Battery pack

Abstract

A battery pack may be provided. The battery pack may include: a plurality of battery modules disposed along rows and columns; a plurality of slave battery management systems (BMS) each disposed between two adjacent battery modules in a corresponding row among a plurality of rows among the plurality of battery modules and configured to detect state information of the two adjacent battery modules; and a master BMS configured to receive state information of the plurality of battery modules through wireless optical communication with the plurality of slave BMSs, in which at least two slave BMSs among the plurality of slave BMSs may be configured to be disposed at different heights.

Description

Technical Field

[0001] The present disclosure relates to a battery pack. Background Art

[0002] A battery management system (BMS) may vary depending on the capacity or application of a battery pack, but generally may include a main BMS and a slave BMS.

[0003] The main BMS may collect measurement data of battery modules from the slave BMS and perform state estimation of the battery modules, life prediction of the battery modules, and fault diagnosis of the battery modules based on the collected data. For this purpose, a data communication technology between the main BMS and the slave BMS is required.

[0004] Wired communication between the main BMS and the slave BMS may pose risks of communication wiring defects and electrical short circuits due to external shocks and vibrations. In addition, the communication wiring should be assembled by workers, which may increase the delivery time.

[0005] Radio frequency (RF) wireless communication between the main BMS and the slave BMS may be vulnerable to security and the cost of RF integrated circuits is high due to the complex manufacturing process of the RF integrated circuits. Summary of the Invention

[0006] At least one of the embodiments may provide a battery pack capable of improving at least one drawback of wired communication or wireless communication between a main BMS and a slave BMS.

[0007] According to one embodiment, a battery pack may be provided. The battery pack may include: a plurality of battery modules arranged along rows and columns; a plurality of slave battery management systems (BMSs), each disposed between two adjacent battery modules in a corresponding row among the plurality of rows of the plurality of battery modules and configured to detect state information of the two adjacent battery modules; and a main BMS configured to receive state information of the plurality of battery modules through wireless optical communication with the plurality of slave BMSs, wherein at least two of the plurality of slave BMSs may be configured to be disposed at different heights.

[0008] Each of the plurality of slave BMSs and the main BMS may include: an optical transmitter configured to transmit a wireless optical signal; and an optical receiver configured to receive a wireless optical signal.

[0009] The optical transmitters of the at least two slave BMSs may be configured to be disposed at different heights from a reference plane, and the optical receivers of the at least two slave BMSs may be configured to be at different heights from the reference plane.

[0010] The at least two slave BMSs may be configured to be disposed at different heights from the uppermost surface or the lowermost surface of the plurality of battery modules.

[0011] The battery pack may further include: a reflector configured to reflect wireless optical signals received from the optical transmitters of each of the plurality of slave BMSs to the master BMS, and configured to reflect wireless optical signals received from the optical transmitter of the master BMS to the plurality of slave BMSs.

[0012] Each of the plurality of slave BMSs may further include: a first analog front-end integrated circuit (AFE IC) configured to measure the state information of any one of the corresponding two battery modules; and a second AFE IC configured to measure the state information of the other of the corresponding two battery modules.

[0013] Each of the plurality of slave BMSs may be configured to be fixed to any one of the two facing side surfaces of the corresponding two battery modules.

[0014] Each of the plurality of slave BMSs may be configured to be connected to the corresponding two battery modules through a flexible printed circuit board (FPCB).

[0015] Wireless optical communication may use an infrared transmission medium.

[0016] A battery pack according to another embodiment may include: a plurality of battery modules arranged in rows and columns; a plurality of slave battery management systems (BMSs) each disposed on any one of the two facing side surfaces of two adjacent battery modules in a corresponding row among the plurality of rows of the plurality of battery modules; and a master BMS configured to communicate with the plurality of slave BMSs, wherein among the plurality of slave BMSs, the slave BMSs disposed in different rows and the same column may be configured to be disposed at different heights.

[0017] Each of the plurality of slave BMSs and the master BMS may include: an optical transmitter configured to transmit a wireless optical signal; and an optical receiver configured to receive a wireless optical signal.

