rotating or pivoting battery pack, wherein the battery pack 100 can be detachably locked to the housing 305 of the handheld power tool 300 by means of a latch, screw, clip, or clamp on the side opposite to the pivot axis. This effectively prevents the battery pack from potentially falling off the housing 305.

[0044] For detachable mounting of the battery pack 100 to the hand-held power tool 300 or charger, the battery pack 100 has an interface 180 for a detachable mechanical and electrical connection to a corresponding interface 380 of the hand-held power tool 300 or a corresponding interface of the charger. When installing the battery pack 100, receiving devices of the hand-held power tool 300 or charger, such as guide slots and guide ribs, engage with the corresponding guiding element of the battery pack 100, wherein the battery pack 100 is inserted along the receiving device and the interface 180 of the battery pack 100 is pushed into the corresponding interface 380 of the hand-held power tool 300 or the corresponding interface of the charger. The battery pack 100 can be assigned to the hand-held power tool 300 and / or charger via interface 180.

[0045] As in Figure 2As identifiable, interface 180 also includes contact elements for electrical contact between battery pack 100 and handheld power tool 300 or charger. The contact elements are either configured as voltage contact elements and used as charging and / or discharging contact elements, or as signal contact elements enabling signal transmission from battery pack 100 to handheld power tool 300 or charger and / or from handheld power tool 300 or charger to battery pack 100. Interface 180 includes at least one first contact element 140 and at least one second contact element 150 for electrical contact with corresponding corresponding contact elements on handheld power tool 300 and / or on charger. Contact elements 140 and 150 relate to voltage contact elements. Here, contact elements 140 and 150 are respectively connected to the highest and lowest potentials of at least one, but generally multiple, interconnected battery cells, i.e., connected to the battery (+) and ground, such that current can be drawn or supplied via battery contact elements 140 and 150. Figure 2 As can be seen in the exploded view, reference numeral 150 marks a position where, with the battery pack 100 assembled, the corresponding contact element passes through the battery pack housing and contacts the contact element 150 at that position.

[0046] like Figure 2 As shown, the first contact element 140 and the second contact element 150 are connected to the battery pack electronics 800, which is configured to perform defined switching and control processes of the battery pack 100. Specifically, the battery pack electronics 800 is configured to connect the first contact element 140 and the second contact element 150 to the battery cell via a charging current path during charging of the at least one battery cell. The battery pack electronics 800 is also configured to connect the first contact element 140 and the second contact element 150 to the battery cell via a discharging current path during discharging of the at least one battery cell.

[0047] To lock the battery pack 100 onto the handle 315 of the handheld power tool 300, the battery pack 100 is pushed along the handle 315, and more specifically, along the lower surface of the handle 315 oriented substantially perpendicular to the longitudinal direction y of the handle 315. Figure 1 In the position shown, the battery pack 100 is locked to the handle 315 by a locking device. The locking device specifically includes... Figure 2The locking element 210 and the operating element 220 are shown. The battery pack 100 can be detached from the handle 315 of the hand-held power tool 300 by operating the operating element 220. After the battery pack 100 is unlocked, it can be separated from the handle 315. When the battery pack 100 is installed in the hand-held power tool 300, the locking element 210 engages with a corresponding receiving portion (not shown in detail) in the handle 315 of the hand-held power tool 300.

[0048] As mentioned at the beginning, the present invention enables the maintenance of known interface configurations with consistent contact elements 140, 150 for charging and discharging processes, for example... Figure 2 In the case of the interface 180 shown, the charging current path and the discharging current path are at least partially separated from each other and thus implemented differently.

[0049] Figure 3 and 4 Relatedly, a portion of the battery pack electronics 800 is shown, along with portions of the charging and discharging current paths from contact element 140 to the at least one battery cell, the battery cell being shown via a corresponding battery contact 142. A portion of the charging and discharging current paths from another potential of the at least one battery cell to contact element 150 is not shown. However, those skilled in the art will recognize that this portion, in its simplest case, is merely a continuous electrical connection. Alternatively, the portion of the charging and discharging current paths from the other potential of the at least one battery cell to contact element 150 may be connected to… Figure 3 and 4 The parts shown are constructed identically.

