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

Abstract

A battery pack, an electric energy device, and a control method for a battery pack. The battery pack comprises a first battery, a second battery, a direct-current converter and a battery management system, wherein the first battery is electrically connected to the battery management system, so as to supply power to the battery management system; and the second battery is used for outputting a high voltage to the outside, and is connected to the first battery by means of the direct-current converter, so as to charge the first battery when the battery level of the first battery is less than a first preset battery level. A direct-current converter is provided between a second battery and a first battery to convert a high-voltage current of the second battery into a low-voltage current which is available to the first battery, so as to charge the first battery. In this way, when the first battery is in an offline state, the energy supply time for a battery management system is prolonged, the number of samples acquired by the battery management system with regard to parameters of a battery pack is increased, parameters of the battery pack recorded by the battery management system are increased, and thus the accuracy of a response to a change in the state of the battery pack is improved.

Description

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

[0001] The present disclosure claims priority to the Chinese patent application No. 202410875081.3, filed on June 28, 2024, entitled "Battery pack, electric energy device and control method of battery pack", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure 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, a low-voltage battery is usually arranged in the battery pack, which is used to supply power to the battery management system of the battery pack, so that the battery pack can still work normally in an offline state, and then record and update the parameter information such as the power change value of the battery pack in the offline state, the self-discharge data of the battery cell, the storage temperature data, and the storage duration.

[0005] However, the low-voltage battery has limited storage capacity. When the battery pack is in a long-term offline state, the low-voltage battery will stop supplying power to the battery management system due to insufficient power, thereby causing the loss of offline state data of the battery pack, which leaves a safety hazard for the subsequent use of the battery pack. SUMMARY

[0006] The purpose of the present disclosure is to provide a battery pack, an electric energy device and a control method of the battery pack, which aims to solve the problem that the low-voltage battery in the battery pack cannot supply power to the battery pack for a long time in the offline state in the related art.

[0007] To achieve the purpose of the present disclosure, in a first aspect, the present disclosure provides a battery pack, comprising a first battery, a second battery, a direct current converter and a battery management system; the battery management system is used to determine the parameter information of the first battery and the second battery;

[0008] The first battery is electrically connected with the battery management system to supply power to the battery management system; the second battery is used to output a high-voltage voltage to the outside, and the second battery is connected with the first battery through the direct current converter to charge the first battery when the power of the first battery is less than a first preset power.

[0009] In a possible implementation, the battery pack further includes a first switch module, a first end of the first switch module is connected with the positive pole of the first battery, and a second end of the first switch module is connected with the negative pole of the direct current converter.

[0010] The positive pole of the second battery is connected with the negative pole of the first battery through the positive pole of the direct current converter.

[0011] In a possible implementation, the battery pack further includes a first power supply interface and a second switch module.

[0012] A first end of the second switch module is connected with the positive pole of the second battery, and a second end of the second switch module is connected with the positive pole of the first power supply interface.

[0013] The negative pole of the first power supply interface is connected with the negative pole of the first battery.

[0014] In a possible implementation, the battery pack further includes a first power supply interface, and the second battery is connected with the first power supply interface through the direct current converter.

[0015] In a possible implementation, the battery pack further includes a power supply distribution unit and a second power supply interface.

[0016] The second power supply interface and the second battery and the direct current converter form a current loop through the power supply distribution unit.

[0017] The power supply distribution unit is configured to control a flow direction between the second battery, the second power supply interface, and the direct current converter.

[0018] In a possible implementation, the power supply distribution unit includes a third switch module and a fourth switch module.

[0019] A first end of the third switch module is connected with the second battery, and a second end of the third switch module is connected with the first end of the second switch module and the direct current converter.

[0020] A second end of the fourth switch module is connected with the second power supply interface.

[0021] In a possible implementation, the power supply distribution unit includes a third switch module and a fourth switch module.

[0022] A first end of the third switch module is connected with the second battery, and a second end of the third switch module is connected with the second power supply interface.

[0023] The first end of the fourth switch module is connected with the second battery, and the second end of the fourth switch module is connected with the direct current converter.

[0024] In a possible implementation, the power distribution unit comprises a third switch module and a fourth switch module.

[0025] The first end of the third switch module is connected with the second battery, and the second end of the third switch module is connected with the first end of the second switch module and the second power interface.

[0026] The second end of the fourth switch module is connected with the direct current converter.

[0027] In a second aspect, the disclosure further provides a control method, which is applied to the battery pack and comprises the following steps:

[0028] When the battery pack is in an offline state, the battery management system determines parameters of the battery pack; the parameters of the battery pack comprise at least one of the following parameters: the single-cell voltage of each cell of the first battery, the temperature of each cell of the first battery, and the remaining power of each cell of the first battery.

[0029] When the power of the first battery is less than a first preset power, the second battery charges the first battery.

[0030] In a possible implementation, after the battery management system obtains the parameters of the battery pack, the method further comprises the following steps:

[0031] The parameters of the battery pack are stored.

[0032] In a possible implementation, the battery management system determines the parameters of the battery pack, and the battery management system enters a sleep state; in the sleep state, the battery management system stops obtaining the parameters of the battery pack.

[0033] 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 the sleep state is woken up.

[0034] In a possible implementation, the step of waking up the battery management system in the sleep state comprises the following steps:

[0035] When the battery pack is connected with an external wake-up source, the battery management system in the sleep state is woken up.

[0036] When the duration of the battery management system in the sleep state reaches a preset duration, the battery management system in the sleep state is woken up.

