CN220106771U

CN220106771U - Battery pack and vehicle with same

Info

Publication number: CN220106771U
Application number: CN202222566693.3U
Authority: CN
Inventors: 赵云; 黄毅轩
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2022-09-27
Filing date: 2022-09-27
Publication date: 2023-11-28
Anticipated expiration: 2032-09-27

Abstract

The utility model provides a battery pack and a vehicle with the battery pack, wherein the battery pack comprises a lower shell, an upper shell and a battery module, the upper shell is detachably connected with the lower shell, the battery module is arranged between the lower shell and the upper shell, and the battery pack further comprises: the BDU comprises a first electric unit and a second electric unit which are mutually independent, the lower shell further comprises a second installation space and a third installation space which are arranged at intervals, the first electric unit is installed in the second installation space, and the second electric unit is installed in the third installation space; BMS and coupling assembling, BMS and battery module pass through coupling assembling and electrically connect; the BMS, the first electrical unit and the second electrical unit are electrically connected through the connecting component. The utility model solves the problem of unreasonable arrangement of the electrical units of the battery pack in the prior art.

Description

Battery pack and vehicle with same

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery pack and a vehicle with the battery pack.

Background

With the continuous development of electric vehicles, the requirement for quick charge of battery packs is increasing. Compared with a common 400V battery system, the 800V high-voltage system can greatly improve the charging efficiency. However, the 800V battery system has more complicated electrical architecture, more electrical components, and a larger space occupied by the electrical unit than the 400V battery system. This presents significant difficulties in the placement and integration within the battery pack in a limited space.

In the prior art, all electrical components are arranged in one large electrical unit (BDU, battery energy distribution unit), and in a limited battery envelope space, the BDU and the battery module are arranged to collide, either to reduce the amount of electricity or to increase the space, which affects the performance of the battery system.

Disclosure of Invention

The utility model mainly aims to provide a battery pack and a vehicle with the battery pack, so as to solve the problem that the arrangement of electrical units of the battery pack in the prior art is unreasonable.

In order to achieve the above object, according to one aspect of the present utility model, there is provided a battery pack including a lower case, an upper case, and a battery module detachably connected between the upper case and the lower case, the battery module being mounted between the lower case and the upper case, the battery pack further comprising: the BDU comprises a first electric unit and a second electric unit which are mutually independent, the lower shell further comprises a second installation space and a third installation space which are arranged at intervals, the first electric unit is installed in the second installation space, and the second electric unit is installed in the third installation space; BMS and coupling assembling, BMS and battery module pass through coupling assembling and electrically connect; the BMS, the first electrical unit and the second electrical unit are electrically connected through the connecting component.

Further, the connecting assembly comprises a first copper bar and a second copper bar, the first electrical unit comprises a first output interface, the second electrical unit comprises a second output interface, and the second output interface is connected with the first output interface through the first copper bar at high voltage; the second electrical unit comprises a third output interface, the first electrical unit comprises a fourth output interface, and the fourth output interface is connected with the third output interface through a second copper bar in a high-voltage manner; the polarity of the second output interface is the same as that of the first output interface, and the polarity of the third output interface is the same as that of the fourth output interface.

Further, the connecting assembly further comprises a third copper bar and a fourth copper bar, the second electrical unit comprises a first PACK interface, the first electrical unit comprises a second PACK interface, and the first PACK interface is connected with the second PACK interface through the third copper bar in a high-voltage mode; the second electrical unit comprises a third PACK interface, the first electrical unit comprises a fourth PACK interface, and the third PACK interface is connected with the fourth PACK interface through a fourth copper bar in a high-voltage manner; the first copper bar, the second copper bar, the third copper bar and the fourth copper bar are mutually overlapped, and an insulating plate is arranged between every two adjacent copper bars; the polarity of the first PACK interface is the same as the polarity of the second PACK interface, and the polarity of the third PACK interface is the same as the polarity of the fourth PACK interface.

Further, the lower case has a first installation space in which the battery module is installed, and the second installation space and the third installation space are located at both ends of the first installation space in a first predetermined direction.

