Battery pack, electric energy device, and control method for battery pack

Abstract

A battery pack (100), an electric energy device, and a control method for the battery pack (100). The battery pack (100) comprises a first battery (1), a second battery (2) and a battery management system (3), wherein the first battery (1) is electrically connected to the battery management system (3), so as to supply power to the battery management system (3); and the second battery (2) is electrically connected to the battery management system (3), and the second battery (2) is used for outputting a high voltage to the outside. In the technical solution of the present application, the first battery (1) is disposed in the battery pack (100), and power is supplied to the battery management system (3) by means of the first battery (1), thereby solving the problem of it being impossible to acquire the parameters of the battery pack (100) due to a power loss of the battery management system (3) during transportation or storage of the battery pack (100).

Description

Battery pack, electric energy device and control method of battery pack

[0001] The present application claims priority to the Chinese patent application No. 202410869713.5, filed on June 28, 2024, and entitled "Battery pack, electric energy device and control method of battery pack", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery pack, an electric energy device and a control method of the battery pack. BACKGROUND

[0003] The battery pack, as the main energy source of the electric energy device, plays a crucial role in the operation of the electric energy device.

[0004] In the related art, the battery management system of the battery pack needs to be connected with an external low-voltage power supply to realize normal work, which also leads to the fact that the battery management system in the battery pack cannot obtain the battery pack parameters such as the battery capacity change value, the self-discharge data of the battery cell, the storage temperature data, the storage duration, etc. during the storage or transportation process of the battery pack, leaving a safety hazard for the subsequent use of the battery pack. SUMMARY

[0005] The purpose of the present application is to provide a battery pack, an electric energy device and a control method of the battery pack, aiming at solving the problem that the battery pack parameters cannot be obtained during the offline transportation process of the battery pack in the related art.

[0006] To achieve the purpose of the present application, in a first aspect, the present application provides a battery pack, comprising a first battery, a second battery and a battery management system, wherein the battery management system is configured to obtain parameters of the first battery and the second battery.

[0007] The first battery is electrically connected with the battery management system to supply power for the battery management system.

[0008] The second battery is configured to output a high-voltage voltage externally.

[0009] In a possible implementation manner, the battery pack further comprises a first power supply interface, wherein a positive electrode of the first battery is connected with a first input end of the first power supply interface through the battery management system.

[0010] A negative electrode of the first battery is connected with a second input end of the first power supply interface.

[0011] In a possible implementation manner, the battery pack further comprises a second power supply interface.

[0012] The positive pole of the second battery is connected with the positive pole of the second power interface, and the negative pole of the second battery is connected with the negative pole of the second power interface.

[0013] In a possible implementation, the battery pack further comprises a power distribution unit, which is connected with the second battery and the second power interface respectively.

[0014] In a possible implementation, the battery pack further comprises a signal interface, which is connected with the first power interface, the second power interface and the battery management system respectively.

[0015] In a possible implementation, the battery management system comprises a wake-up module, which is configured to generate a wake-up signal for waking up the battery management system in a sleep state.

[0016] In a second aspect, the application further provides a control method, which comprises the following steps:

[0017] When the battery pack is in an offline mode, determining parameters of the battery pack by a battery management system;

[0018] The parameters of the battery pack comprise at least one of the following parameters: a single-cell voltage of each cell of the first battery, a single-cell voltage of each cell of the second battery, a temperature of each cell of the first battery, a temperature of each cell of the second battery, a remaining capacity of each cell of the first battery, and a remaining capacity of each cell of the second battery.

[0019] In a possible implementation, after the step of determining the parameters of the battery pack by the battery management system, the method further comprises the following step:

[0020] Storing the parameters of the battery pack.

[0021] In a possible implementation, after the step of determining the parameters of the battery pack by the battery management system, the battery management system enters a sleep state, and in the sleep state, the battery management system stops determining the parameters of the battery pack.

[0022] In a possible implementation, before the step of determining the parameters of the battery pack by the battery management system, the battery management system in a sleep state is woken up.

[0023] In a possible implementation, the step of waking up the battery management system in a sleep state comprises the following steps:

[0024] wake up the battery management system in the sleep state when the battery pack is connected with an external wake-up source;

[0025] wake up the battery management system in the sleep state when the duration of the battery management system in the sleep state reaches a preset duration.

[0026] In a possible implementation, when the remaining power of the first battery is greater than a preset power, the control wake-up module formulates a time interval for waking up the battery management system next time;

[0027] when the remaining power of the first battery is less than a preset power, the wake-up function of the wake-up module is prohibited.

[0028] In a possible implementation, after the step of waking up the battery management system in the sleep state, the method further includes the following steps:

[0029] If the number of times of waking up the battery management system is N, N≥2, at the Nth time of waking up, the self-discharge amount and the self-discharge rate of the battery pack are calculated, and the values of the self-discharge amount and the self-discharge rate are recorded.