[0037] In a possible implementation, the step of determining the parameters of the battery pack by the battery management system and storing the parameters further comprises the following steps:

[0038] When the current of the first battery is less than a first preset electric quantity and the current of the second battery is less than a second preset electric quantity, the wake-up function of the battery management system is disabled.

[0039] In a possible implementation, the step of waking up the battery management system in the sleep state further comprises the following steps:

[0040] 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 quantity and the self-discharge rate of the battery pack are calculated, and the values of the self-discharge quantity and the self-discharge rate are recorded.

[0041] In a possible implementation, before the step of calculating the self-discharge quantity and the self-discharge rate of the battery pack, the following steps are further included:

[0042] The values of OCV_N-OCV_N-n and △OCV_set are compared in sequence;

[0043] When OCV_N-OCV_N-n≥△OCV_set exists, the comparison is stopped, and the self-discharge quantity and the self-discharge rate of the battery management system at the Nth and the N-nth times of being woken up are calculated.

[0044] If OCV_N-OCV_N-n≥△OCV_set does not exist, the calculation of the self-discharge quantity and the self-discharge rate of the battery pack is skipped.

[0045] Wherein, OCV_N is the voltage of the battery pack at the Nth time of being woken 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.

[0046] In a third aspect, the disclosure further provides an electric energy device, which comprises a load and a battery pack electrically connected to the load, the battery pack comprising a first battery, a second battery, a direct current converter and a battery management system; the battery management system is configured to obtain parameter information 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 configured to output high-voltage voltage externally, and the second battery is connected to the first battery through the direct current converter to charge the first battery when the electric quantity of the first battery is less than a first preset electric quantity.

[0047] The present disclosure sets a direct current converter between the second battery and the first battery to convert the high voltage current of the second battery into a low voltage current available for the first battery to charge. In this way, the power supply time of the battery management system in the offline state of the first battery is prolonged, the sample number of the parameter acquisition of the battery management system for the battery pack is increased, and the accuracy of the parameters of the battery management system recorded for the battery pack in response to the change of the state of the battery pack is improved. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and other drawings can also be obtained by those skilled in the art without creative labor.

[0049] Fig. 1 is a structural schematic diagram of an embodiment of the battery pack provided by the present disclosure;

[0050] Fig. 2 is a structural schematic diagram of the battery pack in an online state in Fig. 1;

[0051] Fig. 3 is a structural schematic diagram of a first embodiment of the power distribution unit connected with the second battery, the direct current converter and the second power interface in Fig. 1;

[0052] Fig. 4 is a structural schematic diagram of a second embodiment of the power distribution unit connected with the second battery, the direct current converter and the second power interface in Fig. 1;

[0053] Fig. 5 is a structural schematic diagram of a third embodiment of the power distribution unit connected with the second battery, the direct current converter and the second power interface in Fig. 1;

[0054] Fig. 6 is a flow schematic diagram of a first embodiment of the control method provided by the present disclosure;

[0055] Fig. 7 is a flow schematic diagram of a second embodiment of the control method provided by the present disclosure;

[0056] Fig. 8 is a flow schematic diagram of a third embodiment of the control method provided by the present disclosure;

[0057] Fig. 9 is a flow schematic diagram of an embodiment of the control method provided by the present disclosure for calculating the self-discharge amount and the self-discharge rate;

[0058] Fig. 10 is a flow schematic diagram of another embodiment of the control method provided by the present disclosure for calculating the self-discharge amount and the self-discharge rate;

[0059] Fig. 11 is a logic diagram of the control method provided by the present disclosure.

[0060] Reference signs: 100-battery pack; 1-first battery; 2-second battery; 3-direct current converter; 4-battery management system; 5-first switch module; 6-second switch module; 7-first power interface; 8-second power interface; 9-power distribution unit, 91-third switch module, 92-fourth switch module; 10-signal interface; 200-high-voltage load; 300-low-voltage load. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present disclosure.

[0062] 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 an intervening component. 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 an intervening component.

[0063] Unless otherwise defined, all technical and scientific terms used in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. The terminology used in the description of the present disclosure solely for the purpose of describing a specific embodiment of the present disclosure is not intended to be limiting of the present disclosure. The term "and / or" used in the present disclosure includes any and all combinations of one or more of the associated listed items.

[0064] Some embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0065] For the convenience of understanding, the related technical terms involved in the embodiments of the present disclosure are explained and described below.

[0066] Offline state: the present disclosure refers to the state when the battery pack is not connected to the load of the electric energy device as the offline state of the battery pack.

[0067] Online state: the present disclosure refers to the state when the battery pack is connected to the load of the electric energy device as the online state of the battery pack.

[0068] SOC: the charge amount of the battery pack or the battery cell.

[0069] OCV: the voltage of the battery pack or the battery cell.

[0070] The present disclosure proposes an electric energy device, which can be a vehicle, a ship, or an aircraft, and the present disclosure does not limit the same. For ease of illustration, 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 disclosure does not limit the same.

[0071] The vehicle includes 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, and the load can be an instrument panel, an electric motor, or a window lifting mechanism, and the present disclosure does not limit the same. The battery pack is arranged in a battery compartment of the vehicle body, and the battery pack is electrically connected with the load. The battery pack is used to store and deliver electric energy to the outside to maintain the normal use of the load.

[0072] The battery pack includes a first battery and a battery management system (BMS). The battery management system is used to monitor and adjust parameters of the battery pack, including but not limited to a voltage of the battery pack, which can be a total voltage of the battery pack or a single voltage of each battery cell in the battery pack, a temperature of the battery pack, which can be a total temperature of the battery pack or a single temperature of each battery cell in the battery pack, a state of charge (SOC) of the battery pack, which can be a total state of charge of the battery pack or a state of charge of each battery in the battery pack, and the present disclosure does not limit the same.

