Battery packs, tool systems and charging systems

Abstract

The present invention provides a battery pack, a tool system and a charging system. The battery pack includes a shell, a battery pack contained in the shell, and a terminal assembly electrically connected to the battery pack. The battery pack also includes a conversion assembly electrically connected to the battery pack. The conversion assembly is slidably arranged, and when the conversion assembly is in a first position, the battery pack outputs a first voltage value; when the conversion assembly slides to a second position, the battery pack outputs a second voltage value; when the conversion assembly slides to a third position, the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value. Compared with the prior art, the battery pack of the present invention realizes the series-parallel state switching of each battery cell module in the battery pack by controlling the sliding position of the conversion assembly, thereby realizing the change of the output voltage of the battery pack, thereby improving the adaptability of the tool system having the battery pack.

Description

Technical Field

[0001] The present invention relates to the technical field of battery packs, and in particular to a battery pack, a tool system and a charging system. Background Art

[0002] In the garden machinery and power tool industries, tools with different rated voltages usually need to be powered by battery packs with different rated voltages, which results in an increase in the types of battery packs and an increase in costs.

[0003] In view of this, it is indeed necessary to design an improved battery pack, tool system and charging system to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a battery pack, a tool system and a charging system that can achieve quick switching and three voltage outputs.

[0005] To achieve the above-mentioned purpose, the present invention provides a battery pack, comprising a shell, a battery pack accommodated in the shell, and a terminal assembly electrically connected to the battery pack, the battery pack comprising at least a first battery cell module, a second battery cell module, a third battery cell module and a fourth battery cell module, the battery pack further comprising a conversion assembly electrically connected to the battery cell module, the conversion assembly being slidably arranged, and when the conversion assembly is in a first position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in parallel with each other, and the battery pack outputs a first voltage value; when the conversion assembly slides to a second position When the conversion component is in the third position, the positive electrode of the first battery cell module is connected to the positive electrode of the second battery cell module, the negative electrode of the first battery cell module is connected to the negative electrode of the second battery cell module, and then to the positive electrode of the third battery cell module and the positive electrode of the fourth battery cell module, and the negative electrode of the third battery cell module is connected to the negative electrode of the fourth battery cell module, and the battery pack outputs a second voltage value; when the conversion component slides to the third position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in series, and the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value.

[0006] As a further improvement of the present invention, the conversion assembly includes a first connecting assembly, a second connecting assembly and a third connecting assembly corresponding to the terminal assembly and arranged at intervals. When the conversion assembly is in the first position, the terminal assembly is electrically connected to the first connecting assembly. When the conversion assembly slides to the second position, the terminal assembly is electrically connected to the second connecting assembly. When the conversion assembly slides to the third position, the terminal assembly is electrically connected to the third connecting assembly.

[0007] As a further improvement of the present invention, the first connecting component includes a first positive connecting plate and a first negative connecting plate, the first positive connecting plate has four positive pins, respectively connected to the positive electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module; the first negative connecting plate has four negative pins, respectively connected to the negative electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

[0008] As a further improvement of the present invention, the second connecting component includes a second positive electrode connecting plate connecting the positive electrode of the first battery cell module with the positive electrode of the second battery cell module, a fourth connecting plate respectively connected to the positive electrode of the third battery cell module, the positive electrode of the fourth battery cell module, the negative electrode of the first battery cell module and the negative electrode of the second battery cell module, and a second negative electrode connecting plate connecting the negative electrode of the third battery cell module with the negative electrode of the fourth battery cell module.

[0009] As a further improvement of the present invention, the third connecting component includes a first connecting plate connecting the positive electrode of the second battery cell module with the negative electrode of the first battery cell module, a second connecting piece connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, and a third connecting piece connecting the positive electrode of the fourth battery cell module with the negative electrode of the third battery cell module, so as to realize the series connection of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

[0010] As a further improvement of the present invention, the conversion assembly includes an electrode plug seat and an internal plug seat, the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat, and the first connection assembly, the second connection assembly and the third connection assembly are all integrally formed on the internal plug seat.

[0011] As a further improvement of the present invention, the internal insert seat is slidably arranged, and the first connecting component, the second connecting component and the third connecting component are spaced apart along the sliding direction of the internal insert seat.

[0012] As a further improvement of the present invention, the conversion component also includes a pushing portion for pushing the internal insert seat to slide, the third connecting component is closer to the pushing portion than the second connecting component, and the first connecting component is farther away from the pushing portion than the second connecting component.

[0013] As a further improvement of the present invention, the internal plug seat includes a base and a spring structure abutting against the base, the first connecting component, the second connecting component and the third connecting component are integrally formed with the base, and the spring structure is compressed or released when the internal plug seat slides, so that the terminal assembly can be switchably connected between the first connecting component, the second connecting component and the third connecting component.

[0014] As a further improvement of the present invention, the electrode plug seat is provided with a accommodating cavity, and the terminal assembly and the internal plug seat are both accommodated in the accommodating cavity. The base is provided with a slide rail protruding toward one side of the electrode plug seat, and the electrode plug seat is correspondingly provided with a through groove, and the slide rail is accommodated in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

[0015] To achieve the above-mentioned purpose, the present invention further provides a battery pack, comprising a shell, a battery pack contained in the shell, and a terminal assembly electrically connected to the battery pack, wherein the battery pack comprises at least a first battery cell module, a second battery cell module, a third battery cell module, and a fourth battery cell module, and the battery pack further comprises a conversion assembly electrically connected to the battery cell module, wherein the conversion assembly is slidably arranged, and when the conversion assembly is in a first position, the first battery cell module, the second battery cell module, the third battery cell module, and the fourth battery cell module are connected in parallel with each other, and the battery pack outputs a first voltage value; when the conversion assembly slides to a second position, the first battery cell module, the second battery cell module, the third battery cell module, and the fourth battery cell module are connected in parallel with each other, and the battery pack outputs a first voltage value; when the conversion assembly slides to a second position, the first battery cell module, the second battery cell module, the third battery cell module, and the fourth battery cell module are connected in parallel with each other, and the battery pack outputs a first voltage value. position, the positive electrode of the first battery cell module is connected to the positive electrode of the second battery cell module, the negative electrode of the first battery cell module is connected to the positive electrode of the fourth battery cell module, the negative electrode of the second battery cell module is connected to the positive electrode of the third battery cell module, and the negative electrode of the third battery cell module is connected to the negative electrode of the fourth battery cell module, and the battery pack outputs a second voltage value; when the conversion component slides to the third position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in series, and the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value.

