Battery charging method, battery management system and charging / discharging device

Abstract

The present disclosure provides a battery charging method, a battery management system, and a charging / discharging device, which can ensure the safety performance of a battery. The battery charging method includes the steps of: a battery management system BMS acquiring a first charging current and sending the first charging current to a charging / discharging device to cause the charging / discharging device to charge the battery based on the first charging current; when a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and the voltage of a battery cell of the battery does not exceed a full charge voltage of the battery cell, the BMS acquiring a first discharging current and sending the first discharging current to the charging / discharging device to cause the charging / discharging device to control the discharge of the battery based on the first discharging current; and when the first accumulated discharge amount of the battery is equal to or greater than the first accumulated discharge amount threshold, the BMS acquiring a second charging current and sending the second charging current to the charging / discharging device to cause the charging / discharging device to charge the battery based on the second charging current.

Description

[Technical field]

[0001] The present application relates to the field of batteries, and in particular to a battery charging method, a battery management system and a charging / discharging device. [Background technology]

[0002] With the development of the times, electric vehicles have good market prospects due to their advantages such as high environmental protection, low noise, and low usage costs, and can effectively promote energy conservation and emission reduction, thereby contributing to the development and progress of society.

[0003] For electric vehicles and related fields, battery technology is a key factor related to their development, and in particular, the safety performance of batteries will affect the development and application of battery-related products and the degree of public acceptance of electric vehicles. Therefore, how to ensure the safety performance of batteries is a technical problem to be solved. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present application provide a battery charging method, a battery management system and a charging / discharging device, which can ensure the safety performance of the battery. [Means for solving the problem]

[0005] In a first aspect, a battery charging method is provided, the battery management system BMS acquiring a first charging current, transmitting the first charging current to a charging / discharging device, and causing the charging / discharging device to charge the battery based on the first charging current; if a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the BMS acquiring a first discharging current, transmitting the first discharging current to the charging / discharging device, and causing the charging / discharging device to control discharging of the battery based on the first discharging current; if the first accumulated discharge amount of the battery is equal to or greater than the first accumulated discharge amount threshold, the BMS acquiring a second charging current, transmitting the second charging current to the charging / discharging device, and causing the charging / discharging device to charge the battery based on the second charging current.

[0006] According to the technical solution of the embodiments of the present application, a feasible charging method is provided between a charging / discharging device and a BMS. In the process of charging a battery, the charging / discharging device charges and discharges the battery according to a first charging current and a first discharging current transmitted from the BMS, thereby avoiding problems such as heat generation and lithium ion concentration caused by continuous charging of the battery, and further avoiding battery safety issues caused by problems such as heat generation and lithium ion concentration, such as battery combustion or explosion, and ensuring the safety performance of the battery.

[0007] In a possible implementation, the method further includes a step of, when the second accumulated charge amount of the battery is equal to or greater than a second accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed a fully charged voltage of the battery cell, the BMS acquiring a second discharge current and transmitting the second discharge current to the charging / discharging device to cause the charging / discharging device to control the discharge of the battery based on the second discharge current.

[0008] According to the technical solution of this embodiment, after the charging, discharging and recharging of the battery are completed through information exchange between the BMS and the charging / discharging device, the battery can be re-discharged. Based on this method, the embodiment of the present application can further provide a multi-cycle cyclic charging / discharging method, in which the charging and discharging processes are sequentially cyclically performed, and the battery can be gradually charged while ensuring the performance of the battery.

[0009] In a possible implementation, the method further includes a step in which the BMS sends a charging stop command to the charging / discharging device when the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell, and the charging stop command is used to instruct the charging / discharging device to stop charging the battery.

[0010] In a possible implementation, the charge rate range of the first charging current and / or the second charging current is between 2C and 10C.

[0011] According to the technical solution of this embodiment, while ensuring the safety performance of the battery, the charging rate of the first charging current and / or the second charging current is in the range of 2C to 10C, thereby realizing high-current fast charging, increasing the charging amount of the battery in one charging process, and achieving the purpose of fast charging.

[0012] In addition, the charging current is also limited due to the concentration of lithium ions in the negative electrode during continuous charging, making it impossible to realize rapid charging of the battery with a continuous large current. In the technical solution of the embodiments of the present application, the battery is charged with a large current, and after one large current charge, the battery is discharged to release the lithium ions concentrated in the negative electrode of the battery during the charging process, so that the large current can be reused to charge the battery thereafter, thereby realizing rapid charging of the battery.

[0013] In a possible implementation, the discharge rate range of the first discharge current is between 0.1C and 1C.

[0014] According to the technical solution of this embodiment, the discharge rate of the first discharge current is in the range of 0.1C to 1C, realizing small current discharge, for the purpose of discharging the battery with a small current to release the lithium ions concentrated in the negative electrode of the battery, without causing excessive loss of the amount of electricity charged in the battery.

[0015] In a possible implementation, the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is less than or equal to 10%.

[0016] According to the technical solution of this implementation, by setting the ratio between the accumulated discharge amount threshold in the discharging process and the accumulated charge amount threshold in the charging process, the charge amount of the battery in the charging process and the discharge amount of the battery in the discharging process can be better controlled, and the discharge amount can be reduced to avoid excessive loss of the electricity charged in the battery.

[0017] In a possible implementation, the step of the BMS obtaining the first charging current includes the step of the BMS obtaining a battery state parameter and determining the first charging current based on the state parameter, and / or the step of the BMS obtaining the first discharging current includes the step of the BMS obtaining a battery state parameter and determining the first discharging current based on the state parameter, and / or the step of the BMS obtaining the second charging current includes the step of the BMS obtaining a battery state parameter and determining the second charging current based on the state parameter, the battery state parameters including at least one of battery temperature, battery voltage, battery current, battery charge state, and battery health state parameters.

[0018] According to the technical solution of this implementation, when at least one of the first charging current, the second charging current and the first discharging current is a current determined based on the state parameters of the battery, it can better adapt to the current state parameters of the battery, improve the charging efficiency and / or discharging efficiency of the battery, and do not damage the battery.

[0019] In a possible implementation form, the step of the BMS acquiring a first charging current and transmitting the first charging current to the charging / discharging device includes a step of the BMS acquiring the first charging current periodically and transmitting the first charging current to the charging / discharging device, and / or the step of the BMS acquiring a first discharging current and transmitting the first discharging current to the charging / discharging device includes a step of the BMS acquiring the first discharging current periodically and transmitting the first discharging current to the charging / discharging device, and / or the step of the BMS acquiring a second charging current and transmitting the second charging current to the charging / discharging device includes a step of the BMS acquiring the second charging current periodically and transmitting the second charging current to the charging / discharging device.

[0020] In this implementation, in the process of the charging / discharging device charging and / or discharging the battery once, the charging current and / or discharging current are periodically transmitted by the BMS; on the one hand, the embodiment periodically adjusts the charging current and / or discharging current to improve the charging / discharging efficiency; on the other hand, the periodically transmitted charging current and / or discharging current can further indicate that the status of the BMS and the battery is normal, thereby facilitating the charging / discharging device to continue charging the battery or control the discharging of the battery, and ensuring the safety performance of the battery.

[0021] In a possible implementation, the method further includes a step of the BMS acquiring a first charging voltage and sending the first charging voltage to the charging / discharging device, where the first charging current and the first charging voltage are carried in a first battery charging request BCL message, and / or the method further includes a step of the BMS acquiring a first discharging voltage and sending the first discharging voltage to the charging / discharging device, where the first discharging current and the first discharging voltage are carried in a second BCL message, and / or the method further includes a step of the BMS acquiring a second charging voltage and sending the second charging voltage to the charging / discharging device, where the second charging current and the second charging voltage are carried in a third BCL message.

[0022] In this implementation, the communication between the BMS and the charging / discharging device is compatible with the communication protocol between the conventional charger and the BMS, so that the communication between the BMS and the charging / discharging device is easy to implement and has good application prospects.

[0023] In a second aspect, a battery charging method is provided, the method including the steps of: a charging / discharging device receiving a first charging current transmitted from a battery management system BMS and charging the battery based on the first charging current; a charging / discharging device receiving a first discharging current transmitted from the BMS and controlling discharging of the battery based on the first discharging current, where the first discharging current is the discharging current transmitted from the BMS when a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell; and a charging / discharging device receiving a second charging current transmitted from the BMS and charging the battery based on the second charging current, where the second charging current is the charging current transmitted from the BMS when a first accumulated discharge amount of the battery is equal to or greater than the first accumulated discharge amount threshold.

[0024] In a possible implementation, the method further includes a step of the charging / discharging device receiving a second discharge current transmitted from the BMS and controlling the discharge of the battery based on the second discharge current, the second discharge current being the discharge current transmitted from the BMS when the second accumulated charge amount of the battery is greater than or equal to a second accumulated charge amount threshold and the voltage of the battery cell does not exceed the fully charged voltage of the battery cell.

[0025] In a possible implementation, the method further includes a step in which the charging / discharging device receives a charging stop command sent from the BMS to stop charging the battery, the charging stop command being a command sent from the BMS when the voltage of a battery cell of the battery exceeds a fully charged voltage of the battery cell.

[0026] In a possible implementation, the charge rate range of the first charging current and / or the second charging current is between 2C and 10C.

[0027] In a possible implementation, the discharge rate range of the first discharge current is between 0.1C and 1C.

[0028] In a possible implementation, the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is less than or equal to 10%.

[0029] In a possible implementation, at least one of the first charging current, the first discharging current, and the second charging current is determined by the BMS based on battery state parameters, the battery state parameters including at least one of battery temperature, battery voltage, battery current, battery charge state, and battery health state parameters.