[0073] The first battery is electrically connected with the battery management system, and the first battery is used to supply power to the battery management system in an offline state to ensure that the battery management system can still record the parameters of the battery pack in the offline state and improve the use safety of the battery pack.

[0074] However, the first battery has a limited storage capacity, and when the battery pack is in a long-term offline state, the first battery will stop supplying power to the battery management system due to insufficient power, thereby causing the loss of offline state data of the battery pack and leaving a safety hazard for the subsequent use of the battery pack.

[0075] Please refer to FIG. 1 and FIG. 2, to solve the above problems, the battery pack 100 provided by the present disclosure further comprises a second battery 2 and a direct current converter 3, the second battery 2 is used to output high voltage to the outside, and the second battery 2 is connected with the first battery 1 through the direct current converter 3, so as to charge the first battery 1 when the electric quantity of the first battery 1 is less than the first preset electric quantity. The present disclosure sets the direct current converter 3 between the second battery 2 and the first battery 1, so as to convert the high-voltage current of the second battery 2 into low-voltage current available for the first battery 1, so as to charge the first battery 1. In this way, the energizing time of the battery management system 4 in the offline state of the first battery 1 is prolonged, the number of samples of the parameter acquisition of the battery management system 4 for the battery pack 100 is increased, and the accuracy of the parameter recorded by the battery management system 4 for the state change of the battery pack 100 is improved.

[0076] In the following, the battery pack 100 provided by the present disclosure will be described in detail in combination with the accompanying drawings.

[0077] The battery pack 100 comprises a battery management system 4, which is connected with the first battery 1 and the second battery 2 through a signal line, so as to acquire the parameters of the first battery 1 and the second battery 2; the parameters 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 residual electric quantity of each single battery cell in the first battery 1, and the residual electric quantity of each single battery cell in the second battery 2. In addition, the battery management system 4 can also control the charging and discharging current of the first battery 1 and the second battery 2.

[0078] The battery pack 100 comprises a first battery 1, which is composed of a plurality of 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 4, so as to provide low-voltage current for the battery management system 4 when the battery pack 100 is in an offline state, thereby maintaining the normal use of the battery management system 4, and solving the problem that the parameters of the battery pack 100 cannot be recorded in the offline state of the battery pack 100.

[0079] On the other hand, the battery pack 100 further comprises a first power interface 7, and the first battery 1 is electrically connected with the first power interface 7. When the battery pack 100 is in an online state, the electric quantity of the first battery 1 can supply power to the low-power low-voltage load 300 in the electric energy equipment through the first power interface 7, so as to maintain the normal operation of the low-power low-voltage load 300.

[0080] It should be noted that when the electric energy equipment is a vehicle, the above-mentioned low-power low-voltage load 300 can be the instrument panel light of the vehicle, can be the display screen of the vehicle, and can also be the door switch of the vehicle, which is not limited by the present disclosure.

[0081] To control the output of the first battery 1 to the first power interface 7, in an embodiment of the present disclosure, the battery pack 100 further comprises a second switch module 6, which can be a relay, a contactor, or an electronic switch, and the present disclosure does not limit it. The first end of the second switch module 6 is connected to the positive electrode of the second battery 2, and the second end of the second switch module 6 is connected to the positive electrode of the first power interface 7. The negative electrode of the first power interface 7 is connected to the negative electrode of the first battery 1. A loop is formed among the first battery 1, the first power interface 7, and the second switch module 6. When the second switch module 6 is open, the current between the first battery 1 and the first power interface 7 is disconnected, and when the second switch module 6 is closed, the current between the first battery 1 and the first power interface 7 is closed. In this way, the current between the first battery 1 and the first power interface 7 is controlled.

[0082] To avoid over-discharge of the first battery 1, in an embodiment of the present disclosure, the positive electrode of the first battery 1 is connected to the positive electrode of the first power interface 7 through the battery management system 4, and the negative electrode of the first battery 1 is connected to the second input end of the first power interface 7. In this embodiment, the battery management system 4 is connected between the loop formed by the first battery 1 and the first power interface 7, and the battery management system 4 controls the power output of the first battery 1 to the first power interface 7, thereby avoiding over-discharge of the first battery 1 to the first power interface 7 and damaging the service life of the first battery 1.

[0083] The battery pack 100 further comprises a second battery 2, which is electrically connected to the battery management system 4 to enable the battery management system 4 to monitor and manage the battery parameters of the second battery 2. The second battery 2 is formed by connecting multiple single cells in series, and the total voltage of the series connection of the single cells is between 200V and 1000V.

[0084] The second battery 2 is provided to, on the one hand, in an embodiment of the present disclosure, the battery pack 100 further comprises a second power interface 8, when the battery pack 100 is in an online state, the second battery 2 can be connected to the high-voltage load 200 of the power device through the second power interface 8, thereby providing power for the operation of the high-voltage load 200.

[0085] It should be noted that when the power device is a vehicle, the above-mentioned high-voltage load 200 can be a motor, an air conditioner compressor, or a PTC heater of the vehicle, and the present disclosure does not limit it.

