Battery management device and its operation method

Abstract

A battery management device according to one embodiment disclosed in this document may include a buck converter that generates a driving voltage based on a voltage of a battery pack, a comparator that compares a distribution voltage generated based on the voltage of the battery pack with a reference voltage and controls the operation of the buck converter based on a comparison result, and a detection unit that detects whether the battery pack is connected to a target device and controls the operation of the comparator based on the detection result.

Description

Technical Field

[0001] The embodiments disclosed in this document claim the benefit of priority based on Korean Patent Application No. 10-2021-0120043 filed on September 8, 2021, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety. The embodiments disclosed in this document relate to a battery management device and an operating method thereof.

Background Art

[0002] An electric vehicle receives electrical supply from the outside to charge battery cells, and then drives a motor with the voltage charged in the battery cells to obtain power. The battery cells of an electric vehicle can generate heat due to chemical reactions occurring during the charging and discharging of electricity, and such heat can damage the performance and lifespan of the battery cells. Therefore, a battery management device (BMS, Battery Management System) that monitors the temperature, voltage, and current of the battery cells is driven to diagnose the state of the battery cells.

[0003] However, when the battery cells become over-discharged due to the continuous driving of the battery management device in a low-voltage state, the battery cells cannot be regenerated, and a problem may occur in that the entire battery pack cannot be used.

Summary of the Invention

Problems to be Solved by the Invention

[0004] One object of the embodiments disclosed in this document is to provide a battery management device and an operating method thereof that can prevent over-discharge of battery cells.

[0005] The technical problems of the embodiments disclosed in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description.

Means for Solving the Problems

[0006] The battery management device according to one embodiment disclosed in this document includes a buck converter that generates a driving voltage based on the voltage of the battery pack, a comparator that compares the distributed voltage generated based on the voltage of the battery pack with a reference voltage and controls the operation of the buck converter based on the comparison result, and a detection unit that detects whether the battery pack and the target device can be connected and controls the operation of the comparator based on the detection result.

[0007] According to one embodiment, when the distributed voltage is less than or equal to the reference voltage, the comparator can generate a cut-off signal that disables the buck converter.

[0008] According to one embodiment, the buck converter can turn off when the cut-off signal is input from the comparator. According to one embodiment, the battery management device can operate in an ultra-low power mode when the buck converter turns off.

[0009] According to one embodiment, the detection unit includes a photocoupler, and when the detection unit detects that the target device is connected to the battery pack, it can transmit an enable voltage to the comparator.

[0010] According to one embodiment, when the enable voltage is input from the detection unit, the comparator can generate an open signal that enables the buck converter. According to one embodiment, the buck converter can turn on when the open signal is input from the comparator.

[0011] According to one embodiment, the battery management device can operate in an active mode when the buck converter turns on. According to one embodiment, it can further include a voltage dividing resistor that distributes the voltage of the battery pack based on the input power supply of the comparator to generate the distributed voltage.

[0012] The operation method of the battery management device according to an embodiment disclosed in this document includes: a step in which a buck converter generates a driving voltage based on the voltage of a battery pack; a step in which a comparator compares a divided voltage generated based on the voltage of the battery pack with a reference voltage; and a step in which the comparator controls the operation of the buck converter based on the comparison result.

[0013] The step in which, according to an embodiment, the comparator controls the operation of the buck converter based on the comparison result may include a step in which the comparator generates a cut-off signal for disabling the buck converter when the divided voltage is less than or equal to the reference voltage.

[0014] The step in which, according to an embodiment, the comparator controls the operation of the buck converter based on the comparison result may include a step in which the buck converter turns off.

[0015] The step in which, according to an embodiment, the comparator controls the operation of the buck converter based on the comparison result may include a step in which the battery management device operates in an extremely low power mode.

[0016] According to an embodiment, the detection unit may further include a step of detecting whether the battery pack can be connected to the target device and controlling the operation of the comparator based on the detection result.