[0018] Each of the plurality of slave BMSs may further include: a first analog front-end integrated circuit (AFE IC) configured to measure the state information of any one of the corresponding two battery modules; and a second AFE IC configured to measure the state information of the other of the corresponding two battery modules.

[0019] The master BMS and the plurality of slave BMSs may communicate using an infrared transmission medium.

[0020] Each of the plurality of slave BMSs may be configured to be connected to the corresponding two battery modules through a flexible printed circuit board (FPCB).

[0021] The battery pack may further include: a reflector configured to reflect wireless optical signals received from the optical transmitters of each of the plurality of slave BMSs to the master BMS, and configured to reflect wireless optical signals received from the optical transmitter of the master BMS to the plurality of slave BMSs. Description of the Drawings

[0022] Figure 1 is a diagram showing an example of a battery pack according to an embodiment.

[0023] Figure 2 is a diagram showing Figure 1 an example of the battery module shown in

[0024] Figure 3 is a schematic plan view of a battery pack for explaining the arrangement position of the slave BMS according to an embodiment.

[0025] Figure 4 is a diagram showing the slave BMS provided between two battery modules.

[0026] Figure 5 is a diagram showing Figure 3 the master BMS shown in

[0027] Figure 6 is a diagram illustrating an example of the spatial arrangement position of the slave BMS in the battery pack according to an embodiment.

[0028] Figure 7 is a diagram showing another example of the spatial arrangement position of the slave BMS.

[0029] Figure 8 is a diagram illustrating another example of the spatial arrangement position of the slave BMS in the battery pack according to an embodiment.

[0030] Figure 9 is a schematic plan view of a battery pack for explaining the arrangement position of the slave BMS according to another embodiment.

[0031] <Description of Reference Numerals>

[0032] 10: Battery pack

[0033] 110, 120, 130, 140, 150, 160: Battery modules

[0034] 210, 220, 230: Slave BMSs

[0035] 300: Master BMS

[0036] 211, 212: AFE ICs

[0037] 213, 330: MCUs

[0038] 214, 310: Optical transmitter

[0039] 215, 320: Optical receiver Detailed implementation manners

[0040] Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, the example embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the exemplary implementation manners to those skilled in the art. The drawings and the description are to be regarded as illustrative rather than restrictive. Throughout the specification, the same reference numerals denote the same elements. In the flowcharts described with reference to the accompanying drawings in this specification, the order of operations may be changed, several operations may be combined, some operations may be split, and specific operations may not be performed.

[0041] Throughout the specification and the claims, if a part is referred to as "including" a certain element, this may mean that it may further include other elements rather than excluding other elements, unless otherwise specifically indicated.

[0042] In addition, expressions described in the singular may be construed as singular or plural unless an explicit expression such as "one" or "single" is used.

[0043] Furthermore, terms including ordinals such as first, second, etc. may be used to describe various elements, but these elements are not limited by these terms. The above terms are only used to distinguish one element from another. For example, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element without departing from the scope of this disclosure.

[0044] In addition, if a component is referred to as "connected" to another component, this may include not only the case where the two components are "directly connected", but also the case where the two components are "indirectly or non-contact connected" (where an intermediate component is interposed therebetween) or the case where the two components are "electrically connected". On the other hand, if an element is referred to as "directly connected" to another element, it should be understood that there are no other elements in between.

[0045] Figure 1 is a diagram showing an example of a battery pack according to an embodiment.

[0046] Reference Figure 1 , the battery pack 10 may include a plurality of battery modules 110, 120, 130, 140, 150 and 160, a plurality of slave battery management systems (BMSs) 210, 220 and 230, and a main BMS 300. For ease of explanation, Figure 1Six battery modules 110, 120, 130, 140, 150, and 160 are shown.

[0047] The multiple battery modules 110, 120, 130, 140, 150, and 160 can be connected in series and / or in parallel with each other.

