Circuit control method, battery and its controller and management system, and power-consuming device

Abstract

The embodiments of the present application relate to the field of battery technology and provide a circuit control method, a battery controller, a battery management system, a battery, an electrical device, and a vehicle. The circuit control method includes: obtaining a device wake-up signal; judging whether the power supply terminal voltage of the charging circuit of the battery on the device is greater than a first threshold value, and whether the rate of change within a first time period is less than a second threshold value, the charging circuit is a circuit connecting the battery on the device and the generator, and the power supply terminal voltage is the output voltage of the generator; when the power supply terminal voltage of the charging circuit of the battery on the device is greater than the first threshold value, and the rate of change within the first time period is less than the second threshold value, a first instruction is issued to turn on the charging circuit. In this way, it is possible to avoid the battery charging circuit being turned on when the device is not started, and to avoid the lithium battery being overcharged when the device is subsequently started, causing the battery to go into thermal runaway, thereby improving the safety of the battery.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery technology, and specifically to a circuit control method, a battery controller, a battery management system, a battery, an electrical device, and a vehicle. Background Art

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, cars, airplanes, ships, toy cars, toy ships, toy airplanes and power tools, etc.

[0003] In the development of battery technology, safety is an issue that cannot be ignored. In particular, when batteries are overcharged, they can easily cause serious safety accidents. Therefore, how to prevent battery overcharging and improve battery safety performance has always been a problem that has attracted much attention in this field. Summary of the Invention

[0004] In view of the above problems, the embodiments of the present application provide a circuit control method, a battery controller, a battery management system, a battery, an electrical device and a vehicle, which can prevent battery overcharging and improve the safety performance of the battery.

[0005] According to a first aspect of an embodiment of the present application, a circuit control method is provided, including: obtaining a device wake-up signal; determining whether a power supply terminal voltage of a charging circuit of a battery on the device is greater than a first threshold value, and whether a rate of change within a first time period is less than a second threshold value, the charging circuit being a circuit connecting the battery on the device and a generator, and the power supply terminal voltage being the output voltage of the generator; when the power supply terminal voltage of the charging circuit of the battery on the device is greater than the first threshold value, and a rate of change within the first time period is less than a second threshold value, issuing a first instruction, the first instruction being used to control a first switch unit in the charging circuit to close, so that the charging circuit is turned on.

[0006] The circuit control method of the embodiment of the present application obtains the device wake-up signal and the power supply terminal voltage of the charging circuit, and determines whether the power supply terminal voltage of the charging circuit is greater than a first threshold and whether the rate of change within the first time period is less than a second threshold. Since the device wake-up signal, the power supply terminal voltage of the charging circuit is greater than the first threshold and the rate of change within the first time period is less than the second threshold only exist after the device is started, the method controls the battery charging circuit to be turned on when all the above conditions are met, so that the device is started when the battery charging circuit is turned on, avoiding the battery charging circuit being turned on when the device is not started, and causing a large current discharge in the battery charging circuit when the device is subsequently started, resulting in sticking of the switch on the charging circuit, avoiding overcharging of the lithium battery and causing thermal runaway of the battery, thereby improving the safety of the battery.

[0007] In some embodiments, the method also includes: determining whether the state of charge (SOC) of the battery is greater than a third threshold, whether the battery has a fault alarm, and whether the battery cell temperature is within a first range; issuing a first instruction when the power supply terminal voltage of the charging circuit of the battery on the device is greater than the first threshold and the rate of change within a first time period is less than a second threshold, further including: issuing a first instruction when the power supply terminal voltage of the charging circuit of the battery on the device is greater than the first threshold, the rate of change within the first time period is less than the second threshold, the SOC of the battery is greater than a third threshold, the battery has no fault alarm, and the battery cell temperature is within the first range.

[0008] In the above embodiment, by judging whether the SOC of the battery is greater than the third threshold, whether the battery has a fault alarm, and whether the battery cell temperature is within the first range, the battery charging circuit is controlled to be turned on only when the SOC of the battery is greater than the third threshold, there is no battery fault alarm, and the battery cell temperature is within the first range, thereby avoiding battery floating charge and safety problems.