[0017] The step in which, according to an embodiment, the photocoupler detects whether the battery pack can be connected to the target device and controls the operation of the comparator based on the detection result may include a step in which the detection unit transmits an enable voltage to the comparator when detecting the connection between the battery pack and the target device.

[0018] In one embodiment, the step in which the photocoupler detects whether the battery pack is connected to the target device and controls the operation of the comparator based on the detection result may include the step in which the comparator generates an enabling signal to enable the buck converter.

[0019] In one embodiment, the step in which the photocoupler detects whether the battery pack is connected to the target device and controls the operation of the comparator based on the detection result is that the buck converter can be turned on when the enabling signal is input from the comparator.

Advantages of the Invention

[0020] According to the battery management device and its operation method according to one embodiment disclosed in this document, over-discharge of the battery cell can be prevented and the efficiency of the battery management device can be improved.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0022] Hereinafter, some embodiments disclosed in this document will be described in detail with exemplary drawings. When assigning reference numerals to the components of each drawing, it should be noted that the same components are assigned the same numerals as much as possible when they are shown on other drawings. Also, in describing the embodiments disclosed in this document, if a specific description of a related known configuration or function is determined to impede the understanding of the embodiments disclosed in this document, the detailed description thereof will be omitted.

[0023] In describing the components of the embodiments disclosed in this document, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are merely for distinguishing the components from other components, and the essence, order, or sequence of the components are not limited by such terms. Also, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those having ordinary knowledge in the technical field to which the embodiments disclosed in this document belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or overly formal sense unless clearly defined in this document.

[0024] FIG. 1 is a diagram showing the configuration of a battery pack according to an embodiment disclosed in this document. Referring to FIG. 1, a battery pack 1000 according to an embodiment disclosed in this document can include a battery module 100, a battery management device 200, and a switching unit 300.

[0025] The battery pack 1000 can supply power to the target device 2000. For this purpose, the battery pack 1000 can be electrically connected to the target device 2000. Here, the target device 2000 can include an electrical, electronic, or mechanical device that operates by receiving power supply from the battery pack 1000 including a plurality of battery cells 110, 120, 130, 140. For example, the target device 2000 can include not only small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also large products that require high power such as electric vehicles and hybrid vehicles, as well as power storage devices and backup power storage devices that store surplus generated power and renewable energy, but are not limited thereto.

[0026] For example, when an external charger (not shown) is connected to the target device 2000, the battery pack 1000 can receive power supply from the target device 2000. For example, the battery module 100 and / or the plurality of battery cells 110, 120, 130, 140 included in the battery pack 1000 can be charged using the DC power supplied from an external charger connected to the target device 2000.

[0027] The battery module 100 can include a first battery cell 110, a second battery cell 120, a third battery cell 130, and a fourth battery cell 140. Although it is shown in FIG. 1 that there are four battery cells, the present invention is not limited thereto, and the battery module 110 can be configured to include n (n is a natural number of 2 or more) battery cells. On the other hand, although it is shown in FIG. 1 that there is one battery module 100, depending on the embodiment, a plurality of battery modules 100 may be configured.

[0028] A battery management device (BMS, Battery Management System) 200 can manage and / or control the state and / or operation of a battery module 100. For example, the battery management device 200 can manage and / or control the state and / or operation of a plurality of battery cells 110, 120, 130, 140 included in the battery module 100. The battery management device 200 can monitor the voltage, current, temperature, etc. of each of the battery module 100 and / or the plurality of battery cells 110, 120, 130, 140 included in the battery module 100.

[0029] The battery management device 200 can calculate the cell balancing time of each of the battery module 100 and / or the plurality of battery cells 110, 120, 130, 140 included in the battery module 100. Here, the cell balancing time can be defined as the time required for balancing the battery cells. For example, the battery management device 200 can calculate the cell balancing time based on the SOC (State of Charge), battery capacity, and balancing efficiency of each of the battery module 100 and / or the plurality of battery cells 110, 120, 130, 140 included in the battery module 100.

