Vehicle battery management system and method

Abstract

Disclosed is a vehicle battery management system including a first controller that controls power on and power off states of a plurality of controllers in a vehicle and wakes up at least a part of the plurality of controllers by periodically waking up in the power off state, and a second controller that, when the power off state starts, disconnects a main relay connecting a first battery in the vehicle and a vehicle system, maintains power for a first reference time set in advance and monitors a state of the first battery storing energy for generating power of the vehicle, and wakes up to monitor the state of the first battery according to a wake-up period of the first controller after the first reference time elapses.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle battery management system and method, and more particularly, to a vehicle battery management system and method that can effectively monitor the state of a battery in a power-off state of various controllers in a vehicle after termination of travel of the vehicle, thereby preventing various problems occurring in the battery in the power-off state. BACKGROUND

[0002] Generally, an environmentally-friendly vehicle using electric power is a vehicle that generates power by driving an electric motor as an electric rotating mechanism using electric power stored in a battery. The dynamic performance of the environmentally-friendly vehicle is closely related to the performance of the battery, and thus, the battery needs to be effectively monitored and managed.

[0003] Generally, the battery of the environmentally-friendly vehicle is managed by a controller generally called a battery management system (BMS). The battery management system collects various information (battery voltage, battery current, battery temperature, etc.) for battery management from the battery, and applies the collected information to various algorithms stored in advance to calculate various parameters for battery management.

[0004] The conventional battery management method of the vehicle is mainly performed in a state in which power is supplied to the battery management system, that is, a power-on (IG ON) state. That is, a main relay connected to the battery monitors the state of the battery in a state in which the battery is electrically connected between the battery and other components (for example, a power module for converting power of the battery and supplying the power to the electric motor, or a charger for generating power for charging the battery, etc.).

[0005] As described above, in the conventional vehicle battery management method, since the information for battery management is collected in a state in which the battery is electrically connected to the other components, there is a problem that the battery cannot be correctly monitored due to the influence of the other components on the collected information.

[0006] In addition, when only the battery management system continues in an awake state and continuously monitors the battery in a power-off (IG OFF) state, power is continuously consumed in a state in which the vehicle battery is not charged, and thus, a method suitable for monitoring the battery in the power-off state has not been conventionally applied.

[0007] The matters described as background technology above are only for enhancing the understanding of the background of the present application, and should not be considered as prior art known to those skilled in the art.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] (Patent Document 1) KR 10-2013-0061964 A

[0011] (Patent Document 2) KR 10-2016-0153874 A SUMMARY

[0012] (I) Technical Problem to be Solved

[0013] Accordingly, an object of the present application is to provide a vehicle battery management system and method that can effectively monitor a battery in a vehicle off state, thereby preventing accidents such as a battery fire.

[0014] (II) Technical Solution

[0015] As a technical solution for solving the above technical problem, the present application provides a vehicle battery management system including a first controller that controls power on (IG ON) and power off (IG OFF) states of a plurality of controllers in a vehicle and wakes up at least a part of the plurality of controllers by periodically waking up in the power off state, and a second controller that, when the power off state starts, disconnects a main relay that connects a first battery in the vehicle and a vehicle system, maintains power for a first reference time set in advance and monitors a state of the first battery that stores energy for generating power of the vehicle, and wakes up to monitor the state of the first battery according to a wake-up period of the first controller after the first reference time elapses.

[0016] According to one embodiment of the present application, the second controller can set the wake-up period of the first controller.

[0017] According to one embodiment of the present application, the second controller can set the wake-up period of the first controller to a first wake-up period for a second reference time set from a time point when the power off state starts, and set the wake-up period of the first controller to a second wake-up period longer than the first wake-up period from a time point after the second reference time elapses.

[0018] According to one embodiment of the present application, when the main relay connected to the first battery is turned on, the second controller can suspend the monitoring of the first battery performed in the power off state and perform initialization.

[0019] According to one embodiment of the present invention, after the main relay is disconnected, the state of the first battery may not be monitored when the second controller cannot determine the charging state of the second battery that provides power supply voltage to the first controller and the second controller, or when the charging state of the first battery is lower than a preset reference value, or when communication is not possible with the low-voltage converter that reduces the voltage of the first battery and applies it to the second battery or the first controller.