[0030] In a possible implementation form, the step of the charging / discharging device receiving the first charging current transmitted from the BMS includes a step of the charging / discharging device periodically receiving the first charging current transmitted from the BMS, and / or the step of the charging / discharging device receiving the first discharging current transmitted from the BMS includes a step of the charging / discharging device periodically receiving the first discharging current transmitted from the BMS, and / or the step of the charging / discharging device receiving the second charging current transmitted from the BMS includes a step of the charging / discharging device periodically receiving the second charging current transmitted from the BMS.

[0031] In possible implementations, the method further includes the charging / discharging device receiving a first charging voltage transmitted from the BMS, the first charging voltage and the first charging current being carried in a first battery charging request BCL message, and / or the method further includes the charging / discharging device receiving a first discharging voltage transmitted from the BMS, the first discharging voltage and the first discharging current being carried in a second BCL message, and / or the method further includes the charging / discharging device receiving a second charging voltage transmitted from the BMS, the second charging voltage and the second charging current being carried in a third BCL message.

[0032] In a third aspect, a battery management system BMS is provided, comprising: an acquisition unit for acquiring a first charging current; a transmission unit for transmitting the first charging current to a charging / discharging device to cause the charging / discharging device to charge the battery based on the first charging current; and a processing unit, wherein if the acquisition unit is used for determining that a first accumulated charging amount of the battery is equal to or greater than a first accumulated charging amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the acquisition unit is further used for acquiring a first discharging current, the transmission unit is further used for transmitting the first discharging current to the charging / discharging device to cause the charging / discharging device to control discharging of the battery based on the first discharging current, and if the processing unit is further used for determining that the first accumulated discharging amount of the battery is equal to or greater than the first accumulated discharging amount threshold, the acquisition unit is further used for acquiring a second charging current, and the transmission unit is further used for transmitting the second charging current to the charging / discharging device to cause the charging / discharging device to charge the battery based on the second charging current.

[0033] In a fourth aspect, a charging / discharging device is provided, comprising: a receiving unit for receiving a first charging current transmitted from a battery management system BMS; and a processing unit for charging a battery based on the first charging current, wherein the receiving unit is further used for receiving a first discharging current transmitted from the BMS, and the processing unit is further used for controlling discharging of the battery based on the first discharging current, the first discharging current being the discharging current transmitted from the BMS when a first accumulated charging amount of the battery is equal to or greater than a first accumulated charging amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the receiving unit is further used for receiving a second charging current transmitted from the BMS, and the processing unit is further used for charging the battery based on the second charging current, and the second charging current being the charging current transmitted from the BMS when a first accumulated discharging amount of the battery is equal to or greater than the first accumulated discharging amount threshold.

[0034] In a fifth aspect, a charging / discharging device is provided, comprising a control unit and a power conversion unit, the control unit is used to receive a first charging current transmitted from a BMS, and control the power conversion unit to charge a battery based on the first charging current; receive a first discharging current transmitted from the BMS, and control the power conversion unit to discharge the battery based on the first discharging current, where the first discharging current is the discharging current transmitted from the BMS when a first accumulated charging amount of the battery is equal to or greater than a first accumulated charging amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell; receive a second charging current transmitted from the BMS, and control the power conversion unit to charge the battery based on the second charging current, where the second charging current is the charging current transmitted from the BMS when a first accumulated discharging amount of the battery is equal to or greater than the first accumulated discharging amount threshold.

[0035] In a possible implementation, the power conversion unit is connected to an AC power source and a battery, the power conversion unit includes an AC / DC converter and a DC / DC converter, the control unit is used to control the AC / DC converter and the DC / DC converter based on a first charging current to charge the battery via the AC power source, and the control unit is used to control the AC / DC converter and the DC / DC converter based on a second charging current to charge the battery via the AC power source.

[0036] In a possible implementation, the AC / DC converter is a bidirectional AC / DC converter and the DC / DC converter is a bidirectional DC / DC converter, and the control unit is used to control the bidirectional AC / DC converter and the bidirectional DC / DC converter based on the first discharge current to discharge the battery into the AC power source.

[0037] In a possible implementation, the control unit is further used to receive a second discharge current sent from the BMS, and control the bidirectional AC / DC converter and the bidirectional DC / DC converter based on the second discharge current to discharge the battery to the AC power source, where the second discharge current is the discharge current sent from the BMS when the second accumulated charge amount of the battery is greater than or equal to a second accumulated charge amount threshold and the voltage of the battery cells of the battery does not exceed the fully charged voltage of the battery cells.

[0038] In a possible implementation, the control unit is further used for receiving a stop charging command sent from the BMS, and controlling the bidirectional AC / DC converter and the bidirectional DC / DC converter based on the stop charging command to stop charging the battery, where the stop charging command is a command sent from the BMS when the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell.

[0039] In a possible implementation, the charge rate range of the first charging current and / or the second charging current is between 2C and 10C.

[0040] In a possible implementation, the discharge rate range of the first discharge current is between 0.1C and 1C.

[0041] In a possible implementation, the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is less than or equal to 10%.

[0042] In a possible implementation, at least one of the first charging current, the first discharging current, and the second charging current is determined by the BMS based on battery state parameters, the battery state parameters including at least one of battery temperature, battery voltage, battery current, battery charge state, and battery health state parameters.

[0043] In a possible implementation, the control unit is used to periodically receive a first charging current transmitted from the BMS, and / or the control unit is used to periodically receive a first discharging current transmitted from the BMS, and / or the control unit is used to periodically receive a second charging current transmitted from the BMS.

[0044] Optionally, the control unit is further adapted to receive a first charging voltage transmitted from the BMS, the first charging voltage and the first charging current being carried in a first Battery Charging Request BCL message, and / or the control unit is further adapted to receive a first discharging voltage transmitted from the BMS, the first discharging voltage and the first discharging current being carried in a second BCL message, and / or the control unit is further adapted to receive a second charging voltage transmitted from the BMS, the second charging voltage and the second charging current being carried in a third BCL message.

[0045] In a sixth aspect, there is provided a battery management system BMS, comprising a processor and a memory, the memory being adapted to store a computer program, the processor being adapted to call the computer program and to execute the method of the first aspect above and any possible embodiment of the first aspect.

[0046] In a seventh aspect, there is provided a charging / discharging device, comprising a processor and a memory, the memory being adapted to store a computer program, the processor being adapted to call the computer program and to execute the method of the second aspect above and any possible embodiment of the second aspect.

[0047] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly describes the drawings that need to be used in the embodiments of the present application. It is obvious that the drawings described below are only some embodiments of the present application, and those skilled in the art can further obtain other drawings based on the drawings without requiring creative labor. [Brief description of the drawings]

[0048] [Figure 1] 1 is a structural diagram of a charging system to which an embodiment of the present application is applied; [Diagram 2] FIG. 2 is a schematic flow block diagram of a battery charging method according to an embodiment of the present application. [Diagram 3]FIG. 2 is a schematic flow block diagram of another battery charging method according to an embodiment of the present application. [Figure 4] FIG. 2 is a schematic waveform diagram of the charging current and discharging current of a battery according to an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic flow block diagram of another battery charging method according to an embodiment of the present application. [Figure 6] FIG. 2 is a schematic flow block diagram of another battery charging method according to an embodiment of the present application. [Figure 7] FIG. 2 is a schematic flow block diagram of another battery charging method according to an embodiment of the present application. [Figure 8] FIG. 2 is a schematic flow block diagram of another battery charging method according to an embodiment of the present application. [Figure 9] FIG. 2 is a schematic structural block diagram of a battery management system BMS according to an embodiment of the present application. [Figure 10] FIG. 1 is a schematic structural block diagram of a charging / discharging device according to an embodiment of the present application. [Figure 11] FIG. 2 is a schematic structural block diagram of another charging / discharging device according to an embodiment of the present application. [Figure 12] FIG. 2 is a schematic structural block diagram of a power conversion unit in the charging / discharging device according to the embodiment of the present application. [Figure 13] FIG. 1 is a schematic structural block diagram of an electronic device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] Hereinafter, the embodiments of the present application will be described in more detail with reference to the drawings and examples. The detailed description of the following examples and the drawings are intended to illustratively explain the principles of the present application, but are not intended to limit the scope of the present application, i.e., the present application is not limited to the examples described.

[0050] In the description of this application, unless otherwise specified, "plurality" means two or more, and the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", and "outer" is merely for the purpose of easily explaining and simplifying the description of this application, and does not indicate or imply that the devices or elements shown necessarily have a specific orientation, or must be constructed and operated in a specific orientation, and therefore cannot be understood as limiting this application. Furthermore, terms such as "first", "second", and "third" are merely for the purpose of explanation, and cannot be understood as indicating or implying relative importance.

[0051] In the new energy field, the power battery can function as the main power source of the power consuming device (such as a vehicle, ship or spacecraft), and the energy storage battery can function as a charging source for the power consuming device, and the importance of both is self-evident. By way of example and not of limitation, in some application scenarios, the power battery can be the battery of the power consuming device, and the energy storage battery can be the battery of the charging device. For convenience of explanation, hereinafter, both the power battery and the energy storage battery can be collectively referred to as a battery.

[0052] Currently, most of the batteries on the market are rechargeable storage batteries, most commonly lithium batteries, such as lithium ion batteries or lithium ion polymer batteries, etc. In the charging process, batteries are generally charged in a continuous charging manner, and continuous charging of a battery can cause phenomena such as lithium deposition and heat generation in the battery, which not only reduces the performance of the battery and significantly shortens the cycle life, but also limits the fast charging capacity of the battery and can cause catastrophic consequences such as combustion and explosion, which can lead to serious safety issues.

[0053] In order to ensure the safety performance of the battery, this application proposes a new battery charging method and charging system.