[0030] The operating modes of the battery management device 200 can include an active mode (Wake-up mode) and a sleep mode (Sleep mode). The active mode (Wake-up mode) can be defined as a state in which power is supplied to the battery management device 200 and the process of the battery management device 200 is driven. For example, when the battery management device 200 operates in the active mode, it can consume 1A per hour.

[0031] Sleep mode can be defined as a state in which the process of the battery management device 200 does not operate, but the battery management device 200 supplies power to the target device 2000. According to an embodiment, when operating in sleep mode, the battery management device 200 can receive power supply from the battery module 100. For example, when the battery management device 200 operates in sleep mode to supply power to the target device 2000, it can consume 5 mA per hour.

[0032] The battery management device 200 can control the operation of the switching unit 300. For example, the battery management device 200 can short-circuit the switching unit 300 to supply power to the target device 2000. Also, when a charging device is connected to the battery module 100, the battery management device 200 can short-circuit the switching unit 300.

[0033] The switching unit 300 is a switching device for controlling the flow of current for charging or discharging the battery module 100. The switching unit 300 can include a first switching unit 310 connected in series to the + terminal side of the battery module 100, or a second switching unit 320 connected in series to the - terminal side of the battery module 100. For example, the first switching unit 310 or the second switching unit 320 can be realized in the form of a contactor. The contactor can open and close the flow of current through the battery module 100 by becoming in an on state or an off state according to the switching signal of the battery management device 200.

[0034] Hereinafter, with reference to FIG. 2, the configuration of the above-described battery management device 200 will be described. FIG. 2 is a block diagram showing the configuration of a battery management device according to an embodiment disclosed in this document.

[0035] Referring to FIG. 2, the battery management device 200 can include a buck converter 210, a comparator 220, a detection unit 230, and a voltage dividing resistor 240.

[0036] The buck converter 210 can generate the driving voltage of the battery management device 200 based on the voltage of the battery module 100. Also, the buck converter 210 can generate the output voltage supplied to the target device 2000 based on the voltage of the battery module 100. For example, the buck converter 210 (Buck Converter) is a step-down converter rectified by a diode and can be used as a non-isolated step-down switching DC / DC converter.

[0037] The buck converter 210 can perform a low voltage cut-off (EN / UVLO, Enable / Under Voltage Lock Out) function. Here, the low voltage cut-off function may be a function that stops the output of the buck converter 210 and protects its own output transistor and load when the input voltage applied to the buck converter 210 is below the operating voltage range of the buck converter 210. That is, the buck converter 210 can forcibly stop the operation of the circuit using the low voltage cut-off function.

[0038] The comparator 220 can compare the divided voltage generated based on the voltage of the battery module 100 with the reference voltage. Here, the divided voltage can be generated via the voltage dividing resistor 240. The voltage dividing resistor 240 can divide the voltage of the battery module 100 based on the input power supply of the comparator 220. For example, the voltage dividing resistor 240 can generate a divided voltage that is 1 / 10 of the voltage of the battery module 100.

[0039] The comparator 220 can determine whether the divided voltage generated based on the voltage of the battery module 100 is below the reference voltage and control the operation of the buck converter 210. Specifically, when the divided voltage generated based on the voltage of the battery module 100 is below the reference voltage, the comparator 220 can generate a cut-off signal that disables the buck converter 210.

[0040] For example, the voltage of a normal battery module 100 can be defined as 40 to 60V, the voltage of a low-voltage battery module 100 is 20V to 30V, and the voltage of a battery module 100 that must be discarded in an over-discharged state is 20V or less. When the battery module 100 is left uncharged in a low-voltage state for a certain period of time, the battery module 100 can reach an over-discharged state after a certain period of time due to the current consumed for generating the driving voltage of the battery management device 200. When the battery module 100 reaches an over-discharged state, the battery cells 110, 120, 130, 140 included in the battery module 100 cannot be regenerated and recovered, and a problem may occur where the entire battery pack 1000 cannot be used.

