DE202013102567U1 - Mobile electrical device with at least two lithium-ion batteries and arrangement of two such electrically connected in series accumulators - Google Patents

Abstract

Mobile electrical device (10), in particular hand tool (12), garden implement or hand-guided garden tool, with electrically operated drive motor (14) for rotating, oscillating and / or rotating tool carrier (16) or machining tools (18), the electrical power supply (20) at least comprises two electrically connected in series lithium-ion batteries (22) of the same type and largely the same capacity and rated voltage, each separately operating monitoring devices (24) for permanent monitoring electrical and / or physical parameters such as current voltages, currents and / or temperatures the individual accumulators (22) are associated, which are coupled to a protective circuit (26), the at least at undervoltages and / or overtemperatures a voltage and / or current limiting and / or a separation of the affected accumulator (22) or the affected accumulators (22) from we Provide iteren electrical components of the electrical device (10).

Description

The present invention relates to a mobile electrical device, in particular a hand tool or garden tool o. The like. With electrically operated drive motor for rotating, oscillating and / or rotating tool carrier or machining tools, the electrical power supply at least two electrically connected in series lithium-ion batteries of the same type and largely equal capacity and rated voltage. The invention further relates to an arrangement with at least two electrically connected in series lithium-ion batteries of the same type and largely the same capacity and rated voltage, in particular for the electrical power supply of a mobile electrical device such as a hand tool, a garden tool o.

Mobile electrical devices with accumulators that can be operated independently of the power supply have been known for a long time. With the increasingly higher energy density and the falling costs of modern accumulators not only portable computing devices, but also, for example, hand tools, gardening equipment or other devices are equipped with batteries so that they are independent of a public power grid to power and thus without disturbing cables for longer Periods can be used and operated at almost any location.

As accumulators with sufficiently high energy density in particular so-called. Lithium-ion accumulators are used. Such lithium-ion batteries not only have a relatively high energy density, but they are thermally stable and subject to only a very small memory effect, whereby they can keep a sufficiently high capacity available even with little careful charging behavior. Depending on the type of accumulator used, these may have different operating parameters, for example different cell voltages, temperature sensitivities or maximum permissible charging or discharging currents.

Despite their wide range of applications and their universal applicability, a long service life of lithium-ion batteries nevertheless requires their careful handling. The so-called cycle life depends on the type and quality of the battery, the temperature, and the type of use of the battery, in particular the (discharge) loading strokes, the end-of-charge voltage and the strength of the charging and discharging currents. At high temperatures, the cycle life can be significantly reduced, which is why the battery should be used best at room temperature. Low temperatures during operation can also damage the batteries, while storage at low temperatures usually causes no problems. Loading and unloading with relatively flat charging curves can significantly increase the durability. For example, a lithium-ion battery, from which instead of 100% only 50% of the maximum capacity can be discharged and then recharged, can withstand more than twice the number of cycles. The reason for this is that when fully discharged and fully charged battery high loads for the electrodes. Likewise, high charge and discharge currents increase the mechanical and thermal loads and thus have a negative effect on the number of cycles.

Mobile use in electrical appliances can cause many of these risks, which can reduce the life of the batteries used as an electrical power supply. This is especially true when using hand tools, as this can occur more often unfavorable operating conditions, such as. Relatively high or low temperatures, voltage spikes or more frequent deep discharges by a robust use of hand tools, eg. On construction sites or in the field of outdoor installations. For this reason, the reliability of the accumulators should be given increased attention in such conditions of use.

The primary object of the present invention is seen to provide a particularly reliable and durable mobile electrical device, in particular a hand tool with electrically powered drive motor for rotating, oscillating and / or rotating tool carriers or machining tools available, the electrical power supply at least two electrically in series switched lithium-ion batteries of the same type and largely the same capacity and rated voltage includes. In this electrical device, in particular, the electrical power supply should be protected and protected as well as possible against damage of all kinds by improper treatment and / or by particularly harsh operating conditions, which should be realized primarily by a suitably designed monitoring circuit.

These stated objects of the invention are achieved by the subject-matter of the independent claims. Further advantageous embodiments of the invention can be found in the subclaims. Thus, the invention proposes to solve the above problem, a mobile electrical device, which may be in particular a hand tool with electrically operated drive motor for rotating, oscillating and / or rotating tool carrier or processing tools. The electrical power supply of the electrical device or the hand tool comprises at least two electrically connected in series lithium-ion batteries of the same type and largely the same capacity and rated voltage, each separately operating monitoring devices for permanent monitoring electrical and / or physical parameters such as current voltages, currents and / or temperatures at the individual batteries are assigned, which in turn are coupled to a protection circuit, which provide at least when occurring undervoltages and / or excess temperatures, a voltage and / or current limiting and / or separation of the affected accumulator or affected accumulators of other electrical components of the electrical device. In addition, other parameters can be monitored and used to control the accumulators, which can have an influence on the function and / or life of the accumulators. Such additional parameters may be, in particular, a current consumption or an under temperature.