[0050] exist Figure 3 In the circuit shown, as already mentioned, contact element 140 is connected to battery contacts 142 of battery pack 100 via charging current path and discharging current path. The direction of current during battery pack discharge is indicated by arrow S. E The direction of current during battery pack charging is indicated by arrow S. L Characterization.

[0051] As can be seen, the charging current path and the discharging current path are electrically separated from each other between nodes 144 and 146 and include a common section outside this area.

[0052] A first current limiter 170, which in this embodiment is a MOSFET, is arranged in the common section. The at least one first current limiter 170 is configured as an n-type MOSFET in the figure and is configured to turn off the discharge current when limits are exceeded, particularly discharge current limits and / or temperature limits. Accordingly, the current carrying capacity of the first current limiter is set for the expected discharge current. Also shown are the parasitic body diodes 171 and 172 of the MOSFET 170, which allow current in the direction of charging current even when the first current limiter 170 turns off the discharge current, which is undesirable.

[0053] In the illustrated embodiment, the charging current path therefore includes a second current limiter 160. Figure 3 Also shown as a MOSFET, the second current limiter 160 is configured to turn off the charging current when limits are exceeded, particularly charging current limits and / or temperature limits and / or individual cell voltage limits. Accordingly, the current carrying capacity of the second current limiter is set for the expected charging current. The body diode 161 of the second current limiter 160 is oriented such that it does not carry current when the charging current is turned off. It can be seen that the first current limiter 170 and the second current limiter 160 are connected in series-free configuration in the charging current path.

[0054] A first switching element 148 is used to switch between a charging current path and a discharging current path. The switching element 148 is arranged in the discharging current path, wherein the first switching element 148 and the second current limiter 160 are connected in parallel between nodes 144 and 146. Accordingly, when the first switching element 148 switches on the discharging current path, it bridges the second current limiter 160 and diverts any potentially high discharge current past the second current limiter 160. The unit for operating the switching element will be discussed later.

[0055] With this invention, it is possible to ensure that charging and discharging currents are connected by respective current limiters 170 and 160 even when charging and discharging of the battery pack 100 occur through the same contact elements 140 and 150. Simultaneously, the solution according to the invention avoids the use of anti-series MOSFET circuitry in the discharge current path, thereby minimizing the cost and power loss of additional components energized during the operation of the handheld machine tool 300.

[0056] In embodiments where the switch is operated via the switching element 148, the switching element 148 may be manually operated by the user, for example via a switch located on the outside of the battery pack housing and connected to the battery pack electronics 800. Alternatively or additionally, digital, radio-, infrared, optical, or magnetic technologies may be used to operate the switch 148 when the battery pack is connected to the handheld power tool 100 or a charger, wherein the corresponding interfaces must also have corresponding technologies, such as via a radio transmitter and a radio receiver.

[0057] In an alternative embodiment of the invention that is advantageous in terms of compatibility with conventional appliances, interface 180 has a first mechanism (not shown) for operating the first switching element 148. Here, the first mechanism is integrated into interface 180 of the first battery pack 100, so that when the battery pack 100 is connected via interface 180 to a corresponding interface of the handheld power tool 300 and / or charger, the first mechanism operates the first switching element 148. This enables automatic switching and operation to the corresponding operating modes, i.e., discharging or charging, when the user uses the battery pack on the handheld power tool or the charger.

[0058] Accordingly, in one embodiment of the invention, the first switching element 148 and the first mechanism are configured such that, in a basic state in which the interface 180 of the battery pack 100 is not connected to the corresponding interface of the handheld machine tool 300 and / or the charger, the discharge current path or the charging current path is connected.

[0059] In the case where the charging current path is connected in the basic state, the first mechanism is configured such that when the battery pack 100 is connected to the handheld power tool 300 via interface 180, the first switching element 148 connects the discharge current path. This first mechanism can, for example, be operated by a mechanism integrated into the interface 380 of the handheld power tool 300, such as a locking mechanism or mechanical coding element, which is already present in conventional handheld power tools 300. If the battery pack 100 is then disconnected from the handheld power tool 300, the first mechanism reconnects the charging current path via the switching element 148. That is, in this embodiment, the first mechanism does not need to be operated when connecting the battery pack to the charger.