[0016] As a further improvement of the present invention, the conversion assembly includes a first connecting assembly, a second connecting assembly and a third connecting assembly corresponding to the terminal assembly and arranged at intervals. When the conversion assembly is in the first position, the terminal assembly is electrically connected to the first connecting assembly. When the conversion assembly slides to the second position, the terminal assembly is electrically connected to the second connecting assembly. When the conversion assembly slides to the third position, the terminal assembly is electrically connected to the third connecting assembly.

[0017] As a further improvement of the present invention, the first connecting component includes a first positive connecting plate and a first negative connecting plate, the first positive connecting plate has four positive pins, respectively connected to the positive electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module; the first negative connecting plate has four negative pins, respectively connected to the negative electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

[0018] As a further improvement of the present invention, the second connecting component includes a second positive electrode connecting plate connecting the positive electrode of the first battery cell module with the positive electrode of the second battery cell module, a fifth connecting plate connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, a sixth connecting plate connecting the positive electrode of the fourth battery cell module with the negative electrode of the first battery cell module, and a second negative electrode connecting plate connecting the negative electrode of the third battery cell module with the negative electrode of the fourth battery cell module.

[0019] As a further improvement of the present invention, the third connecting component includes a first connecting plate connecting the positive electrode of the second battery cell module with the negative electrode of the first battery cell module, a second connecting piece connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, and a third connecting piece connecting the positive electrode of the fourth battery cell module with the negative electrode of the third battery cell module, so as to realize the series connection of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

[0020] As a further improvement of the present invention, the conversion assembly includes an electrode plug seat and an internal plug seat, the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat, and the first connection assembly, the second connection assembly and the third connection assembly are all integrally formed on the internal plug seat.

[0021] As a further improvement of the present invention, the internal insert seat is slidably arranged, and the first connecting component, the second connecting component and the third connecting component are spaced apart along the sliding direction of the internal insert seat.

[0022] As a further improvement of the present invention, the conversion component also includes a pushing portion for pushing the internal insert seat to slide, the third connecting component is closer to the pushing portion than the second connecting component, and the first connecting component is farther away from the pushing portion than the second connecting component.

[0023] As a further improvement of the present invention, the internal plug seat includes a base and a spring structure abutting against the base, the first connecting component, the second connecting component and the third connecting component are integrally formed with the base, and the spring structure is compressed or released when the internal plug seat slides, so that the terminal assembly can be switchably connected between the first connecting component, the second connecting component and the third connecting component.

[0024] As a further improvement of the present invention, the electrode plug seat is provided with a accommodating cavity, and the terminal assembly and the internal plug seat are both accommodated in the accommodating cavity. The base is provided with a slide rail protruding toward one side of the electrode plug seat, and the electrode plug seat is correspondingly provided with a through groove, and the slide rail is accommodated in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

[0025] To achieve the above object, the present invention provides a tool system, comprising:

[0026] A battery pack, the battery pack comprising a housing, a battery pack contained in the housing, and a terminal assembly and a conversion assembly electrically connected to the battery pack, the conversion assembly being slidably arranged;

[0027] a first electric tool, the first electric tool being capable of operating at a first rated voltage, the first electric tool being provided with a first external plug socket;

[0028] a second electric tool capable of operating at a second rated voltage, the second electric tool being provided with a second external plug socket;

[0029] a third electric tool, the third electric tool being capable of operating at a third rated voltage and being provided with a third external plug socket;

[0030] When the battery pack is connected to the first external plug socket of the first electric tool, the conversion component is located at the first position, and the battery pack outputs a first voltage value;

[0031] When the battery pack is connected to the second external plug socket of the second electric tool, the conversion assembly slides to the second position, and the battery pack outputs a second voltage value;

[0032] When the battery pack is connected to the third external plug socket of the third electric tool, the conversion assembly slides to a third position, and the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value.

[0033] As a further improvement of the present invention, the first voltage value is "n"V, the second voltage value is "2n"V, and the third voltage value is "4n"V.

[0034] As a further improvement of the present invention, the conversion assembly includes an electrode plug seat and an internal plug seat, the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat, and the internal plug seat is slidably arranged.

[0035] As a further improvement of the present invention, the electrode plug seat is provided with a accommodating cavity, the terminal assembly and the internal plug seat are both accommodated in the accommodating cavity, the internal plug seat is provided with a slide rail protruding toward one side of the electrode plug seat, and the electrode plug seat is correspondingly provided with a through groove, and the slide rail is accommodated in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

[0036] As a further improvement of the present invention, the conversion assembly further includes a push rod for pushing the internal insert seat to slide, and the push rod is integrally formed with the external insert seat.

[0037] As a further improvement of the present invention, the length of the push rod on the first external plug-in seat is smaller than the length of the push rod on the second external plug-in seat, and the length of the push rod on the second external plug-in seat is smaller than the length of the push rod on the third external plug-in seat.

[0038] To achieve the above object, the present invention further provides a charging system, comprising:

[0039] A battery pack, the battery pack comprising a shell, a battery pack contained in the shell, and a terminal assembly and a conversion assembly electrically connected to the battery pack, the battery pack comprising at least a first battery cell module, a second battery cell module, a third battery cell module and a fourth battery cell module, the conversion assembly being slidably arranged, and when the conversion assembly is in a first position, the battery pack outputs a first voltage value; when the conversion assembly slides to a second position, the battery pack outputs a second voltage value; when the conversion assembly slides to a third position, the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value;

[0040] A charger is used to charge the battery pack. When the charger is docked with the battery pack for charging, the conversion component is located in a first position, and the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in parallel.