In addition, the protection circuits can provide that voltage and / or current limiting are provided even in the event of overvoltages and / or undercurrents, optionally also a separation of the affected accumulator or the affected accumulators of other electrical components of the electrical device can be provided. While overvoltages can occur in particular during charging processes and can lead to problems here, undervoltages can lead to serious problems and damage to the accumulators, especially during operation of the device. Occurring overvoltages can be secured by appropriate precautions in the charger normally, while under-voltages that occur in operation, either by a suitable protection circuit in the device and / or by a corresponding protection circuit in the accumulator are hedged.

In particular, two identical and electrically connected in series lithium-ion batteries can be installed in the electrical device according to the invention, which are arranged in a common housing compartment of the electrical device or spatially separated from each other in each separate housing compartments of the device. It makes sense to the accumulators can be removed for maintenance purposes without the aid of tools from their housing compartments and used there again. The location of the batteries in the device, i. the arrangement of the corresponding housing compartments for receiving the batteries depends on the space available or according to the available installation space or optionally according to specifications of a weight balance of the device, which, for example, may be of importance in hand tools, since a meaningful weight distribution usually ergonomic advantages brings, while an unfavorable weight distribution can lead to a faster fatigue of the user, since this unnecessarily high holding forces can occur.

The monitoring devices of the electrical device according to the invention, according to an advantageous embodiment, each protection circuits for detecting electrical short circuits in a detected exceeding a maximum allowable current to the battery or to the series-connected accumulators and the separation of the affected accumulator or affected accumulators of other electrical Provide components of the electrical device. In this way, the batteries can be protected from damage caused by excessive current or by an electrical short circuit. In addition, the protective circuits may preferably also each have means for at least temporary current limiting in a detected overshoot of the maximum permissible defined current.

A variant of the electrical device according to the invention provides that its monitoring devices each have protective circuits which are assigned to each individual battery and provide for a separation of the affected accumulator or affected accumulators of other electrical components of the electrical device, as soon as a protective circuit of at least one accumulator responds. It is provided that each of a plurality of accumulators each have a protective circuit is assigned, each autonomously monitors the parameters of its associated accumulator and / or ensures its electrical isolation from the device as soon as a fault and / or malfunction was detected. That is, the protection electronics for securing the batteries and their reliability is circuitry and physically always arranged on the battery itself, so that they can be protected and secured under all circumstances, regardless of their state of charge. The protection electronics associated with the individual batteries can provide the required protection even with a half-empty or a relatively old battery, even if this is possibly combined with a new battery. A typical problem that can occur here is the faster discharge of old batteries and / or their faster voltage drop. The protective circuits assigned to the individual batteries can even protect this case. If, on the other hand, only one protective electronics were present in the device, but not in the battery, this could lead to many problems, eg when using an unsuitable or incorrect charger. In contrast, the According to the invention insured batteries are used in any foreign equipment, without causing any risks for the life of the batteries are connected.

A further variant of the electrical device according to the invention can provide that the protective circuits provide an at least temporary electrical separation of the drive motor and / or other electrical consumers of the accumulators at a detected overshoot of the maximum permissible current strength defined. In addition, it can preferably be provided that the protective circuits provide for an at least temporary electrical separation of the drive motor and / or other electrical loads from the accumulators at a detected overshoot or undershoot of the maximum permissible voltage defined.

Thus, the monitoring devices each protection circuits for detection and detection of electrical surges when exceeding a maximum allowable voltage and / or excessive current to the battery or to the series-connected accumulators and the separation of the affected accumulator or affected accumulators of other electrical Provide components of the electrical device. Preferably, in this variant, the protective circuits each have means for limiting the voltage at a detected excess of the maximum permissible voltage defined on the accumulators. In this case, the protective circuits can provide an at least temporary electrical separation of the drive motor and / or further electrical load from the accumulators, if the exceeding of the maximum permissible defined voltage, which in turn serve to avoid damage to the accumulators and / or associated with these electrical control circuits can.

In addition, the protection circuits preferably each have means for limiting the voltage or current limitation and / or for deactivating the batteries in the event of a detected undervoltage of the batteries, i. when falling below the minimum required voltages defined on the accumulators. In this case, the protective circuits can provide an at least temporary electrical separation of the drive motor and / or further electrical load from the accumulators, which in turn can serve to avoid damage to the accumulators and / or connected to these electrical control circuits at a detected shortfall of the minimum necessary voltages. Under-voltages can lead directly to decomposition phenomena at the cathodes of the accumulators and to the dissolution of the metal oxide and metallic electrode carriers. Since undervoltages that occur in the operation of the batteries, the cells are overwhelmed or at the end of a charge cycle, it is necessary to provide for these cases, a shutdown and disconnection of the electrical connections between the batteries and the consumers of the electrical device.

Optionally, the protective circuits may also each have means for limiting the current at a detected overshoot of the maximum permissible defined current to the accumulators. In this case, the protective circuits can provide an at least temporary electrical separation of the drive motor and / or other electrical loads from the accumulators when a detected exceeding the maximum allowable defined current, which in turn serve to avoid damage to the accumulators and / or associated with these electrical control circuits can.