[0041] Therefore, when the divided voltage based on the voltage of the battery module 100 is below the reference voltage, the comparator 220 can prevent the current consumed by the battery management device 200 and drive the battery management device 200 in an ultra-low power mode. When the battery management device 200 operates in an ultra-low power mode (UVLO, Under Voltage Lock Out), the output voltage consumed by the buck converter 210 can be removed to achieve the lowest power state. For example, when the battery management device 200 operates in an ultra-low power mode, it can consume 200 μA or less per hour.

[0042] For example, if the allowable capacity of the battery module 100 until it reaches an over-discharged state is 1.5 Ah, and the battery management device 200 operates in sleep mode and consumes 5 mA per hour, the battery module 100 can become over-discharged after 1.5 Ah / 0.005 A = 300 h, approximately 300 hours. In contrast, if the battery management device 200 operates in an ultra-low power mode and consumes 200 μA per hour, the battery module 100 can become over-discharged after 1.5 Ah / 0.0002 A = 7500 h, approximately 7500 hours.

[0043] That is, when the battery management device 200 operates in the ultra-low power mode, the time during which the battery module 100 can reach the over-discharged state can be extended compared to when the battery management device 200 operates in the sleep mode. By operating the battery management device 200 in the ultra-low power mode, the standby time during which the battery module 100 can be supplied with power from the target device 2000 can be extended.

[0044] The buck converter 210 can be turned off when a cutoff signal is input from the comparator 220. That is, when a cutoff signal is input from the comparator 220, the buck converter 210 no longer generates a driving power supply based on the power supply of the battery module 100. When the buck converter 210 is turned off, the battery management device 200 can operate in the ultra-low power mode because no power is supplied.

[0045] The detection unit 230 can detect whether the battery module 100 and the target device 2000 are connected, and can control the operation of the comparator 220 based on the detection result. For example, the detection unit 230 can include a photo coupler. Hereinafter, an explanation will be given assuming that the detection unit 230 is a photo coupler. According to an embodiment, a photo coupler is a component optically coupled by inserting a high-insulation substance between a light-emitting element and a light-receiving element, and can transmit an electrical signal as light. For example, the photo coupler can include a light-emitting diode (LED) as a light-emitting element and a field effect transistor (FET) as a light-receiving element that performs the role of a switch. Specifically, when the detection unit 230 detects the connection between the battery module 100 and the target device 2000, it can transmit an enable voltage to the comparator 220.

[0046] The detection unit 230 can detect whether the battery pack 1000 and the target device 2000 are connected, and can control the operation of the comparator 220 based on the detection result. That is, the detection unit 230 can detect whether the battery pack 1000 and the target device 2000 are connected. Specifically, when the detection unit 230 detects the connection between the battery pack 1000 and the target device 2000, it can transmit an enable voltage to the comparator 220.

[0047] When an enable voltage is input from the detection unit 230, the comparator 220 can generate an enable signal to enable the buck converter 210. When an enable signal is input from the comparator 220, the buck converter 210 can be turned on. When the buck converter 210 is turned on, the battery management device 200 can operate in the active mode again.

[0048] FIG. 3 is a circuit diagram showing an implementation example of a battery management device according to an embodiment disclosed in this document. Referring to FIG. 3, the battery management device 200 may include a buck converter 210, a comparator 220, a detection unit 230, a voltage dividing resistor 240, a linear regulator 250, and a reference voltage circuit 260.

[0049] The buck converter 210 can output a driving voltage using the input voltage. The buck converter 210 may include a power input terminal V_IN and a power output terminal V_OUT. The power input terminal V_IN of the buck converter 210 can receive the application of the input voltage from the battery module 100. For example, the power output terminal V_OUT of the buck converter 210 can output a driving voltage generated based on the input voltage of the battery module 100.

[0050] The driving voltage generated by the buck converter 210 can be supplied to the controller 2100 of the target device 2000. The controller 2100 of the target device 2000 can manage and / or control the state and / or operation of an electric circuit composed of a plurality of electrical elements and components included in the target device 2000. The controller 2100 can drive the electric circuit composed of electrical elements and components using the driving voltage generated by the buck converter 210.