[0048] The multiple battery modules 110, 120, 130, 140, 150, and 160 can be connected to a charging device or a load through system terminals T+ and T−, and can be charged by the charging device or discharged by the load.

[0049] Each of the multiple battery modules 110, 120, 130, 140, 150, and 160 can include multiple battery cells electrically connected in series and / or in parallel.

[0050] Each of the multiple slave BMSs 210, 220, and 230 can correspond to at least one of the battery modules 110, 120, 130, 140, 150, and 160.

[0051] Each of the multiple slave BMSs 210, 220, and 230 can be electrically connected to the corresponding battery module among the battery modules 110, 120, 130, 140, 150, and 160.

[0052] According to one embodiment, each of the slave BMSs 210, 220, and 230 can correspond to two battery modules. That is, one slave BMS can control two battery modules.

[0053] For example, the slave BMS 210 can be electrically connected to the battery modules 110 and 120, the slave BMS 220 can be electrically connected to the battery modules 130 and 140, and the slave BMS 230 can be electrically connected to the battery modules 150 and 160.

[0054] Each of the multiple slave BMSs 210, 220, and 230 can detect the overall state of the electrically connected battery module and can perform various control functions to adjust the state of the electrically connected battery module. The state can include battery cell voltage, module voltage, module current, and temperature, etc., and the control functions can include charging, discharging, balancing, etc. The control functions can be directly executed by the slave BMSs 210, 220, and 230 based on the state of the battery modules 110, 120, 130, 140, 150, and 160, or can be executed according to commands from the master BMS 300. For example, the slave BMS 210 can be electrically connected to two battery modules 110 and 120, and can perform control functions to adjust the states of the two battery modules 110 and 120.

[0055] The main BMS 300 can perform wireless optical communication with multiple slave BMSs 210, 220, and 230. The wireless optical communication can include infrared communication.

[0056] The main BMS 300 receives the status information of the battery modules 110, 120, 130, 140, 150, and 160 from the multiple slave BMSs 210, 220, and 230 through wireless optical communication, and can perform control functions such as state of charge (SOC), power control, battery cell balancing control, fault diagnosis control, cooling control, and thermal runaway detection based on the received status information. Additionally, the main BMS 300 can control the relay for supplying the power of the battery modules 110, 120, 130, 140, 150, and 160 to the load or blocking the power of the battery modules 110, 120, 130, 140, 150, and 160 to the load based on the status information of the battery modules 110, 120, 130, 140, 150, and 160.

[0057] Through the wireless optical communication between the main BMS 300 and each of the multiple slave BMSs 210, 220, and 230, the wiring complexity according to the wired communication method can be reduced, and the security can be enhanced compared with RF wireless communication.

[0058] Figure 2 is a diagram showing Figure 1 an example of the battery module shown in

[0059] In Figure 2 it, x, y, and z can represent a three-dimensional coordinate system.

[0060] Referring to Figure 2 , the battery module 110 can include a plurality of battery cells 112 arranged in one direction.

[0061] The battery cell 112 can accommodate an electrode assembly and an electrolyte inside a battery cell case forming its main body, and an opening 118, as well as electrode terminals 114 and 116, can be formed on the outer surface of the battery cell case.

[0062] The opening 118 can be configured to normally remain closed, and can be configured to open if an event such as thermal runaway of the battery cell 112 occurs and gas or flame is generated inside the battery cell 112, so as to discharge the gas or flame to the outside of the battery cell 112. For example, the opening 118 can be provided by forming a notch in a specific part of the battery cell 112, such that if the internal pressure of the battery cell 112 increases, that specific part breaks.

[0063] The battery cell 112 may be composed of prismatic battery cells. Alternatively, the battery cell 112 may be composed of another type of battery cell (e.g., cylindrical battery cell), and the shape of the battery cell 112 is not limited thereto.

[0064] The battery module 110 may be a component in which a plurality of battery cells 112 are combined in a single frame to increase the output power of the battery pack 10 and prevent external shock or vibration.

[0065] Figure 3 is a schematic plan view of a battery pack according to an embodiment for explaining the arrangement position of the BMS.