Optionally, the electrical device may also be provided with monitoring devices, each of which protective circuits for detecting excess temperatures when exceeding a maximum allowable temperature on the battery or battery connected in series and for separating the battery or the affected accumulators of other electrical components of the provide electrical device. Another useful variant of the electrical device provides that its monitoring devices each protection circuits for detecting under-temperatures when falling below a minimum allowable temperature at the affected battery or to the series-connected accumulators, in particular of temperatures below 0 ° C, and to separate the affected Provide accumulator or the affected accumulators of other electrical components of the electrical device. Since the lithium-ion batteries used in the electrical device according to the invention typically sensitive to under-temperatures, especially to temperatures below about 0 ° C, it may be useful in such Te mperaturbereichen the operation by switching off or deactivating the batteries or to prevent their control electronics, so that the batteries are not permanently damaged by prolonged operation at too low temperatures.

In the variants of the electrical device, which are equipped with such a monitoring of the temperature ranges, a time-controlled re-activation of electrical components and / or the electric drive motor may be provided, provided that the detected temperature of the Accumulators after a defined period of time is within a certain range. In this way it is prevented that the user is prevented in a no longer given risk of damage to the batteries on further intended use of the electrical device according to the invention.

Alternatively or additionally, in the electrical device, however, also be provided that for re-release of the batteries and / or their electrical connection with other components of the device and / or with the electric drive motor after disconnection or shutdown an acknowledgment via an additional push button or switch is required. In addition, in the interest of increased user friendliness, an additional optical display or a signaling device or the like may be advantageous. Thus, for example, a temporary or can only be canceled by active release separation of the batteries of other components of the device and / or the electric drive motor via at least one optical display or signaling device be identified.

In the case of the electrical device according to the invention, the lithium-ion accumulators may, for example, each have a rated voltage of between about 12 and about 25 volts, with rated electrical voltages of in each case approx. 18 V being sensible and practicable for electric hand tools. It can be provided that the lithium-ion batteries each have an overvoltage resistance of up to 45 volts, in particular in each case up to 60 V. In addition, lithium-ion batteries with nominal capacities of about 1 to 5 ampere hours have proven to be practicable, with typical electric hand tools in particular batteries with nominal capacities between about 1.5 and 3 ampere hours can be used.

The present invention furthermore relates to an arrangement having at least two lithium-ion accumulators connected in series of the same design and substantially the same capacity and rated voltage, in particular the electrical power supply of a mobile electrical device such as a hand-held power tool with electrically driven drive motor for rotating, oscillating and / or or rotating tool carrier or machining tools can serve. In this case, the at least two lithium-ion batteries each separately operating monitoring devices for permanent monitoring of electrical and / or physical parameters such as current voltages, currents and / or temperatures can be assigned to the individual accumulators, which are coupled to a protective circuit, at least when occurring Overvoltages and / or excess temperatures provide a voltage limitation and / or a separation of the affected accumulator or the affected accumulators of other electrical components of the electrical device. Other variants of this arrangement according to the invention may have features as they have been explained above with reference to various embodiments of the electrical device according to the invention. These device variants relate equally to different embodiments of the arrangement of two electrically connected in series lithium-ion batteries.

Another, in practice very advantageous function of the accumulators according to the invention may consist in that they have a kind of stair-step-shaped switching system, whereby in each case the same batteries can be used in different devices, eg battery-operated screwdrivers, lawnmowers, etc. This can be achieved in that the protective and control electronics associated with the batteries are adapted to the respective devices and ensure that the batteries are protected and protected in a wide variety of operating situations. By the term staircase-shaped switching system is meant in particular that, depending on the battery cells used different currents can be allowed, some of which may only flow for a very short period of time (quasi-stationary operation). Since the universal batteries used are not previously known in which devices they are used and which power profiles can occur there, the control concept provides that in each case a defined continuous current for a defined maximum period of time is allowed, which depends on the cell. For example, a current between 30 and 60 amperes may be allowed for a maximum period of one to 1.5 seconds. A higher current of, for example, 60 to 90 amps can therefore be allowed for a shorter period of, for example, a maximum of 150 milliseconds, while higher currents of, for example, over 100 amperes are only allowed for a maximum period of, for example, two milliseconds. This switching characteristic, referred to here as a step-step characteristic, makes it possible to use the batteries in a wide variety of devices without it being necessary to first know what the exact consumption and requirement profile of the devices looks like. The maxim, which is not violated here at any time, is that the accumulator modules themselves ensure that their cells are not overwhelmed at any time, so that so a large variety of different devices can be operated equally. Another advantage is that no elaborate protocols, production and / or operating protocols are required, otherwise for a smooth communication between the devices and the batteries would be indispensable, otherwise there would be a risk of damaging or destroying the battery by certain operating conditions that are not secured.

It will be understood by those skilled in the art that these stated values for the step-like protection and protection characteristic are merely exemplary and vary depending on the capacity of the batteries, their specific properties, the ambient and / or operating conditions and the typically occurring load cases of various devices can.