[0020] As another technical solution to solve the above-mentioned technical problems, the present invention provides a vehicle battery management method, which includes the following steps: when an external input for terminating vehicle operation is generated, a first controller controls to put multiple controllers in the vehicle into a power-off state; a second controller disconnects the main relay connected to the first battery storing energy for generating vehicle power while maintaining power; a first monitoring, wherein the second controller sets the wake-up cycle of the first controller and maintains power and monitors the state of the first battery of the vehicle for a preset first reference time; and a second monitoring, wherein when the first reference time has elapsed, the second controller wakes up according to the wake-up cycle of the first controller to monitor the state of the first battery.

[0021] According to one embodiment of the present invention, after the step of disconnecting the main relay, the following steps may be further included: when the second controller cannot determine the charging state of the second battery that provides power supply voltage to the first controller and the second controller, or when the charging state of the first battery is lower than a preset reference value, or when communication is not possible with the low-voltage converter that reduces the voltage of the first battery and applies it to the second battery or the first controller, it is determined that the first monitoring will not be performed.

[0022] According to an embodiment of the present invention, in the first monitoring step, the second controller can determine the wake-up cycle of the first controller as a preset first wake-up cycle. In the second monitoring step, the second controller can be woken up by the first controller according to the first wake-up cycle within a preset second reference time starting from the time point after the first reference time has elapsed. After the second reference time has elapsed, the wake-up cycle of the first controller can be set to a second wake-up cycle that is longer than the first wake-up cycle, and the first controller can be woken up by the first controller according to the second wake-up cycle.

[0023] According to one embodiment of the present invention, in the first monitoring step, when the power is on under the control of the first controller, the second controller can determine whether the main relay is turned on, and when the main relay is turned on, the monitoring of the state of the first battery can be terminated.

[0024] According to an embodiment of the present invention, in the second monitoring step, the second controller can determine the reason for wake-up after wake-up, and the reason for determination is that the state of the first battery can be monitored when the wake-up occurs during the wake-up cycle set in the first controller.

[0025] According to an embodiment of the present invention, in the second monitoring step, the second controller can determine the reason for wake-up after wake-up, and when the reason is wake-up by external input rather than wake-up by the wake-up cycle set in the first controller, it can determine whether the main relay is turned on, and when the main relay is turned on, the monitoring of the state of the first battery can be terminated.

[0026] (III) Beneficial Effects

[0027] According to the vehicle battery management system and method, even when the electrical connection between the vehicle battery and the vehicle system is disconnected and all controllers are in a power-off state, the battery status can be monitored, thereby preventing various problems that may occur in the battery, such as battery fire.

[0028] In particular, according to various embodiments of the vehicle battery management system and method of the present invention, the number of times the battery is monitored is appropriately determined over time after the power-off state begins, thereby minimizing power consumption and effectively monitoring the battery state in the power-off state. Attached Figure Description

[0029] Figure 1 This is a block diagram of a vehicle battery management system according to an embodiment of the present invention.

[0030] Figure 2 This is a diagram illustrating the monitoring process of a vehicle battery management system over time according to an embodiment of the present invention.

[0031] Figures 3 to 5 This is a flowchart illustrating a vehicle battery management method according to an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached figures

[0033] 11: First Controller (VCU) 12: Second Controller (BMS)

[0034] 13: First battery (high-voltage battery, main battery)

[0035] 14: Low-voltage converter

[0036] 15: Second battery (low-voltage battery, auxiliary battery)

[0037] MR: Main Relay Detailed Implementation

[0038] Hereinafter, vehicle battery management systems and methods according to various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0039] Figure 1 This is a block diagram of a vehicle battery management system according to an embodiment of the present invention.

[0040] Reference Figure 1 According to an embodiment of the present invention, a vehicle battery management system may include: a first controller 11, which controls the power-on (IG ON) and power-off (IG OFF) states of a plurality of controllers in the vehicle, and wakes up at least a portion of the controllers by periodically waking them up in the power-off state; and a second controller 12, which disconnects the main relay MR connecting the first battery 13 in the vehicle and the vehicle system when the power-off state begins, maintains power and monitors the state of the first battery 13 in the vehicle for a preset first reference time, and wakes up according to the wake-up cycle of the first controller 11 after the first reference time has elapsed to monitor the state of the first battery 13.

[0041] like Figure 1 As shown, the first controller 11 can be implemented as a vehicle control unit (VCU) that controls the overall operation of the vehicle, and the second controller 12 can be implemented as a controller called a battery management system (BMS), which mainly monitors the state of the battery and controls the state of the range energizers (MRs) connected to the battery.