[0054] FIG. 1 shows a structural diagram of a charging system to which an embodiment of the present invention is applied.

[0055] As shown in FIG. 1, the charging system 100 may include a charging / discharging device 110 and a battery system 120, and optionally, the battery system 120 may be a battery system for electric vehicles (pure electric vehicles and plug-in hybrid electric vehicles) or a battery system in other application scenarios.

[0056] Optionally, at least one battery pack may be installed in the battery system 120, and the at least one battery pack may be collectively referred to as a battery 121. In terms of the type of battery, the battery 121 may be any type of battery, including but not limited to a lithium ion battery, a lithium metal battery, a lithium sulfur battery, a lead acid battery, a nickel cadmium battery, a nickel metal hydride battery, or a lithium air battery. In terms of the size of the battery, the battery 121 in the embodiment of the present application may be a cell / battery cell, or a battery module or a battery pack, and the battery module or the battery pack may be formed of a plurality of batteries in series and parallel, and the embodiment of the present application is not specifically limited in terms of the type and size of the battery 121.

[0057] In order to intelligently manage and maintain the battery 121, prevent the battery from being overcharged or overdischarged, and extend the service life of the battery, the battery system 120 is generally provided with a battery management system (BMS) 122 for monitoring the status of the battery 121. Optionally, the BMS 122 may be integrated and installed in the same device / apparatus as the battery 121, or the BMS 122 may be installed outside the battery 121 as an independent device / apparatus.

[0058] Specifically, the charging / discharging device 110 is a device that replenishes electric energy to the battery 121 of the battery system 120 and / or controls the discharge of the battery 121.

[0059] Optionally, the charging / discharging device 110 of the embodiment of the present application may be a normal charging post, a super charging post, a charging post supporting a vehicle to grid (V2G) mode, or a charging / discharging device / equipment capable of charging and / or discharging a battery, etc. The embodiment of the present application does not limit the specific type and specific application scenario of the charging / discharging device 110.

[0060] Optionally, as shown in FIG. 1 , the charging / discharging device 110 is connected to the battery 121 via a wire 130, and is connected to the BMS 122 via a communication line 140, which is used to realize information exchange between the charging / discharging device 110 and the BMS.

[0061] By way of example, and without limitation, the communication line 140 may include a controller local area network (CAN) communication bus or a daisy chain communication bus.

[0062] Optionally, the charging / discharging device 110 can communicate with the BMS 122 not only through the communication line 140 but also through a wireless network. The embodiment of the present application does not specifically limit the type of wired communication or wireless communication between the charging / discharging device and the BMS 122.

[0063] 2 shows a schematic flow block diagram of a battery charging method 200 according to an embodiment of the present application. Optionally, the method 200 of the embodiment of the present application can be applied to the charging / discharging device 110 and the battery system 120 shown in FIG.

[0064] As shown in FIG. 2, the battery charging method 200 may include the following steps.

[0065] Step 210, the battery management system BMS obtains a first charging current.

[0066] Step 220, the BMS sends a first charging current to the charging / discharging device.

[0067] Step 230, the charger / discharger charges the battery based on the first charging current.

[0068] Step 240: if the first accumulated charge amount of the battery is greater than or equal to the first accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a first discharge current.

[0069] Step 250, the BMS transmits a first discharge current to the charging / discharging device.

[0070] Step 260, the charger / discharger controls the discharge of the battery based on the first discharge current.

[0071] In the embodiment of the present application, a feasible charging method is provided between the charging / discharging device and the BMS. In the process of charging the battery, the charging / discharging device realizes charging and discharging of the battery based on the first charging current and the first discharging current transmitted from the BMS, and avoids continuous charging of the battery, thereby avoiding problems such as heat generation and lithium ion concentration caused by continuous charging of the battery. Heat generation leads to an increase in the battery temperature, and crystals generated by lithium ion concentration may penetrate the battery, causing electrolyte leakage and short-circuiting the battery. Both the increase in battery temperature and the short-circuiting of the battery may lead to safety issues of the battery, such as battery combustion or explosion. Therefore, according to the technical solution of the embodiment of the present application, the charging / discharging device realizes charging and discharging of the battery based on the first charging current and the first discharging current transmitted from the BMS, and ensures the safety performance of the battery. In addition, in the process of continuous charging, the continuous concentration of lithium ions also leads to the problem of lithium precipitation, which affects the service life and charging capacity of the battery, and therefore, according to the technical solution of the embodiment of the present application, the service life and charging capacity of the battery can also be ensured.

[0072] Specifically, in steps 210 to 230, the BMS first enters a charging mode and controls the charging / discharging device to charge the battery. First, the BMS obtains a first charging current. After the BMS transmits the first charging current to the charging / discharging device, the charging / discharging device charges the battery based on the received first charging current.

[0073] Optionally, the BMS may obtain the first charging current from its own functional unit (e.g., a storage unit or a processing unit), or the BMS may obtain the first charging current from another device. In some embodiments, the first charging current may be a preset current, which may be a fixed value or may vary in a preset manner over time. Or, in some other embodiments, the first charging current may be a current determined based on a state parameter of the battery, which varies with the change in the state parameter of the battery.

[0074] Optionally, the charging / discharging device may be connected to a power source, which may be an AC power source and / or a DC power source, and after receiving the information of the first charging current, the charging / discharging device charges the battery via the AC power source and / or the DC power source based on the first charging current.

[0075] Furthermore, in the process of the charging / discharging device charging the battery based on the first charging current, the BMS obtains a first accumulated charge amount of the battery, and can determine whether the first accumulated charge amount is equal to or greater than a first accumulated charge amount threshold; if the first accumulated charge amount of the battery is equal to or greater than the first accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a first discharging current.

[0076] Specifically, as can be seen from the description of the battery in FIG. 1 above, the battery may include one or more battery cells, and the BMS can monitor whether the battery has reached a fully charged state by monitoring the voltage of one or more battery cells of the battery. Optionally, when the battery includes multiple battery cells, the voltages of the multiple battery cells may be different, and in this situation, it can be determined whether the battery has reached a fully charged state by determining whether the maximum voltage of the battery cell exceeds the fully charged voltage of the battery cell. Or, in another embodiment, other voltages of the battery cells of the battery besides the maximum voltage of the battery cell can also be used to determine whether the battery has reached a fully charged state.

[0077] On the premise that the voltage of the battery cell of the battery does not exceed the fully charged voltage of the battery cell, i.e., the battery has not reached a fully charged state, when the first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold, the BMS obtains a first discharge current, i.e., the battery transitions from a charge mode to a discharge mode.

[0078] Optionally, the first accumulated charge amount may be a first accumulated charge capacity or a first accumulated charge amount. Correspondingly, when the first accumulated charge amount is the first accumulated charge capacity, the first accumulated charge amount threshold is a first accumulated charge capacity threshold, and when the first accumulated charge amount is the first accumulated charge amount, the first accumulated charge amount threshold is a first accumulated charge amount threshold.

[0079] In some embodiments, the first accumulated charge threshold may be a preset threshold, which may be a fixed threshold or which may vary in a preset manner over time.

[0080] In some other embodiments, the first accumulated charge threshold may be determined based on the state parameters of the battery, i.e., when the state parameters of the battery change, the first accumulated charge threshold also changes; according to the embodiment, the first accumulated charge threshold can better adapt to the current state parameters of the battery, better control the current charging process, improve the charging efficiency of the battery, and not damage the battery.

[0081] Furthermore, in steps 240 to 260, the BMS acquires the first discharge current and transmits the first discharge current to the charging / discharging device, which controls the discharge of the battery based on the received first discharge current.

[0082] Optionally, the BMS may obtain the first discharge current from its own functional unit (e.g., a storage unit or a processing unit), or the BMS may obtain the first discharge current from another device. In some embodiments, the first discharge current may be a preset current, and the preset current may be a fixed value or may change in a preset manner over time. Or, in some other embodiments, the first discharge current may be a current determined based on a state parameter of the battery, and the first discharge current also changes with the change in the state parameter of the battery. In some embodiments, in the discharge mode or discharge stage, the battery's electricity can be transmitted to an energy storage device and / or a power grid, which is advantageous for cyclic use of electric energy. The energy storage device may be installed inside or outside the charging / discharging device so as to receive the battery's discharge current. The embodiments of the present application do not limit the specific installation of the energy storage device. Optionally, in the discharge mode, the battery's electric quantity may be consumed in other ways, and the embodiments of the present application do not limit the specific manner of consuming electric energy.

[0083] Furthermore, in the process in which the charging / discharging device controls the discharge of the battery, the BMS can obtain a first accumulated discharge amount in the discharge process of the battery, and determine whether the first accumulated discharge amount is greater than or equal to a first accumulated discharge amount threshold.

[0084] Selectively, the first cumulative discharge amount may be a first cumulative discharge capacity or a first cumulative discharged quantity of electricity. Correspondingly, when the first cumulative discharge amount is the first cumulative discharge capacity, the first cumulative discharge amount threshold is a first cumulative discharge capacity threshold, and when the first cumulative discharge amount is the first cumulative discharged quantity of electricity, the first cumulative discharge amount threshold is a first cumulative discharged quantity of electricity threshold.

[0085] In some embodiments, the first cumulative discharge threshold may be a preset threshold, which may be a fixed threshold or which may vary over time in a preset manner.

[0086] In some other embodiments, the first accumulated discharge amount threshold may be determined based on the state parameters of the battery, i.e., when the state parameters of the battery change, the first accumulated discharge amount threshold also changes, and according to the embodiment, the first accumulated discharge amount threshold can better adapt to the current state parameters of the battery, better control the current discharge process, improve the discharge efficiency of the battery, and not damage the battery.

