GB2538169A - System with two accumulator packs - Google Patents

Abstract

A system with a first accumulator pack 12, in particular a hand tool machine accumulator pack and/or a house appliance accumulator pack. The pack has at least one accumulator cell 14 of a first accumulator cell type, an interface unit 16 for a detachable coupling to a hand tool machine and a nominal voltage. A further accumulator pack 18 of the same kind, which has at least a same interface unit (22, Fig 1) as and an at least substantially equal nominal voltage to the first accumulator pack 12 also having at least one accumulator cell 20 of a further accumulator cell type different from the first accumulator type and a reduced active accumulator cell volume compared with the first accumulator pack 12. The further accumulator pack 18 may have a fewer number of cells than the first battery pack 12. Preferably both accumulator packs have a number of cells with a common divisor different from one. The further accumulator pack 18 can have at least one cell with a greater specific capacity than at least one cell in the first accumulator pack 12. The battery packs may also both have dust-tight and/or water-proof housing (24, 26, Fig 1).

Description

Description

System with two accumulator packs

Prior art

A system with a first accumulator pack and a further accumulator pack has already been proposed.

Disclosure of the invention

There is proposed a system with a first accumulator pack, in particular a hand tool machine accumulator pack and/or a house appliance accumulator pack, which has at least one accumulator cell of a first accumulator cell type, an interface unit for a detachable coupling to a hand tool machine and a nominal voltage, and a further accumulator pack of the same kind, which has at least a same interface unit as and an at least substantially equal nominal voltage to the first accumulator pack, at least one accumulator cell of a further accumulator cell type different from the first accumulator type and a reduced active accumulator cell volume compared with the first accumulator pack.

As a result a particularly light accumulator pack can be made available. A particularly flexibly usable accumulator pack can be made available. A particularly high level of user convenience can be achieved. A particularly versatile system of accumulator packs can be made available. Further, heat can be dissipated from the further accumulator pack particularly effectively. By an "accumulator pack" there is to be understood in this context in particular an electrical energy storage unit which is provided to supply a machine, in particular a hand tool machine, a house appliance and/or a household appliance, with electrical energy. Preferably the accumulator pack is provided to supply at least an electric drive unit of the machine with electrical energy. Preferably the accumulator pack is provided for temporarily storing electrical energy. By a "hand tool machine" there is to be understood in this context in particular a drilling machine, a drilling and/or percussive hammer, a saw, a plane, a screwdriver, a milling cutter, a grinder, an angle grinder, a gardening implement, in particular a lawn mower, and/or a multifunction tool. By a "house appliance accumulator pack" there is to be understood in this context in particular a "household appliance accumulator pack". By a "house appliance" there is to be understood in this context in particular an appliance which is provided to be used in a household, and in particular to perform and/or assist with housework and/or which is provided for personal hygiene, entertainment, sporting activity and/or information transmission. Preferably the house appliance is formed in particular an electrically operated, alternatively and/or additionally gas-and/or oil-operated appliance. The house appliance is formed, for example, as a vacuum cleaner, a hair dryer, a receiving and/or playback device or sports equipment. By an "accumulator cell" there is to be understood in this context in particular an element which is provided to make available a chemically stored electrical energy. Preferably the accumulator cell comprises a galvanic cell, a case, and electrical connection means for a contacting of electrodes of the galvanic cell. Preferably the accumulator cell is formed as a rechargeable accumulator cell. By an "accumulator cell type" there is to be understood in this context in particular a preferably standardised type of accumulator cells which specifies in particular external dimensions, a shape, a nominal voltage and/or a chemical structure. Preferably the at least one accumulator cell of the further accumulator pack has an at least substantially equal nominal voltage to the at least one accumulator cell of the first accumulator pack. Preferably the first accumulator pack has a plurality of accumulator cells which are formed overall analogously to one another, preferably the accumulator cells of the first accumulator pack have a same accumulator cell type. Preferably the further accumulator pack has a plurality of accumulator cells which are formed overall analogously to one another, preferably the accumulator cells of the further accumulator pack have a same accumulator cell type. The accumulator cells of the first accumulator pack and/or of the further accumulator pack are, for example, of the type 18650, 20700, 26650, 26700 or of another type considered appropriate by a person skilled in the art. By "of the same kind" there is to be understood in this context in particular that the accumulator packs for an energy supply of a hand tool machine are interchangeable with one another and in particular have an at least substantially equal nominal voltage, a same interface unit, a same mechanical coding and/or at least substantially equal housing dimensions.