The electrical device can optionally have two lithium-ion batteries with a total rated voltage of about 36 volts or three lithium-ion batteries with a total nominal voltage of about 54 volts. Upwards, these values can be extended if necessary, since devices with four or more similar accumulators are conceivable, for example mobile welding devices or the like, which have a higher current consumption and require higher voltages (eg ultrasonic welding device) for a sensible use ,

Possibly. Individual devices can be supplemented by additional capacitors or coils. Thus, a further embodiment variant of the electrical device according to the invention provides that the accumulators are assigned at least one capacitor module and / or a coil set for briefly increasing the retrievable current intensity when load peaks of the device occur. In this way, the capacity can be increased in the short term advantageously at very low additional cost, which may, for example, be advantageous for a delivery torque of an electric drive motor, which may have a higher power consumption at high loads occurring at short notice.

In addition, it should be mentioned that individual accumulators, as described above, are used in devices and can be quickly replaced there as needed. Due to the configuration according to the invention with the protection circuit associated with the individual battery, it is no problem in practice to use and exchange even those batteries that do not have their full charge state, since their protection circuit protects them from deep discharge, under and over temperature and other operating conditions And beyond that, it can safeguard all sorts of conceivable malfunctions.

Another advantageous aspect, which has not yet been mentioned, is that with the help of the accumulators targeted influence on the ergonomics and manageability of portable electrical devices can be influenced, since depending on the placement and positioning of the batteries in the device different weight distributions can be achieved so that the weight balance can ideally be achieved already during the construction of the device for optimum ergonomics. This can affect a wide variety of hand tools, but also for all types of portable gardening tools and other portable tools application, eg. For hedge trimmers, chainsaws, etc.

In addition, it makes sense to provide suitable protective elements in the electrical device according to the invention, in particular for a suitable ESD protection, i. to provide protection against damage due to electrostatic discharge. Thus, it is advantageous if at least one of the at least two batteries connected in series has a bidirectional diode (Diac) connected in parallel. Of course, it is even more advantageous if each of the at least two series-connected accumulators in each case a bidirectional diode (Diac) is connected in parallel. In addition, the electric load, in particular the electric drive motor of the device, a freewheeling diode may be connected in parallel. Thus, within the two battery packs, each of the two accumulators can each have a bidirectional diode, a so-called diac, connected in parallel. These diacs ensure that in unequally charged batteries or accumulators with very different electrical values or capacities no unwanted discharge effects, but at the same time when exceeding the breakdown voltages, the protection electronics is relieved by the bypass, which corresponds to an effective ESD protection. Thus, the diacs connected in parallel ensure that the power supply of the motor is interrupted if one of the rechargeable batteries or rechargeable battery packs does not work properly, the other one already, in order to prevent in such situations, the discharge or damage of the properly working battery. In addition, it makes sense to connect a freewheeling diode in parallel to the motor or the electrical load, which can provide protection of the power supply consisting of the battery or the two series-connected battery packs when voltage spikes occur on the motor.

For the sake of clarity, it should be noted that the term "accumulator", which is frequently used in the present context, normally designates the ready-to-install and exchangeable accumulator module or accumulator pack, but not the individual cell of such a module. That is, when the term "accumulator" is used herein, it usually means the battery module or battery pack.

In the following, embodiments of the invention and their advantages based on the explain in more detail attached figures. The proportions of the individual elements to one another in the figures do not always correspond to the actual size ratios, since some shapes are simplified and other shapes are shown enlarged in relation to other elements for better illustration.

1 shows a schematic representation of an embodiment of an electrical machine according to the invention, which has an electric drive motor whose electrical power supply has two series-connected lithium-ion batteries.

2 shows a schematic plan view of an electric lawn mower as an application example of the electrical device according to the invention.

3 shows a schematic perspective view of the electric lawn mower according to 2 ,

4a shows a schematic perspective view of an embodiment of an accumulator, as in the lawnmower according to 2 and 3 or in an electrical device according to 1 can be used.

4b shows an enlarged plan view of a contact area of the battery according to 4a ,

5 shows a schematic block diagram of an electrical power supply of the device according to 1 or the lawnmower according to 2 and 3 ,

6 shows a block diagram for clarifying various functionalities of the electrical power supply according to 5 ,

7 shows a perspective view of an electric chain saw as an embodiment of a battery-powered, portable gardening tool or garden tool.

8th shows in two perspective views of a cordless drill or cordless screwdriver with a removable battery on its housing bottom.

9 shows in two circuit diagrams ( 9a and 9b ) the connection of the battery packs with additional protective devices to ensure ESD protection.

For identical or equivalent elements of the invention, identical reference numerals are used. Furthermore, for the sake of clarity, only reference symbols are shown in the individual figures, which are required for the description of the respective figure. The illustrated embodiments are merely examples of how the device or method of the invention may be configured and are not an exhaustive limitation.