[0051] Comparator 220 can have a predetermined voltage applied as a power supply. The non-inverting input terminal (+) V_IN+ of comparator 220 can receive the application of the divided voltage, and the inverting input terminal (-) V_IN- of comparator 220 can receive the application of the reference voltage V_ref. Here, the reference voltage V_ref can be defined as the voltage supplied from linear regulator 250 and reference voltage circuit 260.

[0052] Linear regulator (LDO) 250 can convert and supply the power supply to a preset constant voltage. For example, linear regulator 250 can output 5V, which is a preset voltage, using the voltage of battery module 100.

[0053] Reference voltage circuit (REF IC) 260 can receive the input of the 5V output voltage of linear regulator 250 and generate the reference voltage V_REF. For example, reference voltage circuit 260 can output a voltage of 3V based on the output voltage of linear regulator 250.

[0054] The divided voltage can be generated via voltage dividing resistor 240. Voltage dividing resistor 240 can include first resistor 241 and second resistor 242. The magnitudes of first resistor 241 and second resistor 242 can be set based on the input power supply of comparator 220. For example, the divided voltage may be the voltage applied to first node N1. According to an embodiment, the voltage applied to first node N1 can be the voltage across second resistor 242 due to the voltage division of first resistor 241 and second resistor 242.

[0055] Comparator 220 can compare the distributed voltage with the reference voltage V_ref and control the operation of the buck converter 210 based on the comparison result. The output signal of comparator 220 can be input to the EN / UVLO terminal of buck converter 210. For example, when the reference voltage V_ref is less than the distributed voltage, comparator 220 can output a logic high signal. For example, when the reference voltage V_ref is greater than or equal to the distributed voltage, comparator 220 can output a logic low signal.

[0056] For example, when the reference voltage V_ref is greater than or equal to the distributed voltage, comparator 220 can generate a cutoff signal to disable buck converter 210. Specifically, when it is determined that the battery module 100 is in a low voltage state, comparator 220 can input a logic low signal to the EN / UVLO terminal of buck converter 210. Buck converter 210 can turn off when a cutoff signal from comparator 220, that is, a logic low signal, is input to the EN / UVLO terminal. Therefore, since buck converter 210 turns off and no power is supplied, battery management device 200 can operate in an extremely low power mode.

[0057] Detection unit 230 can detect whether the battery pack 1000 and the target device 2000 can be connected and control the operation of comparator 220 based on the detection result. Detection unit 230 can detect the current flowing through both ends and confirm that the target device 2000 is connected to the battery pack 1000 and power is supplied. When detection unit 230 detects that the target device 2000 is connected to the battery pack 1000 and power is supplied, it can transmit the enable voltage V_LDO_5V to comparator 220.

[0058] When an enable voltage is input from detection unit 230, comparator 220 can generate an open signal to enable buck converter 210. For example, comparator 220 can receive the input of the 5V enable voltage V_LDO_5V from detection unit 230 and compare the input voltage with the reference voltage.

[0059] For example, when the reference voltage V_ref is less than the distributed voltage, the comparator 220 can generate a release signal to enable the buck converter 210. That is, the comparator 220 can input a logic high signal to the EN / UVLO terminal of the buck converter 210. The buck converter 210 can turn on when a release signal from the comparator 220, that is, a logic high signal, is input to the EN / UVLO terminal.

[0060] When the buck converter 210 is changed to the turn-on state, the battery management device 200 can transmit a switching signal to the first switching unit 310 and the second switching unit 320. The first switching unit 310 and the second switching unit 320 can be switched on or off based on the switching signal of the battery management device 200.

[0061] For example, when the first switching unit 310 and the second switching unit 320 are switched on based on the switching signal of the battery management device 200, the battery module 100 can be charged by receiving power supply from the target device 2000.

[0062] As described above, the battery management device 200 according to an embodiment disclosed in this document can prevent over-discharge of battery cells. In addition, the battery management device 200 adds an extremely low power mode to the operation mode, and can delay the discard of the battery pack 1000 due to over-discharge of the battery cells to the maximum extent.