[0086] In another aspect, the second battery 2 is connected with a direct current converter 3, which is used to convert the high-voltage current of the second battery 2 into a low-voltage current that can be used by other low-voltage loads 300, and is outputted outwardly to supply the other low-voltage loads 300. Specifically, in an implementation of the present disclosure, the second battery 2 can be connected with the first battery 1 through the direct current converter 3, so that when the electric quantity of the first battery 1 is less than the first preset electric quantity, the second battery 2 can charge the first battery 1 through the direct current converter 3, thereby prolonging the time for the battery management system 4 to be powered in the offline state, increasing the number of samples of the parameters of the battery pack 100 acquired by the battery management system 4, and improving the accuracy of the parameters of the battery pack 100 recorded by the battery management system 4 in response to the change of the state of the battery pack 100.

[0087] In another implementation of the present disclosure, the second battery 2 can also be connected with the first power interface 7 through the direct current converter 3. When the battery pack 100 is in the online state, the second battery 2 can be connected with the high-power low-voltage loads 300 of the electric energy device through the first power interface 7, thereby providing electric energy for the operation of the high-power low-voltage loads 300.

[0088] It should be noted that when the electric energy device is a vehicle, the above-mentioned high-power low-voltage loads 300 can be vehicle headlamps, can be air conditioner blowers, and can also be sunroofs or adjustment mechanisms of electric seats, which are not limited by the present disclosure.

[0089] The battery pack 100 further comprises a first switch module 5, which can be a relay, can be a contactor, and can also be an electronic switch, which are not limited by the present disclosure. The first switch module 5 is used to control the on-off of the current between the second battery 2 and the first battery 1. Specifically, a first end of the first switch module 5 is connected with the positive electrode of the first battery 1, a second end of the first switch module 5 is connected with the negative electrode of the direct current converter 3, and the positive electrode of the second battery 2 is connected with the negative electrode of the first battery 1 through the positive electrode of the direct current converter 3. The first battery 1, the second battery 2, and the first switch module 5 constitute a circulation loop. When the current of the first battery 1 is greater than the first preset electric quantity, the first switch module 5 is opened, so that the current between the second battery 2 and the first battery 1 is disconnected. When the electric quantity of the first battery 1 is less than the first preset electric quantity, the first switch module 5 is closed, so that the current between the second battery 2 and the first battery 1 is connected, thereby charging the first battery 1.

[0090] The battery pack 100 further comprises a power distribution unit 9, the second power interface 8, the second battery 2 and the DC converter 3 form a current loop through the power distribution unit 9. When the first power interface 7 has a working load and the second power interface 8 has no working load, the power distribution unit 9 can control the flow direction of the current among the second battery 2, the second power interface 8 and the DC converter 3, so as to control the first power interface 7 to be powered and the second power interface 8 to be powered off. 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 8 in the idle state of the second power interface 8 is reduced, and the safety of the battery pack 100 is improved. When the first power interface 7 has no working load and the second power interface 8 has a working load, the power distribution unit 9 can also control the current so that the first power interface 7 is powered off and the second power interface 8 is powered on, thereby reducing the energy consumption of the battery pack 100.

[0091] The connection mode of the power distribution unit 9 with the second battery 2, the DC converter 3 and the second power interface 8 is various. Please refer to FIG. 3, which is a structural schematic diagram of the first embodiment of the connection of the power distribution unit 9 with the second battery 2, the DC converter 3 and the second power interface 8. In the first embodiment, the power distribution unit 9 comprises a third switch module 91 and a fourth switch module 92. The first end of the third switch module 91 is connected with the second battery 2, the second end of the third switch module 91 is connected with the first end of the fourth switch module 92 and the DC converter 3; the second end of the fourth switch module 92 is connected with the second power interface 8.

[0092] When the first power interface 7 and the second power interface 8 are connected with loads, the power distribution unit 9 can control the third switch module 91 and the fourth switch module 92 to be closed, the current of the second battery 2 can flow to the DC converter 3 through the third switch module 91 and flow to the first power interface 7 through the DC converter 3, thereby supplying power to the first power interface 7; the current of the second battery 2 can also flow to the second power interface 8 through the third switch module 91 and the fourth switch module 92, thereby supplying power to the second power interface 8.

[0093] When the second power interface 8 is idle, the power distribution unit 9 only needs to disconnect the second switch to stop supplying power to the second power interface 8, so as to reduce 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 8 in the idle state of the second power interface 8, and improve the safety of the battery pack 100.

[0094] Referring to FIG. 4, FIG. 4 is a structural schematic diagram of a second embodiment in which the power distribution unit 9 is connected with the second battery 2, the DC converter 3 and the second power interface 8, and in which the power distribution unit 9 comprises a third switch module 91 and a fourth switch module 92; the first end of the third switch module 91 is connected with the second battery 2, the second end of the third switch module 91 is connected with the first end of the fourth switch module 92 and the second power interface 8; the second end of the fourth switch module 92 is connected with the DC converter 3.

[0095] When the first power interface 7 and the second power interface 8 are connected with loads, the power distribution unit 9 can control the third switch module 91 and the fourth switch module 92 to be closed, the current of the second battery 2 can flow to the second power interface 8 through the third switch module 91, so as to realize the power supply to the second power interface 8. The current of the second battery 2 can also flow to the DC converter 3 through the third switch module 91 and the fourth switch module 92, and flow to the first power interface 7 through the DC converter 3, so as to realize the power supply to the first power interface 7.

[0096] When the first power interface 7 is not connected with a load, the power distribution unit 9 only needs to disconnect the second switch, so as to stop the power supply to the first power interface 7, thereby reducing the energy consumption of the battery pack 100 at the first power interface 7 and prolonging the use time of the battery pack 100.