[0041] The beneficial effect of the present invention is that the battery pack of the present invention realizes the series-parallel state switching of each battery cell module in the battery pack by controlling the sliding position of the conversion component, and then realizes the change of the output voltage of the battery pack, thereby improving the adaptability of the tool system with the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a three-dimensional diagram of the tool system of the present invention.

[0043] Figure 2 yes Figure 1 Exploded view of tool system shown.

[0044] Figure 3 yes Figure 2 Exploded view of the conversion assembly.

[0045] Figure 4 yes Figure 1 A partially assembled stereoscopic view of the tool system shown.

[0046] Figure 5 yes Figure 3 Schematic diagram of the structure of the internal plug-in seat.

[0047] Figure 6 yes Figure 5 Another perspective structural schematic diagram of the internal insert seat is shown.

[0048] Figure 7 yes Figure 5 Schematic diagram of the structure after removing the base of the internal insert seat.

[0049] Figure 8 yes Figure 3 Schematic diagram of the structure of the middle terminal assembly.

[0050] Fig. 9 yes Figure 3 Schematic diagram of the structure of the middle electrode plug holder.

[0051] Fig.10 yes Figure 3 A three-dimensional exploded view of the first external plug-in seat.

[0052] Fig.11 yes Fig.10 The structure diagram shown is a schematic diagram of the terminal assembly being connected to the first connecting assembly after the first external plug-in seat is inserted.

[0053] Fig.12 yes Fig.10 The diagram shows the circuit connection status in the battery pack after the first external plug-in socket is inserted.

[0054] Fig.13 yes Fig.10 The connection circuit diagram of the battery pack after the first external plug-in socket is inserted is shown.

[0055] Fig.14 It is a three-dimensional exploded view of the second external plug-in socket.

[0056] Fig.15 yes Fig.14 The structure diagram shown is a schematic diagram of the connection between the terminal assembly and the second connecting assembly after the second external plug-in seat is inserted.

[0057] Fig.16 yes Fig.14 The diagram shows the circuit connection status in the battery pack after the second external plug-in socket is inserted.

[0058] Fig.17 yes Fig.14 The connection circuit diagram of the battery pack after the second external plug-in socket is inserted is shown.

[0059] Fig.18 yes Figure 7 Another embodiment of the second connecting component.

[0060] Fig.19 yes Fig.14 After the second external blade seat is inserted, the terminal assembly is connected with Fig.18 The structural schematic diagram of the second connecting component when connected is shown.

[0061] Fig. 20 is corresponding to Fig.19 Schematic diagram of the circuit connection status inside the battery pack.

[0062] Fig.21 is corresponding to Fig.19 The connection circuit diagram of the battery pack.

[0063] Fig. 22 It is a three-dimensional exploded view of the third external plug-in socket.

[0064] Fig.23 yes Fig. 22 The structure diagram shown is a schematic diagram of the connection between the terminal assembly and the third connecting assembly after the third external plug-in seat is inserted.

[0065] Fig.24 yes Fig. 22 The diagram shows the circuit connection status in the battery pack after the third external plug-in socket is inserted.

[0066] Fig.25 yes Fig. 22 The connection circuit diagram of the battery pack after the third external plug-in socket is inserted is shown. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0068] like Figures 1 to 3 As shown, the present invention discloses a battery pack, including a shell 10 and a battery pack 20 housed in the shell 10, a PCB board 30, and a conversion assembly 40 and a terminal assembly 42 electrically connected to the battery pack 20. The battery pack 20 includes a plurality of battery cell modules, and the conversion assembly 40 is electrically connected to the battery cell modules. The conversion assembly 40 includes an electrode plug seat 41 and an internal plug seat 43 arranged opposite to the terminal assembly 42. In the present invention, the terminal assembly 42 is preferably a female terminal assembly, but it should not be limited to this. The battery pack of the present invention is used on a tool system, which also includes an external plug seat 50 that can be inserted into the battery pack to dock with the female terminal assembly 42 of the battery pack.

[0069] like Figure 4 and Figure 8 Combined with Figure 2 and Figure 3As shown, the electrode plug seat 41 is provided with a receiving cavity 411, and the female terminal assembly 42 and the internal plug seat 43 are both received in the receiving cavity 411, and the female terminal assembly 42 is electrically connected to the electrode of the battery module through the PCB board 30. Specifically, the female terminal assembly 42 includes a positive terminal 421 and a negative terminal 422, wherein the positive terminal 421 includes a first positive terminal 423 and a second positive terminal 424, the first positive terminal 423 is connected to the external plug seat 50 as a total positive output terminal, and the second positive terminal 424 is electrically connected to the positive electrode of the corresponding battery module; the negative terminal 422 also includes a first negative terminal 425 and a second negative terminal 426, the first negative terminal 425 is connected to the external plug seat 50 as a total negative output terminal, and the second negative terminal 426 is electrically connected to the negative electrode of the corresponding battery module, so as to realize the output of the voltage in the battery pack.

[0070] In this embodiment, the first positive terminal 423 and the first negative terminal 425 are arranged near one end of the electrode plug seat 41, the second positive terminal 424 and the second negative terminal 426 are approximately located in the middle of the electrode plug seat 41, and the second positive terminal 424 and the second negative terminal 426 are arranged left and right in a straight line. The battery pack 20 includes at least four battery modules, namely the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24; correspondingly, the first positive terminal 423 is connected to the positive electrode of the first battery module 21, and the first negative terminal 425 is connected to the negative electrode of the fourth battery module 24; the second positive terminal 424 and the second negative terminal 426 are each provided with four, and are arranged in a ++++---- manner from right to left to be connected to the four battery modules respectively.