[0087] When the first accumulated discharge amount is equal to or greater than the first accumulated discharge amount threshold, the charging / discharging device controls the battery to stop discharging.

[0088] Through the above process, the charging / discharging device realizes charging and discharging to the battery based on the first charging current and the first discharging current transmitted from the BMS, thereby avoiding problems such as heat generation and lithium ion concentration caused by continuous charging of the battery, and avoiding battery safety problems caused by problems such as heat generation and lithium ion concentration, such as battery combustion or explosion, and ensuring the safety performance of the battery. In addition, after charging the battery to a first accumulated charge amount based on the first charging current, the battery's electricity is discharged to a first accumulated discharge amount based on the first discharging current, releasing the lithium ions concentrated in the negative electrode of the battery during the charging process, preventing the problem of lithium precipitation caused by continuous charging, thereby improving the service life and charging capacity of the battery.

[0089] Regarding the charging of the battery, after one charge and one discharge, the battery may be continuously charged for a second time.

[0090] Optionally, as shown in FIG. 2, the battery charging method 200 in the embodiment of the present application may further include the following steps:

[0091] Step 270: if the first accumulated discharge amount of the battery is greater than or equal to the first accumulated discharge amount threshold, the BMS obtains a second charging current.

[0092] In step 280, the BMS transmits a second charging current to the charging / discharging device.

[0093] In step 290, the charger / discharger charges the battery based on the second charging current.

[0094] Specifically, in the above steps 270 to 290, if the BMS determines that the first accumulated discharge amount of the battery is the first accumulated discharge amount threshold, the BMS obtains the second charging current and transmits the second charging current to the charging / discharging device, and the charging / discharging device continues charging the battery based on the received second charging current, i.e., the battery re-enters the charging mode from the discharging mode.

[0095] Alternatively, other related technical solutions of steps 270 to 290 may refer to the related descriptions of steps 210 to 230 above, and will not be described again here.

[0096] As can be understood, in the embodiment of the above application, in addition to the current information required for charging and discharging, the charging and discharging of the battery also requires voltage information required for charging and discharging, for example, in steps 210-230, the BMS obtains a first charging current and a first charging voltage, and transmits the first charging current and the first charging voltage to the charging and discharging device, which is used to charge the battery according to the first charging current and the first charging voltage, and in steps 240-260, the BMS obtains a first discharging current and a first discharging voltage, and transmits the first discharging current and the first discharging voltage to the charging and discharging device, which is used to discharge the battery according to the first discharging current and the first discharging voltage. The subsequent charging and discharging processes may be similar to the above charging and discharging processes, and will not be described again.

[0097] FIG. 3 shows a schematic flow block diagram of another battery charging method 300 according to an embodiment of the present application.

[0098] As shown in FIG. 3, the battery charging method 300 not only includes the above steps 210 to 290, but also may further include the following steps.

[0099] Step 310: if the second accumulated charge amount of the battery is greater than or equal to the second accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a second discharging current.

[0100] In step 320, the BMS sends a second discharge current to the charging / discharging device.

[0101] Step 330, the charger / discharger controls the discharge of the battery based on the second discharge current.

[0102] In the embodiment of the present application, the charging, discharging, recharging and re-discharging of the battery are completed through information exchange between the BMS and the charging and discharging device. Based on this method, the embodiment of the present application can further provide a multi-cycle charging and discharging method, which performs charging and discharging processes in a cyclical manner, ensures the safety performance of the battery, and realizes gradual charging of the battery.

[0103] Specifically, in step 310, during the process of the charging / discharging device charging the battery based on the second charging current, the BMS can obtain a second accumulated charge amount of the battery, and determine whether the second accumulated charge amount is greater than or equal to a second accumulated charge amount threshold.

[0104] Optionally, the second accumulated charge amount may be only the charge amount to the battery based on the second charging current of the charging / discharging device, or the second accumulated charge amount may be the current total charge amount of the battery, for example, the current total charge amount of the battery=the charge amount based on the first charging current+the charge amount based on the second charging current-the discharge amount based on the first discharging current. Correspondingly, the second accumulated charge amount threshold may be a charge amount threshold based on one charging, or the second accumulated charge amount threshold may be a charge amount threshold based on the total charge amount.

[0105] The first cumulative charge amount described above is similar to the first cumulative charge amount threshold, and in the embodiment of the present application, the second cumulative charge amount can be the second cumulative charge capacity or the second cumulative charge amount. Correspondingly, when the second cumulative charge amount is the second cumulative charge capacity, the first cumulative charge amount threshold is the second cumulative charge capacity threshold, and when the second cumulative charge amount is the second cumulative charge amount, the second cumulative charge amount threshold is the second cumulative charge amount threshold.

[0106] Optionally, in some embodiments, the second accumulated charge threshold may be a preset threshold, which may be a fixed threshold or which may vary in a preset manner over time.

[0107] In some further embodiments, the second accumulated charge threshold may be determined based on a state parameter of the battery, i.e., as the state parameter of the battery changes, the second accumulated charge threshold also changes.

[0108] Furthermore, in step 310, if the second accumulated charge amount is equal to or greater than the second accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a second discharge current, and in steps 320 to 330, the BMS transmits the second discharge current to a charging / discharging device, and the charging / discharging device controls the discharge of the battery according to the received second discharge current.

[0109] Specifically, for other related technical solutions in the above steps, please refer to the related descriptions of steps 240 to 260 above, and they will not be described again here.

[0110] For example, FIG. 4 shows schematic waveform diagrams of the charging current and discharging current of a battery according to an embodiment of the present application.

[0111] As shown in Fig. 4, during a period from t1 to t2, the charging / discharging device charges the battery based on a first charging current, and charges the battery so that a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and the voltage of the battery cell does not exceed a full charge voltage of the battery cell; during a period from t2 to t3, the charging / discharging device controls the discharge of the battery based on a first discharging current, and discharges the battery so that a first accumulated discharge amount of the battery is equal to or greater than a first accumulated discharge amount threshold, and the duration of the first discharging current may be selectably shorter than the duration of the first charging current; during a period from t3 to t4, the charging / discharging device continues to charge the battery based on a second charging current, and charges the battery so that a second accumulated charge amount of the battery is equal to or greater than a second accumulated charge amount threshold and the voltage of the battery cell does not exceed a full charge voltage of the battery cell; during a period from t4 to t5, the charging / discharging device controls the discharge of the battery based on a second discharging current, and discharges the battery so that a second accumulated discharge amount of the battery is equal to or greater than a second accumulated discharge amount threshold, and the duration of the second charging current may be selectably shorter than the duration of the first charging current. As can be seen, the above charging and discharging process continues until the battery is fully charged.

[0112] 4 shows only the waveforms of the first charging current, the second charging current, the first discharging current, and the second discharging current, and the first charging current may be a constant current shown in FIG. 4 from t1 to t2, or may be a varying current that changes with time, and similarly, the second charging current, the first discharging current, and the second discharging current may be a constant current shown in FIG. 4, or may be a varying current that changes with time. Also, the magnitudes of the first charging current and the second charging current shown in FIG. 4 are the same, and the magnitudes of the first discharging current and the second discharging current are the same, and the magnitudes of the first charging current and the second charging current may be different, and the magnitudes of the first discharging current and the second discharging current may be different, and the embodiments of the present application are not specifically limited thereto.

[0113] FIG. 5 shows a schematic flow block diagram of another battery charging method 500 according to an embodiment of the present application.

[0114] As shown in FIG. 5, the battery charging method 500 not only includes the above steps 210 to 290, but also may further include the following steps.

[0115] Step 510: if the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell, the BMS sends a charging stop command to the charging / discharging device.

[0116] Step 520: The charger / discharger stops charging the battery.

[0117] Specifically, as described above, the BMS can monitor whether the battery has reached a fully charged state by monitoring the voltage of one or more battery cells of the battery. Optionally, in some embodiments, the BMS can determine whether the battery has reached a fully charged state by determining whether the maximum voltage of the battery cell exceeds the fully charged voltage of the battery cell. If the maximum voltage of the battery cell exceeds the fully charged voltage of the battery cell, it indicates that the battery has reached a fully charged state, and at this time, the BMS sends a charge stop command to the charging / discharging device, and the charge stop command is used to instruct the charging / discharging device to stop charging the battery, and to cause the charging / discharging device to stop charging the battery.

[0118] Optionally, steps 510 to 520 may be performed during the battery charging phase, in other words, after the BMS enters the charging mode and the charging / discharging device receives the charging current sent from the BMS, in the process of charging the battery, the BMS can obtain the voltage of the battery cells of the battery to determine whether the battery has reached a full charge state; when the voltage of the battery cells of the battery exceeds the full charge voltage of the battery cells, the BMS will send a charging stop command to the charging / discharging device, causing the charging / discharging device to stop charging the battery.

[0119] Therefore, FIG. 5 only shows diagrammatically that steps 510 and 520 are performed after step 290, i.e., in the second charging process, and it can be understood that steps 510 and 520 may be further performed in any one of multiple charging / discharging processes.

[0120] Optionally, in the above method embodiment, a charging / discharging device is used to charge, discharge and recharge the battery, so that the safety issues of the battery caused by continuous charging can be prevented; furthermore, the charging current in the above method can be a large current, so as to improve the charging amount of the battery in one charging process and achieve the purpose of rapid charging.

[0121] In addition, since the lithium ions are limited to be concentrated in the negative electrode during the continuous charging process and the charging current is also limited, it is not possible to realize rapid charging of the battery using a continuous large current. The technical solution of the embodiments of the present application charges the battery using a large current, and after one large current charging, the battery is discharged to release the lithium ions concentrated in the negative electrode of the battery during the charging process, and then the large current is reused to charge the battery, thereby realizing rapid charging of the battery.