The schematic representation of 1 shows a mobile electrical device 10 , in particular by a hand tool 12 with electrically driven drive motor 14 for rotating, oscillating and / or rotating tool carriers 16 or editing tools 18 can be formed. The electrical energy supply 20 of the drive motor 14 of the electrical device 10 includes in the illustrated embodiment, two electrically connected in series lithium-ion batteries 22 same type and largely the same capacity and rated voltage. The two lithium-ion batteries 22 are each separately operating monitoring devices 24 For permanent monitoring of electrical and / or physical parameters such as current voltages, currents and / or temperatures at the individual accumulators 22 associated with a protection circuit 26 coupled, at least in the event of overvoltages and / or excess temperatures, a voltage limitation and / or a separation of the affected accumulator 22 or the affected accumulators 22 of other electrical components of the electrical device 10 , in particular of the electric drive motor 14 , provide. Preferably, the electrical device 10 or the hand tool 12 two identical series-connected lithium-ion batteries 22 on that in a common housing compartment 28 of the electrical device 10 or spatially separated from each other in each separate housing compartments of the device 10 are arranged.

The schematic plan view of 2 shows an alternative embodiment of the mobile electrical device according to the invention 10 in the form of a lawnmower 30 , whose electrically driven drive motor 14 an unrecognizable rotating knife drives on its underside. The electrical energy supply 20 of the drive motor 14 is carried out by two lithium-ion accumulators connected in series 22 same design, same capacity and rated voltage. The batteries 22 associated monitoring devices 24 , each with protection circuits 26 coupled, for example, above the engine 14 be arranged like this in the 2 is indicated. Like the 2 In addition, the batteries are recognizable 22 in a common housing compartment 28 placed on a front of the lawnmower 30 located. The easy accessibility in their housing compartment 28 placed batteries 22 is through a hinged housing cover 32 given in the presentation of the 3 pivoted forward and thus open. Optionally, the batteries can 22 when open cover 32 removed and from the device 10 or from the lawnmower 30 be separated.

The schematic perspective view of 4a shows an embodiment of one of the at least two for the power supply of an electrical device 10 provided batteries 22 (Lithium ion secondary battery 22 ), the cuboid battery housing 34 with top-side electrical connection contacts 36 having, on both sides of a drawer frame 38 flanked, leaving a slot of the batteries 22 at their intended location only in the direction indicated by an arrow insertion direction 40 can be done. The electrical connection contacts shown 36 are arranged in parallel slots, so that a direct contact is excluded. The in the 4 shown design of the electrical connection contacts 36 requires a corresponding design of the respective mating contacts in the housing compartment of the electrical device 10 , so that an electrical contact can be made.

The top view of 4b illustrates the inside of the slot frame 38 arranged connection contacts 36 at the top of the battery case 34 of the lithium-ion battery 22 (short: battery 22 ), which with a not shown here corresponding contact strip in the region of the housing 28 interact in such a way that by inserting the battery 22 in the insertion direction 40 , in the direction of drawing the 4b pointing to the right and parallel to the plane of the drawing, ie parallel to the top or bottom of the cuboid housing 34 of the battery 22 , The connection contacts 36 In the embodiment shown, a total of five contact slots 42 of which, however, only three with metal pairs of contact springs 44 are occupied while two of the contact slots 42 due to the lack of contact springs are not prepared and able to make an electrical contact. Depending on the version of the batteries 22 can the total of five contact slots 42 the connection contacts 36 be occupied and activated in different ways as needed.

Like the top view of the 4b continues to recognize, are the contact slots 42 each with different connection symbols 46 in each case the assignment of the contact slots 42 and the correct electrical contact with the electrical device 10 ( 1 ) facilitate.

The 4b also shows two additional contacts, which are currently not used. From these additional contacts, for example, a contact can be used for newer devices to transmit an additional communication protocol for new devices. Thus, for example, certain specifications of the device are possible, the to the battery 22 be transmitted, for example, a power cut to protect a motor, a pulse current operation, etc., for example. For ultrasonic welding. However, these additional contacts can also be used for a permanent temperature query, a state of charge query o. The like., Which may also be done via this (optional) communication interface.

The schematic block diagram of 5 illustrates the electrical wiring of the electrical power supply 20 , which are essentially the two series-connected accumulators 22 - characterized by a battery pack 23 - and the drive motor 14 includes, supplemented by the monitoring device 24 and the protection circuit 26 for the monitoring and demand-based separation of the electrical connection between the battery pack 23 and the drive motor 14 , this should protect the batteries 22 to be required. So the monitoring device 24 different parameters of the batteries 22 of the battery pack 23 monitor and, as needed, the electrical connection to the engine 14 interrupt what the protection circuit 26 is responsible, which preferably has electronic switching elements such as FETs or other suitable semiconductor switching elements.

So the monitoring device 24 according to 5 For example, protective circuits 26 to detect electrical short circuits when a maximum permissible current is exceeded on the accumulator concerned 22 or on the series-connected accumulators 22 and for the separation of the battery pack 23 of other electrical components of the electrical device 10 in particular its drive motor 14 provide. Optionally, the protection circuits 26 each having means for at least temporary current limit in a detected overrun of the maximum allowable defined current. It makes sense if the protection circuits 26 in the case of an ascertained exceeding of the maximum permissible current intensity, an at least temporary electrical separation of the drive motor 14 and / or other electrical loads from the accumulators 22 . 23 provide.