Further, the first copper bar, the second copper bar, the third copper bar and the fourth copper bar form a first copper bar assembly, the first copper bar assembly is positioned above the battery module, and an insulating plate is arranged between the first copper bar assembly and the battery module; or, along a first preset direction, the battery modules are provided with a plurality of groups of battery module assemblies which are arranged at intervals, so that a first avoidance space for installing a cross beam is formed between two adjacent battery module assemblies, each group of battery module assemblies is provided with a plurality of battery modules, and the plurality of battery modules are arranged at intervals along a second preset direction, so that the first copper bar assembly is positioned in a second avoidance space between two adjacent battery modules; the first copper bar assembly is positioned above the cross beam, and an insulating plate is arranged between the first copper bar assembly and the cross beam; the first predetermined direction is perpendicular to the second predetermined direction.

Further, the BMS comprises a main control board system and a slave control board system, and the slave control board system is electrically connected with the battery module and the main control board system; at least part of the main control board system is positioned above the first electric unit, so that the main control board system and the first output interface of the first electric unit are overlapped, and the first copper bar is positioned between the first output interface of the first electric unit and the main control board system, so that the main control board system and the first electric unit are connected through fasteners penetrating through the main control board system, the first copper bar and the first output interface.

Further, the number of the slave control board systems is multiple, the slave control board systems are all located in the second installation space, the slave control board systems are all electrically connected with the master control board system, and the slave control board systems are all electrically connected with the battery module; the slave control board systems and the master control board systems are arranged at intervals; the first electric unit and the main control board system are both positioned between two adjacent slave control board systems.

Further, the first electrical unit and the second electrical unit each include a contactor, a relay, and a current sensor; wherein the number of contactors, relays and current sensors in the second electrical unit is greater than the number of contactors, relays and current sensors in the first electrical unit.

Further, the battery pack further includes: the liquid cooling plate is arranged on the upper surface of the battery module, the lower shell is provided with a water inlet and a water outlet, and the liquid cooling plate is communicated with the water inlet and the water outlet through the liquid cooling pipe; the water inlet and the water outlet are positioned on the wall surface of one side of the second installation space, which is far away from the battery module.

According to another aspect of the present utility model, there is provided a vehicle including: the battery pack described above; the first output interface and the fourth output interface of the first electric unit of the battery pack are connected with a precursor plug connector of the first driving wheel assembly; the second output interface and the third output interface of the second electrical unit are both connected with a rear drive plug of the second drive wheel assembly.

By applying the technical scheme of the utility model, the battery pack comprises a lower shell, an upper shell and a battery module, wherein the upper shell is detachably connected with the lower shell, the battery module is arranged between the lower shell and the upper shell, and the battery pack further comprises: the BDU comprises a first electric unit and a second electric unit which are mutually independent, the lower shell further comprises a second installation space and a third installation space which are arranged at intervals, the first electric unit is installed in the second installation space, and the second electric unit is installed in the third installation space; the BMS is in conductive connection with the battery module through the connecting component; the BMS, the first electric unit and the second electric unit are electrically connected through the connecting assembly, and therefore the BDU is divided into the first electric unit and the second electric unit which are independent of each other, so that one large BDU is divided into two small electric units, arrangement of the battery pack is facilitated, the two small electric units are placed in different installation spaces, the installation space of the battery pack is fully utilized, and the problem that arrangement of the battery pack in the prior art is unreasonable is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

fig. 1 shows a schematic diagram of a connection structure of an embodiment of a battery pack according to the present utility model;

fig. 2 shows an enlarged schematic view of region a of the battery pack according to fig. 1;

fig. 3 shows an enlarged schematic view of region B of the battery pack according to fig. 1;

fig. 4 illustrates a position schematic view of a BDU, a BMS, and a battery module according to an embodiment of a battery pack of the present utility model;

fig. 5 shows a top view of the battery pack according to fig. 4;

fig. 6 shows an assembly schematic of the upper and lower cases of the battery pack according to the present utility model;

fig. 7 shows an electrical connection schematic of a battery pack according to the present utility model.