[0030] In a possible implementation, before the step of calculating the self-discharge amount and the self-discharge rate of the battery pack, the method further includes the following steps:

[0031] the values of OCV_N-OCV_N-n and △OCV_set are compared in sequence;

[0032] when OCV_N-OCV_N-n≥△OCV_set exists, the comparison is stopped, and the self-discharge amount and the self-discharge rate of the battery management system at the Nth and the N-nth times of being woken up are calculated;

[0033] If OCV_N-OCV_N-n≥△OCV_set does not exist, the calculation of the self-discharge amount and the self-discharge rate of the battery pack is skipped;

[0034] wherein, OCV_N is the voltage of the battery pack at the Nth time of waking up, OCV_N-n is the voltage of the battery pack at the N-nth time of being woken up, n (1, 2, 3, …, N-1), and △OCV_set is a preset voltage change value of the battery pack.

[0035] In a third aspect, the application further provides an electric energy device, which comprises a battery pack, the battery pack comprising a first battery, a second battery and a battery management system, the first battery being electrically connected with the battery management system to supply power for the battery management system;

[0036] the second battery is electrically connected with the battery management system, and the second battery is configured to output a high-voltage voltage to the outside.

[0037] The technical scheme of the application solves the problem that the battery management system loses power and the parameters of the battery pack cannot be acquired in the case of transportation or storage of the battery pack by arranging a first battery in the battery pack and supplying power to the battery management system by the first battery. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0039] Fig. 1 is a structural schematic diagram of an embodiment of the battery pack provided by the application;

[0040] Fig. 2 is a structural schematic diagram of the battery pack in an application scenario in Fig. 1;

[0041] Fig. 3 is a flow schematic diagram of an embodiment of the control method provided by the application;

[0042] Fig. 4 is a flow schematic diagram of a second embodiment of the control method provided by the application;

[0043] Fig. 5 is a flow schematic diagram of the second embodiment of the control method provided by the application;

[0044] Fig. 6 is a flow schematic diagram of an embodiment of the control method provided by the application for calculating the self-discharge amount and the self-discharge rate;

[0045] Fig. 7 is a flow schematic diagram of another embodiment of the control method provided by the application for calculating the self-discharge amount and the self-discharge rate;

[0046] Fig. 8 is a logic diagram of the control method of the battery pack provided by the application.

[0047] Legend: 100-battery pack; 1-first battery; 2-second battery; 3-battery management system; 4-first power supply interface; 5-second power supply interface; 6-power supply distribution unit, 61-first switch, 62-second switch; 7-signal interface; 200-direct current converter; 300-low-voltage load, 300a-low-power low-voltage load, 300b-high-power low-voltage load. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0049] It should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or there can be intervening components. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or there can be intervening components.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety.

[0051] Some embodiments of the present application will be described in detail with reference to the drawings. The following embodiments and features of the embodiments can be combined with each other without conflict.

[0052] For the convenience of understanding, the related technical terms involved in the embodiments of the present application are explained and described below.

[0053] Offline mode: the present application refers to the state when the battery pack is not connected to the load of the electric energy device as the offline mode of the battery pack. For example, the state before the battery pack is assembled to the electric energy device, or the state when the battery pack is detached from the electric energy device, or the state when the battery pack is assembled to the electric energy device but not connected to the load of the electric energy device.

[0054] Online mode: the present application refers to the state when the battery pack is connected to the load of the electric energy device as the online mode of the battery pack.

[0055] SOC: the charge amount of the battery pack or the battery cell.

[0056] OCV: the voltage of the battery pack or the battery cell.

[0057] The present application proposes an electric energy device, which can be a vehicle, a ship or an aircraft, and the present application does not limit it. For the convenience of description, the vehicle is taken as an example, and when the electric energy device is a vehicle, the vehicle can be an electric vehicle, a fuel vehicle or a hybrid vehicle, and the present application does not limit it.

[0058] The vehicle comprises a vehicle body, a load and a battery pack. The vehicle body serves as a support framework of the vehicle and is used to support and connect various component assemblies of the vehicle. The load is arranged on the vehicle body. The load can be an instrument panel, a motor or a window lifting mechanism, and the application does not limit the load. The battery pack is arranged in a battery compartment of the vehicle body and is electrically connected to the load. The battery pack is used to store and deliver electric energy to the outside to maintain the normal use of the load.