In addition, the monitoring devices 24 the electrical energy supply 20 each protective circuits 26 for detecting and detecting electrical overvoltages that exceed a maximum allowable voltage on the affected accumulator 22 or on the series-connected accumulators 22 recognize and separate the affected accumulator 22 or the affected accumulators 22 of other electrical components of the electrical device 10 , in particular of its drive motor 14 provide. Furthermore, the protective circuits 26 each means for limiting the voltage at a detected overshoot of the maximum permissible voltage defined at the accumulators 22 exhibit. So can the protection circuits 26 at a detected excess of the maximum permissible voltage defined an at least temporary electrical separation of the drive motor 14 and / or other electrical loads from the accumulators 22 provide.

Another useful variant of the electrical energy supply 20 of the electrical device provides that its monitoring devices 24 each protective circuits 26 to detect overtemperatures that exceed a maximum allowable temperature on the affected accumulator 22 or on the series-connected accumulators 22 for a separation of the affected accumulator 22 or the affected accumulators 22 of other electrical components of the electrical device 10 or from its drive motor 14 provide. Due to the special features of the lithium-ion batteries used 22 In addition, it may be useful if the monitoring devices 24 each protective circuits 26 to detect under-temperatures, which falls below a minimum allowable temperature on the affected accumulator 22 or on the series-connected accumulators 22 , in particular of temperatures below 0 ° C, a separation of the affected accumulator 22 or the affected accumulators 22 of other electrical components of the electrical device 10 cause, in particular a shutdown of the drive motor 14 to further consumption of electrical energy from the battery pack 23 to prevent. Optionally, this can be a temperature monitoring and a timed reactivation of electrical components and / or the electric drive motor 14 be provided, provided the detected temperature of the accumulators 22 after a defined period of time is within a certain range.

The schematic representation of 6 shows by means of a block diagram various functionalities of the electrical power supply 20 according to 5 especially during a charging process. So the monitoring device 24 (BMS - Battery Management System) either by activating a push button to query a state of charge (Push Battery LED Switch) or a push button to activate a device function (Push Application Button) or by activating a charger, for example by its connection to a power grid ( Plug in Charger to charge) are activated (Wakeup of BMS) or put into a standby state, after which the monitoring device 24 initially initialized (initialization). After this initialization is the monitoring device 24 initially active (BMS active), which also causes the activation of the corresponding semiconductor switching element, the FET (Discharge FET on). Before this activation of the monitoring device 24 (BMS), however, a query is made by default as to whether an overvoltage and / or an excess temperature or too high a current has been detected (current protection, voltage protection, temperature protection). If this is the case, the FET (Discharge FET off) is switched off, as well as if the charging temperature is too high (Temperature Protection - Discharge Temperature to high), too high a FET temperature (Current Protection - FET Temperature to high) or too high charging current (Discharge Current too high) or if a short circuit was detected (Short Circuit detected). Even if the cell voltage detected is too low (voltage protection - cell voltage too low) or too large a difference of several cell voltages (voltage protection - cell voltage difference too big), such a shutdown of the monitoring device takes place 24 (BMS active - Discharge FET off). Furthermore, such a shutdown of the monitoring device takes place 24 (BMS active - Discharge FET off) if a cell voltage below 2.5 volts is detected (Voltage below 2.5 V / Cell) or if no use has been made for a period of more than three hours (3h no use); both pull a shutdown of the monitoring device 24 by itself (BMS off - Discharge FET off). After such a shutdown, the activation in turn by pressing a push button to query a state of charge (Push Battery LED Switch) or a push button to activate a device function (Push Application Button) or by activating a charger, for example. By its connection to a power grid ( Plug in Charger to charge) are activated (Wakeup of BMS).

The lithium ion accumulators 22 of the device 10 can each have a rated voltage between about 12 and about 25 volts, in particular a nominal voltage of about 18 V each have. In addition, the batteries can 22 of the device 10 preferably in each case have an overvoltage resistance of up to 45 volts, in particular in each case up to 60 V. Furthermore, the lithium-ion batteries 22 each having a nominal capacity of about 1 to 5 ampere hours, in particular a nominal capacity between about 1.5 and 3 ampere hours.

The schematic perspective view of 7 shows with a chainsaw 48 , as an example of an electrical device according to the invention 10 or a hand tool 12 acts like that Placement of the two lithium-ion batteries 22 on the housing for a favorable weight distribution on the device 10 can provide. In the illustrated embodiment, the two batteries are located 22 next to each other in the vicinity of a backward projecting handle 50 , so that the center of mass of the device 10 between the back handle 50 and a front handlebar 52 located. The batteries 22 are each in slots in the immediate vicinity of an electric drive motor 54 that drives the revolving saw chain 56 serves, on the saw blade 58 is guided. The placement of the two batteries 22 on the back of the housing of the drive motor 54 and near the rear handle of the handle 50 can ensure a favorable weight balance, making the chainsaw 48 Ideally balanced and ergonomically designed is particularly advantageous.

What here on the basis of the chainsaw 48 is shown, basically applies equally to other portable garden tools in which such ergonomic design and a favorable weight distribution in the interest of comfortable and safe handling are important.