[0071] Each battery module is provided with a plurality of battery cells, which can be connected in series or in parallel, and will not be described in detail here. Assume that the rated output voltage of each battery module is "n" V, that is, the rated output voltage u1 of the first battery module 21 = the rated output voltage u2 of the second battery module 22 = the rated output voltage u3 of the third battery module 23 = the rated output voltage u4 of the fourth battery module 24 = "n" V.

[0072] The conversion component 40 is slidably arranged. When the conversion component 40 is located at the first position, the first battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24 are connected in parallel, and the battery pack outputs a first voltage value; when the conversion component 40 slides to the second position, the positive electrode of the first battery cell module 21 is connected to the positive electrode of the second battery cell module 22, the negative electrode of the first battery cell module 21 is connected to the negative electrode of the second battery cell module 22, and then connected to the positive electrode of the third battery cell module 23 and the positive electrode of the fourth battery cell module 24, and the negative electrode of the third battery cell module 23 is connected to the negative electrode of the fourth battery cell module 24, and the battery pack outputs a second voltage value; when the conversion component 40 slides to the third position, the first battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24 are connected in series, and the battery pack outputs a third voltage value. The first voltage value is smaller than the second voltage value, and the second voltage value is smaller than the third voltage value.

[0073] like Figures 5 to 8 Combined with Figure 3 and Figure 4 As shown, the internal plug seat 43 is provided with a first connecting component 44, a second connecting component 45 and a third connecting component 46 corresponding to the female terminal component 42 and arranged at intervals. The internal plug seat 43 is slidably arranged, and when it is located at the first position, the female terminal component 42 is electrically connected to the first connecting component 44, when it slides to the second position, the female terminal component 42 is electrically connected to the second connecting component 45, and when it slides to the third position, the female terminal component 42 is electrically connected to the third connecting component 46.

[0074] The first connecting component 44, the second connecting component 45 and the third connecting component 46 are arranged at intervals along the sliding direction (up and down direction) of the internal plug-in seat 43. When the female terminal component 42 is electrically connected to the first connecting component 44, the first battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24 are connected in parallel with each other. At this time, the first voltage value output by the battery pack is "n" V; when the female terminal component 42 is electrically connected to the second connecting component 45, the first The battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24 are connected in series and parallel (i.e., first connected in series and then connected in parallel or first connected in parallel and then connected in series), and the second voltage value output by the battery pack is "2n" V; when the female terminal assembly 42 is electrically connected to the third connecting assembly 46, the first battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24 are connected in series with each other, and the third voltage value output by the battery pack is "4n" V.

[0075] Specifically, the first connection component 44 includes a first positive electrode connection sheet 441 and a first negative electrode connection sheet 442. The first positive electrode connection sheet 441 has four positive pins, which are respectively connected to the positive electrodes of the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24; the first negative electrode connection sheet 442 has four negative pins, which are respectively connected to the negative electrodes of the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24. In this design, the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24 are connected in parallel with each other, and the first voltage value "n" V is equal to the rated output voltage of each battery module.

[0076] The second connection component 45 includes a second positive electrode connecting piece 451 connecting the positive electrode of the first battery cell module 21 with the positive electrode of the second battery cell module 22, a fourth connecting piece 452 connected to the positive electrode of the third battery cell module 23, the positive electrode of the fourth battery cell module 24, the negative electrode of the first battery cell module 21 and the negative electrode of the second battery cell module 22, and a second negative electrode connecting piece 453 connecting the negative electrode of the third battery cell module 23 with the negative electrode of the fourth battery cell module 24. With such a design, a connection mode can be formed in which the first battery cell module 21 is connected in parallel with the second battery cell module 22, the third battery cell module 23 is connected in parallel with the fourth battery cell module 24, and then connected in series (i.e., first in parallel and then in series), at which time the second voltage value "2n" V is equal to the sum of the rated output voltages of the two battery cell modules.

[0077] The third connecting component 46 includes a first connecting piece 461 connecting the positive electrode of the second battery cell module 22 with the negative electrode of the first battery cell module 21, a second connecting piece 462 connecting the positive electrode of the third battery cell module 23 with the negative electrode of the second battery cell module 22, and a third connecting piece 463 connecting the positive electrode of the fourth battery cell module 24 with the negative electrode of the third battery cell module 23, so as to realize the series connection of the first battery cell module 21, the second battery cell module 22, the third battery cell module 23 and the fourth battery cell module 24. At this time, the third voltage value "4n" V is equal to the sum of the rated output voltages of the four battery modules.

[0078] The internal plug seat 43 includes a base 431 and a spring structure 432 abutting against the base 431. The first connecting component 44, the second connecting component 45 and the third connecting component 46 are integrally formed with the base 431. The base 431 is provided with a rib 433 and a slide groove 434 located on both sides of the rib 433. The first connecting component 44, the second connecting component 45 and the third connecting component 46 are formed and exposed on the rib 433. The two contact pieces 427 of each terminal of the second positive terminal 424 and the second negative terminal 426 are both accommodated in the slide groove 434 and clamp the rib 433, so that when the internal plug seat 43 slides, it can be ensured that the second positive terminal 424 and the second negative terminal 426 always slide in the slide groove 434 and maintain a state of clamping and abutting against the rib 433.

[0079] like Figure 5 , Figure 6 and Fig. 9 Combined with Figure 4 As shown, the base 431 is provided with a receiving portion 435 extending outward, and a positioning column 412 is provided on the inner side wall of the electrode plug seat 41. One end of the spring structure 432 is sleeved on the outer periphery of the positioning column 412, and the other end abuts against the inner wall of the receiving portion 435. When the internal plug seat 43 slides, the spring structure 432 is compressed or released, so that the female terminal assembly 42 is switchably connected between the first connection assembly 44, the second connection assembly 45 and the third connection assembly 46.