[0097] Referring to FIG. 5, FIG. 5 is a structural schematic diagram of a third embodiment in which the power distribution unit 9 is connected with the second battery 2, the DC converter 3 and the second power interface 8, and in which the power distribution unit 9 comprises a third switch module 91 and a fourth switch module 92; the first end of the third switch module 91 is connected with the second battery 2, the second end of the third switch module 91 is connected with the second power interface 8; the first end of the fourth switch module 92 is connected with the second battery 2, the second end of the fourth switch module 92 is connected with the DC converter 3.

[0098] When the first power interface 7 and the second power interface 8 are connected with loads, the power distribution unit 9 can control the third switch module 91 and the fourth switch module 92 to be closed, the current of the second battery 2 can flow to the second power interface 8 through the third switch module 91, so as to realize the power supply to the second power interface 8. The current of the second battery 2 can also flow to the DC converter 3 through the fourth switch module 92, and flow to the first power interface 7 through the DC converter 3, so as to realize the power supply to the first power interface 7.

[0099] When the second power interface 8 is idle, the power distribution unit 9 disconnects the third switch module 91, and then the power supply to the second power interface 8 can be stopped, thereby reducing 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 8 in the idle state, and improving the safety of the battery pack 100.

[0100] When the first power interface 7 is idle, the power distribution unit 9 disconnects the fourth switch module 92, and then the power supply to the first power interface 7 can be stopped, thereby reducing the energy consumption of the battery pack 100 at the first power interface 7 and prolonging the use time of the battery pack 100.

[0101] Compared with the first embodiment and the second embodiment, the third embodiment can realize independent control of the first power interface 7 and the second power interface 8 and can adjust more modes. On the other hand, the parallel connection of the third switch module 91 and the fourth switch module 92 also makes the fourth switch module 92 no longer need to bear high-voltage current, and therefore, a switch module with smaller power and lower price can be selected as the fourth switch module 92 connected between the second battery 2 and the DC converter 3, thereby reducing the manufacturing cost of the battery pack 100.

[0102] It should be noted that in each of the above embodiments, the third switch module 91 and the fourth switch module 92 can be a relay, a contactor, or an electronic switch, and the present disclosure does not limit this. Meanwhile, in each of the above embodiments, the power distribution unit 9 can also be provided with active insurance, passive insurance, pre-charge resistance, and other electronic devices, which are used in series with the third switch module 91 and the fourth switch module 92 to protect the circuit safety.

[0103] The battery pack 100 also includes a signal interface 10, a first end of the signal interface 10 is connected with the first power interface 7, and a second end of the signal interface 10 is connected with the second power interface 8. The signal interface 10 is electrically connected with the battery management system 4. The battery management system 4 can transmit the battery parameters of the battery pack 100 to the control system of the vehicle through the signal interface 10, 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.

[0104] Please refer to FIG. 6, the present disclosure also proposes a control method applied to the above battery pack, the control method comprising the following steps:

[0105] S101, when the battery pack is in an offline state, determining the parameters of the battery pack by the battery management system; the parameters of the battery pack include at least one of the following parameters: the single-cell voltage of each cell of the first battery, the temperature of each cell of the first battery, and the remaining capacity of each cell of the first battery.

[0106] S102, when the first battery is less than the first preset amount of electricity, the second battery is charged to the first battery.

[0107] The present disclosure provides a control method, under the control method of the present disclosure, when the controller judges that the battery pack is in an offline state, the controller will acquire the parameters of the battery pack through the battery management system, so that the vehicle system or the operator of the battery pack can timely master the state change of the battery pack in the offline state, reduce the safety hidden trouble of the battery pack in the subsequent use process, and improve the safety of the use of the battery pack. When the controller detects that the current of the first battery is less than the first preset amount of electricity, the controller will close the first switch module between the second battery and the first battery, and drive the current of the second battery to enter the first battery through the DC converter, thereby charging the first battery, thereby prolonging the energy supply time of the battery management system to the first battery in the offline state, increasing the sample number of the parameter acquisition of the battery management system to the battery pack, and improving the accuracy of the battery pack state change reaction recorded by the battery management system. The parameters of the battery pack.

[0108] It should be noted that the value of the first preset amount of electricity is usually manually set by artificial, generally, the value of the first preset amount of electricity is associated with the type of battery, for example, when the first battery uses lithium battery, in order to avoid excessive discharge of the first battery, the first preset amount of electricity is usually set between 10% to 20% of the total amount of the first battery, so as to reduce the influence of excessive discharge on the service life of the first battery.

[0109] The controller can judge whether the battery pack enters the offline state in many ways, the controller can judge whether the battery pack enters the offline state by judging the high voltage interlock (HVIL) signal in the battery pack. The HVIL signal is mainly used for detecting the electrical connection integrity of the high voltage system in the vehicle, to ensure the safety and reliability of the connection between high voltage components such as 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 separated, and the controller can make a judgment that the battery pack enters the offline state.

[0110] The controller can also judge whether the battery pack enters the offline state through the vehicle CAN (controller area network) signal. The battery pack mainly realizes communication and exchange with the vehicle through the CAN line and the CAN signal. When the vehicle CAN signal in the battery pack is in the no communication state, it proves that the connection between the battery pack and the vehicle is separated, and the controller can make a judgment that the battery pack enters the offline state.

[0111] To improve the accuracy of the controller for the off-line state of the battery pack, in an embodiment of the present disclosure, when the battery pack meets the following conditions, it is determined that the battery pack enters the off-line state:

[0112] Condition 1: the HVIL signal is in an open state; and

[0113] Condition 2: the battery pack and the vehicle CAN signal are in a non-communication state.