[0066] Reference Figure 3 , a plurality of battery modules 110, 120, 130, 140, 150, and 160 may be arranged in a plurality of rows and a plurality of columns.

[0067] In one embodiment, two battery modules may be arranged in a row, and the slave BMS for managing these two battery modules may be arranged between the two battery modules arranged in a row.

[0068] Specifically, if the battery pack 10 includes six battery modules 110, 120, 130, 140, 150, and 160, the battery modules 110 and 120 are arranged in the first row, and the slave BMS 210 may be arranged between the battery modules 110 and 120. The battery modules 130 and 140 may be arranged in the second row, and the slave BMS 220 may be arranged between the battery modules 130 and 140. Additionally, the battery modules 150 and 160 may be arranged in the third row, and the slave BMS 230 may be arranged between the battery modules 150 and 160.

[0069] In some embodiments, the slave BMS 210 may be coupled to the side surface of any one of the battery modules 110 and 120 (e.g., battery module 120). Similarly, the slave BMS 220 may be coupled to the side surface of any one of the battery modules 130 and 140 (e.g., battery module 140), and the slave BMS 230 may be coupled to the side surface of any one of the battery modules 150 and 160 (e.g., battery module 160).

[0070] Figure 4 is a diagram showing the slave BMS arranged between two battery modules.

[0071] Reference Figure 4, the slave BMS 210 may include analog front-end (AFE) integrated circuits (ICs) 211 and 212, a microcontroller unit (MCU) 213, and at least one optical transmitter 214 and at least one optical receiver 215. Although, for convenience, Figure 4 the slave BMS 210 disposed between the battery modules 110 and 120 is shown, the slave BMSs 220 and 230 may also be configured to be the same as or similar to the slave BMS 210.

[0072] Each of the AFE ICs 211 and 212 may be connected to each of the battery modules 110 and 120 via a flexible printed circuit board (FPCB).

[0073] The AFE IC 211 may measure physical state information such as voltage, current, and temperature of the battery module 110, and control charging and discharging of the battery module 110 or balancing of the battery module 110. The AFE IC 211 may transmit the measured state information of the battery module 110 to the MCU 213.

[0074] The AFE IC 212 may measure physical state information such as voltage, current, and temperature of the battery module 120, and control charging and discharging of the battery module 120 or balancing of the battery module 120. The AFE IC 212 may transmit the measured state information of the battery module 120 to the MCU 213.

[0075] The MCU 213 may control the operations of the AFE ICs 211 and 212. The MCU 213 may transmit the state information of the battery modules 110 and 120 respectively transmitted from the AFE ICs 211 and 212 to the optical transmitter 214.

[0076] In addition, the MCU 213 may receive a control signal from the master BMS 300 via the optical receiver 215, and may control or command the AFE ICs 211 and 212 according to the control signal from the master BMS 300. The MCU 213 may transmit the control signal from the master BMS 300 to the AFE ICs 211 and 212.

[0077] The optical transmitter 214 may perform signal processing on the state information of the battery modules 110 and 120, and transmit the state information of the battery modules 110 and 120 via a wireless optical signal.

[0078] The optical receiver 215 may receive a control signal from the master BMS 300 via a wireless optical signal, perform signal processing on the received control signal from the master BMS 300, and transmit the signal-processed control signal to the MCU 213.

[0079] According to an embodiment, the optical transmitter 214 and the optical receiver 215 may use an infrared transmission medium to transmit and receive signals respectively.

[0080] Figure 5 is a diagram showing Figure 3 the main BMS shown in

[0081] Referring to Figure 5 , the main BMS 300 may include an optical transmitter 310, an optical receiver 320, and an MCU 330.

[0082] The optical transmitter 310 may perform signal processing on the control signal of the main BMS 300 and transmit the control signal of the main BMS 300 through a wireless optical signal.

[0083] The optical receiver 320 may receive the status information of the battery modules 110, 120, 130, 140, 150, and 160 through a wireless optical signal and may transmit the received status information of the battery modules 110, 120, 130, 140, 150, and 160 to the MCU 330.