[0063] FIG. 4 is a flowchart showing an operation method of a battery data management device according to an embodiment disclosed in this document. FIG. 5 is a flowchart showing an operation method of a battery data management device according to another embodiment disclosed in this document.

[0064] Hereinafter, with reference to FIGS. 1 to 3, the operation method of the battery management device 200 will be described. The battery management device 200 can include a buck converter 210, a comparator 220, a detection unit 230, and a voltage dividing resistor 240.

[0065] Since the battery management device 200 can be substantially the same as the battery management device 200 described with reference to FIGS. 1 to 3, the following description will be simplified to avoid duplication.

[0066] First, referring to FIG. 4, the operation method of the battery management device 200 includes a step (S101) in which the buck converter 210 generates a driving voltage based on the voltage of the battery module 100, a step (S102) in which the comparator 220 compares the divided voltage generated based on the voltage of the battery module 100 with a reference voltage, a step (S103) in which the comparator 220 determines whether the divided voltage is less than or equal to the reference voltage, a step (S104) in which the comparator 220 generates a cut-off signal to disable the buck converter 210, a step (S105) in which the buck converter 210 turns off, and a step (S106) in which the battery management device 200 is driven in an extremely low power mode.

[0067] Hereinafter, steps S101 to S106 will be specifically described. In step S101, the buck converter 210 can output a driving voltage using the input voltage. In step S101, the buck converter 210 can output a driving voltage based on the voltage of the battery module 100. In step S101, for example, the buck converter 210 (Buck Converter) is a step-down converter rectified by a diode and can be used as a non-isolated step-down switching DC / DC converter.

[0068] In step S102, the comparator 220 can compare the divided voltage generated based on the voltage of the battery module 100 with the reference voltage. In step S103, the comparator 220 can determine whether the divided voltage is less than or equal to the reference voltage.

[0069] In step S104, when the reference voltage is equal to or higher than the distributed voltage, the comparator 220 can generate a cutoff signal for disabling the buck converter 210.

[0070] In step S105, the buck converter 210 can be turned off when a cutoff signal is input from the comparator 220. In step S105, that is, when a cutoff signal is input from the comparator 220, the buck converter 210 no longer generates a driving power supply based on the power supply of the battery module 100.

[0071] In step S106, when the buck converter 210 is turned off, since no power supply is provided, the battery management device 200 can operate in an extremely low power mode.

[0072] Referring to FIG. 5, the operation method of the battery management device 200 may include a step (S201) in which the buck converter 210 is turned off, a step (S202) in which the detection unit 230 detects whether the battery pack 1000 and the target device 2000 can be connected, a step (S203) in which the detection unit 230 transmits an enable voltage to the comparator 220, a step (S204) in which the comparator 220 generates an open signal for enabling the buck converter 210, and a step (S205) in which the buck converter 210 is turned on when an open signal is input from the comparator 220.

[0073] In step S201, the buck converter 210 can be turned off when a cutoff signal is input from the comparator 220. In step S201, since the buck converter 210 of the battery management device 200 is turned off and no power supply is provided, the battery management device 200 can operate in an extremely low power mode.

[0074] In step S202, the detection unit 230 can detect whether the battery module 100 and the target device 2000 can be connected and control the operation of the comparator 220 based on the detection result.

[0075] In step S203, when the detection unit 230 detects the connection between the battery module 100 and the target device 2000, it can transmit an enable voltage to the comparator 220.

[0076] In step S204, the comparator 220 can generate an open signal to enable the buck converter 210. In step S205, the buck converter 210 can be turned on when an open signal is input from the comparator 220.

[0077] The above description is only an exemplary illustration of the technical idea of the present disclosure. Those with ordinary knowledge in the technical field to which the present disclosure belongs can make various modifications and variations without departing from the essential characteristics of the present disclosure.

[0078] Therefore, the embodiments disclosed in the present disclosure are for illustrative purposes rather than for limiting the technical idea of the present disclosure, and the scope of the technical idea of the present disclosure is not limited by such embodiments. The protection scope of the present disclosure should be interpreted according to the claims described below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present disclosure.