The 8th shows in two perspective views ( 8a . 8b ) a cordless drill or cordless screwdriver 60 with a replaceable battery 22 on its housing bottom. The battery 22 has a structure and a design, as already in the two representations of 4a and the 4b was shown. The 8a and 8b clarify in particular that even single accumulators 22 , as described above, in devices 10 respectively. 12 be used and can be quickly replaced there as needed. The inventive configuration with the individual battery 22 associated protection circuit 26 (see. 6 ) it does not pose a problem in practice, even such batteries 22 short-term use and replace, which do not have their full state of charge, since their respective associated protection circuit 26 protects it from deep discharge, under temperature and other operating conditions and, moreover, can protect all types of possible malfunctions.

The 9a shows an electrical diagram of the electrical device 10 in which two accumulators 22 for the electrical power supply of an electric drive motor 14 , for example, an electric hand tool 12 , connected in series. Inside the two battery packs 23 are each of the two accumulators 22 bidirectional diodes 62 , so-called diacs, connected in parallel, which ensure that at unequally charged accumulators 22 or with accumulators 22 with very different electrical values or capacities do not result in unwanted discharge effects. This is how the diacs are connected in parallel 62 for that the power supply of the engine 14 is interrupted when one of the batteries 22 or battery packs 23 does not work properly, the other hand, in order to discharge or damage the properly working battery in such situations 22 to prevent. In addition, the Diacs deliver 62 an effective ESD protection, since when exceeding the breakdown voltage, the protective electronics of the battery pack 23 Relieved by the bypass reliably.

In addition, the circuit should be in accordance with 9a with a freewheeling diode 64 according to 9b Be provided to the engine 14 is connected in parallel and the voltage peaks occurring at the motor 14 for protection of the energy supply, consisting of the battery 22 or the two battery packs connected in series 23 ( 9a ), can provide.

For clarity, it should also be pointed out at this point that the term "accumulator 22 "Usually the ready-to-install and replaceable battery module or battery pack (denoted by reference numeral 23 ), but not the single cell of such a module. That is, if in the present context the term accumulator 22 is used, so it is usually the battery module or battery pack 23 meant.

The invention has been described with reference to a preferred embodiment. However, it is conceivable for a person skilled in the art that modifications or changes of the invention can be made within the scope of the following claims, without departing from the scope of the following claims.

LIST OF REFERENCE NUMBERS

10

 mobile electrical device, electrical device

12

 hand tool

14

 Drive motor, electric drive motor

16

 tool carrier

18

 processing tool

20

 electric energy supply

22

 Lithium-ion battery, lithium-ion battery, rechargeable battery

23

 battery Pack

24

 monitoring device

26

 protection circuit

28

 housing specialist

30

 mowing machine

32

 housing cover

34

 battery case

36

 Connection contacts, electrical connection contacts

38

 guide frame

40

 insertion direction

42

 contact slot

44

 contact spring

46

 connector icon

48

 chainsaw

50

 Handle, hand guide handle, rear handle

52

 Handle, front handlebar

54

 electric drive motor

56

 saw chain

58

 sawbar

60

 Cordless Screwdriver

62

 Bidirectional diode, bidirectional diode, Diac

64

 Freewheeling diode

Claims (27)