[0080] The base 431 is also provided with a slide rail 436 protruding toward one side of the electrode plug seat 41. The electrode plug seat 41 is correspondingly provided with a through slot 413. The slide rail 436 is received in the through slot 413 so as to guide the internal plug seat 43 to slide along the through slot 413 in the electrode plug seat 41. The number and location of the slide rails 436 and through slots 413 can be determined according to actual conditions and are not limited here. A push portion 437 is formed on the side of the base 431 away from the receiving portion 435. The slide rail 436 is arranged on the push portion 437. The push portion 437 can be used to push the internal plug seat 43 to slide. The third connecting component 46 is closer to the push portion 437 than the second connecting component 45, and the first connecting component 44 is farther away from the push portion 437 than the second connecting component 45.

[0081] The conversion assembly 40 further includes a push rod for further pushing the internal plug seat 43 to slide, the third connection assembly 46 is closer to the push rod than the second connection assembly 45, and the first connection assembly 44 is farther away from the push rod than the second connection assembly 45. The push rod can be integrally formed with the base 431, or integrally formed with the external plug seat 50, so that when the external plug seat 50 is inserted, the push rod can be used to force the internal plug seat 43 to slide, thereby electrically connecting the female terminal assembly 42 to the first connection assembly 44, the second connection assembly 45, or the third connection assembly 46.

[0082] When the push rod is formed on the external plug-in seat 50, the external plug-in seat 50 can be set as three separate external plug-in seats according to the different lengths of the push rod, or push rods of different lengths can be set on one external plug-in seat, and different configurations can be achieved by switching push rods of different lengths. For the convenience of description, the tool system is defined to include a first electric tool, a second electric tool and a third electric tool. The first electric tool is provided with a first external plug-in seat and can operate at a first rated voltage; the second electric tool is provided with a second external plug-in seat and can operate at a second rated voltage; the third electric tool is provided with a third external plug-in seat and can operate at a third rated voltage. The following will use these three separate external plug-in seats to describe in detail the use principle of the tool system of the present invention.

[0083] The external plug-in seat 50 includes a first external plug-in seat 51, a second external plug-in seat 52 and a third external plug-in seat 53, and the length of the push rod on the first external plug-in seat 51 is smaller than the length of the push rod 47 on the second external plug-in seat 52, and the length of the push rod 47 on the second external plug-in seat 52 is smaller than the length of the push rod 47' on the third external plug-in seat 53.

[0084] like Figure 8 and Fig.10 As shown, the first external plug-in seat 51 includes a body 511 and a male terminal 512 plugged into the body 511, and the length of the push rod on the body 511 is zero. The male terminal 512 includes a positive male terminal 513 and a negative male terminal 514, the positive male terminal 513 is used to dock with the first positive terminal 423, and the negative male terminal 514 is used to dock with the first negative terminal 425, so as to achieve electrical conduction between the battery pack female terminal assembly 42 and the male terminal 512 of the first external plug-in seat 51, and realize the transmission of current and voltage.

[0085] like Figures 11 to 13As shown, when the first external plug-in seat 51 is inserted, the positive male terminal 513 is connected to the first positive terminal 423, the negative male terminal 514 is connected to the first negative terminal 425, and the internal plug-in seat 43 is in the first position (i.e., located at the bottom position of the electrode plug-in seat 41). At this time, the female terminal assembly 42 is electrically connected to the first connecting assembly 44, and the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24 are connected in parallel. According to the principle of "parallel voltage division and series current division", the first voltage value output by the battery pack is equal to the rated output voltage of each battery module, that is, U = u1 = u2 = u3 = u4 = "n" V.

[0086] like Fig.14 As shown, the second external plug-in seat 52 includes a main body 521 and a male terminal 522 plugged into the main body 521, the male terminal 522 includes a positive male terminal 523 and a negative male terminal 524, the positive male terminal 523 is used to dock with the first positive terminal 423, and the negative male terminal 524 is used to dock with the first negative terminal 425, so as to achieve electrical conduction between the battery pack female terminal assembly 42 and the male terminal 522 of the second external plug-in seat 52, and realize the transmission of current and voltage.

[0087] and Fig.10 The difference between the first external insert seat 51 shown is that a push rod 47 is provided on the main body 521 of the second external insert seat 52 .

[0088] like Figures 15 to 17 As shown, when the second external plug-in seat 52 is inserted, the push rod 47 will push the push part 437 on the internal plug-in seat 43, forcing the internal plug-in seat 43 to slide upward, and the spring structure 432 is compressed until the positive male terminal 523 is docked with the first positive terminal 423, and the negative male terminal 524 is docked with the first negative terminal 425. At this time, the internal plug-in seat 43 slides to the second position (i.e., the middle position of the electrode plug-in seat 41), and the female terminal assembly 42 is electrically connected to the second connecting assembly 45, realizing the connection mode of the first battery cell module 21 and the second battery cell module 22 in parallel, the third battery cell module 23 and the fourth battery cell module 24 in parallel, and then connected in series with each other (i.e., first in parallel and then in series). According to the principle of "parallel voltage division, series current division", the second voltage value output by the battery pack at this time is equal to the sum of the rated output voltages of the two battery cell modules, i.e., U = u1 + u2 = u3 + u4 = "2n" V.

[0089] like Fig.18As shown, another embodiment of the second connection component 45. In this embodiment, the second connection component 45' includes a second positive electrode connecting piece 451' connecting the positive electrode of the first battery cell module 21 with the positive electrode of the second battery cell module 22, a fifth connecting piece 452' connecting the positive electrode of the third battery cell module 23 with the negative electrode of the second battery cell module 22, a sixth connecting piece 453' connecting the positive electrode of the fourth battery cell module 24 with the negative electrode of the first battery cell module 21, and a second negative electrode connecting piece 454' connecting the negative electrode of the third battery cell module 23 with the negative electrode of the fourth battery cell module 24. With such a design, a connection mode can be formed in which the first battery cell module 21 is connected in series with the fourth battery cell module 24, the second battery cell module 22 is connected in series with the third battery cell module 23, and then connected in parallel (i.e., series connection first and then parallel connection).