[0042] Alternatively, the first battery 13 may be the vehicle's main battery (or high-voltage battery), which supplies energy to the drive motor used to generate power for the vehicle or is charged by receiving regenerative energy from the drive motor.

[0043] exist Figure 1 In the figure, reference numeral "14" indicates a low voltage DC-DC converter (LDC) that reduces the high voltage of the main battery 13 to a low voltage corresponding to the power supply of the electrical load, and reference numeral "15" indicates an auxiliary battery 15 or low-voltage battery that can be charged by applying the voltage converted in the low voltage converter and can supply power voltage to various controllers in the vehicle.

[0044] In one embodiment of the invention, the first controller 11 can control the power-on and power-off states of multiple controllers in the vehicle based on signals input from an external source. For example, in the power-off state, when the driver inputs to press the vehicle's start button, the first controller 11 can recognize this and allow power to be supplied to multiple other controllers in the vehicle to put them in the power-on state. Conversely, when the driver inputs to press the vehicle's start button in the power-on state, the first controller 11 can recognize this and cut off the power supply to multiple other controllers in the vehicle to put them in the power-off state.

[0045] When the second controller 12 operates according to the power-on and power-off state control executed by the first controller 11, it can immediately maintain the power-on state for a certain period of time using the built-in power latch function after the vehicle stops driving through the driver's input and switches from the power-on state to the power-off state, and disconnect the main relay MR, and then monitor the first battery 13.

[0046] Here, the power latch function is a function in which the second controller 12 maintains a power supply state for a certain period of time by utilizing the power line directly connected to the second battery 15 that supplies power as needed, even in the event of a power shutdown control by the first controller 11.

[0047] The monitoring performed by the second controller 12 is to identify potential problems in the first battery 13 after the vehicle has stopped driving, and mainly includes measuring the insulation resistance value of the first battery 13, the voltage deviation between the battery cells constituting the first battery 13, and the degree of degradation of the first battery 13. The insulation resistance of the battery, the voltage deviation between the battery cells, and the degree of degradation can be derived or calculated by employing some of the various methods known in the art.

[0048] In addition, the second controller 12 can set the wake-up cycle of the first controller 11. After the power-off state begins, a built-in counter is used to calculate the reference time for changing the wake-up cycle of the first controller 11.

[0049] Figure 2 This is a diagram illustrating the monitoring process of a vehicle battery management system over time according to an embodiment of the present invention.

[0050] When a driver input is generated to terminate vehicle operation, the first controller 11 initiates a power-off state, shutting down the power to multiple controllers in the vehicle. In this way, when switching from a power-on state to a power-off state, the second controller 12 performs a power latch operation to maintain power at the start of the power-off state, and the first battery 13 can be monitored for a first reference time T1. For example, the first reference time T1 can be preset to approximately several hours.

[0051] Furthermore, since each embodiment of the present invention is used to monitor the state of the first battery 13, the second controller 12, which is the main body for monitoring the state of the first battery 13, can set the wake-up cycle of the first battery 13.

[0052] Specifically, from the point when the second controller 12 switches from the power-on state to the power-off state, that is, from the point when the power-off state begins, within a preset second reference time T2, the wake-up cycle of the first controller 11 can be set to the first wake-up cycle P1, and from the point when the second reference time T2 has elapsed, the wake-up cycle of the first controller 11 can be set to the second wake-up cycle P2, which is longer than the first wake-up cycle P1.

[0053] For example, the second reference time T2 can be about a few days, the first wake-up cycle P1 can be a few hours, and the second wake-up cycle P2 can be from tens of hours to a few days.

[0054] In summary, within the second reference time T2, the first controller 11 wakes up the second controller 12 according to the first wake-up cycle P1, and the woken second controller 12 can monitor the battery status. The wake-up time can be appropriately preset according to the time required for the second controller 12 to monitor the battery.

[0055] When the second reference time T2 has elapsed, the first controller 11 can wake up the second controller 12 according to the second wake-up period P2, which is longer than the first wake-up period P1.

[0056] The second controller 12 can use a built-in counter (not shown) to calculate the first reference time T1 and the second reference time T2. Here, the first reference time T1 and the second reference time T2 can be appropriately adjusted based on the state of charge or degradation of the second battery 15 supplying power voltage to the first controller 11 and the second controller 12, or the state of charge or degradation of the first battery 13, which provides energy for charging the second battery 15 via the low-voltage converter 14. For example, when the state of charge or degradation of the first battery 13 or the second battery 15 is lower than a reference value, the first reference time T1 and the second reference time T2 can be set to be relatively short; conversely, when the state of charge or degradation of the first battery 13 or the second battery 15 is higher than a reference value, the first reference time T1 and the second reference time T2 can be set to be relatively long.