[0060] Instead, for the case where "the discharge current path is connected in the basic state," the first mechanism is configured such that when the battery pack 100 is connected to the charger via interface 180, the first switching element 148 connects the charging current path. This first mechanism can also be operated, for example, by a mechanism integrated into the charger's interface, such as a locking mechanism or mechanical coding element, which is already present in conventional chargers. If the battery pack 100 is then disconnected from the charger, the first mechanism connects the discharge current path again via the switching element 148. That is, in this embodiment, it is not necessary to operate the first mechanism when connecting the battery pack to the handheld machine tool 300.

[0061] exist Figure 3 In the embodiment shown, as long as the first current limiter 170 and the second current limiter 160 are not turned off, the battery cell or battery contact 142 is always electrically connected to the contact element 140.

[0062] In contrast, Figure 4 In another embodiment shown, the first switching element 148 is configured to switch between a charging current path, a discharging current path, and a neutral state, wherein, in the neutral state, the at least one battery cell is electrically disconnected from the first contact element 140. Figure 4 In this context, the neutral state is shown by the switching state 1483 of the first switching element 148, while in the switching state 1481 of the first switching element 148, the charging current path is connected, and in the switching state 1482 of the first switching element 148, the discharging current path is connected. Generally, in... Figure 3 and 4 Consistent reference numerals are used for consistent features.

[0063] As can be seen, in the switching state 1481 where the charging current path is connected, the charging current is guided through the first current limiter 170 and the second current limiter 160, and the first current limiter 170 and the second current limiter 160 are arranged in the charging current path in a series-avoided manner. In the switching state 1482 where the discharging current path is connected, the discharging current passes past the second current limiter 160, so as not to unnecessarily increase the power loss, just like with... Figure 3 As explained.

[0064] It should be mentioned that, in Figure 4 In the circuit shown, the switching element 148 is not arranged in parallel with the second current limiter 160, but in series.

[0065] Such as combination Figure 3 As described, in one embodiment of the present invention, in Figure 4In the circuit shown, a first mechanism switches the switching element 148 between a discharge current path, a charging current path, and an additional neutral state. In this case, the neutral state is active in the base state of the battery pack, and the first mechanism is configured such that when the battery pack 100 is connected to the handheld power tool 300 via interface 180, the first switching element 148 activates the discharge current path. The first mechanism is also configured such that when the battery pack 100 is connected to the charger via interface 180, the first switching element 148 activates the charging current path.

[0066] Accordingly, in connection with this embodiment, the machine-side interface 380 of the handheld power tool 300 is configured such that when the battery pack 100 is connected to the machine-side interface 380 of the handheld power tool 300, the first mechanism of the battery pack 100 switches on the discharge current path via the first switching element 148. Similarly, the charger interface is configured such that when the battery pack 100 is connected to the appliance-side interface of the charger, the first mechanism of the battery pack 100 switches on the charging current path via the first switching element 148.

[0067] As for readily conceivable alternatives to pairing the battery pack 100 with the handheld power tool 300 or the charger, alternatives are also conceivable in terms of the switching element 148 being operated, for example, by the corresponding Bluetooth tag or magnetic trigger of the handheld power tool 300 and the battery pack 100.

[0068] Although the invention has been explained in detail through preferred embodiments, those skilled in the art can also devise other combinations of the mentioned features without departing from the scope of protection of this application.

Claims

1. A battery pack (100) for a handheld power tool (300), comprising: A battery pack housing (110) having an interface (180) for establishing a mechanical and electrical connection between the battery pack (100) and the handheld machine tool (300) and / or the charger; wherein, The interface (180) has at least one first contact element (140) and a second contact element (150) for electrical contact with corresponding contact elements on the handheld power tool (300) and / or corresponding contact elements on the charger; At least one battery cell; A battery pack electronic component (800); wherein the battery pack electronic component (800) includes a charging current path and a discharging current path; wherein the charging current path is configured to connect a first contact element (140) and a second contact element (150) to the battery cell during charging of the at least one battery cell; wherein the discharging current path is configured to connect the first contact element (140) and the second contact element (150) to the battery cell during discharging of the at least one battery cell; wherein the charging current path and the discharging current path are at least partially electrically separated from each other; and A first switching element (148) is used to switch between at least the charging current path and the discharging current path. The charging current path and the discharging current path include a common section, and the common section includes at least one first current limiter (170). The at least one first current limiter (170) is configured to shut off the discharge current when a limit is exceeded. The at least one first current limiter (170) includes a first metal-oxide-semiconductor field-effect transistor and a second metal-oxide-semiconductor field-effect transistor connected in parallel, and wherein the parasitic body diode (171) of the first metal-oxide-semiconductor field-effect transistor and the parasitic body diode (172) of the second metal-oxide-semiconductor field-effect transistor are configured to allow current in the direction of charging current even when the first current limiter (170) turns off the discharge current.