[0084] The MCU 330 may diagnose and control the battery modules 110, 120, 130, 140, 150, and 160 based on the status information of the battery modules 110, 120, 130, 140, 150, and 160. The MCU 330 may generate a control signal for controlling the battery modules 110, 120, 130, 140, 150, and 160 and transmit the control signal to the optical transmitter 310.

[0085] The optical transmitter 310 and the optical receiver 320 may use an infrared transmission medium to transmit and receive signals respectively.

[0086] If there is a wall or an obstacle, such wireless optical communication cannot transmit or receive signals. Therefore, the slave BMSs 210, 220, and 230 may be arranged as shown in Figure 6 such that there is no wall or obstacle between the main BMS 300 and each of the slave BMSs 210, 220, and 230 to transmit and receive signals.

[0087] Figure 6 is a diagram illustrating an example of the spatial arrangement position of the slave BMS in a battery pack according to an embodiment, and Figure 7 is a diagram showing another example of the spatial arrangement position of the slave BMS.

[0088] Referring to Figure 3 and Figure 6, the main BMS 300 can be combined and fixed to a side surface of the electronic component 400. The slave BMS 210 can be disposed in the space between the battery modules 110 and 120. More specifically, the slave BMS 210 can be combined and fixed to one of the two side surfaces of the battery modules 110 and 120 facing each other.

[0089] The slave BMS 220 can be disposed in the space between the battery modules 130 and 140. More specifically, the slave BMS 220 can be combined and fixed to one of the two side surfaces of the battery modules 130 and 140 facing each other.

[0090] The slave BMS 230 can be disposed in the space between the battery modules 150 and 160. More specifically, the slave BMS 230 can be combined and fixed to one of the two side surfaces of the battery modules 150 and 160 facing each other.

[0091] In some embodiments, the slave BMS 210 can be combined and fixed on the side surface 121 of the battery module 120 among the two side surfaces of the battery modules 110 and 120 facing each other, and the slave BMS 220 can be combined and fixed on the side surface 141 of the battery module 140 among the two side surfaces of the battery modules 130 and 140 facing each other, and the slave BMS 230 can be combined and fixed on the side surface 161 of the battery module 160 among the two side surfaces of the battery modules 150 and 160 facing each other.

[0092] According to an embodiment, the slave BMSs 210, 220, and 230 can be disposed at different heights based on the top surface or the bottom surface of the battery modules 120, 140, and 160, respectively. The heights of the top surfaces or the bottom surfaces of the battery modules 120, 140, and 160 can be the same.

[0093] If the slave BMSs 210, 220, and 230 are disposed in parallel at the same height, the slave BMS 210 or the slave BMS 220 may act as an obstacle in the wireless optical communication between the slave BMS 230 and the main BMS 300. In addition, the signals from the slave BMS 210 or the slave BMS 220 may act as interference. Furthermore, even though there is no obstacle in the wireless optical communication between the slave BMS 210 and the main BMS 300, the signals from the slave BMS 220 or the slave BMS 230 may act as interference.

[0094] In addition, as Figure 7As shown in the figure, the battery modules 120, 140, and 160 to which the slave BMSs 210, 220, and 230 are respectively coupled can be arranged to be spatially offset from each other such that there are no obstacles between each of the slave BMSs 210, 220, and 230 and the main BMS 300. In this way, interference caused by signals between them can be reduced. However, this structure results in wasted space, so the size of the battery pack 10 may increase.

[0095] Alternatively, the slave BMSs 210, 220, and 230 are arranged in parallel at the same height and the position of the main BMS 300 can be adjusted. However, in this case, the space between the two battery modules 110 and 120, between the two battery modules 130 and 140, and between the two battery modules 150 and 160 should be wide, and this structure may also result in wasted space.

[0096] To solve these drawbacks, as Figure 6 shown in the figure, the slave BMSs 210, 220, and 230 can be arranged at different heights.