[0059] Referring to FIGS. 1 and 2, the battery pack 100 comprises a battery management system 3 (BMS). The battery management system 3 is used to monitor and adjust parameters of the battery pack 100, including but not limited to a voltage of the battery pack 100, which can be a total voltage of the battery pack 100 or a single voltage of each battery cell in the battery pack 100, a temperature of the battery pack 100, which can be a total temperature of the battery pack 100 or a single temperature of each battery cell in the battery pack 100, a remaining capacity (SOC) of the battery pack 100, which can be a total remaining capacity of the battery pack 100 or a remaining capacity of each battery in the battery pack 100, and the application does not limit the parameters.

[0060] During the operation of the battery management system 3, an external low-voltage power supply is required to supply power to the battery management system 3. Therefore, in the related art, a starting battery is usually arranged in the vehicle body. The starting battery is used to supply power to the battery management system 3 in the battery pack 100 after the battery pack 100 is connected to the vehicle. This also causes that when the battery pack 100 is in an offline mode, for example, when the battery pack 100 is in a storage or transportation process, the battery management system 3 cannot acquire the parameters of the battery pack 100 in the offline mode due to lack of power supply, thereby leaving a safety hazard for the transportation, storage and subsequent use of the battery pack 100.

[0061] To solve the above problems, the battery pack 100 provided in the application further comprises a first battery 1 and a second battery 2. The first battery 1 is electrically connected to the battery management system 3 to supply power to the battery management system 3. The second battery 2 is used to provide high-voltage current to the outside. The technical solution of the application solves the problem that the battery management system 3 loses power and the parameters of the battery pack 100 cannot be acquired when the battery pack 100 is in a transportation or storage state by arranging the first battery 1 in the battery pack 100 and supplying power to the battery management system 3 by the first battery 1.

[0062] In the following, the battery pack 100 provided in the application will be described in detail with reference to the accompanying drawings.

[0063] The battery pack 100 comprises a battery management system 3 connected with the first battery 1 and the second battery 2 through signal lines to collect parameters of the first battery 1 and the second battery 2, which include but are not limited to the temperature of each single battery cell in the first battery 1, the temperature of each single battery cell in the second battery 2, the remaining capacity of each single battery cell in the first battery 1, and the remaining capacity of each single battery cell in the second battery 2. In addition, the battery management system can also control the charging and discharging current of the first battery 1 and the second battery 2.

[0064] The battery pack 100 comprises the first battery 1, which is composed of multiple single battery cells connected in series, and the total voltage V1 of each single battery cell satisfies the relationship: 6V≤V1≤60V. The first battery 1 is electrically connected with the battery management system 3, so as to provide low-voltage current for the battery management system 3 when the battery pack 100 is in offline mode, thereby maintaining the normal use of the battery management system 3, and solving the problem that the parameters of the battery pack 100 cannot be obtained in offline mode.

[0065] On the other hand, in an embodiment of the present application, the battery pack 100 further comprises a first power interface 4, and the first battery 1 is electrically connected with the first power interface 4. When the battery pack 100 is in online mode, the power of the first battery 1 can be supplied to the low-power low-voltage load 300a in the electric energy equipment through the first power interface 4 to maintain the normal operation of the low-power low-voltage load 300a.

[0066] It should be noted that when the electric energy equipment is a vehicle, the above-mentioned low-power low-voltage load 300a can be the instrument panel light of the vehicle, can be the display screen of the vehicle, and can also be the door switch, which is not limited in the present application.

[0067] In order to realize the control of the output power of the first battery 1, in an embodiment of the present application, the positive electrode of the first battery 1 is connected with the positive electrode of the first power interface 4 through the battery management system 3, and the negative electrode of the first battery 1 is connected with the second input end of the first power interface. In this embodiment, the battery management system 3 is connected between the loop composed of the first battery 1 and the first power interface 4, and the power output from the first battery 1 to the first power interface 4 is controlled by the battery management system 3, so as to avoid over-discharge of the first battery 1 to the first power interface 4 and damage the service life of the first battery 1.

[0068] The battery pack 100 further comprises a second battery 2, which is electrically connected with the battery management system 3 to enable the battery management system 3 to monitor and manage the battery parameters of the second battery 2. The second battery 2 is composed of multiple single battery cells connected in series, and the total voltage of each single battery cell is between 200V-1000V. The second battery 2 is used to output high-voltage voltage.

[0069] The battery pack 100 further comprises a second power interface 5, the positive pole of the second battery 2 is connected with the positive pole of the second power interface 5, and the negative pole of the second battery 2 is connected with the negative pole of the second power interface 5. When the battery pack 100 is in the online mode, the second battery 2 can be connected with the high-voltage load of the electric energy device through the second power interface 5, thereby providing electric energy for the work of the high-voltage load.

[0070] The second power interface 5 can also be connected with the high-power low-voltage load 300b through the direct current converter 200 (DC / DC). When the high-power low-voltage load 300b is connected to the direct current converter 200, the high-voltage current of the second battery 2 can reach the direct current converter 200 through the second power interface 5, and after being converted by the direct current converter 200, the high-voltage current reaches the high-power low-voltage load 300b, thereby maintaining the normal use of the high-power low-voltage load 300b.