Preferably the first accumulator pack and the further accumulator pack have an equal number of receiving regions for accumulator cells. By an "active accumulator cell volume" there is to be understood in this context in particular a volume which is filled with at least one electrochemically active substance, in particular with an electrolyte. It is conceivable for the accumulator cells of the further accumulator cell type to have a smaller active accumulator cell volume than the accumulator cells of the first accumulator cell type. By an active accumulator cell volume of an accumulator pack there is to be understood in this context in particular a total of the active accumulator cell volume of the accumulator cells of the accumulator pack. By "provided" there is to be understood in this context, in particular, specially designed and/or equipped. By an object being provided for a specific function there is to be understood in particular that the object fulfils and/or performs this specific function in at least an application state and/or operating state. Preferably the further accumulator pack has, compared with the first accumulator pack, an at least 20% reduced accumulator cell volume, more preferably an at least 30-(= reduced accumulator cell volume, particularly preferably an at least 40(3 reduced accumulator cell volume and very particularly preferably an at least 50 reduced accumulator cell volume.

Further, it is proposed that the first accumulator pack has a number of accumulator cells and the further accumulator pack has a number of accumulator cells which is less than the number of accumulator cells of the first accumulator pack. As a result a particularly lightweight accumulator pack can be made available in a constructionally simple manner. A user convenience can be further increased. An accumulator pack with low costs for accumulator cells can be made available. Preferably the number of accumulator cells of the further accumulator pack is at least 20' less, more preferably at least 30% less, particularly preferably at least 40' less and very particularly preferably at least 50' less than the number of accumulator cells of the first accumulator pack. Preferably the accumulator cells in the first accumulator pack and in the further accumulator pack are arranged in layers. Preferably the layers have respectively an equal number of receiving regions for accumulator cells. Particularly preferably the further accumulator pack has an equal number of layers to the first accumulator pack. It is however also conceivable for the further accumulator pack to have a number of layers which differs from the number of layers of the first accumulator pack. Preferably a number of accumulator cells in a layer of the further accumulator pack differs by at most three, more preferably by at most two and particularly preferably by at most one from a number of accumulator cells in the other layers. It is conceivable for the further accumulator pack to have an empty layer. Preferably the further accumulator pack has at least one plane of symmetry arranged centrally with reference to a housing extent, on the sides of which plane a respectively equal number of accumulator cells are arranged, except for respectively a difference of at most three, preferably at most two and more preferably at most one.

In an advantageous configuration the number of accumulator cells of the further accumulator pack and the number of accumulator cells of the first accumulator pack have a common divisor different from one. As a result accumulator packs of the same kind can be made available in a constructionally particularly simple manner. Preferably the common divisor is a number between three and twelve, with three and twelve being included. More preferably the common divisor is a number between four and ten, with four and ten being included. Preferably the first accumulator pack has a plurality of groups connected in series which respectively comprise an equal number of accumulator cells connected in parallel which corresponds to a group size. Preferably the further accumulator pack has an equal number to the first accumulator pack of groups connected in series which respectively comprise an equal number of accumulator cells connected in parallel which corresponds to a further group size, and the number of groups corresponds to the common divisor. Preferably the further group size of the further accumulator pack is less the group size of the first accumulator pack.

Further, it is proposed that the further accumulator pack has a number of accumulator cells which corresponds to fourth fifths, three quarters, two thirds, half or one third of a number of accumulator cells of the first accumulator pack. As a result accumulator packs with equal nominal voltage can be made available in a constructionally particularly simple manner. Preferably the first accumulator pack has one degree of parallel connection, and the further accumulator pack has a further degree of parallel connection which corresponds to four fifths, three quarters, two thirds, half or one third of the degree of parallel connection of the first accumulator pack. By a "degree of parallel connection" there is to be understood in this context a factor by which a theoretical maximum nominal voltage of the accumulator, which corresponds to the sum of the nominal voltages of the accumulator cells, is reduced by means of parallel connection.

Further, it is proposed that the at least one accumulator cell of the further accumulator pack has a greater specific capacity than the at least one accumulator cell of the first accumulator pack. As a result a powerful accumulator pack with a reduced active accumulator cell volume can be made available. By a "specific capacity" there is to be understood in this context a maximum storable charge quantity by the accumulator cell with reference to a volume and/or a mass of the accumulator cell. Preferably the accumulator cells of the first accumulator cell type and the accumulator cells of the further accumulator cell type have different electrochemical cells. For example, the accumulator cells of the further accumulator cell type are formed as lithium-ion cells. Preferably the at least one accumulator cell of the further accumulator pack has a greater absolute capacity than the at least one accumulator cell of the first accumulator pack.