[0090] like Figures 19 to 21 As shown, when inserting Fig.14 When the second external plug-in seat 52 is shown, the push rod 47 will push the push part 437 on the internal plug-in seat 43, forcing the internal plug-in seat 43 to slide upward, and the spring structure 432 is compressed until the positive male terminal 523 is docked with the first positive terminal 423, and the negative male terminal 524 is docked with the first negative terminal 425. At this time, the internal plug-in seat 43 slides to the second position (i.e., the middle position of the electrode plug-in seat 41), and the female terminal assembly 42 is electrically connected to the second connecting assembly 45', realizing the connection mode of connecting the first battery module 21 in series with the fourth battery module 24, the second battery module 22 in series with the third battery module 23, and then in parallel. According to the principle of "parallel voltage division, series current division", the second voltage value output by the battery pack at this time is also equal to the sum of the rated output voltages of the two battery modules, that is, U = u1 + u4 = u2 + u3 = "2n" V.

[0091] like Fig. 22 As shown, the third external plug-in seat 53 includes a main body 531 and a male terminal 532 plugged into the main body 531, and the male terminal 532 includes a positive male terminal 533 and a negative male terminal 534. The positive male terminal 533 is used to dock with the first positive terminal 423, and the negative male terminal 534 is used to dock with the first negative terminal 425, so as to achieve electrical conduction between the battery pack female terminal assembly 42 and the male terminal 532 of the third external plug-in seat 53, and realize the transmission of current and voltage.

[0092] and Fig.14 The difference between the second external insert seat 52 shown is that a push rod 47 ′ is also disposed on the body portion 531 of the third external insert seat 53 , and the length of the push rod 47 ′ is greater than that of the push rod 47 .

[0093] like Figure 23 to Figure 25As shown, when the third external plug-in seat 53 is inserted, the push rod 47' pushes the push part 437 on the internal plug-in seat 43, forcing the internal plug-in seat 43 to slide upward, and the spring structure 432 is compressed until the positive male terminal 533 docks with the first positive terminal 423, and the negative male terminal 534 docks with the first negative terminal 425. At this time, the internal plug-in seat 43 slides to the third position (i.e., the top position of the electrode plug-in seat 41), and the female terminal assembly 42 is electrically connected to the third connecting assembly 46, realizing the series connection of the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24. According to the principle of "parallel voltage division, series current division", the third voltage value output by the battery pack at this time is equal to the sum of the rated output voltages of the four battery modules, that is, U = u1 + u2 + u3 + u4 = "4n" V.

[0094] Based on the above, it can be seen that: after selecting different external plug-in sockets 50, different voltage outputs of the battery pack can be achieved to meet the voltage requirements of three different power tools, and the switching between the three voltages is fast and convenient.

[0095] The battery pack of the present invention can also be applied to a charging system (not shown), which includes the aforementioned battery pack and a charger for charging the battery pack. When the charger is docked with the battery pack for charging, the internal plug-in seat 43 is in the first position. At this time, the first battery module 21, the second battery module 22, the third battery module 23 and the fourth battery module 24 are connected in parallel with each other, and the charging voltage output by the charger is equal to the rated output voltage of a single battery module, which is a low voltage, protecting the battery pack from the impact of high current and high voltage.

[0096] To summarize, the battery pack of the present invention arranges the first connecting component 44, the second connecting component 45, 45' and the third connecting component 46 at different positions of the internal plug-in seat 43, so that when the internal plug-in seat 43 slides to the first position, the second position or the third position, the female terminal component 42 can be selectively connected with the first connecting component 44, the second connecting component 45, 45' or the third connecting component 46 to achieve the series-parallel state switching of the battery cell modules in the battery pack, and then achieve the change of the output voltage of the battery pack, thereby improving the adaptability of the tool system with the battery pack.

[0097] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A battery pack, comprising a housing, a battery pack contained in the housing, and a terminal assembly electrically connected to the battery pack, wherein the battery pack comprises at least a first battery cell module, a second battery cell module, a third battery cell module, and a fourth battery cell module, and the battery pack further comprises a conversion assembly electrically connected to the battery cell module, characterized in that: The conversion component is slidably arranged, and when the conversion component is located at the first position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in parallel, and the battery pack outputs a first voltage value; when the conversion component slides to the second position, the positive electrode of the first battery cell module is connected to the positive electrode of the second battery cell module, the negative electrode of the first battery cell module is connected to the negative electrode of the second battery cell module, and then connected to the positive electrode of the third battery cell module and the positive electrode of the fourth battery cell module, and the negative electrode of the third battery cell module is connected to the negative electrode of the fourth battery cell module, and the battery pack outputs a second voltage value; when the conversion component slides to the third position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in series, and the battery pack outputs a third voltage value; The first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value; The conversion assembly includes a first connection assembly, a second connection assembly and a third connection assembly corresponding to the terminal assembly and arranged at intervals. When the conversion assembly is located at the first position, the terminal assembly is electrically connected to the first connection assembly. When the conversion assembly slides to the second position, the terminal assembly is electrically connected to the second connection assembly. When the conversion assembly slides to the third position, the terminal assembly is electrically connected to the third connection assembly. The conversion assembly includes an internal plug-in seat that is slidably arranged. The first connection assembly, the second connection assembly and the third connection assembly are all integrally formed on the internal plug-in seat, and the first connection assembly, the second connection assembly and the third connection assembly are arranged at intervals along the sliding direction of the internal plug-in seat. The terminal assembly includes a second positive terminal electrically connected to the positive pole of the corresponding battery cell module and a second negative terminal electrically connected to the negative pole of the corresponding battery cell module; the internal plug-in seat includes a base, the base is provided with ribs and slide grooves on both sides of the ribs, the first connecting assembly, the second connecting assembly and the third connecting assembly are formed and exposed on the ribs, and the two contact pieces of each terminal in the second positive terminal and the second negative terminal are accommodated in the slide groove and clamp the ribs, so that when the internal plug-in seat slides, the second positive terminal and the second negative terminal always slide in the slide groove and maintain a state of clamping and abutting with the ribs.