Mobile electrical device ( 10 ), in particular hand tools ( 12 ), Gardening tool or hand-held garden tool, with electrically driven drive motor ( 14 ) for rotating, oscillating and / or rotating tool carriers ( 16 ) or editing tools ( 18 ), whose electrical power supply ( 20 ) at least two electrically connected in series lithium-ion batteries ( 22 ) of the same type and largely the same capacity and rated voltage, each of which has separate monitoring devices ( 24 ) for permanent monitoring of electrical and / or physical parameters such as current voltages, currents and / or temperatures at the individual accumulators ( 22 ) associated with a protection circuit ( 26 ) are coupled, at least when occurring undervoltages and / or excess temperatures, a voltage and / or current limiting and / or a separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to claim 1, whose protective circuit ( 26 ) at least in the event of overvoltages and / or under-temperatures a voltage and / or current limiting and / or a separation of the accumulator concerned ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to claim 1 or 2, comprising two identical series-connected lithium ion accumulators ( 22 ), which in a common housing compartment ( 28 ) of the electrical device ( 10 ) or spatially separated from each other in separate housing compartments ( 28 ) of the device ( 10 ) are arranged. Electrical device according to one of claims 1 to 3, whose monitoring devices ( 24 ) protective circuits ( 26 ) for detecting electrical short circuits when a maximum permissible current intensity is exceeded on the accumulator in question ( 22 ) or on the series-connected accumulators ( 22 ) as well as for the separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to claim 4, whose monitoring devices ( 24 ) protective circuits ( 26 ), each individual accumulator ( 22 ) and the one separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ), as soon as a protective circuit ( 26 ) at least one accumulator ( 22 ) appeals. Electrical apparatus according to any one of claims 1 to 5, wherein each of several accumulators ( 22 ) each have a protective circuit ( 26 ), each autonomously the parameters of its associated accumulator ( 22 ) and / or for its electrical isolation from the device ( 10 ) as soon as an error and / or malfunction has been detected. Electrical device according to one of Claims 4 to 6, in which the protective circuits ( 26 ) each having means for at least temporary current limit in a detected overrun of the maximum allowable defined current. Electrical device according to one of Claims 4 to 7, in which the protective circuits ( 26 ) at an ascertained excess of the maximum permissible current intensity defined an at least temporary electrical separation of the drive motor ( 14 ) and / or other electrical consumers of the accumulators ( 22 ). Electrical device according to one of claims 1 to 8, whose monitoring devices ( 24 ) protective circuits ( 26 ) for the detection and detection of electrical overvoltages when exceeding a maximum allowable voltage at the affected accumulator ( 22 ) or on the series-connected accumulators ( 22 ) as well as for the separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to Claim 9, in which the protective circuits ( 26 ) in each case devices for limiting the voltage in the case of an ascertained exceeding of the maximum permissible voltage defined on the accumulators ( 22 ) exhibit. Electrical device according to Claim 9 or 10, in which the protective circuits ( 26 ) at a detected exceeding of the maximum permissible voltage defined an at least temporary electrical separation of the drive motor ( 14 ) and / or other electrical consumers of the accumulators ( 22 ). Electrical device according to one of claims 1 to 11, whose monitoring devices ( 24 ) protective circuits ( 26 ) for the detection of excess temperatures when exceeding a maximum allowable temperature at the affected accumulator ( 22 ) or on the series-connected accumulators ( 22 ) as well as for the separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to one of claims 1 to 11, whose monitoring devices ( 24 ) protective circuits ( 26 ) for the detection of low temperatures when a minimum permissible temperature is not reached at the affected accumulator ( 22 ) or on the series-connected accumulators ( 22 ), in particular of temperatures below 0 ° C, as well as for the separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Electrical device according to claim 12 or 13, the temperature monitoring and a timed re-activation of electrical components and / or the electric drive motor ( 14 ), provided that the temperature of the accumulators ( 22 ) is within a certain range after a defined period of time. Electrical device according to one of claims 1 to 14, in which for the re-release of the accumulators ( 22 ) and / or their electrical connection with other components of the device ( 10 ) and / or with the electric drive motor ( 14 ) is provided after disconnection or shutdown an acknowledgment via an additional pushbutton or switch. Electrical device according to one of claims 1 to 15, in which a temporary or only by active release reversible separation of the accumulators ( 22 ) of other components of the device ( 10 ) and / or the electric drive motor ( 14 ) is identifiable via at least one optical display or signaling device. Electrical device according to one of Claims 1 to 16, the lithium ion accumulators ( 22 ) each have a rated voltage between about 12 and about 25 volts, in particular a nominal voltage of about 18 V each have. Electrical device according to one of Claims 1 to 17, comprising two lithium-ion accumulators ( 22 ) having a total rated voltage of about 36V. Electrical device according to one of Claims 1 to 17, comprising three lithium-ion accumulators ( 22 ) having a total nominal voltage of about 54 volts. Electrical device according to Claims 17 to 19, the lithium ion accumulators ( 22 ) each have an overvoltage resistance of up to 45 volts, in particular each of up to 60 volts. Electrical device according to one of Claims 1 to 20, of which the lithium ion accumulators ( 22 ) each having a nominal capacity of about 1 to 5 ampere hours, in particular a nominal capacity between about 1.5 and 3 ampere hours. Electrical device according to one of Claims 1 to 21, in which the accumulators ( 22 ) at least one capacitor module and / or a coil set for a short-term increase in the retrievable current intensity occurring peak loads of the device ( 10 ) assigned. Electrical device according to one of Claims 1 to 22, in which at least one of the at least two accumulators connected in series ( 22 ) a bidirectional diode (Diac) is connected in parallel. Electrical device according to one of claims 1 to 23, in which each of the at least two series-connected accumulators ( 22 ) in each case a bidirectional diode (Diac) is connected in parallel. Electrical device according to Claim 23 or 24, in which the electrical load, in particular the electric drive motor ( 14 ) of the device ( 10 ) A freewheeling diode is connected in parallel. Arrangement with at least two series-connected lithium ion accumulators ( 22 ) of the same type and largely the same capacity and rated voltage, in particular for the supply of electrical energy ( 20 ) of a mobile electrical device ( 10 ) like a hand tool ( 12 ), Gardening tool or hand-held garden tool, with electrically driven drive motor ( 14 ) for rotating, oscillating and / or rotating tool carriers ( 16 ) or editing tools ( 18 ), wherein the at least two lithium ion accumulators ( 22 ) each separately operating monitoring devices ( 24 ) for permanent monitoring of electrical and / or physical Parameters such as current voltages, currents and / or temperatures at the individual accumulators ( 22 ) associated with a protection circuit ( 26 ) are coupled, at least in the event of over and / or under-voltages and / or excess temperatures, a voltage limitation and / or a separation of the affected accumulator ( 22 ) or the affected accumulators ( 22 ) of other electrical components of the electrical device ( 10 ). Arrangement according to Claim 26, which is part of an electrical appliance ( 10 ) according to one of claims 1 to 25.

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