[0097] In one embodiment, the slave BMS 210 can be coupled to the side surface 121 of the battery module 120 at the same height as the top surfaces of the battery modules 120, 140, and 160, and the slave BMS 220 can be coupled to the side surface 141 of the battery module 140 at a height spaced apart from the top surfaces of the battery modules 120, 140, and 160 by a distance d1. Additionally, the slave BMS 230 can be coupled to the side surface 161 of the battery module 160 at a height spaced apart from the top surfaces of the battery modules 120, 140, and 160 by a distance d2. The distance d1 and the distance d2 can be different. The distance d2 can be greater than the distance d1. In this way, the arrangement positions of the light emitters of each of the slave BMSs 210, 220, and 230 can have different heights from the reference plane, and the arrangement positions of the light receivers of each of the slave BMSs 210, 220, and 230 can have different heights from the reference plane.

[0098] Since the slave BMSs 210, 220, and 230 have different heights, other slave BMSs do not act as obstacles in the wireless optical communication between each of the slave BMSs 210, 220, and 230 and the main BMS 300, interference caused by signals from other slave BMSs can be reduced, and wasted space can also be reduced.

[0099] Figure 8 is a diagram illustrating another example of the spatial arrangement positions of the slave BMSs in the battery pack according to an embodiment.

[0100] Referring to Figure 3 and Figure 8 , a reflector 500 can be disposed atFigure 6 The position of the main BMS 300 shown in, for example, a reflective film or a mirror can be used as the reflector 500.

[0101] The reflector 500 can reflect signals between each of the slave BMSs 210, 220, and 230 and the main BMS 300. The reflector 500 can reflect the signals received from the slave BMSs 210, 220, and 230 to the main BMS 300, and can reflect the signals received from the main BMS 300 to the slave BMSs 210, 220, and 230. Specifically, the reflector 500 can reflect the wireless optical signals received from the optical transmitters of each of the slave BMSs 210, 220, and 230 to the main BMS 300, and can reflect the wireless optical signals received from the optical transmitter of the main BMS 300 to the slave BMSs 210, 220, and 230. The reflector 500 can be set at a reflection angle capable of transmitting and receiving signals between each of the slave BMSs 210, 220, and 230 and the main BMS 300.

[0102] Since the slave BMSs 210, 220, and 230 can be respectively disposed between two battery modules 110 and 120, between two battery modules 130 and 140, and between two battery modules 150 and 160, there may be restrictions on the layout position of the main BMS 300 even if the slave BMSs 210, 220, and 230 have different heights.

[0103] However, as Figure 8 shown in, if the reflector 500 can be set and the angle of the reflector 500 can be adjusted, the degree of freedom of setting the main BMS 300 can be improved without wasting the space between two battery modules 110 and 120, between two battery modules 130 and 140, and between two battery modules 150 and 160.

[0104] Figure 9 FIG. is a diagram of a battery pack for explaining the placement position of a slave BMS according to another embodiment. This is a schematic plan view.

[0105] Refer to Figure 9 , in adjacent rows, the slave BMSs 210, 220, and 230 may not be coupled to the battery modules 120, 140, and 160 disposed in the same column, but for adjacent rows, the slave BMSs 210, 220, and 230 may be coupled and fixed to the side surfaces of battery modules in different columns.

[0106] For example, slave BMS 210 can be fixed to the side surface of battery module 120, and slave BMS 220 can be fixed to the side surface of battery module 130. Slave BMS 230 can be fixed to the side surface of battery module 160. At this time, slave BMSs (e.g., slave BMS 210 and slave BMS 230) that are arranged in the same column in different rows can be arranged at different heights from the reference plane as shown in Figure 6 shown.

[0107] By doing so, slave BMSs 210, 220, and 230 can have different positions and / or different heights. Therefore, other slave BMSs will not act as obstacles in the wireless optical communication between each of slave BMSs 210, 220, and 230 and master BMS 300, interference caused by signals from other slave BMSs can be reduced, and space waste can also be reduced.