[0071] It should be noted that when the electric energy device is a vehicle, the above-mentioned high-voltage load can be a motor, can be a compressor of an air conditioner, and can also be a PTC heater of the vehicle.

[0072] When the electric energy device is a vehicle, the above-mentioned high-power low-voltage load 300b can be a vehicle headlamp, can be an air conditioner blower, and can also be a sunroof or an adjusting mechanism of an electric seat, which is not limited in the present application.

[0073] The battery pack 100 further comprises a power distribution unit 6 (PDU), and the power distribution unit 6 comprises a first switch 61 and a second switch 62. The first switch 61 and the second switch 62 can be relays, contactors or electronic switches, which are not limited in the present application. The first end of the first switch 61 is connected with the positive pole of the second battery 2, the second end of the first switch 61 is connected with the positive pole of the second power interface 5, the first end of the second switch 62 is connected with the negative pole of the second battery 2, and the second end of the second switch 62 is connected with the negative pole of the second power interface 5. The power distribution unit 6 can control the on-off of the current between the second battery 2 and the second power interface 5 by controlling the on-off of the first switch 61 and the second switch 62. When the second power interface 5 does not need to output high-voltage current, the power distribution unit 6 can disconnect the connection of the first switch 61 or the second switch 62, thereby disconnecting the connection between the second battery 2 and the second power interface 5. In this way, the possibility of current breakdown caused by excessively high voltage at the first input end and the second input end of the second power interface 5 in the no-load state of the second power interface 5 is reduced, and the safety of the battery pack 100 is improved.

[0074] It can be understood that in some other embodiments of the present application, active insurance, passive insurance, pre-charging resistance and other electronic devices can also be arranged in the power distribution unit 6 to protect the circuit safety.

[0075] The battery pack 100 further comprises a signal interface 7, a first end of the signal interface 7 being connected with the first power interface 4, and a second end of the signal interface 7 being connected with the second power interface 5, and the signal interface 7 being electrically connected with the battery management system 3. The battery management system 3 can transmit the battery parameters of the battery pack 100 to the control system of the vehicle through the signal interface 7, so that the vehicle control system can know the working state of the battery pack 100 at any time, thereby performing corresponding control and adjustment to ensure the safe and efficient operation of the battery pack 100.

[0076] The acquisition of the battery parameters by the battery management system 3 can be continuous real-time acquisition or interval acquisition in time periods, which is not limited in the application. In an implementation of the application, the battery management system 3 has a sleep module for controlling the battery management system 3 to sleep periodically. In the sleep mode, the battery management system 3 stops collecting the parameters of the battery pack 100, thereby reducing the energy consumption of the battery pack 100. At the same time, in order to ensure that the collection of the parameters of the battery pack 100 can be quickly restored when needed, the battery management system 3 comprises a wake-up module for generating a wake-up signal for waking up the battery management system 3 in the sleep state and making the battery management system 3 continue to monitor and collect the parameters of the battery pack 100. The design of the sleep module and the wake-up module ensures that the battery management system 3 can flexibly switch between the sleep state and the working state, which can meet the energy-saving requirement and ensure the effective monitoring of the state of the battery pack 100 at critical moments. The standby time of the battery pack 100 in the offline state is effectively prolonged.

[0077] Please refer to FIG. 3, the application further provides a control method based on the above battery pack structure, the control method comprising the following steps:

[0078] S101, when the battery pack is in the offline mode, determining the parameters of the battery pack by the battery management system; the parameters of the battery pack comprising at least one of the following parameters: the single-cell voltage of each cell of the first battery, the single-cell voltage of each cell of the second battery, the temperature of each cell of the first battery, the temperature of each cell of the second battery, the remaining capacity of each cell of the first battery, and the remaining capacity of each cell of the second battery.

[0079] In the embodiment, when the controller of the battery pack determines that the battery pack is in the offline mode, the controller will acquire the parameters of the battery pack by the battery management system, so that the vehicle system or the operator of the battery pack can know the state change of the battery pack in the offline mode in time, reduce the safety hazards of the battery pack in the subsequent use process, and improve the safety of the use of the battery pack.

[0080] There are various ways for the controller to determine whether the battery pack enters the offline mode. The controller can determine whether the battery pack enters the offline mode by judging the high voltage interlock (HVIL) signal in the battery pack. The HVIL signal is mainly used in a vehicle to detect the electrical connection integrity of the high voltage system in the vehicle, to ensure the safe and reliable connection between high voltage components such as the battery pack, motor controller, DC converter, etc. When the HVIL signal in the battery pack is in the disconnected state, it proves that the connection between the battery pack and the vehicle is disconnected, and the controller can determine that the battery pack enters the offline mode.