[0122] Specifically, in the above method, the first charging current and / or the second charging current may be a large current, and after the charging / discharging device charges the battery based on the second charging current, the charging current in the subsequent charging process may be a large current.

[0123] Optionally, the charging rate of the first charging current and / or the second charging current is in the range of 2C to 10C to realize high current fast charging.

[0124] Furthermore, in the embodiments of the present application, the discharge current is a small current, and the purpose is to release the lithium ions concentrated in the negative electrode of the battery by discharging the battery at a small current without causing an excessive loss of the amount of electricity charged in the battery.

[0125] Specifically, the first discharge current and / or the second discharge current in the above method may be a small current, and after the charging / discharging device controls the discharge of the battery based on the second discharge current, the discharge current in the subsequent discharging process may be a small current.

[0126] Optionally, the charge rate of the first discharge current and / or the second discharge current is in the range of 0.1C to 1C to achieve low current discharge.

[0127] Optionally, in the above method, in order to better control the charge amount of the battery in the charging process and the discharge amount of the battery in the discharging process, a ratio between an accumulated discharge amount threshold in the discharging process and an accumulated charge amount threshold in the charging process is set to reduce the discharge amount without causing excessive loss of the amount of electricity charged in the battery.

[0128] For example, in the above method, the ratio between the first accumulated discharge amount threshold and the first accumulated charge amount threshold is less than or equal to 10% and / or the ratio between the second accumulated discharge amount threshold and the second accumulated charge amount threshold is less than or equal to 10%.

[0129] In addition, after the charging / discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the ratio of the accumulated discharge amount threshold to the accumulated charge amount threshold in the subsequent charging / discharging process may be less than or equal to 10%.

[0130] It should be noted that the above ratio of 10% can be adjusted according to changes in application scenarios and application demands, and the present application does not limit the specific value of the ratio.

[0131] Optionally, in the method embodiment, the first charging current and the second charging current acquired by the BMS may be the same or different. The first charging current and / or the second charging current may be a preset current, or the first charging current and / or the second charging current may also be a current determined based on the battery state parameters, and when the battery state parameters change, the first charging current and / or the second charging current may be a different current corresponding to the different state parameters. The battery state parameters may include at least one of parameters such as battery temperature, battery voltage, battery current, battery state of charge (SOC), and battery state of health (SOH).

[0132] Similarly, the first and second discharge currents obtained by the BMS may be the same or different, the first and / or second discharge currents may be preset currents, or the first and / or second discharge currents may be currents determined based on the state parameters of the battery.

[0133] When at least one of the first charging current, the second charging current, the first discharging current and the second discharging current is a current determined based on the state parameters of the battery, it can better adapt to the current state parameters of the battery, can improve the charging efficiency and / or discharging efficiency of the battery, and does not damage the battery.

[0134] Furthermore, after the charging / discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the charging current and / or discharging current in the subsequent charging / discharging process may also be a preset current, or may be a current determined based on the state parameters of the battery.

[0135] FIG. 6 shows a schematic flow block diagram of another battery charging method 600 according to an embodiment of the present application.

[0136] Based on the method 200 shown in FIG. 2 above, as shown in FIG. 6 , the above step 210 may include: Step 610, the BMS obtains a state parameter of the battery, and determines a first charging current based on the state parameter.

[0137] The above step 240 may include: Step 640: if the first accumulated charge amount of the battery is greater than or equal to the first accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the fully charged voltage of the battery cell, the BMS obtains state parameters of the battery, and determines a first discharge current based on the state parameters.

[0138] The above step 270 may include: Step 670: if the first accumulated discharge amount of the battery is greater than or equal to the first accumulated discharge amount threshold, the BMS obtains a state parameter of the battery, and determines a second charging current based on the state parameter.

[0139] In addition, other steps of the method 600 in the embodiment of the present application may be referred to the relevant description of the embodiment shown in FIG. 2 above, and will not be described again here.

[0140] Specifically, in the embodiment of the present application, the first charging current, the first discharging current and the second charging current are all currents determined based on the state parameters of the battery, and the BMS can obtain different state parameters of the battery in different periods and determine the current charging current and discharging current according to the state parameters.

[0141] Selectively determining the charge current and discharge current based on the battery state parameters may have multiple embodiments, for example, obtaining a mapping relationship between the battery state parameters and the charge current and discharge current, and determining a specific charge current and discharge current based on the battery state parameters based on the mapping relationship, which may be a mapping relationship obtained by fitting a large amount of experimental data, and has high reliability and accuracy, and the mapping relationship may be a mapping table, a mapping diagram, a mapping formula, etc. In another example, a dedicated neural network model may be trained based on a large amount of experimental data, and the neural network model can output the charge current and discharge current based on the input battery state parameters.

[0142] Optionally, in addition to the charge current and the discharge current, in the method embodiment, the first and second accumulated charge thresholds may be the same or different; the first and second accumulated discharge thresholds may be the same or different; at least one of the first, second, accumulated charge thresholds, first and second accumulated discharge thresholds may be a preset threshold; or at least one of the first, second, accumulated charge thresholds, first and second accumulated discharge thresholds may be a threshold determined based on a state parameter of the battery.

[0143] In addition, after the charging / discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the cumulative discharge amount threshold and the cumulative charge amount threshold in the subsequent charging / discharging process may be preset thresholds or may be thresholds determined based on the state parameters of the battery.

[0144] According to the above embodiment of the present application, when at least one of the first accumulated charge amount threshold, the second accumulated charge amount threshold, the first accumulated discharge amount threshold and the second accumulated discharge amount threshold is a threshold determined based on the state parameters of the battery, it can better adapt to the current state parameters of the battery, better control the current charging process and / or discharging process, ensure the charging amount and discharging amount, and realize efficient charging of the battery.

[0145] Optionally, in the above method embodiment, at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current may be a current that is acquired by the BMS periodically or non-periodically. For example, at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current may be a current that is determined by the BMS periodically or non-periodically based on a state parameter of the battery, and the current changes with a change in the state parameter of the battery. Specifically, the BMS can acquire the state parameter of the battery periodically and thereby determine at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current, or the BMS acquires the state parameter of the battery in real time, and when the state parameter changes non-periodically, the BMS determines at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current based on the state parameter that changes non-periodically.

[0146] Further, based on this, the BMS periodically or non-periodically transmits at least one of the first charging current, the second charging current, the first discharging current, and the second discharging current to the charging / discharging device, and periodically transmits the first charging current, the second charging current, the first discharging current, and the second discharging current to the charging / discharging device. Or irregularly The battery is charged or the discharge of the battery is controlled based on the current transmitted to the power supply.

[0147] In this embodiment, in the process of charging and / or discharging the battery once, the charging and / or discharging current is transmitted by the BMS periodically or non-periodically, and the charging and / or discharging current can be adjusted periodically or non-periodically to improve the charging and discharging efficiency according to this embodiment, and the charging and / or discharging current transmitted periodically or non-periodically indicates that the BMS and the battery are in a normal state, and the charging and / or discharging device can continue charging the battery or control discharging the battery. Therefore, in this embodiment, if the charging and / or discharging device does not receive the charging and / or discharging current transmitted by the BMS periodically or non-periodically, the charging and / or discharging device can stop charging the battery and / or stop controlling discharging the battery to ensure the safety performance of the battery.

[0148] FIG. 7 shows a schematic flow block diagram of another battery charging method 700 according to an embodiment of the present application.

[0149] Based on the method 200 shown in FIG. 2 above, as shown in FIG. 7 , the above step 210 may include: Step 710, the BMS periodically obtains a first charging current.

[0150] The above step 220 may include: In step 720, the BMS periodically transmits a first charging current to the charging / discharging device.

[0151] The above step 240 may include: Step 740: if the first accumulated charge amount of the battery is greater than or equal to the first accumulated charge amount threshold and the voltage of the battery cell does not exceed the full charge voltage of the battery cell, periodically obtain a first discharge current.

[0152] The above step 250 may include: In step 750, the BMS periodically transmits a first discharge current to the charging / discharging device.

[0153] The above step 270 may include: Step 770: if the first accumulated discharge amount of the battery is greater than or equal to the first accumulated discharge amount threshold, periodically obtain the second charging current.

[0154] The above step 280 may include: In step 780, the BMS periodically transmits a second charging current to the charging / discharging device.

[0155] In addition, other steps of the method 700 of the embodiment of the present application may be referred to the relevant description of the embodiment shown in FIG. 2 above, and will not be described again here.

[0156] In an embodiment of the present application, the BMS can periodically obtain the first charging current, the first discharging current, and the second charging current. Correspondingly, the BMS can periodically transmit the first charging current, the first discharging current, and the second charging current to the charging / discharging device.

[0157] As can be understood, in the above embodiment, charging and discharging a battery requires not only current information required for the charging and discharging, but also voltage information required for the charging and discharging, and the method of acquiring the voltage required for charging and discharging is not limited to any embodiment of the present invention.

[0158] Optionally, in the above method embodiment, the communication between the BMS and the charging / discharging device is compatible with the communication protocol between a conventional charger and a BMS, so that the communication between the BMS and the charging / discharging device is easily realized and has good application prospects.

[0159] Specifically, based on the above method embodiment, the BMS can further obtain at least one of a first charging voltage, a second charging voltage, a first discharging voltage, and a second discharging voltage, and send the at least one of the first charging voltage, the second charging voltage, the first discharging voltage, and the second discharging voltage to the charging / discharging device, and the first charging current and the first charging voltage are determined as a first battery charging request ( battery charging lab, BCL) message, and / or the first discharge current and the first discharge voltage are carried in a second BCL message, and / or the second charge current and the second charge voltage are carried in a third BCL message, and / or the second discharge current and the second discharge voltage are carried in a fourth BCL message.