[0057] The first reference time T1, the second reference time T2, the first wake-up cycle P1, and the second wake-up cycle P2 mentioned above are all preset values. In order to set these values, the capacity and degradation degree of the second battery 15 that provides power voltage to the controller, the capacity of the first battery 13 used to store energy for charging the second battery 15, the vehicle's fuel efficiency, etc. can be considered.

[0058] According to various embodiments of the present invention, the first battery 13 is monitored when it is not connected to the vehicle system, i.e., when the main relay MR is in an off (open) state. Therefore, while the first battery 13 remains in an off-system state, monitoring as described above can be performed over time. When the electrical connection state of the first battery 13 changes during the monitoring process described above, i.e., when the main relay MR is on (short-circuited), battery monitoring according to various embodiments of the present invention is suspended, the monitoring process can be initialized, and when the main relay MR is off, it can restart from the initial process for monitoring the battery (i.e., continuous monitoring via the power latch of the second controller 12).

[0059] On the other hand, when the driver presses the vehicle start button to generate an input to terminate the vehicle's operation while the vehicle is parked, and the first controller 11 controls the vehicle controller in the power-off state, the second controller 12 maintains the power supply using the power latch function and disconnects the main relay MR, and then it can be determined whether the requirements for monitoring the first battery 13 are met.

[0060] Here, as a requirement for monitoring the first battery 13, it may be considered whether to calculate the state of charge (SOC) of the second battery 15, the state of charge of the first battery 13, and the communication status between the controller.

[0061] For example, when the second controller 12 cannot determine the charging state of the second battery 15 that supplies power to the first controller 11 and the second controller 12, the first controller 11 and the second controller 13 cannot determine whether they can supply enough power to monitor the first battery 13 when the second battery 15 is not being charged, so monitoring can be omitted.

[0062] Additionally, when the state of charge of the second battery 15 is lower than a preset reference value, the low-voltage converter 14 can be operated to charge the second battery 15 using the energy stored in the first battery 13, in order to subsequently perform battery monitoring. If charging the second battery 15 is performed when the state of charge of the first battery 13 is insufficient, the state of charge of the first battery 13 may further decrease, potentially causing the vehicle to malfunction. Therefore, when the state of charge of the first battery 13 is lower than the preset reference value, monitoring can be omitted.

[0063] Additionally, when the first controller 11 and the second controller 12 or the second controller 12 and the low-voltage converter 14 are in a state where communication is not possible (e.g., CAN communication, CAN timeout, etc.), monitoring may not be performed because the various data required for monitoring cannot be exchanged.

[0064] Figures 3 to 5 This is a flowchart illustrating a vehicle battery management method according to an embodiment of the present invention. The vehicle battery management system according to an embodiment of the present invention described above can be used to implement the vehicle battery management method according to an embodiment of the present invention.

[0065] Reference Figures 3 to 5 First, when a driver input to terminate vehicle operation is generated while the vehicle is parked, the process can begin from step S11, which involves turning off the power in the vehicle controller from the first controller 11.

[0066] When the power is off via the first controller 11, the second controller 23 can use the power latch function to maintain the power and disconnect the main relay MR (S12), and determine whether the requirement to perform monitoring in the state where the main relay MR is disconnected is met (S13).

[0067] In step S13, when the second controller 12 cannot determine the charging state of the second battery 15 that provides power voltage to the first controller 11 and the second controller 12, or when the charging state of the first battery 13 is lower than a preset reference value, or when it cannot communicate with the low-voltage converter 14 that reduces the voltage of the first battery 13 and applies it to the second battery 15 or the first controller 11, it can be determined that monitoring will not be performed.

[0068] When the requirement to perform monitoring in step S13 is met, the second controller 12 operates the counter to calculate the time and sets the first wake-up period P1 of the first controller 11, so that the first controller 11 can be woken up according to the first wake-up period P1 (S14).