[0081] The controller can also determine whether the battery pack enters the offline mode by the vehicle CAN (controller area network) signal. The battery pack mainly communicates with the vehicle through the CAN line and the CAN signal. When the vehicle CAN signal in the battery pack is in the non-communication state, it proves that the connection between the battery pack and the vehicle is disconnected, and the controller can determine that the battery pack enters the offline mode.

[0082] To improve the accuracy of the controller in determining the offline mode of the battery pack, in an embodiment of the present application, when the battery pack meets the following conditions, it is determined that the battery pack enters the offline mode:

[0083] Condition 1: the HVIL signal is in the disconnected state. And

[0084] Condition 2: the battery pack and the vehicle CAN signal are in the non-communication state.

[0085] This embodiment introduces two conditions, "the HVIL signal is in the disconnected state" and "the battery pack and the vehicle CAN signal are in the non-communication state", as the common basis for determining whether the battery pack is in the offline mode. In this way, a double check mechanism is formed between the controller and the battery pack, thereby improving the accuracy of the controller in determining the offline mode of the battery pack, and facilitating the subsequent reading and recording of the battery pack parameters.

[0086] To facilitate subsequent devices to query the data obtained by the battery management system, after determining the parameters of the battery pack by the battery management system, the method further includes the steps of:

[0087] storing the parameters of the battery pack.

[0088] There are various storage modes for the battery pack parameters. In an embodiment of the present application, a non-volatile memory (RAM) is arranged in the battery pack. After the battery management system acquires the parameters of the battery pack, the parameters of the battery pack are stored in the non-volatile memory (RAM). When the electric energy device is connected with the battery pack, the electric energy device can acquire the state change of the battery pack in the offline mode by reading the information in the non-volatile memory (RAM), and take corresponding measures (for example, charge the battery pack) according to the state change of the battery pack, so as to ensure the safety of the battery pack in the subsequent use process.

[0089] In other embodiments of the present application, after the battery management system determines the parameters of the battery pack, the battery management system can also send the parameters of the battery pack to the cloud through Bluetooth, WIFI or other communication modules for storage. When the electric energy device is connected with the battery pack, the electric energy device can download the parameters of the battery pack through the cloud, so as to acquire the state change of the battery pack in the offline mode.

[0090] After the battery management system acquires the parameters of the battery pack, the parameters of the battery pack acquired by the battery management system are stored.

[0091] Please refer to FIG. 4. The acquisition of the battery pack parameters by the battery management system can be continuous real-time acquisition or interval acquisition in time periods, which is not limited in the present application. In order to reduce the energy consumption of the battery pack in the offline mode, in an embodiment of the present application, the control method comprises the following steps:

[0092] S201, when the battery pack is in the offline mode, determining the parameters of the battery pack by the battery management system.

[0093] S202, storing the parameters of the battery pack.

[0094] S203, the battery management system enters a sleep state, in which the battery management system stops determining the parameters of the battery pack.

[0095] S204, waking up the battery management system in the sleep state.

[0096] The battery management system can be woken up in various situations. In an embodiment of the present application, the battery management system can be woken up by an external wake-up source. The wake-up source can be a parameter detection instrument of the battery pack or a control system of the vehicle, which is not limited in the present application. The wake-up source has a hardware circuit therein, which is connected to the battery pack through a signal line, which can be a CAN line or a hard line, which is not limited in the present application. When the external wake-up source is connected to the battery pack, the hardware circuit in the wake-up source will send a wake-up signal to the battery management system in the battery pack through the signal line connected between the wake-up source and the battery pack, and wake up the battery management system through the wake-up signal. The woken-up battery management system will collect and record the parameters of the battery pack.

[0097] In other embodiments of the present application, the battery management system can also be self-woken up. Specifically, the battery management system is provided with a wake-up module. When the time length of the battery management system in the sleep state reaches a preset time length, the wake-up module will generate a wake-up signal and wake up the battery management system in the sleep state through the wake-up signal. The woken-up battery management system will collect and record the parameters of the battery pack.

[0098] It should be noted that the above-mentioned preset time length is mainly determined by the charge amount of the battery pack and the duration of the offline mode of the battery pack. When the charge amount of the battery pack is relatively large or the duration of the offline mode is short, the preset time length can be set within a relatively short time limit. In this way, the collection frequency of the battery management system for the parameters of the battery pack is improved, the reaction accuracy of the parameters collected by the battery management system for the actual state change of the battery pack is improved, and the safety of the use of the battery pack is improved. When the charge amount of the battery pack is relatively small or the duration of the offline mode is relatively long, the preset time length can be set to a relatively long time limit. In this way, the frequency of waking up the battery management system is reduced, thereby reducing the energy consumption of the battery pack and prolonging the use time of the battery pack in the offline mode.