[0160] In addition, after the charging / discharging device charges the battery and controls the discharge of the battery based on the second charging current and the second discharging current, the charging current, charging voltage, discharging current and discharging voltage in the subsequent charging / discharging process may also be carried in a BCL message and transmitted to the charging / discharging device by the BMS.

[0161] FIG. 8 shows a schematic flow block diagram of another battery charging method 800 according to an embodiment of the present application.

[0162] As shown in FIG. 8, the battery charging method 800 may further include the following steps.

[0163] Step 810, the BMS obtains a first charging current and a first charging voltage.

[0164] In step 820, the BMS sends a first BCL message to the charging / discharging device, carrying a first charging current and a first charging voltage.

[0165] In step 830, the charger / discharger charges the battery based on the first charging current and the first charging voltage.

[0166] Step 840: if the first accumulated charge amount of the battery is greater than or equal to the first accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the BMS obtains a first discharge current and a first discharge voltage.

[0167] In step 850, the BMS sends a first discharge current and 1 A second BCL message is transmitted carrying the discharge voltage.

[0168] Step 860, the charging / discharging device receives a first discharge current and 1 The discharge of the battery is controlled based on the discharge voltage.

[0169] Step 870: if the first accumulated discharge amount of the battery is greater than or equal to the first accumulated discharge amount threshold, the BMS obtains a second charging current and a second charging voltage.

[0170] In step 880, the BMS sends a third BCL message to the charging / discharging device, carrying the second charging current and the second charging voltage.

[0171] In step 890, the charger / discharger charges the battery based on the second charging current and the second charging voltage.

[0172] In the embodiment of the present application, a battery charging request BCL message in the communication protocol between a conventional charger and a BMS is used, the BMS transmits a charging current and a discharging current to a charging / discharging device, and the charging / discharging device charges a battery or controls discharging of the battery according to the received charging current and discharging current.

[0173] Optionally, in the BCL message, the ranges of the charging voltage (including the first charging voltage and the second charging voltage) and the discharging voltage (including the first discharging voltage and the second discharging voltage) are different, and the ranges of the charging current (including the first charging current and the second charging current) and the discharging current (including the first discharging current and the second discharging current) are different, and the BCL message received by the charging / discharging device can be determined to belong to the charging voltage and charging current or the discharging voltage and discharging current depending on the magnitude of the voltage and current carried.

[0174] Optionally, the BMS may determine the charge and discharge voltages based on the battery's state parameters, or the charge and discharge voltages may be default values.

[0175] Optionally, in some embodiments, the BMS may periodically acquire a charging current and a charging voltage, and periodically transmit a BCL message carrying the charging current and the charging voltage to the charging / discharging device, and similarly, the BMS may periodically acquire a discharging current and a discharging voltage, and periodically transmit a BCL message carrying the discharging current and the discharging voltage to the charging / discharging device. In such embodiments, the periodic transmission method of the BCL message may be the same as the periodic transmission method of the BCL message in the existing standard.

[0176] In the above embodiment, the information exchange messages of the charging / discharging current and / or voltage are described as an example. As can be understood, in order to realize charging / discharging of the battery, in addition to the charging / discharging stage processing, the information exchange messages may include a handshake exchange between the automobile and the charger before charging / discharging, a parameter configuration exchange for charging / discharging, etc., and the embodiment of the present invention is not specifically limited thereto.

[0177] Optionally, the communication protocol between the charger and the BMS includes a communication protocol in a vehicle to grid (V2G) mode and a grid to vehicle (G2V) mode.

[0178] Above, specific examples of the battery charging method according to the present application have been described with reference to Figures 2 to 8, and below, specific examples of related devices according to the present application have been described with reference to Figures 9 to 12. In order to facilitate understanding, the relevant explanations of the following device embodiments can be made by referring to the above method embodiments, and for the sake of brevity, the explanations will not be repeated.

[0179] 9 shows a schematic structural block diagram of a battery management system BMS 900 according to an embodiment of the present application. As shown in FIG. 9, the BMS 900 includes an acquiring unit 910, a sending unit 920 and a processing unit 930.

[0180] In one embodiment of the present application, the acquisition unit 910 is used for acquiring a first charging current, and the sending unit 920 is used for sending the first charging current to the charging / discharging device to allow the charging / discharging device to charge the battery according to the first charging current; if the processing unit 930 is used for determining that the first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell, the acquisition unit 910 is further used for acquiring a first discharging current, and the sending unit 920 is further used for sending the first discharging current to the charging / discharging device to allow the charging / discharging device to control the discharging of the battery according to the first discharging current; optionally, if the processing unit 930 is further used for determining that the first accumulated discharging amount of the battery is equal to or greater than the first accumulated discharging amount threshold, the acquisition unit 910 is further used for acquiring a second charging current, and the sending unit 920 is further used for sending the second charging current to the charging / discharging device to allow the charging / discharging device to charge the battery according to the second charging current.

[0181] Optionally, when the processing unit 930 is further used for determining that the second accumulated charge amount of the battery is greater than or equal to the second accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the fully charged voltage of the battery cell, the acquisition unit 910 is further used for acquiring a second discharging current, and the sending unit 920 is further used for sending the second discharging current to the charging / discharging device, so as to allow the charging / discharging device to control the discharging of the battery based on the second discharging current.

[0182] Optionally, when the processing unit 930 is further used for determining that the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell, the sending unit 920 is further used for sending a charging stop command to the charging / discharging device, and the charging stop command is used for instructing the charging / discharging device to stop charging the battery.

[0183] Optionally, the charge rate of the first charging current and / or the second charging current is in the range of 2C to 10C.

[0184] Optionally, the discharge rate range of the first discharge current and / or the second discharge current is between 0.1C and 1C.

[0185] Optionally, the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is less than or equal to 10% and / or the ratio of the second accumulated discharge amount threshold to the second accumulated charge amount threshold is less than or equal to 10%.

[0186] Optionally, the acquisition unit 910 is used to acquire a state parameter of the battery, and determine a first charging current according to the state parameter; and / or the acquisition unit 910 is used to acquire a state parameter of the battery, and determine a first discharging current according to the state parameter; and / or the acquisition unit 910 is used to acquire a state parameter of the battery, and determine a first discharging current according to the state parameter. 2nd charging current The battery state parameters include at least one of a battery temperature, a battery voltage, a battery current, a battery charge state, and a battery health state.

[0187] Optionally, the acquisition unit 910 is used for periodically acquiring a first charging current, and the sending unit 920 is used for periodically transmitting the first charging current to the charging / discharging device, and / or the acquisition unit 910 is used for periodically acquiring a first discharging current, and the sending unit 920 is used for periodically transmitting the first discharging current to the charging / discharging device, and / or the acquisition unit 910 is used for periodically acquiring a second charging current, and the sending unit 920 is used for periodically transmitting the second charging current to the charging / discharging device.

[0188] Optionally, the acquisition unit 910 is further used for acquiring a first charging voltage, the sending unit 920 is further used for sending the first charging voltage to the charging / discharging device, and the first charging current and the first charging voltage are carried in a first battery charging request BCL message; and / or the acquisition unit 910 is further used for acquiring a first discharging voltage, the sending unit 920 is further used for sending the first discharging voltage to the charging / discharging device, and the first discharging current and the first discharging voltage are carried in a second BCL message; and / or Acquired Unit 910 the acquiring unit 910 is further used for acquiring a second charging voltage, the sending unit 920 is further used for sending the second charging voltage to the charging / discharging device, and the second charging current and the second charging voltage are carried in a third BCL message; and / or the acquiring unit 910 is further used for acquiring a second discharging voltage, the sending unit 920 is further used for sending the second discharging voltage to the charging / discharging device, and the second discharging current and the second discharging voltage are carried in a fourth BCL message.

[0189] 10 is a schematic structural block diagram of a charging / discharging device 1000 according to an embodiment of the present application. As shown in FIG.

[0190] In one embodiment of the present application, the receiving unit 1010 is used for receiving a first charging current sent from the battery management system BMS, and the processing unit 1020 is used for charging the battery according to the first charging current, the receiving unit 1010 is further used for receiving a first discharging current sent from the BMS, and the processing unit 1020 is further used for controlling discharging of the battery according to the first discharging current, the first discharging current being the discharging current sent from the BMS when a first accumulated charging amount of the battery is equal to or greater than a first accumulated charging amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the receiving unit 1010 is further used for receiving a second charging current sent from the BMS, and the processing unit 1020 is further used for charging the battery according to the second charging current, and the second charging current being the charging current sent from the BMS when a first accumulated discharging amount of the battery is equal to or greater than the first accumulated discharging amount threshold.

[0191] Optionally, the receiving unit 1010 is further used for receiving a second discharging current sent from the BMS, and the processing unit 1020 is further used for controlling discharging of the battery based on the second discharging current, where the second discharging current is the discharging current sent from the BMS when a second accumulated charge amount of the battery is greater than or equal to a second accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell.

[0192] Optionally, the receiving unit 1010 is further used for receiving a stop charging command sent from the BMS, and the processing unit 1020 is used for stopping charging the battery, where the stop charging command is a command sent from the BMS when the voltage of a battery cell of the battery exceeds the full charge voltage of the battery cell.

[0193] Optionally, the charge rate of the first charging current and / or the second charging current is in the range of 2C to 10C.

[0194] Optionally, the discharge rate range of the first discharge current and / or the second discharge current is between 0.1C and 1C.

[0195] Optionally, the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is less than or equal to 10% and / or the ratio of the second accumulated discharge amount threshold to the second accumulated charge amount threshold is less than or equal to 10%.

[0196] Optionally, at least one of the first charging current, the first discharging current, and the second charging current is determined by the BMS based on battery state parameters, the battery state parameters including at least one of battery temperature, battery voltage, battery current, battery charge state, and battery state of health parameters.