In an advantageous configuration the first accumulator pack and the further accumulator pack respectively have an at least dust-tight and/or water-tight housing. As a result a particularly robust first accumulator pack and a particularly robust further accumulator pack can be made available. By the phrase "at least dust-tight and/or water-tight" there is to be understood in this context in particular that the housing is provided to prevent a penetration of water, moisture and/or dust at least into a partial region, preferably into a storage region for storing accumulator cells.

In an advantageous manner the first accumulator pack and the further accumulator pack respectively have a display unit which is provided to display at least one operating parameter of the respective accumulator pack. As a result a particularly reliable operation and/or handling of the first accumulator pack and of the further accumulator pack can be achieved. An incorrect and/or improper operation can be effectively avoided. An accumulator pack with a particularly long service life can be made available. A user convenience can be further increased. By an "operating parameter" there is to be understood in this context in particular a technical quantity which describes a state of the accumulator pack or its environment, such as, for example, a temperature, a stage of charge, a load value, an activation state. Preferably the display unit has at least one display element for a visual, acoustic and/or haptic display of the at least one operating parameter of the accumulator pack.

Further, an accumulator pack of the system according to the invention having the reduced active accumulator cell volume is proposed. As a result housing elements of the same kind can be produced and/or used for a plurality of accumulator pack types. A particularly cost-effective accumulator pack can be made available. An accumulator pack particularly adapted for a specific application can be made available.

In an advantageous manner the accumulator pack comprises a plurality of receiving regions which are respectively provided for a reception of an accumulator cell and some of which are unoccupied at least in an operating state. As a result an accumulator pack with a reduced accumulator cell volume can be made available in a constructionally simple manner. Existing components can be advantageously used. A large number of shared components can be achieved, whereby low development costs and/or production costs can be achieved. A particularly reliable accumulator pack can be made available. By a "receiving region" there is to be understood in particular a region delimited by a cell holder of the accumulator pack which is provided to receive and to hold an accumulator cell. Preferably the cell holder is provided to receive exactly one accumulator cell. Preferably the cell holder has at least one bearing surface which is provided to come into contact with an outer side of the accumulator cell. Particularly preferably the bearing surface is provided for an extensive contact with an outer side of an accumulator cell. By "unoccupied" there is to be understood in this context in particular that at least one of the receiving regions is free from an accumulator cell. Preferably the accumulator pack has in at least an operating mode more receiving regions than accumulator cells. Preferably the cell holder is provided to make available a holding force which is substantially independent of an occupation of a neighbouring receiving region with an accumulator cell. Preferably the receiving regions are arranged in the accumulator pack in layers. Preferably each layer has an equal number of receiving regions. Preferably a number of unoccupied receiving regions in a layer of the accumulator pack differs by at most three, more preferably by at most two and particularly preferably by at most one from a number of unoccupied receiving regions in the other layers. It is conceivable for the accumulator pack to have a layer of unoccupied receiving regions. Preferably the accumulator pack has at least one plane of symmetry arranged centrally with reference to a housing extent, on the sides of which plane respectively an equal number of unoccupied receiving regions are arranged, except for a difference of at most three, preferably at most two and more preferably at most one.

In an advantageous configuration the accumulator pack comprises a number of occupied receiving regions and a number of unoccupied receiving regions which has a common divisor different from one with the number of occupied receiving regions. As a result a particularly simple electrical and/or geometrical construction of the accumulator pack can be achieved. Preferably the common divisor is a number between three and twelve, with three and twelve being included. More preferably the common divisor is a number between four and ten, with four and ten being included. Preferably the accumulator pack has a plurality of groups connected in series which respectively comprise an equal number of accumulator cells connected in parallel, and the number of groups corresponds to the same divisor.

Further, it is proposed that the accumulator pack has a total number of receiving regions and a number of occupied receiving regions which corresponds to four fifths, three quarters, two thirds, one half or one third of the total number of receiving regions. As a result contact means of the same kind can be produced and/or used for a plurality of accumulator pack types. A particularly efficient production process can be achieved. Preferably the accumulator pack has a total number of at least 6, more preferably of at least 10, particularly preferably of at least 20 and very particularly preferably of at least 30 receiving regions.