[0099] The first battery is used to provide power for the operation of the battery management system. In order to avoid frequent self-waking up of the battery management system, which leads to depletion of the power of the first battery, in an embodiment of the present application, when the remaining power of the first battery is less than a preset power, the wake-up function of the wake-up module is prohibited. The preset power can be 20% of the total power of the first battery or 10% of the total power of the first battery, which is not limited in the present application. When the remaining power of the first battery is less than the preset power, the controller of the battery management system will prohibit the wake-up function of the control module. In this way, the wake-up module will not continue to wake up the battery management system when the power of the first battery is too low, thereby preventing the power of the first battery from being depleted, protecting the power safety of the first battery, and prolonging the service life of the first battery.

[0100] S205, when the battery pack is in the offline mode, determining parameters of the battery pack by the battery management system and storing the parameters.

[0101] In the embodiment, when the battery management system ends the collection of the battery pack, the battery management system enters the sleep state. In the sleep state, the battery management system stops the collection of the information of the battery pack, so as to reduce the energy consumption of the battery management system on the first battery. When the controller needs to collect the parameters of the battery pack by the battery management system, the battery management system in the sleep state is woken up by the wake-up signal, and the collection of the parameters of the battery pack is completed by the battery management system. When the collection of the parameters of the battery pack by the battery management system is completed, the battery management system enters the sleep state again, so as to save the energy consumption of the first battery and prolong the use time of the first battery.

[0102] Please refer to FIG. 5 and FIG. 6. After the battery management system is woken up, the battery management system also calculates the self-discharge amount and the self-discharge rate of the battery pack. Specifically, in an embodiment of the present application, after the step of waking up the battery management system in the sleep state, the following steps are further included:

[0103] S301, if the number of times that the battery management system is woken up is N, N≥2, at the Nth time of waking up, the self-discharge amount and the self-discharge rate of the battery pack are calculated, and the values of the self-discharge amount and the self-discharge rate are recorded.

[0104] The self-discharge amount of the battery pack and the self-discharge rate of the battery pack can be calculated by the following steps:

[0105] S3011, when the battery pack is woken up for the N-1th time, the open-circuit voltage OCV1_N-1 of the battery pack is obtained, and the SOC-OCV function SOC=f(OCV) stored in the memory in advance is queried according to the open-circuit voltage OCV1_N-1, so as to obtain the remaining power SOC_N-1 of the battery pack at the open-circuit voltage. When the detection object of the self-discharge amount and the self-discharge rate is a cell in the battery pack, OCV1_N-1 can also be the open-circuit voltage between the cell and the battery pack when the battery pack is woken up for the N-1th time.

[0106] S3012, when the battery pack is woken up for the Nth time, the open-circuit voltage OCV1_N of the battery pack is obtained, and the SOC-OCV function SOC=f(OCV) stored in the memory in advance is queried according to the open-circuit voltage OCV1_N, so as to obtain the remaining power SOC_N of the battery pack at the open-circuit voltage. When the detection object of the self-discharge amount and the self-discharge rate is a cell in the battery pack, OCV1_N can also be the open-circuit voltage between the cell and the battery pack when the battery pack is woken up for the Nth time.

[0107] S3013、According to the relationship formula △SOC=SOC_N-SOC_N-1, the change value of the remaining capacity of the battery pack when the battery pack is woken up for the Nth and the N-1th time is calculated. When the detection object of the self-discharge amount and the self-discharge rate is the battery cell in the battery pack, the change value of the remaining capacity of the battery cell when the battery pack is woken up for the Nth and the N-1th time is calculated.

[0108] S3014、According to the relationship formula Q=Q_rate*△SOC, the self-discharge amount Q of the battery pack is calculated, wherein Q_rate is the rated capacity of the battery pack at the time of factory shipment. When the detection object of the self-discharge amount and the self-discharge rate is the battery cell in the battery pack, Q_rate is the rated capacity of the battery cell at the time of factory shipment.

[0109] S3015、According to the relationship formula P=Q / △t, the self-discharge rate P of the battery pack is calculated. Wherein △t is the time interval of the battery pack when it is woken up for the Nth and the N-1th time.

[0110] In this embodiment, when the number of times of waking up of the battery pack is greater than twice, the controller calculates the self-discharge amount and the self-discharge rate of the battery pack according to the open circuit voltage of the battery pack at this time and the open circuit voltage of the battery pack at the last time of waking up of the battery pack, and records them. In this way, the control system of the vehicle and the detection personnel of the battery pack can have real-time control over the change of the self-discharge amount of the battery pack, and the safety of the battery pack in subsequent use is improved.