[0114] The present embodiment introduces two conditions, "the HVIL signal is in an open state" and "the battery pack and the vehicle CAN signal are in a non-communication state", as the common basis for determining whether the battery pack is in an off-line state. In this way, a double-check mechanism is formed between the controller and the battery pack, thereby improving the accuracy of the controller for the off-line state of the battery pack, facilitating subsequent battery pack parameter reading and recording.

[0115] The power supply of the first battery to the battery management system will cause a difference in charge between the first battery and the second battery. The difference in charge will cause voltage imbalance in the high-voltage battery pack formed by the first battery and the second battery, and further cause loss of electrical energy of the battery pack.

[0116] To facilitate subsequent device query of the data obtained by the battery management system, after obtaining the parameters of the battery pack by the battery management system, the method further includes the steps of:

[0117] storing the parameters of the battery pack.

[0118] There are various storage methods for battery pack parameters. In an embodiment of the present disclosure, a non-volatile memory (RAM) is provided in the battery pack. After the battery management system obtains the parameters of the battery pack, the parameters of the battery pack will be stored in the non-volatile memory (RAM). When the electrical energy device is connected to the battery pack, the electrical energy device can obtain the state change of the battery pack in the off-line mode by reading the information in the non-volatile memory (RAM), and take appropriate measures (such as charging the battery pack) according to the state change of the battery pack, to ensure the safety of the battery pack in the subsequent use process.

[0119] In other embodiments of the present disclosure, after obtaining 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 and store them. When the electrical energy device is connected to the battery pack, the electrical energy device can download the parameters of the battery pack through the cloud to obtain the state change of the battery pack in the off-line mode.

[0120] Referring to FIG. 7, the acquisition of the battery pack parameters by the battery management system can be continuous real-time acquisition or interval acquisition in time periods, and the present disclosure does not limit this. In order to reduce the energy consumption of the battery pack in the offline state, in an implementable manner of the present disclosure, the control method comprises the following steps:

[0121] S201. When the battery pack is in the offline state, the parameters of the battery pack are acquired by the battery management system.

[0122] S202. The parameters of the battery pack are stored.

[0123] S203. The battery management system enters the sleep state, and in the sleep state, the battery management system stops determining the parameters of the battery pack.

[0124] S204. The battery management system in the sleep state is woken up.

[0125] The battery management system can be woken up in various situations. In an implementable manner of the present disclosure, 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, and the present disclosure does not limit this. The wake-up source has a hardware circuit therein, and the wake-up source is connected to the battery pack through a signal line, which can be a CAN line or a hard line, and the present disclosure does not limit this. When the 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 hardware circuit and the battery pack, and wake up the battery management system through the wake-up signal. The battery management system after being woken up will acquire and record the parameters of the battery pack.

[0126] In other implementable manners of the present disclosure, the battery management system can also be self-woken up. Specifically, the battery management system is provided with a wake-up module, and when the sleep state of the battery management system 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 battery management system after being woken up will acquire and record the parameters of the battery pack.

[0127] It should be noted that the preset time period is mainly determined by the battery pack power and the duration of the offline state of the battery pack. When the battery pack has more charge or the offline state lasts for a short time, the preset time period can be set within a shorter time limit. In this way, the frequency of the battery management system acquiring parameters of the battery pack is improved, the accuracy of the battery management system acquiring parameters of the battery pack in response to the actual state change of the battery pack is improved, and the safety of the battery pack is improved. When the battery pack has less charge or the offline state lasts for a long time, the preset time period can be set to a longer time limit. In this way, the frequency of the battery management system being awakened is reduced, thereby reducing the energy consumption of the battery pack and prolonging the use time of the battery pack in the offline state.

[0128] The first battery is used to provide power for the operation of the battery management system. In order to avoid the frequent self-awakening of the battery management system, which leads to the depletion of the power of the first battery, in an embodiment of the present disclosure, when the current of the first battery is less than a first preset power and the current of the second battery is less than a second preset power, the awakening function of the battery management system 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 disclosure. In the embodiment, when the power of the first battery is less than the first preset power and the power of the second battery is less than the second preset power, the controller of the battery management system will prohibit the awakening function of the control module. In this way, the awakening module continues to awaken the battery management system in the case that the power of the first battery and the second battery is too low, thereby causing the power of the first battery and the second battery to be depleted, protecting the power safety of the first battery and the second battery, and prolonging the service life of the first battery and the second battery.

[0129] S205, when the battery pack is in an offline state, acquiring parameters of the battery pack by the battery management system.

[0130] In the embodiment, after the battery management system finishes acquiring the parameters of the battery pack, the battery management system will enter a sleep state. In the sleep state, the battery management system will stop acquiring information of the battery pack. In this way, the energy consumption of the battery management system on the first battery is reduced. When the controller needs to acquire the parameters of the battery pack by the battery management system, the battery management system in sleep state will be awakened by the awakening signal, and the acquisition of the parameters of the battery pack by the battery management system will be completed. After the acquisition of the parameters of the battery pack by the battery management system is completed, the battery management system will continue to enter the sleep state, so as to save the energy consumption of the first battery and prolong the use time of the first battery.

[0131] Please refer to FIG. 8 and FIG. 9, after the battery management system is awakened, the self-discharge amount and the self-discharge rate of the battery pack will also be calculated. Specifically, after the step of awakening the battery management system in the sleep state, the following steps are further included in an embodiment of the present disclosure:

[0132] S301, if the number of times the battery management system is woken up is N, N≥2, then 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.