Further, it is proposed that in at least an operating state, some of the receiving regions are at least substantially filled by an electrical insulator and/or by at least one functional unit different from an accumulator cell. As a result an accumulator pack can be made available with particularly effective cooling. A heat load of the accumulator cells, for example during a charging process, can be reduced. A particularly long-life accumulator pack can be made available. A mechanically particularly stable accumulator pack can be made available. An accumulator pack with a large range of functions can be made available. By an "electrical insulator" there is to be understood in this context in particular an electrically non-conductive material, for example a gas, a gas mixture, preferably air or a plastics material. By a "functional unit" there is to be understood in this context in particular a unit which is provided to at least assist an operation of the accumulator pack. Preferably the functional unit is formed as a cooling unit or as part of a cooling unit, as a sensor, an electronic component and/or as a unit for an electromagnetic signal transmission and/or energy transmission.

The system according to the invention is not intended to be limited here to the above-described application and embodiment. In particular, the system according to the invention can have, for a fulfilling of a functioning described herein, a number of individual elements, components and units differing from a number mentioned herein.

Drawing Further advantages emerge from the following description of the drawing. An exemplary embodiment of the invention is represented in the drawing. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will consider the features expediently also individually and combine them to form useful further combinations.

In the drawing: Fig. 1 shows a system according to the invention with a first accumulator pack and a further accumulator pack in a perspective view, Fig. 2 shows a cross-section through the first accumulator pack of the system along a plane C-C perpendicular to a longitudinal extent of accumulator cells, through the further accumulator pack of the system along a plane D-D and Fig. 3 shows a longitudinal section through the first accumulator pack of the system along a plane A-A parallel to a longitudinal extent of accumulator cells and through the further accumulator pack of the system along a plane B-B and Fig. 4 shows the further accumulator pack coupled to a hand tool machine.

Description of the exemplary embodiments

Figure 1 shows a system 10 with a first accumulator pack 12 which has an accumulator cell 14 of a first accumulator cell type, an interface unit 16 for a detachable coupling to a hand tool machine (not shown specifically) and a nominal voltage, and a further accumulator pack 18 of the same kind, which has a same interface unit 22 as and an at least substantially equal nominal voltage to the first accumulator pack 12, an accumulator cell 20 of a further accumulator cell type different from the first accumulator type and a reduced active accumulator cell volume compared with the first accumulator pack 12.

The first accumulator pack 12 and the further accumulator pack 18 are respectively formed as a hand tool machine 30 accumulator pack. The first accumulator pack 12 and the further accumulator pack 18 are respectively provided to supply a hand tool machine, in particular a drive unit of a hand tool machine, with electrical energy. The first accumulator pack 12 and the further accumulator pack 18 respectively comprise a housing 24, 26 which receives a plurality of accumulator cells 14, 20 connected in parallel and/or in series. The housing 24 of the first accumulator pack 12 and the housing 26 of the further accumulator pack 18 have a same external form. The first accumulator pack 12 and the further accumulator pack 18 are at least partly produced according to a same method and/or with the same machines. The housing 24 of the first accumulator pack 12 and the housing 26 of the further accumulator pack 18 are respectively of substantially parallelepipedal form. The housings 24, 26 have equal housing dimensions. The housings 24, 26 respectively comprise a first housing element 42, 44 and a second housing element 46, 48. The first housing element 42, 44 is respectively formed as a cover element and the second housing element 46, 48 is respectively formed as a housing base body. The first accumulator pack 12 and the further accumulator pack 18 are respectively formed in the manner of a sliding accumulator pack in the embodiment variant shown.

The interface units 16, 22 of the first accumulator pack 12 and of the further accumulator pack 18 are respectively provided for detachable mechanical and electrical connection to a corresponding interface unit of the hand tool machine or of a charging set. The interface units 16, 22 of the first accumulator pack 12 and of the further accumulator pack 18 are formed analogously to one another, and therefore only the interface unit 22 of the further accumulator pack 18 is described below. The interface unit 22 comprises guide elements 50, 52 in the form of guide grooves which cooperate with corresponding guide elements in the form of guide ribs on the hand tool machine or the charging set. The interface unit 22 comprises mechanical coding elements which are provided to cooperate with corresponding elements on the hand tool machine. The interface unit 22 is arranged on the first housing element 42 formed as the cover element. The interface unit 22 further comprises contact elements for electrical contacting of the accumulator pack with the hand tool machine or the charging set. The contact elements are formed as voltage contact elements and serve as charging and/or discharging contact elements. The contact elements are formed as signal contact elements and serve for signal transmission from the accumulator pack 18 to the hand tool machine or the charging set and/or from the hand tool machine or the charging set to the accumulator pack 18.