[0069] Subsequently, the second controller 12 can continuously monitor the state of the first battery 13 by maintaining the power latch function for a preset first reference time T1 (S15). As described above, during the monitoring of the state of the first battery 13, the insulation resistance of the first battery 13, the voltage deviation between the battery cells constituting the first battery 13, the degree of degradation of the first battery 13, etc. are calculated, and the state of the first battery 13 is monitored by comparing the calculated values ​​with the preset reference values ​​respectively.

[0070] When the second controller 12 has continuously monitored the state of the first battery 13 for a first reference time (S16), the second controller 12 can terminate the power latch function and shut down (S17). Thereafter, the second controller 12 can be woken up again by the first controller 11.

[0071] Although not shown in the figure, during the first reference time T1, while the second controller 12 is monitoring the first battery 13 while maintaining power using the power latch function, when the first controller 11 is woken up, the second controller 12 determines whether the main relay device MR is turned on, and when the main relay device MR is turned on, the counter can be initialized to stop monitoring.

[0072] When the first controller 11 is awakened after the first reference time T1, the first controller 11 can wake up the second controller 12 by supplying power to the second controller 12 (S21). At this time, the first controller 11 can provide the second controller 12 with information about whether the corresponding wake-up is performed by a preset first wake-up cycle or by the driver's input.

[0073] When the second controller 12 is woken up, based on the information received from the first controller 11, it is determined whether the second controller 12 was woken up by power supply input by the driver (S22). If it is woken up according to the first wake-up cycle P1, the state of the first battery 13 can be monitored for a preset time, and then it is turned off again (S23). It can continue to monitor periodically according to the first wake-up cycle P1 until a preset second reference time T2 has elapsed (S24).

[0074] In step S24, when the second controller 12 determines that the second reference time T2 has elapsed based on the time calculated by the counter, it sets the wake-up cycle of the first controller 11 to a second wake-up cycle P2 that is longer than the first wake-up cycle P1, and sends it to the first controller 11 (S25).

[0075] On the other hand, when it is determined that the first controller 11 is awake and in a power-on state (S21), and the reason for the power-on state is based on the power-on state input by the driver, rather than the periodic wake-up of the first wake-up cycle P1 (S22), the second controller 12 determines whether it is necessary to connect the main power supply MR, and when the main power supply MR is connected (S26), the counter can be initialized (S27). That is, when the first battery 11 is connected to the vehicle system by connecting the main power supply MR, the state of the first battery 11 changes, and the previously executed monitoring of the first battery 13 can be terminated.

[0076] When the first controller 11 is in a power-off state again after the counter initialization (S27) (S28), step S12 can be executed, allowing the monitoring process described above to be executed again from the beginning. If the vehicle starts driving after the counter initialization (S27) without being in a power-off state again through the first controller 11, the monitoring process can be terminated until the next power-off state.

[0077] In step S25 above, after setting the wake-up cycle of the first controller 11 to the second wake-up cycle P2, the first controller 11 wakes up once every second wake-up cycle P2 to supply power to the second controller 12.

[0078] When the first controller 11 is awakened after the second reference time T2, the first controller 11 can wake up the second controller 12 by supplying power to the second controller 12 (S31). At this time, the first controller 11 can provide the second controller 12 with information about whether the corresponding wake-up is performed by a preset first wake-up cycle or by the driver's input.

[0079] When the second controller 12 is woken up, based on the information received from the first controller 11, it is determined whether the second controller 12 is woken up by the power supply input by the driver (S32). If it is woken up by the second wake-up cycle P2, the state of the first battery 13 can be monitored within a preset time and then turned off again (S33).

[0080] On the other hand, when it is determined that the first controller 11 is awake and in a power-on state (S31), and the reason for the power-on state is based on the power-on state input by the driver, rather than the periodic wake-up of the second wake-up cycle P2 (S32), the second controller 12 determines whether it is necessary to connect the main power supply MR, and when the main power supply MR is connected (S34), the counter can be initialized (S35). That is, when the first battery 11 is connected to the vehicle system by connecting the main power supply MR, the state of the first battery 11 changes, and the previously executed monitoring of the first battery 13 can be terminated.

[0081] When the first controller 11 is in a power-off state again after the counter initialization (S27) (S36), step S12 can be executed, allowing the monitoring process described above to be executed again from the beginning. If the vehicle starts driving after the counter initialization (S27) without the first controller 11 being in a power-off state again, the monitoring process can be terminated until the next power-off state.

[0082] As described above, according to various embodiments of the vehicle battery management system and method of the present invention, even when the electrical connection between the vehicle battery and the vehicle system is disconnected and all controllers are in a power-off state, the state of the battery can be monitored, thereby preventing various problems that may occur in the battery, such as battery fire.