[0111] It can be understood that for the self-discharge amount and the self-discharge rate of the battery pack, the smaller the change of the capacity of the battery pack, the greater the calculation error of the self-discharge amount and the self-discharge rate of the battery pack. Referring to FIG. 7, in order to improve the comparison of the self-discharge amount and the self-discharge rate of the battery pack, in an embodiment of the present application, the control method further includes the following steps:

[0112] S401, if the number of times of waking up of the battery management system is N, N≥2, then at the Nth time of waking up, the values of OCV_N-OCV_N-n and △OCV_set are compared in turn.

[0113] S402, when OCV_N-OCV_N-n≥△OCV_set exists, the comparison is stopped, and the self-discharge amount and the self-discharge rate of the battery management system when it is woken up for the Nth and the N-nth time are calculated.

[0114] S403, if OCV_N-OCV_N-n≥△OCV_set does not exist, the calculation of the self-discharge amount and the self-discharge rate of the battery pack is skipped.

[0115] OCV_N-OCV_N-1≥△OCV_set, the controller calculates the self-discharge amount and the self-discharge rate between the Nth time of waking up and the (N-1)th time of waking up, and records the same.

[0116] In the present embodiment, before calculating the self-discharge amount and the self-discharge rate of the battery pack, the controller compares the voltage of the battery pack at the present time of waking up with the voltage variation OCV_N-OCV_N-1 at the last time of waking up and the preset voltage variation value △OCV_set stored in the memory. If OCV_N-OCV_N-1≥△OCV_set, the controller calculates the self-discharge amount and the self-discharge rate between the Nth time of waking up and the (N-1)th time of waking up, and records the same.

[0117] If OCV_N-OCV_N-1<△OCV_set, the controller compares the voltage of the battery pack at the present time of waking up with the voltage variation OCV_N-OCV_N-2 at the (N-2)th time of waking up and the preset voltage variation value △OCV_set stored in the memory. If OCV_N-OCV_N-2≥△OCV_set, the controller calculates the self-discharge amount and the self-discharge rate between the Nth time of waking up and the (N-2)th time of waking up, and records the same.

[0118] If OCV_N-OCV_N-2<△OCV_set, the controller compares the voltage of the battery pack at the present time of waking up with the voltage variation OCV_N-OCV_N-3 at the (N-3)th time of waking up and the preset voltage variation value △OCV_set. If OCV_N-OCV_N-3≥△OCV_set, the controller calculates the self-discharge amount and the self-discharge rate between the Nth time of waking up and the (N-3)th time of waking up, and records the same. If OCV_N-OCV_N-3<△OCV_set, the controller compares the voltage of the battery pack at the present time of waking up with the voltage variation OCV_N-OCV_N-4 at the (N-4)th time of waking up and the preset voltage variation value △OCV_set, and so on.

[0119] If the voltage of the battery pack at the present time of waking up and the voltage variation OCV_N-OCV_1 at the (N-N+1)th time of waking up are still less than △OCV_set, the controller skips the calculation of the self-discharge amount and the self-discharge rate of the battery pack at the present time. In this way, the variation of the capacitance of the battery pack is avoided from being too small, so as to affect the accuracy of the calculation of the self-discharge amount and the self-discharge rate of the battery pack.

[0120] It should be noted that in the above calculation formula, △OCV_set is a value set in the memory in advance, which is associated with the voltage OCV of the battery pack. Before calculating the self-discharge amount and self-discharge rate of the battery pack, the controller will first obtain the current voltage OCV of the battery pack through the battery management system, and query the OCV_set-OCV function OCV_set=f(OCV) stored in the memory according to the current voltage, and obtain the voltage preset change value of the battery pack at the current voltage according to the OCV_set-OCV function.

[0121] In the following, the control process of the battery pack provided by the present application will be described in detail in combination with FIG. 8, which includes the following steps:

[0122] S01: Determine whether the battery pack enters the offline mode, if yes, go to step S02, if no, go to S09.

[0123] S02: Control the battery management system to collect and store the parameters of the battery pack, including but not limited to the voltage of the battery pack, which can be the total voltage of the battery pack or the single voltage of each battery cell in the battery pack, the temperature of the battery pack, which can be the total temperature of the battery pack or the single temperature of each battery cell in the battery pack, and the remaining capacity of the battery pack, which can be the total remaining capacity of the battery pack or the remaining capacity of each battery in the battery pack.

[0124] S03: Determine whether the capacity of the first battery is less than the preset capacity, if yes, go to S04, if no, go to S05.

[0125] S04: Inhibit the wake-up function of the battery management system, which can be the function of the battery management system being awakened by an external wake-up source, or the wake-up function of the battery management system being awakened by the self-wake-up module.

[0126] S05: Set the wake-up time of the battery management system.

[0127] S06: The battery management system sleeps.