Figure 2 shows a cross-section through the first accumulator pack 12 of the system 10 along a plane C-C perpendicular to a longitudinal extent of the accumulator cells and through the further accumulator pack 18 of the system 10 along a plane D-D. The first accumulator pack 12 and the further accumulator pack 18 respectively have a plurality of receiving regions 32, 34, 36, 38 which are respectively provided to respectively receive exactly one accumulator cell 14, 20 and fix it in the housing 24, 26. The receiving regions 32, 34, 36, 38 are respectively provided for receiving an at least substantially cylindrical accumulator cell 14, 20. The first accumulator pack 12 and the further accumulator pack 16 respectively comprise a plurality of cell holders which are provided to hold the accumulator cells 14, 20 in a form-fitting and force-fitting manner. The cell holders respectively have two bearing surfaces 54, 56, 58, 60. The bearing surfaces 54, 56, 58, 60 are respectively provided to be in contact with an outer side of the accumulator cells 14, 20. The bearing surfaces 54, 56, 58, 60 are provided for an extensive contact with the outer sides of the accumulator cells 14, 20. The bearing surfaces 54, 56, 58, 60 are of concave form. The receiving regions 32, 34, 36, 38 respectively have a longitudinal extent 62. The longitudinal extents 62 of the receiving regions 32, 34, 36, 38 are aligned parallel to one another. The first accumulator pack 12 and the further accumulator pack 18 have an equal number of receiving regions 32, 34, 36, 38. In the present exemplary embodiment the first accumulator pack 12 and the further accumulator pack 16 respectively have a number of 30 receiving regions. The receiving regions 32 of the first accumulator pack are formed analogously to one another. The receiving regions 34, 36, 36 of the further accumulator pack are formed analogously to one another. The receiving regions 32 of the first accumulator pack and the receiving regions 34, 36, 38 of the further accumulator pack are formed analogously to one another.

Figure 3 shows a longitudinal section through the first accumulator pack 12 of the system 10 along a plane A-A parallel to a longitudinal extent of the accumulator cells and through the further accumulator pack 18 of the system along a plane B-B. The first accumulator pack 12 and the further accumulator pack 18 in the present exemplary embodiment have layers 64-74, in which the receiving regions 32, 34, 36, 38 for the accumulator cells 14, 20 are arranged. The layers 67-74 are respectively arranged parallel to one another and parallel to a base 76, formed by the base body, of the respective accumulator pack 12, 18. The first accumulator pack 12 and the further accumulator pack 18 in the present exemplary embodiment have an equal number of layers 64-74, in which the receiving regions 32, 34, 36, 38 for the accumulator cells 14, 20 are arranged. The first accumulator pack 12 and the further accumulator pack 18 in the present exemplary embodiment have respectively three layers 64-74, in which the receiving regions 32, 34, 36, 38 for the accumulator cells 14, 20 are arranged. The layers 64-74 are arranged, with reference to a direction perpendicular to a layer plane, in a manner completely covering one another, one above another. Adjacent layers 64-74 are respectively separated from one another by a plane. In the present exemplary embodiment, the layers 64-74 respectively have an equal number of receiving regions 32, 34, 36, 38. The layers 64-74 respectively have 10 receiving regions 32, 34, 36, 38.

The first accumulator pack 12 and the further accumulator pack 18 respectively have two stacks 78, 80, 82, 84 of receiving regions 32, 34, 36, 38 for accumulator cells 14, 20. The stacks 78, 80, 82, 84 are arranged, with reference to the longitudinal extent 62 of the receiving regions 32, 34, 36, 38, one behind the other. The stacks 78, 80, 82, 84 are arranged, with reference to a direction of the longitudinal extent 62 of the receiving regions 32, 34, 36, 38, in a manner completely covering one another, one behind another. The base 76 of the base body is covered in an assembled state substantially in equal proportions by the stacks 78, 80, 82, 64.

The first accumulator pack 12 and the further accumulator pack la respectively have a cooling unit. The cooling units are formed analogously to one another, and therefore only the cooling unit of the further accumulator pack 16 is described below. The cooling unit is provided to dissipate heat from the accumulator cells 20 and to avoid an overheating of the accumulator cells 20, in particular during a charging process. The cooling unit has two heat radiating elements 86, 88. The two heat radiating elements 86, 88 delimit the accumulator pack 18 respectively on one side. The heat radiating elements 86, 88 are formed as aluminium bodies. The heat radiating elements 86, 88 respectively have cooling ribs on an outer side. The heat radiating elements 86, 88, the housing element 46, formed as the base body, and the housing element 44, formed as the cover element, are screwed to one another. Alternatively or additionally, the cooling unit could have further heat radiating elements, for example on the front side, on the rear side and/or on the lower side of the accumulator pack 18. The cooling unit further comprises four heat dissipating elements 90, 92. The heat dissipating elements 90, 92 are respectively arranged between two layers 64-74 of receiving regions 34, 36, 38 of accumulator cells 20.