Description of Reference Numerals

[0079] 100 Battery module 110 Battery module 110 First battery cell 120 Second battery cell 130 Third battery cell 140 Fourth battery cell 200 Battery management device 210 Buck converter 220 Comparator 230 Detection unit 240 Voltage dividing resistor 241 First resistor 242 Second resistor 250 Linear Regulator 260 Reference Voltage Circuit 300 Switching Section 310 First Switching Section 320 Second Switching Section 1000 Battery Pack 2000 Target Device 2100 Controller

Claims

1. A buck converter that generates a drive voltage based on the voltage of a battery pack, a comparator that compares a divided voltage generated based on the voltage of the battery pack with a reference voltage and controls the operation of the buck converter based on the comparison result, a detection unit that detects whether the battery pack and a target device are connected and controls the operation of the comparator based on the detection result, comprising: the detection unit includes an optocoupler, and when the detection unit detects that a target device is connected to the battery pack, the detection unit transmits an enable voltage to the comparator A battery management device.

2. The battery management device according to claim 1, wherein the comparator generates a cutoff signal for disabling the buck converter when the divided voltage is less than or equal to the reference voltage.

3. The battery management device according to claim 2, wherein the buck converter turns off when the cutoff signal is input from the comparator.

4. The battery management device according to claim 3, wherein the battery management device operates in an ultra-low power mode when the buck converter turns off.

5. The battery management device according to claim 1, wherein the comparator generates an open signal for enabling the buck converter when the enable voltage is input from the detection unit.

6. The battery management device according to claim 5, wherein the buck converter turns on when the open signal is input from the comparator.

7. The battery management device according to claim 6, wherein the battery management device operates in an active mode when the buck converter turns on.

8. The battery management device according to claim 1, further comprising a voltage dividing resistor that divides the voltage of the battery pack based on the input power supply of the comparator to generate the divided voltage.

9. A step of generating a drive voltage based on the voltage of a battery pack by a buck converter, a step of comparing a divided voltage generated based on the voltage of the battery pack with a reference voltage by a comparator, a step of controlling the operation of the buck converter based on the comparison result by the comparator, When a detection unit including a photocoupler detects that the battery pack and the target device are connected, a step of transmitting an enable voltage to the comparator A method of operating a battery management device including the above steps.

10. The step of controlling the operation of the buck converter based on the comparison result by the comparator includes the step of generating a cut-off signal for disabling the buck converter when the comparator determines that the distributed voltage is equal to or lower than the reference voltage. The method of operating a battery management device according to claim 9, characterized in that it includes this step.

11. The step of controlling the operation of the buck converter based on the comparison result by the comparator includes the step of turning off the buck converter. The method of operating a battery management device according to claim 10, characterized in that it includes this step.

12. The step of controlling the operation of the buck converter based on the comparison result by the comparator includes the step of operating the battery management device in an extremely low power mode. The method of operating a battery management device according to claim 11, characterized in that it includes this step.

13. The method of operating a battery management device according to claim 9 further includes a step of detecting whether the battery pack and the target device are connected by a detection unit and controlling the operation of the comparator based on the detection result.

14. The step of detecting whether the battery pack and the target device are connected by the detection unit and controlling the operation of the comparator based on the detection result includes the step of transmitting an enable voltage to the comparator when the detection unit detects the connection between the battery pack and the target device. The method of operating a battery management device according to claim 13, characterized in that it includes this step.

15. The step of detecting whether the battery pack and the target device are connected by the detection unit and controlling the operation of the comparator based on the detection result includes the step of generating an open signal for enabling the buck converter by the comparator. The method of operating a battery management device according to claim 14, characterized in that it includes this step.

16. The step of detecting whether the battery pack and the target device are connected by the detection unit and controlling the operation of the comparator based on the detection result includes the step of turning on when the release signal is input from the comparator by the buck converter. The method for operating a battery management device according to claim 15, characterized in that it comprises the above steps.

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