Wherein the above figures include the following reference numerals:

1. a lower housing; 2. an upper housing; 3. a battery module; 10. BDU; 11. a first electrical unit; 12. a second electrical unit; 200. a second installation space; 300. a third installation space; 20. BMS; 110. a first copper bar; 120. a second copper bar; 111. a first output interface; 121. a second output interface; 122. a third output interface; 112. a fourth output interface; 400. an insulating plate; 130. a third copper bar; 140. a fourth copper bar; 123. a first PACK interface; 113. a second PACK interface; 114. a fourth PACK interface; 124. a third PACK interface; 100. a first installation space; 21. a main control board system; 22. a slave control board system; 500. a cross beam; 201. a first space segment; 202. a second space segment; 203. a third space segment; 30. a liquid-cooled tube; 301. a water inlet; 302. and a water outlet.

Detailed Description

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. The utility model will be described in detail below with reference to the drawings in connection with embodiments.

Referring to fig. 1 to 7, the present utility model provides a battery pack including a lower case 1, an upper case 2, and a battery module 3 detachably connected between the upper case 2 and the lower case 1, the battery module 3 being mounted between the lower case 1 and the upper case 2, the battery pack further comprising: the BDU10, the BDU10 includes a first electric unit 11 and a second electric unit 12 independent of each other, the lower housing 1 further includes a second installation space 200 and a third installation space 300 which are disposed at intervals, the first electric unit 11 is installed in the second installation space 200, and the second electric unit 12 is installed in the third installation space 300; BMS20 and coupling assembling, BMS20 and battery module 3 are connected through the coupling assembling is conductive; the BMS20, the first electrical unit 11, and the second electrical unit 12 are electrically connected through a connection assembly.

The battery pack of the present utility model includes a lower case 1, an upper case 2, and a battery module 3 detachably connected between the upper case 2 and the lower case 1, the battery module 3 being installed between the lower case 1 and the upper case 2, the battery pack further including: the BDU10 and the BMS20 and the connection assembly, the BDU10 includes a first electrical unit 11 and a second electrical unit 12 independent of each other, the lower housing 1 further includes a second installation space 200 and a third installation space 300 spaced apart from each other, the first electrical unit 11 is installed in the second installation space 200, and the second electrical unit 12 is installed in the third installation space 300; the BMS20 is electrically connected with the battery module 3 through a connection assembly; the BMS20, the first electric unit 11 and the second electric unit 12 are electrically connected through the connecting component, so that the BDU is divided into the two mutually independent first electric units 11 and the second electric units 12, and one large BDU is divided into two small electric units, so that the arrangement of the battery pack is convenient, the two small electric units are placed in different installation spaces, the installation space of the battery pack is fully utilized, and the problem that the arrangement of the battery pack in the prior art is unreasonable is solved.

Wherein, BMS is battery management system, and BDU is one kind of high voltage distribution box, and battery management system all is connected with the first electric unit 11 and the second electric unit 12 of BDU, and battery management system is connected with battery module to according to information such as voltage, electric current and battery module's the temperature that battery management system obtained, control BDU's work.

Specifically, the connection assembly includes a first copper bar 110 and a second copper bar 120, the first electrical unit 11 includes a first output interface 111, the second electrical unit 12 includes a second output interface 121, and the second output interface 121 is connected to the first output interface 111 through the first copper bar 110 at high voltage; the second electrical unit 12 comprises a third output interface 122, the first electrical unit 11 comprises a fourth output interface 112, the fourth output interface 112 is connected with the third output interface 122 through a second copper bar 120 in a high voltage mode, so that the first electrical unit 11 is connected to the third output interface 122 and the second output interface 121 of the second electrical unit 12 through the first copper bar 110 and the second copper bar 120, and the third output interface 122 and the second output interface 121 are connected with a front drive plug connector of a vehicle to provide power for a front drive wheel of the vehicle; the polarity of the second output interface 121 is the same as the polarity of the first output interface 111, and the polarity of the third output interface 122 is the same as the polarity of the fourth output interface 112, so that the voltages of the output interfaces of the first and second electrical units are equal to each other, so that the rotation speeds of the front and rear wheels of the vehicle are consistent. The polarity of each interface refers to the polarity of the voltage output by each interface. In the embodiment of the present utility model, the second output interface 121 and the first output interface 111 are both negative electrodes, and the third output interface 122 and the fourth output interface 112 are both positive electrodes.