[0197] Optionally, the receiving unit 1010 is used for periodically receiving a first charging current transmitted from the BMS, and / or the receiving unit 1010 is used for periodically receiving a first discharging current transmitted from the BMS, and / or the receiving unit 1010 is used for periodically receiving a second charging current transmitted from the BMS.

[0198] Optionally, the receiving unit 1010 is further used for receiving a first charging voltage transmitted from the BMS, the first charging voltage and the first charging current being carried in a first Battery Charging Request BCL message, and / or the receiving unit 1010 is further used for receiving a first discharging voltage transmitted from the BMS, the first discharging voltage and the first discharging current being carried in a second BCL message, and / or the receiving unit 1010 is further used for receiving a second charging voltage transmitted from the BMS, the second charging voltage and the second charging current being carried in a third BCL message, and / or the receiving unit 1010 is further used for receiving a second discharging voltage transmitted from the BMS, the second discharging voltage and the second discharging current being carried in a fourth BCL message.

[0199] Above, with reference to Figures 2 to 10, an embodiment of a battery charging method and device realized based on information exchange between the charging / discharging device and a BMS according to the present application has been described. Regarding the charging / discharging device, control of charging and discharging of the battery can be realized by different hardware structures.

[0200] FIG. 11 shows a schematic structural block diagram of another charge / discharge device according to an embodiment of the present application.

[0201] As shown in FIG. 11, the charging / discharging device 1100 may further include a control unit 1110 and a power conversion unit 1120.

[0202] In one embodiment, the control unit 1110 is used to receive a first charging current sent from the BMS, and to control the power conversion unit 1120 to charge the battery based on the first charging current; the control unit 1110 is further used to receive a first discharging current sent from the BMS, and to control the power conversion unit 1120 to discharge the battery based on the first discharging current, where the first discharging current is the discharging current sent from the BMS when a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell; the control unit 1110 is further used to receive a second charging current sent from the BMS, and to control the power conversion unit 1120 to charge the battery based on the second charging current, where the second charging current is the charging current sent from the BMS when a first accumulated discharge amount of the battery is equal to or greater than the first accumulated discharge amount threshold.

[0203] Specifically, the power conversion unit 1120 may include a high-voltage device for realizing high-power electric energy conversion, and the control unit 1110 may include a low-voltage circuit for realizing a control function of the high-voltage device of the power conversion unit 1120. The control unit 1110 may also establish a communication connection with the BMS, for example and not by way of limitation, the control unit 1110 may establish a communication connection with the BMS via a communication bus, or the control unit 1110 may establish a communication connection with the BMS via a wireless network.

[0204] Optionally, as an example, FIG. 12 shows a schematic structural block diagram of a power conversion unit 1120 according to an embodiment of the present application.

[0205] As shown in FIG. 12 , the power conversion unit 1120 may be connected to an alternating current (AC) power source and a battery, and the power conversion unit 1120 includes an alternating current / direct current (AC / DC) converter 1210 and a direct current / direct current (DC / DC) converter 1220, a first end of the AC / DC converter 1210 is connected to the AC power source, a second end of the AC / DC converter 1210 is connected to a first end of the DC / DC converter 1220, and a second end of the DC / DC converter 1220 is connected to the battery, thereby realizing current transmission between the battery and the AC power source.

[0206] In this situation, the control unit 1110 can control the AC / DC converter 1210 and the DC / DC converter 1220 based on the first charging current to charge the battery via the AC power source, and the control unit 1110 can control the AC / DC converter 1210 and the DC / DC converter 1220 based on the second charging current to charge the battery via the AC power source.

[0207] In one embodiment, the AC / DC converter 1210 may be a bidirectional AC / DC converter and the DC / DC converter 1220 may be a bidirectional DC / DC converter, in which case the control unit 1110 controls the bidirectional AC / DC converter 1210 and the bidirectional DC / DC converter 1220 based on the first discharge current to discharge the battery into the AC power source.

[0208] In another embodiment, the AC / DC converter 1210 may be a unidirectional AC / DC converter and the DC / DC converter 1220 may be a bidirectional DC / DC converter, in this situation, the bidirectional DC / DC converter may be connected to an energy storage device, for example, an energy storage battery, and the control unit 1110 controls the bidirectional DC / DC converter 1220 based on the first discharge current to discharge the battery's electrical energy to the energy storage battery.

[0209] Optionally, the AC power source includes, but is not limited to, a power grid, which is used to provide three-phase AC power, and the power grid can not only provide a sufficient amount of electricity to charge the battery, but also can accept a large amount of electricity discharged from the battery.

[0210] Alternatively, in other embodiments, the AC power source may be a single-phase AC power source. The embodiments of the present application are not limited to a specific type of AC power source.

[0211] In addition, in the embodiment of the present application, the power conversion unit 1120 may be connected not only to an AC power source as shown in FIG. 12, but also to a DC power source, and in this case, the power conversion unit 1120 may include only a DC / DC converter to realize current transmission between the battery and the DC power source.

[0212] Optionally, when the power conversion unit 1120 is connected to an AC power source and a battery, the power conversion unit 1120 includes a bidirectional AC / DC converter and a bidirectional DC / DC converter, and the control unit 1110 is further used to receive a second discharging current sent from the BMS, and control the bidirectional AC / DC converter and the bidirectional DC / DC converter according to the second discharging current to discharge the battery to the AC power source, where the second discharging current is the discharging current sent from the BMS when the second accumulated charge amount of the battery is greater than or equal to a second accumulated charge amount threshold and the voltage of the battery cell of the battery does not exceed the full charge voltage of the battery cell.

[0213] Optionally, the control unit 1110 is further used to receive a stop charging command sent from the BMS, and control the bidirectional AC / DC converter and the bidirectional DC / DC converter based on the stop charging command to stop charging the battery, where the stop charging command is a command sent from the BMS when the voltage of the battery cell of the battery exceeds the full charge voltage of the battery cell.

[0214] Optionally, the control unit 1110 is used to periodically receive a first charging current transmitted from the BMS, and / or the control unit 1110 is used to periodically receive a first discharging current transmitted from the BMS, and / or the control unit 1110 is used to periodically receive a second charging current transmitted from the BMS.

[0215] Optionally, the control unit 1110 is further used to receive a first charging voltage sent from the BMS, where the first charging voltage and the first charging current are carried in a first battery charging request BCL message, and the control unit 1110 is further used to control the power conversion unit 1120 to charge the battery according to the first charging current and the first charging voltage; and / or the control unit 1110 is further used to receive a first discharging voltage sent from the BMS, where the first discharging voltage and the first discharging current are carried in a second BCL message, and the control unit 1110 is further used to control the power conversion unit 1120 to discharge the battery according to the first discharging current and the first discharging voltage. and / or the control unit 1110 is further used to receive a second charging voltage sent from the BMS, where the second charging voltage and the second charging current are carried in a third BCL message, and the control unit 1110 is further used to control the power conversion unit 1120 to charge the battery based on the second charging current and the second charging voltage; and / or the control unit 1110 is further used to receive a second discharging voltage sent from the BMS, where the second discharging voltage and the second discharging current are carried in a fourth BCL message, and the control unit 1110 is further used to control the power conversion unit 1120 to discharge the battery based on the second discharging current and the second discharging voltage.

[0216] In addition, in the embodiments of the present application, the relevant technical solutions such as charging current, discharging current, accumulated charging amount, accumulated discharging amount, accumulated charging amount threshold, and accumulated discharging amount threshold can be referred to the above related descriptions, and will not be described repeatedly here.

[0217] Figure 13 shows a schematic structural block diagram of an electronic device 1300 according to an embodiment of the present application. As shown in Figure 13, the electronic device 1300 includes a memory 1310 and a processor 1320, where the memory 1310 is used to store a computer program, and the processor 1320 is used to read the computer program and execute the methods of the various embodiments of the present application according to the computer program.

[0218] Optionally, the electronic device 1300 can be used in one or more of the BMS and the charging / discharging device. In the embodiment of the present application, in addition to the processor of the charging / discharging device reading a corresponding computer program and performing the charging method corresponding to the charging / discharging device of the above various embodiments based on the computer program, the processor of the BMS can also read a corresponding computer program and perform the charging method corresponding to the BMS of the above various embodiments based on the computer program.

[0219] In addition, the embodiments of the present application further provide a readable storage medium, which is used to store a computer program, and the computer program is used to execute the methods of the various embodiments of the present application. Optionally, the computer program may be a computer program of the charging / discharging device and / or the BMS.

[0220] As will be understood, the specific examples herein are merely intended to assist those skilled in the art in better understanding the embodiments of the present application, and are not intended to limit the scope of the embodiments of the present application.

[0221] It will be further understood that in various embodiments of the present application, the magnitude of the numbers of each process does not imply the order of execution, and the order of execution of each process should be determined by its function and internal logic, and does not arbitrarily limit the implementation process of the embodiments of the present application.

[0222] It will be further understood that the various embodiments described herein may be implemented individually or in combination, and the examples herein are not intended to be limiting.