2. The battery pack according to claim 1, characterized in that: The first connecting component includes a first positive connecting plate and a first negative connecting plate, the first positive connecting plate has four positive pins, respectively connected to the positive electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module; the first negative connecting plate has four negative pins, respectively connected to the negative electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

3. The battery pack according to claim 1, characterized in that: The second connecting component includes a second positive electrode connecting plate connecting the positive electrode of the first battery cell module with the positive electrode of the second battery cell module, a fourth connecting plate respectively connected to the positive electrode of the third battery cell module, the positive electrode of the fourth battery cell module, the negative electrode of the first battery cell module and the negative electrode of the second battery cell module, and a second negative electrode connecting plate connecting the negative electrode of the third battery cell module with the negative electrode of the fourth battery cell module.

4. The battery pack according to claim 1, characterized in that: The third connecting component includes a first connecting plate connecting the positive electrode of the second battery cell module with the negative electrode of the first battery cell module, a second connecting piece connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, and a third connecting piece connecting the positive electrode of the fourth battery cell module with the negative electrode of the third battery cell module, so as to realize the series connection of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

5. The battery pack according to claim 1, characterized in that: The conversion assembly comprises an electrode plug seat, and the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat.

6. The battery pack according to claim 5, characterized in that: The conversion component also includes a pushing portion for pushing the internal insert seat to slide, the third connecting component is closer to the pushing portion than the second connecting component, and the first connecting component is farther away from the pushing portion than the second connecting component.

7. The battery pack according to claim 5, characterized in that: The internal plug seat includes a spring structure abutting against the base, the first connecting component, the second connecting component and the third connecting component are integrally formed with the base, and the spring structure is compressed or released when the internal plug seat slides, so that the terminal component can be switchably connected between the first connecting component, the second connecting component and the third connecting component.

8. The battery pack according to claim 7, characterized in that: The electrode plug seat is provided with a receiving cavity, and the terminal assembly and the internal plug seat are both received in the receiving cavity. The base is provided with a slide rail protruding toward one side of the electrode plug seat. The electrode plug seat is correspondingly provided with a through groove, and the slide rail is received in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

9. A battery pack, comprising a housing, a battery pack contained in the housing, and a terminal assembly electrically connected to the battery pack, wherein the battery pack comprises at least a first battery cell module, a second battery cell module, a third battery cell module, and a fourth battery cell module, and the battery pack further comprises a conversion assembly electrically connected to the battery cell modules, characterized in that: The conversion component is slidably arranged, and when the conversion component is located at a first position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in parallel with each other, and the battery pack outputs a first voltage value; When the conversion component slides to the second position, the positive electrode of the first battery cell module is connected to the positive electrode of the second battery cell module, the negative electrode of the first battery cell module is connected to the positive electrode of the fourth battery cell module, the negative electrode of the second battery cell module is connected to the positive electrode of the third battery cell module, and the negative electrode of the third battery cell module is connected to the negative electrode of the fourth battery cell module, and the battery pack outputs a second voltage value; when the conversion component slides to the third position, the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in series, and the battery pack outputs a third voltage value; The first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value; The conversion assembly includes a first connection assembly, a second connection assembly and a third connection assembly corresponding to the terminal assembly and arranged at intervals. When the conversion assembly is located at the first position, the terminal assembly is electrically connected to the first connection assembly. When the conversion assembly slides to the second position, the terminal assembly is electrically connected to the second connection assembly. When the conversion assembly slides to the third position, the terminal assembly is electrically connected to the third connection assembly. The conversion assembly includes an internal plug-in seat that is slidably arranged. The first connection assembly, the second connection assembly and the third connection assembly are all integrally formed on the internal plug-in seat, and the first connection assembly, the second connection assembly and the third connection assembly are arranged at intervals along the sliding direction of the internal plug-in seat. The terminal assembly includes a second positive terminal electrically connected to the positive pole of the corresponding battery cell module and a second negative terminal electrically connected to the negative pole of the corresponding battery cell module; the internal plug-in seat includes a base, the base is provided with ribs and slide grooves on both sides of the ribs, the first connecting assembly, the second connecting assembly and the third connecting assembly are formed and exposed on the ribs, and the two contact pieces of each terminal in the second positive terminal and the second negative terminal are accommodated in the slide groove and clamp the ribs, so that when the internal plug-in seat slides, the second positive terminal and the second negative terminal always slide in the slide groove and maintain a state of clamping and abutting with the ribs.

10. The battery pack according to claim 9, characterized in that: The first connecting component includes a first positive connecting plate and a first negative connecting plate, the first positive connecting plate has four positive pins, respectively connected to the positive electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module; the first negative connecting plate has four negative pins, respectively connected to the negative electrodes of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

11. The battery pack according to claim 10, characterized in that: The second connecting component includes a second positive electrode connecting plate connecting the positive electrode of the first battery cell module with the positive electrode of the second battery cell module, a fifth connecting plate connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, a sixth connecting plate connecting the positive electrode of the fourth battery cell module with the negative electrode of the first battery cell module, and a second negative electrode connecting plate connecting the negative electrode of the third battery cell module with the negative electrode of the fourth battery cell module.

12. The battery pack according to claim 10, characterized in that: The third connecting component includes a first connecting plate connecting the positive electrode of the second battery cell module with the negative electrode of the first battery cell module, a second connecting piece connecting the positive electrode of the third battery cell module with the negative electrode of the second battery cell module, and a third connecting piece connecting the positive electrode of the fourth battery cell module with the negative electrode of the third battery cell module, so as to realize the series connection of the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module.

13. The battery pack according to claim 10, characterized in that: The conversion assembly comprises an electrode plug seat, and the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat.

14. The battery pack according to claim 13, characterized in that: The conversion component also includes a pushing portion for pushing the internal insert seat to slide, the third connecting component is closer to the pushing portion than the second connecting component, and the first connecting component is farther away from the pushing portion than the second connecting component.

15. The battery pack according to claim 13, characterized in that: The internal plug seat includes a spring structure abutting against the base, the first connecting component, the second connecting component and the third connecting component are integrally formed with the base, and the spring structure is compressed or released when the internal plug seat slides, so that the terminal component can be switchably connected between the first connecting component, the second connecting component and the third connecting component.