Specifically, the connection assembly further includes a third copper bar 130 and a fourth copper bar 140, the second electrical unit 12 includes a first PACK interface 123, the first electrical unit 11 includes a second PACK interface 113, and the first PACK interface 123 and the second PACK interface 113 are connected at high voltage through the third copper bar 130; the second electrical unit 12 includes a third PACK interface 124, the first electrical unit 11 includes a fourth PACK interface 114, and the third PACK interface 124 is connected to the fourth PACK interface 114 through a fourth copper bar 140 at high voltage to transfer the electric power of the battery module to the first electrical unit 11 through the third copper bar 130 and the fourth copper bar 140.

Wherein the first copper bar 110, the second copper bar 120, the third copper bar 130 and the fourth copper bar 140 are stacked on each other, and an insulating plate 400 is disposed between two adjacent copper bars to prevent short circuit; the polarity of the first PACK interface 123 is the same as the polarity of the second PACK interface 113, and the polarity of the third PACK interface 124 is the same as the polarity of the fourth PACK interface 114. In the embodiment of the present utility model, the first PACK interface 123 and the second PACK interface 113 are both positive, and the third PACK interface 124 and the fourth PACK interface 114 are both negative. The polarity of each interface refers to the polarity of the voltage output by each interface.

As shown in fig. 7, the dotted line portion is connected at low voltage, the solid line portion is connected at high voltage, and the plurality of battery modules are connected in series with each other.

In the embodiment of the utility model, the lower case 1 has the first mounting space 100, the battery module 3 is mounted in the first mounting space 100, and the second mounting space 200 and the third mounting space 300 are located at both ends of the first mounting space 100 in the first predetermined direction.

Specifically, the first copper bar 110, the second copper bar 120, the third copper bar 130 and the fourth copper bar 140 form a first copper bar assembly, the first copper bar assembly is located above the battery module 3, and an insulating plate 400 is arranged between the first copper bar assembly and the battery module 3; or, along a first preset direction, the battery modules 3 are provided with a plurality of groups of battery module assemblies arranged at intervals, so that a first avoidance space for installing the cross beam 500 is formed between two adjacent battery module assemblies, each group of battery module assemblies is provided with a plurality of battery modules 3, and the plurality of battery modules 3 are arranged at intervals along a second preset direction, so that a first copper bar assembly is positioned in a second avoidance space between two adjacent battery modules 3; wherein, the first copper bar assembly is positioned above the cross beam 500, and an insulating plate 400 is arranged between the first copper bar assembly and the cross beam 500; the first predetermined direction is perpendicular to the second predetermined direction.

Specifically, the BMS20 includes a master control board system 21 and a slave control board system 22, and the slave control board system 22 is electrically connected to the battery module 3 and the master control board system 21; at least part of the main control board system 21 is located above the first electric unit 11, so that the main control board system 21 and the first output interface 111 of the first electric unit 11 are overlapped, and the first copper bar 110 is located between the first output interface 111 of the first electric unit 11 and the main control board system 21, so that the main control board system 21 and the first electric unit 11 are connected through fasteners penetrating through the main control board system 21, the first copper bar 110 and the first output interface 111, and therefore, the installation space of a battery pack can be saved.

Specifically, the number of slave control board systems 22 is multiple, the plurality of slave control board systems 22 are all located in the second installation space 200, the plurality of slave control board systems 22 are all electrically connected with the master control board system 21, and the slave control board systems 22 are all electrically connected with the battery module 3; wherein, a plurality of slave control board systems 22 and a master control board system 21 are arranged at intervals; the first electrical unit 11 and the master control board system 21 are both located between two adjacent slave control board systems 22.

In the embodiment of the utility model, two slave control board systems 22 are provided, each slave control board system 22 is connected with the master control board system 21, each slave control board system 22 is connected with the battery module 3, and the master control board system 21 and the first electrical unit 11 are located between the two slave control board systems 22.

Specifically, the second installation space 200 has a first space section 201, a second space section 202, and a third space section 203 that are sequentially communicated, the first space section 201 and the third space section 203 being symmetrically disposed along a center line of the second space section 202; wherein, the main control board system 21 and the first electric unit 11 are both installed in the second space section 202, and each slave control board system 22 is respectively installed in the second space section 202 and the third space section 203. Wherein the distance between the wall surfaces of the lower case 1 for enclosing the first space section 201 and the third space section 203 and the battery module 3 gradually decreases in a direction away from the second space section 202.