[0133] The self-discharge amount of the battery pack and the self-discharge rate of the battery pack can be calculated by the following steps:

[0134] 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 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 the battery cell in the battery pack, OCV1_N-1 can also be the open circuit voltage across the battery cell when the battery pack is woken up for the N-1th time.

[0135] 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 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 the battery cell in the battery pack, OCV1_N can also be the open circuit voltage across the battery cell when the battery pack is woken up for the Nth time.

[0136] S3013, according to the relationship formula △SOC=SOC_N-SOC_N-1, the change value △SOC of the remaining power of the battery pack when the battery pack is woken up for the N-1th and Nth 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, △SOC is the change value of the remaining power of the battery cell when the battery pack is woken up for the N-1th and Nth time.

[0137] 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.

[0138] 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 when the battery pack is woken up for the Nth and N-1th time.

[0139] In the embodiment, when the number of awakenings of the battery pack is greater than two, 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 the present awakening and the open circuit voltage of the battery pack at the last awakening of the battery pack, and records the self-discharge amount and the self-discharge rate. In this way, the control system of the vehicle and the detection personnel of the battery pack can master the real-time change of the self-discharge amount of the battery pack, and the safety of the battery pack in the subsequent use process is improved.

[0140] 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. 10, 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 disclosure, the control method further includes the following steps:

[0141] S401, if the number of awakenings of the battery management system is N, N≥2, then at the Nth awakening, the values of OCV_N-OCV_N-n and △OCV_set are compared in turn.

[0142] 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 at the Nth and the N-nth awakenings are calculated.

[0143] 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.

[0144] Wherein, OCV_N is the voltage of the battery pack at the Nth awakening, OCV_N-n is the voltage of the battery pack at the N-nth awakening, n (1, 2, 3, …, N-1), and △OCV_set is the preset voltage change value of the battery pack.

[0145] In the embodiment, before calculating the self-discharge amount and the self-discharge rate of the battery pack, the controller compares the voltage change amount OCV_N-OCV_N-1 of the battery pack at the present awakening and the voltage at the last awakening with the preset voltage change value △OCV_set stored in the memory, if OCV_N-OCV_N-1≥△OCV_set, the self-discharge amount and the self-discharge rate of the battery pack between the Nth awakening and the N-1th awakening of the battery pack are calculated and recorded.

[0146] If OCV_N-OCV_N-1<△OCV_set, the controller compares the voltage of the battery pack at this time with the voltage change amount OCV_N-OCV_N-2 at the N-2th wakeup with the preset voltage change value△OCV_set stored in the memory, and if OCV_N-OCV_N-2≥△OCV_set, the self-discharge amount and the self-discharge rate between the Nth wakeup of the battery pack and the N-2th wakeup of the battery pack are calculated and recorded.

[0147] If OCV_N-OCV_N-2<△OCV_set, the voltage of the battery pack at this time is compared with the voltage change amount at the N-3th wakeup, and if OCV_N-OCV_N-3≥△OCV_set, the self-discharge amount and the self-discharge rate between the Nth wakeup of the battery pack and the N-3th wakeup of the battery pack are calculated and recorded. If OCV_N-OCV_N-3<△OCV_set, the voltage of the battery pack at this time is compared with the voltage change amount at the N-4th wakeup, and so on.

[0148] If the voltage of the battery pack at this time and the voltage change amount OCV_N-OCV_1 of the N-N+1th are still less than△OCV_set, the calculation of the self-discharge amount and the self-discharge rate of the battery pack at this time is skipped. In this way, the capacitance change amount of the battery pack is too small to affect the calculation of the self-discharge amount and the self-discharge rate of the battery pack.

[0149] 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 the 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 preset voltage change value of the battery pack at the current voltage according to the OCV_set-OCV function.

[0150] In the following, the control process of the battery pack provided by the present disclosure will be described in detail in combination with FIG. 11, which includes the following steps:

[0151] S01: Determine whether the battery pack enters the offline mode, if the battery pack enters the offline mode, go to step S02, if the battery pack does not enter the offline mode, go to S11.

[0152] S02: The battery management system collects and stores 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 power of the battery pack, which can be the total remaining power of the battery pack or the remaining power of each battery in the battery pack.

[0153] S03: Determine whether the power of the first battery is less than the first preset power. If yes, go to S04; if no, go to S07.

[0154] S04: Determine whether the current of the second battery is less than the second preset power. If yes, go to S05; if no, go to S06.

[0155] S05: Inhibit the wake-up function of the battery management system to avoid excessive use of the power of the first battery and the second battery. The wake-up function 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.

[0156] S06: Start the DC converter to control the current to pass through the second battery and the DC converter to the first battery, thereby charging the first battery.

[0157] S07: Set the wake-up time of the battery management system.

[0158] S08: The battery management system is in sleep mode.

[0159] S09: Determine whether a wake-up signal is received. The wake-up signal 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 S10.

[0160] S10: Wake up the battery management system and re-enter S01.

[0161] S11: Enter the online mode. In the online mode, the battery pack supplies power to the load of the power device through the first battery or the second battery.

[0162] In the description of the embodiments of the present disclosure, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like refer to the orientation or positional relationship based on the drawings. They are only used to facilitate the description of the present disclosure and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present disclosure.

[0163] The above merely provides the preferred embodiment of the present disclosure, and cannot represent the full scope of the present disclosure.