The first accumulator pack 12 has a number of accumulator cells 14 and the further accumulator pack 18 has a number of accumulator cells 20 which is less than the number of accumulator cells 14 of the first accumulator pack 18. In the present exemplary embodiment the first accumulator pack 12 has a number of 30 accumulator cells 14 and the further accumulator pack 18 has a number of 20 accumulator cells 20. The further accumulator pack 18 has a mass which is approximately 30' less than a mass of the first accumulator pack 12. The first accumulator pack 12 and the further accumulator pack 18 in the present exemplary embodiment have an equal number of layers 64-74, in which the accumulator cells 14, 20 are arranged. The first accumulator pack 12 and the further accumulator pack 18 respectively have three layers 64-74 of accumulator cells 14, 20. The first accumulator pack 12 has in each layer 64, 68, 72 respectively ten accumulator cells 14. The first accumulator pack 12 has in each stack 78, 62 respectively 15 accumulator cells 14. The further accumulator pack 18 has, in a first layer 66 facing the cover element, seven accumulator cells 20, in a further layer 70 arranged in the middle, six accumulator cells 20 and in a third layer 74 facing the base 76, seven accumulator cells 20. In the present exemplary embodiment the numbers of accumulator cells 20 in the different layers 66, 70, 74 differ by one from one another.

The number of accumulator cells 20 of the further accumulator pack 16 and the number of accumulator cells 14 30 of the first accumulator pack 12 have a common divisor different from one. The number of accumulator cells 20 of the further accumulator pack 18 and the number of accumulator cells 14 of the first accumulator pack 12 have the common divisor ten. The number of accumulator cells 20 of the further accumulator pack 18 and the number of accumulator cells 14 of the first accumulator pack 12 have the common divisor five. The number of accumulator cells 20 of the further accumulator pack 18 and the number of accumulator cells 14 of the first accumulator pack 12 have the common divisor two. In the present exemplary embodiment the further accumulator pack 18 has a number of accumulator cells 20 which corresponds to two thirds of a number of accumulator cells 14 of the first accumulator pack.

In the present exemplary embodiment the first accumulator pack 12 has a number of ten groups of respectively three accumulator cells 14. The three accumulator cells 14 of a group are connected in parallel with one another. The groups are connected in series with one another. The first accumulator pack 12 has a nominal voltage of 36 volts. The accumulator pack 12 has a three-strand arrangement. The further accumulator pack 18 has 10 groups of respectively two accumulator cells 20. The two accumulator cells 20 of a group are connected in parallel with one another. The groups are connected in series. The further accumulator pack 18 has a nominal voltage of 36 volts. The further accumulator pack 18 has a two-strand arrangement. It is conceivable for the further accumulator pack 18 to have a number of ten accumulator cells 20 and be of single-strand form. The first accumulator pack 12 and the further accumulator pack 18 respectively have electrical contact means (not shown specifically) which are respectively provided to electrically connect the accumulator cells 14, 20 to one another. The contact means of the first accumulator pack 12 and the contact means of the further accumulator pack 18 are formed analogously to one another.

Alternatively, it is also conceivable for the first accumulator pack 12 and/or the further accumulator pack 16 to have a different connection arrangement, in which for example respectively ten accumulator cells are connected in series in a group and the groups are connected in parallel 10 with one another.

In the present exemplary embodiment the accumulator cells 14 of the first accumulator pack 12 are formed analogously to one another and have a same accumulator cell type. The accumulator cells 14 of the first accumulator pack 12 have a circular-cylindrical shape. The accumulator cells 14 of the first accumulator pack 12 have an equal diameter and an equal longitudinal extent. The accumulator cells 20 of the further accumulator pack 18 are formed analogously to one another and have a same accumulator cell type. The accumulator cells 20 of the further accumulator pack 18 have a circular-cylindrical shape. The accumulator cells 20 of the further accumulator pack 18 have an equal diameter and an equal longitudinal extent. The accumulator cells 20 of the further accumulator pack 16 have approximately the same diameter and approximately the same longitudinal extent as the accumulator cells 14 of the first accumulator pack 12. The accumulator cells 20 of the further accumulator pack 18 have a greater specific capacity than the accumulator cells 14 of the first accumulator pack 12. The accumulator cells 20 of the further accumulator pack 18 have a greater absolute capacity than the accumulator cells 14 of the first accumulator pack 12. The accumulator cells 14 of the first accumulator pack in the present exemplary embodiment respectively have a capacity of 2.0 Ah. The accumulator cells 20 of the further accumulator pack respectively have a capacity of 3.0 Ah. In the present exemplary embodiment the first accumulator pack 12 has a capacity of 6.0 Ah. The further accumulator pack 18 has a capacity of 6.0 Ah.