[0108] According to at least one of the embodiments, by using wireless optical communication between the master BMS and the slave BMS, the wiring complexity according to the wired communication method can be reduced, and compared with RF wireless communication, security can be enhanced.

[0109] According to at least one of the embodiments, signal interference between the master BMS and the slave BMS can be reduced by the arrangement of the slave BMS, and communication efficiency can be improved by reducing obstacles to interfering communication.

[0110] Although the embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present disclosure defined in the claims are also included in the present disclosure.

Claims

1. A battery pack, comprising: A plurality of battery modules arranged along rows and columns; A plurality of slave battery management systems (BMSs), each disposed between two adjacent battery modules in a corresponding row among the plurality of rows of the plurality of battery modules and configured to detect status information of the two adjacent battery modules; And A master BMS configured to receive the status information of the plurality of battery modules through wireless optical communication with the plurality of slave BMSs, Wherein, at least two of the plurality of slave BMSs are configured to be disposed at different heights.

2. The battery pack according to claim 1, wherein Each of the plurality of slave BMSs and the master BMS includes: An optical transmitter configured to transmit a wireless optical signal; and An optical receiver configured to receive a wireless optical signal.

3. The battery pack according to claim 2, wherein The optical transmitters of the at least two slave BMSs are configured to be disposed at different heights from a reference plane, and the optical receivers of the at least two slave BMSs are configured to be disposed at different heights from the reference plane.

4. The battery pack according to claim 2, wherein The at least two slave BMSs are configured to be disposed at different heights from the uppermost surface or the lowermost surface of the plurality of battery modules.

5. The battery pack according to claim 2, further comprising: A reflector configured to reflect the wireless optical signal received from the optical transmitter of each of the plurality of slave BMSs to the master BMS, and configured to reflect the wireless optical signal received from the optical transmitter of the master BMS to the plurality of slave BMSs.

6. The battery pack according to claim 2, wherein Each of the plurality of slave BMSs further includes: A first analog front-end integrated circuit (AFE IC) configured to measure the status information of any one of the corresponding two battery modules; and A second AFE IC configured to measure the status information of the other one of the corresponding two battery modules.

7. The battery pack according to claim 2, wherein Each of the plurality of slave BMSs is configured to be fixed to any one of the two opposite side surfaces of the corresponding two battery modules that face each other.

8. The battery pack according to claim 1, wherein Each of the plurality of slave BMSs is configured to be connected to the corresponding two battery modules through a flexible printed circuit board (FPCB).

9. The battery pack according to any one of claims 1 to 8, wherein The wireless optical communication uses an infrared transmission medium.

10. A battery pack, comprising: A plurality of battery modules arranged along rows and columns; A plurality of slave battery management systems (BMSs), each disposed on any one of the two opposite side surfaces of two adjacent battery modules in a corresponding row among the plurality of rows of the plurality of battery modules that face each other; And A master BMS configured to communicate with the plurality of slave BMSs, Wherein, among the plurality of slave BMSs, the slave BMSs disposed in different rows and the same column are configured to be disposed at different heights.

11. The battery pack according to claim 10, wherein, each of the plurality of slave BMSs and the master BMS includes: an optical transmitter configured to transmit a wireless optical signal; and an optical receiver configured to receive a wireless optical signal.

12. The battery pack according to claim 11, wherein, each of the plurality of slave BMSs further includes: a first analog front-end integrated circuit (AFE IC) configured to measure state information of any one of the corresponding two battery modules; and a second AFE IC configured to measure state information of the other one of the corresponding two battery modules.

13. The battery pack according to claim 10, wherein: the plurality of slave BMSs and the master BMS communicate using an infrared transmission medium.

14. The battery pack according to claim 10, wherein, each of the plurality of slave BMSs is configured to be connected to the corresponding two battery modules through a flexible printed circuit board (FPCB).

15. The battery pack according to claim 11, further comprising: a reflector configured to reflect the wireless optical signal received from the optical transmitter of each of the plurality of slave BMSs to the master BMS, and configured to reflect the wireless optical signal received from the optical transmitter of the master BMS to the plurality of slave BMSs.

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