[0128] S07: Determine whether a wake-up signal is received, which can be a wake-up signal sent by the wake-up module in the battery management system after the battery management system reaches the preset sleep time, or a wake-up signal generated by the battery management system when the battery pack accesses other wake-up sources, if yes, go to S08.

[0129] S08: Wake up the battery management system and re-enter S01.

[0130] S09: entering an online mode, in which the battery pack supplies power to the load of the electrical energy device by the first battery or the second battery.

[0131] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the drawings described, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0132] The above only discloses one preferred embodiment of the present application, of course cannot limit the scope of the present application, those skilled in the art can understand that the implementation of all or part of the above-mentioned processes, and the equivalent changes made according to the claims of the present application, still belong to the scope covered by the present application.

Claims

1. A battery pack, characterized in that, It includes a first battery, a second battery, and a battery management system, wherein the battery management system is used to acquire parameters of the first battery and the second battery; The first battery is electrically connected to the battery management system to supply power to the battery management system. The second battery is used to output a high voltage.

2. The battery pack as described in claim 1, characterized in that, The battery pack also includes a first power interface, and the positive terminal of the first battery is connected to the first input terminal of the first power interface through the battery management system. The negative terminal of the first battery is connected to the second input terminal of the first power interface.

3. The battery pack as described in claim 2, characterized in that, The battery pack also includes a second power interface; The positive terminal of the second battery is connected to the positive terminal of the second power interface, and the negative terminal of the second battery is connected to the negative terminal of the second power interface.

4. The battery pack as described in claim 3, characterized in that, The battery pack also includes a power distribution unit, which is connected to the second battery and the second power interface respectively.

5. The battery pack as described in claim 3, characterized in that, The battery pack also includes a signal interface, which is connected to the first power interface, the second power interface and the battery management system respectively.

6. The battery pack according to any one of claims 1-5, characterized in that, The battery management system includes a wake-up module, which generates a wake-up signal to wake up the battery management system in a dormant state.

7. A control method, said control method being applied to a battery pack as described in any one of claims 1 to 6, characterized in that, The control method includes the following steps: When the battery pack is in offline mode, the parameters of the battery pack are determined by the battery management system; The parameters of the battery pack include at least one of the following: the single-cell voltage of each cell of the first battery, the single-cell voltage of each cell of the second battery, the temperature of each cell of the first battery, the temperature of each cell of the second battery, the remaining charge of each cell of the first battery, and the remaining charge of each cell of the second battery.

8. The control method as described in claim 7, characterized in that, After determining the parameters of the battery pack through the battery management system, the method further includes the following steps: The parameters of the battery pack are stored.

9. The control method as described in claim 7, characterized in that, After the step of determining the parameters of the battery pack through the battery management system, the battery management system enters a sleep state, in which the battery management system stops determining the parameters of the battery pack.

10. The control method as described in claim 9, characterized in that, Before the step of determining the parameters of the battery pack through the battery management system, the battery management system in a dormant state is woken up.

11. The control method as described in claim 10, characterized in that, The process of waking up the battery management system from its dormant state includes the following steps: When the battery pack is connected to an external wake-up source, the battery management system in sleep mode is woken up; When the battery management system is in a dormant state for a preset period of time, the battery management system in the dormant state is woken up.

12. The control method as described in claim 11, characterized in that, When the remaining power of the first battery is greater than the preset power, the control wake-up module sets the time interval for the next wake-up of the battery management system; When the remaining power of the first battery is less than the preset power, the wake-up function of the wake-up module is disabled.

13. The control method as described in claim 10, characterized in that, After the step of waking up the battery management system from its dormant state, the following steps are also included: If the battery management system is woken up N times, where N≥2, then at the Nth wake-up, the self-discharge amount and self-discharge rate of the battery pack are calculated, and the values ​​of the self-discharge amount and the self-discharge rate are recorded.

14. The control method as described in claim 13, characterized in that, Before calculating the self-discharge amount and self-discharge rate of the battery pack, the following steps are also included: Compare the values ​​of OCV_N-OCV_N-n with △OCV_set in turn; When OCV_N-OCV_N-n≥△OCV_set, stop the comparison and calculate the self-discharge amount and self-discharge rate of the battery management system when it is woken up for the Nth and Nnth times. If OCV_N-OCV_N-n≥△OCV_set does not exist, then the calculation of the self-discharge amount and self-discharge rate of the battery pack is skipped. Wherein, OCV_N is the voltage of the battery pack when it is woken up for the Nth time, OCV_N-n is the voltage of the battery pack when it is woken up for the Nnth time, n (1, 2, 3...N-1), and △OCV_set is the preset voltage change value of the battery pack.

15. An electrical energy device, characterized in that, The electrical power equipment includes a battery pack as described in any one of claims 1 to 6.

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