The first accumulator pack 12 and the further accumulator pack 18 respectively have a water-tight housing 24, 26. The housing 24 of the first accumulator pack 12 and the housing 26 of the further accumulator pack 18 respectively have a sealing unit. The sealing unit of the first accumulator pack 12 and the sealing unit of the further accumulator pack 18 are formed analogously to one another, and therefore only the sealing unit of the further accumulator pack 18 is described in more detail below. The sealing unit is provided to protect at least the receiving regions 34, 36, 38 from moisture and/or dust from an environment of the accumulator pack 18. The sealing unit has a sealing film 94, a first sealing means 96 and a second sealing means 98. The sealing film 94 is of tubular form. Alternatively, the sealing film 94 may be of bag-shaped form. The sealing film 94 is of self-shrinking form. The sealing film 94 lies against the front side, against the rear side and against both lateral sides on the stacks 80, 84.

The first sealing means 96 is formed as a sealing compound. The first sealing means 96 is provided to seal a gap between an inner housing element and the sealing film 94. The second sealing means 98 seals a lower side, facing away from the interface unit 22, of the sealing film 94. The second sealing means 96 is formed as a self-adhesive film.

The second sealing means 98 closes an opening, facing away from the interface unit 22, of the tubular sealing film 94. The sealing unit thus encloses the receiving regions 34, 36, 38 from five sides. The sixth side seals an electronics housing part of the accumulator pack 18.

The first accumulator pack 12 and the further accumulator pack 18 respectively have a display unit 28, 30 which is provided to display at least one operating parameter of the accumulator pack 12, 18. The display unit 28, 30 of the first accumulator pack 12 and of the further accumulator pack 18 are formed analogously to one another, and therefore only the display unit 30 of the further accumulator pack 18 is described below. In the present exemplary embodiment the display unit 30 is provided to display a state of charge and a temperature of the respective accumulator pack 18. The display unit 30 has a visual display element 100 for displaying a state of charge and a further visual display element 102 for displaying a temperature of the accumulator cells 20. In the present exemplary embodiment the display element 100 for displaying the state of charge is provided for displaying four different charging steps. The display element 102 for displaying the temperature is provided for displaying a non-critical and a critical temperature range. The display unit 30 is arranged on an oblique surface of the housing element 44 formed as the cover element.

The further accumulator pack 18 has a plurality of receiving regions 34, 36, 38 which are respectively provided for receiving an accumulator cell 20 and some of which are unoccupied at least in an operating state. In the present exemplary embodiment, 20 of the receiving regions 34 are occupied and 10 of the receiving regions 36, 38 are unoccupied. The further accumulator pack 18 has a number of occupied receiving regions 34 and a number of unoccupied receiving regions 36, 38 which has a common divisor different from one with the number of occupied receiving regions 34. The number of occupied receiving regions 34 and the number of unoccupied receiving regions 36, 38 have the common divisor ten. The number of occupied receiving regions 34 and the number of unoccupied receiving regions 36, 38 have the common divisor five. The number of occupied receiving regions 34 and the number of unoccupied receiving regions 36, 38 have the common divisor two. The further accumulator pack 18 has a total number of receiving regions 34, 36, 38 and a number of occupied receiving regions 34 which corresponds to two thirds of the total number of receiving regions 34.

Some of the receiving regions 36 of the further accumulator pack 18 are filled by an electrical insulator. Some of the receiving regions 36 of the further accumulator pack 18 are filled with air. Some of the receiving regions 36 of the further accumulator pack 18 are provided to have air flowing through them and to cool the accumulator cells 20 of the accumulator pack 18, in an operating state of the accumulator pack 18. Some of the receiving regions 38 of the further accumulator pack 18 have functional units 40. The functional units 40 in the present exemplary embodiment are formed as temperature sensors. The temperature sensors are formed as temperature-dependent resistors. It is conceivable for the functional units 40 to be formed as parts of the cooling unit and, for example, to be provided to conduct and/or temporarily store heat.