2. The battery pack (100) according to claim 1, characterized in that, The interface (180) has a device for manipulating the first switching element (148).

3. The battery pack (100) according to claim 2, characterized in that, The device is the first mechanism.

4. The battery pack (100) according to claim 3, characterized in that, The first mechanism is integrated into the interface (180) of the first battery pack (100) such that when the battery pack (100) is connected via the interface (180) to the corresponding interface (380) of the handheld machine tool (300) and / or the charger, the first mechanism operates the first switching element (148).

5. The battery pack (100) according to claim 3 or 4, characterized in that, The first switching element (148) and the first mechanism are configured such that, in a base state in which the interface (180) of the battery pack (100) is not connected to the corresponding interface (380) of the handheld machine tool (300) and / or the charger, the discharge current path or the charging current path is connected.

6. The battery pack (100) according to claim 3 or 4, characterized in that, The first mechanism is configured such that when the battery pack (100) is connected to the handheld machine tool (300) via the interface (180), the first switching element (148) connects the discharge current path.

7. The battery pack (100) according to claim 3 or 4, characterized in that, The first mechanism is configured such that when the battery pack (100) is connected to the charger via the interface (180), the first switching element (148) turns on the charging current path.

8. The battery pack (100) according to any one of claims 1 to 4, characterized in that, The at least one first current limiter (170) is configured to shut off the discharge current when the discharge current limit and / or temperature limit are exceeded.

9. The battery pack (100) according to claim 7, characterized in that, The charging current path includes at least one second current limiter (160), wherein the at least one second current limiter (160) is configured to shut off the charging current when a limit of charging current and / or a limit of temperature and / or a limit of cell voltage is exceeded.

10. The battery pack (100) according to claim 9, characterized in that, The first switching element (148) is arranged in the discharge current path, wherein the first switching element (148) and the second current limiter (160) are connected in parallel.

11. The battery pack (100) according to claim 9, characterized in that, The first switching element (148) is configured to bridge the at least one second current limiter (160) when the first switching element (148) connects the discharge current path.

12. The battery pack (100) according to any one of claims 1 to 4 and 9 to 11, characterized in that, The first switching element (148) is configured to switch between a charging current path, a discharging current path, and a neutral state, wherein, in the neutral state, the at least one battery cell is electrically separated from the first contact element (140) and / or the second contact element (150).

13. The battery pack (100) according to any one of claims 1 to 4 and 9 to 11, characterized in that, The at least one first current limiter (170) and / or the at least one second current limiter (160) are electrical components from the group consisting of bipolar transistors (BJTs), field-effect transistors (FETs), and metal-oxide-semiconductor field-effect transistors (MOSFETs).

14. A handheld power tool (300), comprising: Electric motor; A machine-side interface (300) for mechanical and electrical coupling between the handheld machine tool (300) and the corresponding interface (180) of the battery pack (100); and, according to any one of claims 3 to 7 and 9 to 11, the machine-side interface (300) is configured such that when the battery pack (100) is connected to the machine-side interface (380) of the handheld machine tool (300), a first mechanism of the battery pack (100) connects a discharge current path via a first switching element (148).

15. A charger for charging a battery pack (100) according to any one of claims 3 to 7 and 9 to 11, comprising: Appliance-side interface for mechanical and electrical coupling of the charger and the corresponding interface (180) of the battery pack (100), wherein the appliance-side interface is configured such that when the battery pack (100) is coupled to the appliance-side interface, a first mechanism of the battery pack (100) connects the charging current path via a first switching element (148).

16. A tool system comprising a battery pack (100) according to any one of claims 1 to 13, a handheld machine tool according to claim 14, and a charger according to claim 15.

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