[0223] Although the present application has been described with reference to the preferred embodiments, various modifications can be made and equivalents can be substituted for the elements therein without departing from the scope of the present application. In particular, the technical features described in each embodiment can be combined in any manner as long as there is no structural contradiction. The present application is not limited to the specific embodiments disclosed in this specification, but includes all technical solutions within the scope of the claims. [Explanation of symbols]

[0224] 100 Charging System 110 Charging and discharging equipment 120 Battery System 121 Batteries 122 Battery management system (BMS) 130 Wire 140 Communication Line 200 Battery charging method 210~290 steps 300 battery charging method 310~330 steps 500 battery charging method 510~520 steps 600 battery charging method 610, 640, 670 steps 700 battery charging method 710~780 steps 800 battery charging method 810~890 steps 900 Battery Management System BMS 910 Acquired Units 920 Sending Unit 930 Processing Unit 1000 charging / discharging equipment 1010 Receiver unit 1020 Processing Unit 1100 Charge / discharge device 1110 Control Unit 1120 Power Conversion Unit 1210 AC / DC converter, alternating current / direct current, AC / DC converter 1220 DC / DC converter, direct current (DC / DC) converter 1300 Electronic equipment 1310 Memory 1320 Processor

Claims

1. The battery management system (BMS) acquires a first charging current, transmits the first charging current to a charging / discharging device, and causes the charging / discharging device to charge a battery based on the first charging current; When a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the BMS acquires a first discharging current and transmits the first discharging current to the charging / discharging device to cause the charging / discharging device to control discharging of the battery based on the first discharging current, the first accumulated charge amount being an amount of electricity discharged in the process of charging the battery based on the first charging current; and when a first accumulated discharge amount of the battery is equal to or greater than a first accumulated discharge amount threshold, the BMS acquires a second charging current, transmits the second charging current to the charging / discharging device, and causes the charging / discharging device to charge the battery based on the second charging current, the first accumulated discharge amount being an amount of electricity discharged in the process of discharging the battery based on the first discharging current. the first accumulated charge threshold and / or the first accumulated discharge threshold are determined based on state parameters of the battery, the state parameters including at least one of a battery temperature, a battery voltage, a battery current, a battery state of charge, and a battery state of health; A battery charging method, wherein a charging rate of the first charging current and / or the second charging current is in a range of 2C to 10C, and a discharging rate of the first discharging current is in a range of 0.1C to 1C.

2. The battery charging method includes:

2. The battery charging method of claim 1, further comprising: when a second accumulated charge amount of the battery is equal to or greater than a second accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, the BMS acquires a second discharging current and transmits the second discharging current to the charging / discharging device to cause the charging / discharging device to control discharging of the battery based on the second discharging current, wherein the second accumulated charge amount is a charge accumulated during a charging process of the battery based on the second charging current of the charging / discharging device, or a current total charge amount of the battery.

3. The battery charging method includes:

3. The battery charging method according to claim 1, further comprising a step in which the BMS transmits a charging stop command to the charging / discharging device when a voltage of a battery cell of the battery exceeds a full charge voltage of the battery cell, the charging stop command being used to instruct the charging / discharging device to stop charging the battery.

4. 4. The battery charging method according to claim 1, wherein a ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is 10% or less.

5. The step of the BMS acquiring a first charging current includes: and / or the BMS obtaining a state parameter of the battery and determining the first charging current based on the state parameter. The step of the BMS acquiring a first discharge current includes: and / or the BMS obtaining a state parameter of the battery and determining the first discharge current based on the state parameter. The step of the BMS acquiring a second charging current includes: The BMS includes acquiring a state parameter of the battery, and determining the second charging current based on the state parameter; The method of any one of claims 1 to 4, wherein the battery state parameters include at least one of the following parameters: battery temperature, battery voltage, battery current, battery charge state and battery health state.

6. The step of the BMS acquiring a first charging current and transmitting the first charging current to a charging / discharging device includes: The BMS periodically acquires the first charging current and periodically transmits the first charging current to the charging / discharging device; and / or The step of the BMS acquiring a first discharge current and transmitting the first discharge current to the charging / discharging device includes: The BMS periodically acquires the first discharge current and periodically transmits the first discharge current to the charging / discharging device; and / or The step of the BMS acquiring a second charging current and transmitting the second charging current to the charging / discharging device includes: The battery charging method according to any one of claims 1 to 5, further comprising the steps of: the BMS periodically acquiring the second charging current and periodically transmitting the second charging current to the charging / discharging device.

7. The battery charging method further includes the step of the BMS obtaining a first charging voltage and sending the first charging voltage to the charging / discharging device, wherein the first charging current and the first charging voltage are carried in a first battery charging request message; and / or The battery charging method further includes the step of the BMS obtaining a first discharge voltage and sending the first discharge voltage to the charging / discharging device, the first discharge current and the first discharge voltage being carried in a second battery charging request message; and / or The battery charging method according to any one of claims 1 to 6, further comprising a step of the BMS acquiring a second charging voltage and transmitting the second charging voltage to the charging / discharging device, wherein the second charging current and the second charging voltage are carried in a third battery charging request message.

8. 1. A method for charging a battery, comprising: The charging / discharging device receives a first charging current transmitted from the battery management system BMS and charges a battery based on the first charging current; a step of receiving a first discharging current transmitted from the BMS and controlling discharging of the battery based on the first discharging current, the first discharging current being transmitted by the BMS under a condition in which a first accumulated charge amount of the battery is equal to or greater than a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell, and the first accumulated charge amount is an amount of electricity discharged in a process in which the battery is charged based on the first charging current; receiving a second charging current transmitted from the BMS and charging the battery based on the second charging current, the second charging current being transmitted by the BMS under a condition in which a first accumulated discharge amount of the battery is equal to or greater than a first accumulated discharge amount threshold, the first accumulated discharge amount being an amount of electricity discharged in a process in which the battery is discharged based on the first discharge current; the first accumulated charge threshold and / or the first accumulated discharge threshold are determined based on state parameters of the battery, the state parameters including at least one of a battery temperature, a battery voltage, a battery current, a battery state of charge, and a battery state of health; A method for charging a battery, wherein a charge rate of the first charging current and / or the second charging current is equal to or greater than a discharge rate of the first discharging current.

9. The battery charging method includes:

9. The battery charging method of claim 8, further comprising: receiving a second discharging current transmitted from the BMS and controlling discharging of the battery based on the second discharging current, the second discharging current being the discharging current transmitted from the BMS when a second accumulated charge amount of the battery is equal to or greater than a second accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a fully charged voltage of the battery cell; and the second accumulated charge amount is a charge accumulated during a charging process of the battery based on the second charging current of the charging / discharging device, or the second accumulated charge amount is a current total charge amount of the battery.

10. The battery charging method includes:

10. The battery charging method according to claim 8 or 9, further comprising the step of receiving a charging stop command transmitted from the BMS and stopping charging of the battery, the charging stop command being a command transmitted from the BMS when a voltage of a battery cell of the battery exceeds a full charge voltage of the battery cell.

11. The battery charging method according to any one of claims 8 to 10, wherein the ratio of the first accumulated discharge amount threshold to the first accumulated charge amount threshold is 10% or less.

12. At least one of the first charging current, the first discharging current, and the second charging current is determined by the BMS based on a state parameter of the battery; The method of any one of claims 8 to 11, wherein the battery state parameters include at least one of the following parameters: battery temperature, battery voltage, battery current, battery charge state and battery health state.

13. The step of receiving a first charging current transmitted from a BMS by the charging / discharging device includes: The charging / discharging device periodically receives the first charging current transmitted from the BMS; and / or The step of receiving a first discharge current transmitted from the BMS by the charging / discharging device includes: The charging / discharging device includes periodically receiving a first discharge current transmitted from the BMS; and / or The step of receiving a second charging current transmitted from the BMS by the charging / discharging device includes: The battery charging method according to any one of claims 8 to 12, further comprising a step of the charging / discharging device periodically receiving the second charging current transmitted from the BMS.

14. The battery charging method further includes the step of the charging / discharging device receiving a first charging voltage transmitted from the BMS, the first charging voltage and the first charging current being carried in a first battery charging request message; and / or The battery charging method further includes the step of: the charging / discharging device receiving a first discharge voltage transmitted from the BMS, the first discharge voltage and the first discharge current being carried in a second battery charging request message; and / or The battery charging method according to any one of claims 8 to 13, further comprising a step of the charging / discharging device receiving a second charging voltage transmitted from the BMS, the second charging voltage and the second charging current being carried in a third battery charging request message.

15. A battery management system (BMS), an obtaining unit for obtaining a first charging current; a transmitting unit for transmitting the first charging current to a charging / discharging device to cause the charging / discharging device to charge a battery based on the first charging current; a processing unit, wherein when a first accumulated charge amount of the battery is greater than or equal to a first accumulated charge amount threshold and a voltage of a battery cell of the battery does not exceed a full charge voltage of the battery cell, the obtaining unit is used for obtaining a first discharging current, the first accumulated charge amount being an amount of electricity discharged in a process in which the battery is charged according to the first charging current; The transmitting unit is further used for transmitting the first discharge current to the charging / discharging device to allow the charging / discharging device to control the discharge of the battery based on the first discharge current; When the processing unit is further used for determining that a first accumulated discharge amount of the battery is equal to or greater than a first accumulated discharge amount threshold, the acquisition unit is further used for acquiring a second charging current, the first accumulated discharge amount being an amount of electricity discharged in a process in which the battery is discharged based on the first discharging current; The sending unit is further used for sending the second charging current to the charging / discharging device, and causing the charging / discharging device to charge the battery based on the second charging current; the first accumulated charge threshold and / or the first accumulated discharge threshold are determined based on state parameters of the battery, the state parameters including at least one of a battery temperature, a battery voltage, a battery current, a battery state of charge, and a battery state of health; A battery management system (BMS), wherein a charging rate of the first charging current and / or the second charging current is equal to or greater than a discharging rate of the first discharging current.

16. A battery management system (BMS) comprising a processor and a memory, the memory being used to store a computer program, and the processor being used to call up the computer program and execute the battery charging method according to any one of claims 1 to 7.

17. A charging / discharging device comprising a processor and a memory, the memory being used to store a computer program, and the processor calling up the computer program to execute the battery charging method according to any one of claims 8 to 14.

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