As shown in fig. 6, the upper case 2 has an avoidance groove for avoiding the first copper bar assembly, the avoidance groove protrudes toward one side far away from the lower case 1, the avoidance groove is elongated, and the central axis of the avoidance groove is the symmetry axis of the second installation space 200 and the third installation space 300.

Specifically, the third installation space 300 is protruded in a direction away from the first installation space 100 such that an outer wall surface of the third installation space 300 and an outer wall surface of the first installation space 100 form a convex structure.

Specifically, the first electrical unit 11 and the second electrical unit 12 each include a contactor, a relay, and a current sensor; wherein the number of contactors, relays and current sensors in the second electrical unit 12 is greater than the number of contactors, relays and current sensors in the first electrical unit 11.

Specifically, the number of contactors, relays and current sensors is plural, the first output interface 111 and the second PACK interface 113 of the first electrical unit 11 are electrically connected to the corresponding relays, and the electric quantity input by the second PACK interface 113 is output by the first output interface 111; the fourth output interface 112 and the fourth PACK interface 114 of the first electric unit 11 are electrically connected to respective relays, and the electric quantity input by the fourth PACK interface 114 is output by the fourth output interface 112 to power a first driving wheel assembly (front wheels) of the vehicle.

Specifically, each battery module is directly output by the second output interface 121 and the third output interface 122 after passing through the contactor, the relay, and the current sensor in the second electric unit 12 to power the second wheel assembly (rear wheel) of the vehicle.

Specifically, the battery pack further includes: the liquid cooling plate and the liquid cooling pipe 30 are arranged on the upper surface of the battery module 3, the lower shell 1 is provided with a water inlet 301 and a water outlet 302, and the liquid cooling plate is communicated with the water inlet 301 and the water outlet 302 through the liquid cooling pipe 30; wherein the water inlet 301 and the water outlet 302 are located on a wall surface of the second installation space 200 at a side remote from the battery module 3.

The utility model also provides a vehicle comprising: the battery pack described above; the first output interface 111 and the fourth output interface 112 of the first electric unit 11 of the battery pack are connected with the precursor plug-in unit of the first driving wheel assembly; the second output interface 121 and the third output interface 122 of the second electrical unit 12 are each connected to a rear drive plug of the second drive wheel assembly.

From the above description, it can be seen that the above embodiments of the present utility model achieve the following technical effects:

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. The utility model provides a battery package, includes casing (1), last casing (2) and battery module (3) down, go up casing (2) with detachably connects between casing (1) down, battery module (3) are installed down casing (1) with go up between casing (2), its characterized in that, battery package still includes:

a BDU (10), the BDU (10) including a first electrical unit (11) and a second electrical unit (12) that are independent of each other, the lower housing (1) further including a second installation space (200) and a third installation space (300) that are disposed at intervals, the first electrical unit (11) being installed in the second installation space (200), the second electrical unit (12) being installed in the third installation space (300);

a BMS (20) and a connection assembly, wherein the BMS (20) and the battery module (3) are connected in a conductive manner through the connection assembly; the BMS (20), the first electrical unit (11) and the second electrical unit (12) are electrically connected through a connecting component.

2. The battery pack of claim 1, wherein the connection assembly comprises a first copper bar (110) and a second copper bar (120),

the first electrical unit (11) comprises a first output interface (111), the second electrical unit (12) comprises a second output interface (121), and the second output interface (121) is connected with the first output interface (111) through a first copper bar (110) in a high voltage mode;

the second electrical unit (12) comprises a third output interface (122), the first electrical unit (11) comprises a fourth output interface (112), and the fourth output interface (112) is connected with the third output interface (122) through the second copper bar (120) in a high voltage mode;

wherein the polarity of the second output interface (121) is the same as the polarity of the first output interface (111), and the polarity of the third output interface (122) is the same as the polarity of the fourth output interface (112).