Figure 4 shows the further accumulator pack 18 coupled to a hand tool machine 104. Analogously the first accumulator pack 12 can also be coupled to the hand tool machine 104. The hand tool machine 104 in the present exemplary embodiment is formed as a cordless screwdriver. The hand tool machine 104 comprises an electric drive unit which has an electric motor. The hand tool machine 104 further comprises a tool receptacle 106 for receiving an insertion tool, such as, for example, a screwdriver blade, a drill or a stirrer. The drive unit is provided for a rotatory drive of the tool receptacle 106.

The hand tool machine 104 comprises a switching unit which is provided to switch the hand tool machine 104 on and/or off and/or to set a rotational speed and/or a torque. The switching unit has an operating element 108 which is provided for an actuation by a user. The operating element 108 is formed as a push switch. The hand tool machine 104 comprises a torque limitation which is provided to set a maximum torque transmitted by the drive unit to the tool receptacle 106. The torque limitation comprises a setting ring 110 which is provided for an operation by the user.

The hand tool machine 104 comprises a gear speed change which is provided to set a gear speed. The gear speed change has an operating element 112 which is provided for an operation by the user. The operating element 112 in the present exemplary embodiment is formed as a sliding element. The hand tool machine 104 is provided for an energy supply by the further accumulator pack 18 or alternatively by the first accumulator pack 12. The hand tool machine 104 has an accumulator interface unit for the further accumulator pack 18 or for the first accumulator pack 10. The accumulator interface unit for the further accumulator pack 18 or for the first accumulator pack 12 is arranged at one end of a handle 114 of the hand tool machine 104. The further accumulator pack 18 is provided for an energy supply of the electric drive unit of the hand tool machine 104.

Claims (14)

1. Claims 1. System with a first accumulator pack (12), in particular a hand tool machine accumulator pack and/or a house appliance accumulator pack, which has at least one accumulator cell (14) of a first accumulator cell type, an interface unit (16) for a detachable coupling to a hand tool machine and a nominal voltage, and a further accumulator pack (18) of the same kind, which has at least a same interface unit (22) as and an at least substantially equal nominal voltage to the first accumulator pack (12), at least one accumulator cell (20) of a further accumulator cell type different from the first accumulator type and a reduced active accumulator cell volume compared with the first accumulator pack (12).
2. 2. System according to Claim 1, characterised in that the first accumulator pack (12) has a number of accumulator cells (14) and the further accumulator pack (18) has a number of accumulator cells (20) which is less than the number of accumulator cells (14) of the first accumulator pack (12).
3. 3. System according to Claim 1 or 2, characterised in that the number of accumulator cells (20) of the further accumulator pack (18) and the number of accumulator cells (14) of the first accumulator pack (12) have a common divisor different from one.
4. 4 System according to one of the preceding claims, characterised in that the further accumulator pack (18) has a number of accumulator cells (20) which corresponds to fourth fifths, three quarters, two thirds, half or one third of a number of accumulator cells (14) of the first accumulator pack (12).
5. 5. System according to one of the preceding claims, characterised in that the at least one accumulator cell (20) of the further accumulator pack (18) has a greater specific capacity than the at least one accumulator cell (14) of the first accumulator pack (12).
6. 6. System according to one of the preceding claims, characterised in that the first accumulator pack (12) and the further accumulator pack (18) respectively have an at least dust-tight and/or water-tight housing (24, 26).
7. 7 System according to one of the preceding claims, characterised in that the first accumulator pack (12) and the further accumulator pack (18) respectively have a display unit (28, 30) which is provided to display at least one operating parameter of the respective accumulator pack (12, 18).
8. 8. Accumulator pack of the system according to one of the preceding claims having the reduced active accumulator cell volume.
9. 9. Accumulator pack according to Claim 6, characterised by a plurality of receiving regions (34, 36, 38) which are respectively provided for a reception of an accumulator cell (20) and some of which are unoccupied at least in an operating state.
10. 10. Accumulator pack according to Claim 9, characterised by a number of occupied receiving regions (34) and a number of unoccupied receiving regions (36) which has a common divisor different from one with the number of occupied receiving regions (34).
11. 11. Accumulator pack at least according to Claim 9, characterised by a total number of receiving regions (34, 36, 38) and a number of occupied receiving regions (34) which corresponds to four fifths, three quarters, two thirds, one half or one third of the total number of receiving regions (34, 36, 38).
12. 12. Accumulator pack at least according to Claim 9, characterised in that, in at least an operating state, some of the receiving regions (36) are at least substantially filled by an electrical insulator and/or by at least one functional unit (40) different from an accumulator cell.
13. 13. A system as hereinbefore described with reference to and as shown in the accompanying drawings.
14. 14. An accumulator pack as hereinbefore described with reference to and as shown in the accompanying drawings.