16. The battery pack according to claim 15, characterized in that: The electrode plug seat is provided with a receiving cavity, and the terminal assembly and the internal plug seat are both received in the receiving cavity. The base is provided with a slide rail protruding toward one side of the electrode plug seat. The electrode plug seat is correspondingly provided with a through groove, and the slide rail is received in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

17. A tool system, characterized in that: include: A battery pack, the battery pack comprising a housing, a battery pack contained in the housing, and a terminal assembly and a conversion assembly electrically connected to the battery pack, the conversion assembly being slidably arranged; The conversion assembly includes a first connection assembly, a second connection assembly and a third connection assembly corresponding to the terminal assembly and arranged at intervals. When the conversion assembly is located at the first position, the terminal assembly is electrically connected to the first connection assembly. When the conversion assembly slides to the second position, the terminal assembly is electrically connected to the second connection assembly. When the conversion assembly slides to the third position, the terminal assembly is electrically connected to the third connection assembly. The conversion assembly includes an internal plug-in seat that is slidably arranged. The first connection assembly, the second connection assembly and the third connection assembly are all integrally formed on the internal plug-in seat, and the first connection assembly, the second connection assembly and the third connection assembly are arranged at intervals along the sliding direction of the internal plug-in seat. The terminal assembly comprises a second positive terminal electrically connected to the positive electrode of the corresponding battery cell module and a second negative terminal electrically connected to the negative electrode of the corresponding battery cell module; the internal plug seat comprises a base, the base is provided with ribs and slide grooves on both sides of the ribs, the first connecting assembly, the second connecting assembly and the third connecting assembly are formed and exposed on the ribs, and the two contact pieces of each terminal of the second positive terminal and the second negative terminal are accommodated in the slide groove and clamp the ribs, so that when the internal plug seat slides, the second positive terminal and the second negative terminal always slide in the slide groove and maintain a state of clamping and abutting with the ribs; a first electric tool, the first electric tool being capable of operating at a first rated voltage, the first electric tool being provided with a first external plug socket; a second electric tool capable of operating at a second rated voltage, the second electric tool being provided with a second external plug socket; a third electric tool, the third electric tool being capable of operating at a third rated voltage and being provided with a third external plug socket; When the battery pack is connected to the first external plug socket of the first electric tool, the conversion component is located at the first position, and the battery pack outputs a first voltage value; When the battery pack is connected to a second external plug-in socket of a second electric tool, the conversion assembly slides to a second position, and the battery pack outputs a second voltage value; When the battery pack is connected to the third external plug socket of the third electric tool, the conversion assembly slides to a third position, and the battery pack outputs a third voltage value; the first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value.

18. The tool system according to claim 17, characterized in that: The first voltage value is "n"V, the second voltage value is "2n"V, and the third voltage value is "4n"V.

19. The tool system according to claim 17, characterized in that: The conversion assembly comprises an electrode plug seat, and the terminal assembly and the internal plug seat are both accommodated in the electrode plug seat.

20. The tool system according to claim 19, characterized in that: The electrode plug seat is provided with a receiving cavity, the terminal assembly and the internal plug seat are both received in the receiving cavity, the internal plug seat is provided with a slide rail protruding toward one side of the electrode plug seat, and the electrode plug seat is correspondingly provided with a through groove, the slide rail is received in the through groove so as to guide the internal plug seat to slide in the electrode plug seat.

21. The tool system according to claim 19, characterized in that: The conversion assembly also includes a push rod for pushing the internal insert seat to slide, and the push rod is integrally formed with the external insert seat.

22. The tool system according to claim 21, characterized in that: The length of the push rod on the first external plug-in seat is smaller than the length of the push rod on the second external plug-in seat, and the length of the push rod on the second external plug-in seat is smaller than the length of the push rod on the third external plug-in seat.

23. A charging system, characterized in that: include: A battery pack, the battery pack comprising a shell, a battery pack contained in the shell, and a terminal assembly and a conversion assembly electrically connected to the battery pack, the battery pack comprising at least a first battery cell module, a second battery cell module, a third battery cell module, and a fourth battery cell module, the conversion assembly being slidably arranged, and when the conversion assembly is in a first position, the battery pack outputs a first voltage value; When the conversion component slides to the second position, the battery pack outputs a second voltage value; when the conversion component slides to the third position, the battery pack outputs a third voltage value; The first voltage value is less than the second voltage value, and the second voltage value is less than the third voltage value; A charger, used to charge the battery pack. When the charger is docked with the battery pack for charging, the conversion component is located at a first position, and the first battery cell module, the second battery cell module, the third battery cell module and the fourth battery cell module are connected in parallel. Wherein, the conversion component includes a first connection component, a second connection component and a third connection component corresponding to the terminal component and arranged at intervals. When the conversion component is located at the first position, the terminal component is electrically connected to the first connection component. When the conversion component slides to the second position, the terminal component is electrically connected to the second connection component. When the conversion component slides to the third position, the terminal component is electrically connected to the third connection component. The conversion component includes an internal plug-in seat that is slidably arranged. The first connection component, the second connection component and the third connection component are all integrally formed on the internal plug-in seat, and the first connection component, the second connection component and the third connection component are arranged along the The internal plug-in seat is arranged at intervals in the sliding direction; the terminal assembly includes a second positive terminal electrically connected to the positive pole of the corresponding battery cell module and a second negative terminal electrically connected to the negative pole of the corresponding battery cell module; the internal plug-in seat includes a base, the base is provided with ribs and slide grooves on both sides of the ribs, the first connecting assembly, the second connecting assembly and the third connecting assembly are formed and exposed on the ribs, and the two contact pieces of each terminal in the second positive terminal and the second negative terminal are both accommodated in the slide groove and clamp the ribs, so that when the internal plug-in seat slides, the second positive terminal and the second negative terminal always slide in the slide groove and maintain a state of clamping and abutting with the ribs.

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