3. The battery pack of claim 2, wherein the connection assembly further comprises a third copper bar (130) and a fourth copper bar (140),

the second electrical unit (12) comprises a first PACK interface (123), the first electrical unit (11) comprises a second PACK interface (113), and the first PACK interface (123) is connected with the second PACK interface (113) through the third copper bar (130) in a high voltage mode;

the second electrical unit (12) comprises a third PACK interface (124), the first electrical unit (11) comprises a fourth PACK interface (114), and the third PACK interface (124) is connected with the fourth PACK interface (114) through the fourth copper bar (140) in a high voltage manner;

wherein the first copper bar (110), the second copper bar (120), the third copper bar (130) and the fourth copper bar (140) are mutually overlapped, and an insulating plate (400) is arranged between two adjacent copper bars; the polarity of the first PACK interface (123) is the same as the polarity of the second PACK interface (113), and the polarity of the third PACK interface (124) is the same as the polarity of the fourth PACK interface (114).

4. A battery pack according to claim 3, wherein the lower case (1) has a first installation space (100), the battery module (3) is installed in the first installation space (100), and the second installation space (200) and the third installation space (300) are located at both ends of the first installation space (100) in a first predetermined direction.

5. The battery pack of claim 4, wherein the first copper bar (110), the second copper bar (120), the third copper bar (130), and the fourth copper bar (140) form a first copper bar assembly,

the first copper bar assembly is positioned above the battery module (3), and the insulating plate (400) is arranged between the first copper bar assembly and the battery module (3); or,

along the first preset direction, the battery modules (3) are provided with a plurality of groups of battery module assemblies which are arranged at intervals, so that a first avoiding space for installing a cross beam (500) is formed between two adjacent battery module assemblies, each group of battery module assemblies is provided with a plurality of battery modules (3), and the plurality of battery modules (3) are arranged at intervals along the second preset direction, so that the first copper bar assemblies are positioned in a second avoiding space between two adjacent battery modules (3); the first copper bar assembly is located above the cross beam (500), and the insulating plate (400) is arranged between the first copper bar assembly and the cross beam (500); the first predetermined direction is perpendicular to the second predetermined direction.

6. The battery pack according to claim 2, wherein the BMS (20) comprises a master control board system (21) and a slave control board system (22), the slave control board system (22) being electrically connected to both the battery module (3) and the master control board system (21);

at least part of the main control board system (21) is located above the first electrical unit (11), so that the main control board system (21) and the first output interface (111) of the first electrical unit (11) are overlapped, and the first copper bar (110) is located between the first output interface (111) of the first electrical unit (11) and the main control board system (21), so that the main control board system (21) and the first electrical unit (11) are connected through fasteners penetrating through the main control board system (21), the first copper bar (110) and the first output interface (111).

7. The battery pack according to claim 6, wherein the number of slave board systems (22) is plural, the plurality of slave board systems (22) are all located in the second installation space (200), the plurality of slave board systems (22) are all electrically connected with the master board system (21), and the slave board systems (22) are all electrically connected with the battery module (3);

wherein a plurality of slave control board systems (22) and the master control board system (21) are arranged at intervals; the first electrical unit (11) and the main control board system (21) are both positioned between two adjacent slave control board systems (22).

8. The battery pack according to any one of claims 1 to 7, wherein the first electrical unit (11) and the second electrical unit (12) each comprise a contactor, a relay and a current sensor;

wherein the number of the contactors, the relays and the current sensors in the second electrical unit (12) is greater than the number of the contactors, the relays and the current sensors in the first electrical unit (11).

9. The battery pack according to any one of claims 1 to 7, further comprising:

the liquid cooling plate and the liquid cooling pipe (30) are arranged on the upper surface of the battery module (3), a water inlet (301) and a water outlet (302) are arranged on the lower shell (1), and the liquid cooling plate is communicated with the water inlet (301) and the water outlet (302) through the liquid cooling pipe (30);

wherein the water inlet (301) and the water outlet (302) are positioned on the wall surface of one side of the second installation space (200) far away from the battery module (3).

10. A vehicle, characterized by comprising:

the battery pack of any one of claims 1 to 9;

a first drive wheel assembly and a second drive wheel assembly, a first output interface (111) and a fourth output interface (112) of a first electrical unit (11) of the battery pack being connected to a precursor plug of the first drive wheel assembly;

the second output interface (121) and the third output interface (122) of the second electrical unit (12) are both connected to a rear drive plug of a second drive wheel assembly.