[0083] In particular, according to various embodiments of the vehicle battery management system and method of the present invention, the number of times the battery is monitored is appropriately determined over time after the power-off state begins, thereby minimizing power consumption and effectively monitoring the battery state in the power-off state.

[0084] Although specific embodiments of the invention have been shown and described above, it will be apparent to those skilled in the art that various modifications and alterations can be made within the scope of the claims.

Claims

1. A vehicle battery management system, comprising: The first controller controls the power-on and power-off states of multiple controllers in the vehicle, and wakes up at least a portion of the multiple controllers by periodically waking them up when the power is off. as well as When the power-off state begins, the second controller disconnects the main relay connecting the first battery in the vehicle and the vehicle system. It maintains the power-on state using a built-in power latch for a preset first reference time and monitors the state of the first battery that stores energy for generating vehicle power. After the first reference time has elapsed, it wakes up according to the wake-up cycle of the first controller to monitor the state of the first battery.

2. The vehicle battery management system according to claim 1, characterized in that, The second controller sets the wake-up period of the first controller.

3. The vehicle battery management system according to claim 2, characterized in that, The second controller sets the wake-up cycle of the first controller to a first wake-up cycle within a preset second reference time starting from the time point from the start of the power-off state, and sets the wake-up cycle of the first controller to a second wake-up cycle that is longer than the first wake-up cycle starting from the time point after the second reference time has elapsed.

4. The vehicle battery management system according to claim 1, characterized in that, When the main relay connected to the first battery is turned on, the second controller stops monitoring the first battery and performs initialization in the power-off state.

5. The vehicle battery management system according to claim 1, characterized in that, After the main relay is disconnected, the state of the first battery is not monitored when the second controller cannot determine the charging state of the second battery that supplies power voltage to the first controller and the second controller, or when the charging state of the first battery is lower than a preset reference value, or when it is unable to communicate with the low-voltage converter that reduces the voltage of the first battery and applies it to the second battery or the first controller.

6. A vehicle battery management method, comprising the following steps: When an external input is generated to terminate vehicle operation, the first controller controls multiple controllers in the vehicle to be powered off. The second controller keeps the power on while disconnecting the main relay connected to the first battery that stores energy used to generate vehicle power, using a built-in power latch. First monitoring, the second controller sets the wake-up cycle of the first controller, and uses a built-in power latch to keep the power on and monitor the status of the vehicle's first battery within a preset first reference time. as well as The second monitoring involves the second controller waking up according to the wake-up cycle of the first controller after the first reference time has elapsed to monitor the state of the first battery.

7. The vehicle battery management method according to claim 6, characterized in that, Following the step of disconnecting the main relay, the following steps are further included: When the second controller cannot determine the charging state of the second battery that supplies power voltage to the first controller and the second controller, or when the charging state of the first battery is lower than a preset reference value, or when it cannot communicate with the low-voltage converter that reduces the voltage of the first battery and applies it to the second battery or the first controller, it is determined that the first monitoring will not be performed.

8. The vehicle battery management method according to claim 6, characterized in that, In the first monitoring step, the second controller determines the wake-up cycle of the first controller as a preset first wake-up cycle. In the second monitoring step, the second controller is woken up by the first controller according to the first wake-up cycle within a preset second reference time starting from the time point after the first reference time. After the second reference time has elapsed, the wake-up cycle of the first controller is set to a second wake-up cycle that is longer than the first wake-up cycle, and it is woken up by the first controller according to the second wake-up cycle.

9. The vehicle battery management method according to claim 6, characterized in that, In the first monitoring step, when the power is on under the control of the first controller, the second controller determines whether the main relay is turned on, and when the main relay is turned on, the monitoring of the state of the first battery is terminated.

10. The vehicle battery management method according to claim 6, characterized in that, In the second monitoring step, the second controller determines the reason for the wake-up after the wake-up, and the reason is to monitor the state of the first battery when the wake-up occurs during the wake-up cycle set in the first controller.

11. The vehicle battery management method according to claim 6, wherein, In the second monitoring step, the second controller determines the reason for the wake-up after the wake-up, and if the reason is wake-up through external input rather than wake-up through the wake-up cycle set in the first controller, it determines whether the main relay is turned on, and when the main relay is turned on, it terminates the monitoring of the state of the first battery.

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