Claims

1. A battery pack (100), characterized by, The battery pack (100) comprises: a first battery (1); a second battery (2) connected with the first battery (1) and used for outputting high-voltage voltage to the outside; a direct current converter (3) having one end electrically connected with the first battery (1) and the other end electrically connected with the second battery (2) to charge the first battery (1) when the electric quantity of the first battery (1) is less than a first preset electric quantity; a battery management system (4) electrically connected with the first battery (1) and used for determining parameter information of the first battery (1) and the second battery (2); the first battery (2) is used for supplying power to the battery management system (4).

2. The battery pack (100) of claim 1, wherein, The battery pack (100) further comprises a first switch module (5), a first end of the first switch module (5) is connected with a positive electrode of the first battery (1), and a second end of the first switch module (5) is connected with a negative electrode of the direct current converter (3). A positive electrode of the second battery (2) is connected with a negative electrode of the first battery (1) through a positive electrode of the direct current converter (3).

3. The battery pack (100) of claim 1, wherein, The battery pack (100) further comprises a first power interface (7) and a second switch module (6). A first end of the second switch module (6) is connected with a positive electrode of the second battery (2), and a second end of the second switch module (6) is connected with a positive electrode of the first power interface (7). A negative electrode of the first power interface (7) is connected with a negative electrode of the first battery (1).

4. The battery pack (100) of claim 1, wherein, The battery pack (100) further comprises a first power interface (7), and the second battery (2) is connected with the first power interface (7) through the direct current converter (3).

5. The battery pack (100) of any one of claims 1 to 4, characterized in that The battery pack (100) further comprises a power distribution unit (9) and a second power interface (8). The second power interface (8) and the second battery (2) and the direct current converter (3) form a current loop through the power distribution unit (9). The power distribution unit (9) is used for controlling the flow direction of the current among the second battery (2), the second power interface (8) and the direct current converter (3).

6. The battery pack (100) of claim 5, wherein, The power distribution unit (9) comprises a third switch module (91) and a fourth switch module (92). A first end of the third switch module (91) is connected with the second battery (2), and a second end of the third switch module (91) is connected with a first end of the second switch module (6) and the direct current converter (3). A second end of the fourth switch module (92) is connected with the second power interface (8).

7. The battery pack (100) of claim 5, wherein, The power distribution unit (9) comprises a third switch module (91) and a fourth switch module (92). A first end of the third switch module (91) is connected with the second battery (2), and a second end of the third switch module (91) is connected with the second power interface (8). A first end of the fourth switch module (92) is connected with the second battery (2), and a second end of the fourth switch module (92) is connected with the direct current converter (3).

8. The battery pack (100) of claim 5, wherein, The power distribution unit (9) comprises a third switch module (91) and a fourth switch module (92); The first end of the third switch module (91) is connected with the second battery (2), and the second end of the third switch module (91) is connected with the first end of the second switch module (6) and the second power interface (8); The second end of the fourth switch module (92) is connected with the DC converter (3).

9. A control method applied to the battery pack (100) according to any one of claims 1 to 8, characterized in that, The control method comprises the following steps: When the battery pack (100) is in an offline state, the battery management system (4) determines the parameters of the battery pack (100); the parameters of the battery pack (100) include at least one of the following parameters: the single cell voltage of each cell of the first battery (1), the temperature of each cell of the first battery (1), and the remaining capacity of each cell of the first battery (1); When the capacity of the first battery (1) is less than a first preset capacity, the second battery (2) charges the first battery (1).

10. The control method according to claim 9, characterized by, After the battery management system (4) determines the parameters of the battery pack (100), the method further comprises the following steps: The parameters of the battery pack (100) are stored.

11. The control method according to claim 9, characterized by, The battery management system (4) acquires the parameters of the battery pack (100), and the battery management system (4) enters a sleep state, in which the battery management system (4) stops determining the parameters of the battery pack (100).

12. The control method according to claim 11, characterized by, Before the step of determining the parameters of the battery pack (100) by the battery management system (4), the battery management system (4) in the sleep state is awakened.

13. The control method according to claim 12, characterized by, The step of awakening the battery management system (4) in the sleep state comprises the following steps: When the battery pack (100) is connected with an external wake-up source, the battery management system (4) in the sleep state is awakened; When the duration of the battery management system (4) in the sleep state reaches a preset duration, the battery management system (4) in the sleep state is awakened.

14. The control method according to claim 13, characterized by, After the battery management system (4) determines the parameters of the battery pack (100) and stores them, the method further comprises the following steps: When the current of the first battery (1) is less than a first preset capacity and the current of the second battery (2) is less than a second preset capacity, the awakening function of the battery management system (4) is disabled.

15. The control method according to claim 12, wherein After the step of awakening the battery management system (4) in the sleep state, the method further comprises the following steps: If the battery management system (4) is awakened N times, N≥2, then at the Nth awakening, the self-discharge amount and the self-discharge rate of the battery pack (100) are calculated, and the values of the self-discharge amount and the self-discharge rate are recorded.

16. The control method according to claim 15, characterized by Before calculating the self-discharge amount and the self-discharge rate of the battery pack (100), the method further comprises the following steps: The values of OCV_N-OCV_N-n and △OCV_set are compared in turn; 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 awakenings are calculated. 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 (100) is skipped. OCV_N-OCV_N-n≥△OCV_set, wherein OCV_N is the voltage of the battery pack (100) at the Nth wake-up, OCV_N-n is the voltage of the battery pack (100) at the N-nth wake-up, n (1, 2, 3, …, N-1), and △OCV_set is the preset voltage change value of the battery pack (100).

17. An electrical energy device, characterized by The electric energy device comprises a load and a battery pack (100) electrically connected with the load, and the battery pack (100) is the battery pack (100) according to any one of claims 1 to 8.

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