[0009] In some embodiments, the method further includes: after the charging circuit of the battery is turned on, determining whether the rate of change of the charging current of the battery is greater than a fourth threshold value within a second time period, or whether the voltage of the battery cell in the battery is greater than or equal to a fifth threshold value, or whether the battery has a fault alarm, or whether the temperature of the battery cell is not within a first range, or whether the SOC of the battery is less than or equal to a third threshold value; if the rate of change of the charging current of the battery is greater than the fourth threshold value within the second time period, or the voltage of the battery cell in the battery is greater than or equal to the fifth threshold value, or the battery has a fault alarm, or the temperature of the battery cell is not within the first range, or the SOC of the battery is less than or equal to the third threshold value, issuing a second instruction, the second instruction being used to control the first switch unit in the charging circuit to disconnect, so that the charging circuit is disconnected.

[0010] In the above embodiment, by judging whether the SOC of the battery is greater than the third threshold, whether the battery has a fault alarm, and whether the battery cell temperature is within the first range, the battery charging circuit is controlled to be turned on only when the SOC of the battery is greater than the third threshold, there is no battery fault alarm, and the battery cell temperature is within the first range, thereby avoiding battery floating charge and safety problems.

[0011] In some embodiments, the method further includes: determining whether there is a device wake-up signal and whether the power supply terminal voltage is less than a sixth threshold; if there is a device wake-up signal and the power supply terminal voltage is less than the sixth threshold, issuing a third instruction, wherein the third instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on and the charging circuit is in a first conduction state.

[0012] In the above embodiment, by judging whether there is a device wake-up signal and whether the voltage at the power supply end is less than the sixth threshold, the charging circuit is controlled to be turned on when there is a device wake-up signal and the voltage at the power supply end is less than the sixth threshold, and the lithium battery charges the lead-acid battery, thereby avoiding the problem of the vehicle being unable to start due to depletion of the lead-acid battery when the vehicle is parked for a long time.

[0013] In some embodiments, the method also includes: determining whether the SOC of the battery is greater than a thirty-seventh threshold and whether the battery has a fault alarm; issuing a third instruction when there is a device wake-up signal and the power supply terminal voltage is less than a sixth threshold, further including: issuing a third instruction when there is a device wake-up signal, the power supply terminal voltage is less than the sixth threshold, the SOC of the battery is greater than a seventy-third threshold, and there is no fault alarm of the battery.

[0014] In the above embodiment, by judging whether the SOC of the battery is greater than the seventh threshold and whether the battery has a fault alarm, the charging circuit is controlled to be turned on when the SOC of the battery is greater than the seventh threshold and no battery fault alarm exists, thereby avoiding over-discharge of the lithium battery and safety problems.

[0015] In some embodiments, the method further includes: in the first conduction state, determining whether the conduction time of the charging circuit is greater than an eighty-seventh threshold; if the conduction time of the charging circuit is greater than the eighty-seventh threshold, issuing a fourth instruction, the fourth instruction being used to control the first switch unit in the charging circuit to disconnect, so that the charging circuit is disconnected.

[0016] In the above embodiment, by determining whether the charging circuit is on for longer than the eighth threshold, the charging circuit is controlled to be disconnected when the charging circuit is on for longer than the eighth threshold, thereby ensuring that the lithium battery charges the lead-acid battery to a level sufficient to meet the electrical energy required for one start of the vehicle and preventing the lithium battery from being over-discharged.

[0017] In some embodiments, the method further includes: determining whether the SOC of the battery is greater than a seventy-third threshold; if the SOC of the battery is greater than the seventy-third threshold, issuing a fifth instruction, the fifth instruction being used to control the second switch unit in the discharge circuit of the battery to close, so that the discharge circuit is turned on, and the discharge circuit is a circuit connecting the battery on the device and the electrical equipment.

[0018] In the above embodiment, by determining whether the SOC of the battery is greater than the seventh threshold, when the SOC of the battery is greater than the seventh threshold, the discharge circuit of the battery is controlled to be turned on to avoid over-discharge of the lithium battery.

[0019] In some embodiments, the method further includes: after the discharge circuit of the battery is turned on, determining whether there is a device wake-up signal, or whether there is a fault alarm for the battery, or whether the SOC of the battery is less than or equal to or greater than the seventy-third threshold; in the event that there is a device wake-up signal, or there is a fault alarm for the battery, or the SOC of the battery is less than or equal to or greater than the seventy-third threshold, issuing a sixth instruction, the sixth instruction being used to control the second switch unit in the discharge circuit to disconnect, so that the discharge circuit is disconnected.

[0020] In the above embodiment, by judging whether there is no device wake-up signal, whether there is a battery fault alarm, or whether the battery SOC is less than or equal to the seventh threshold, when there is no device wake-up signal, or there is a battery fault alarm, or the battery SOC is less than or equal to the seventh threshold, the discharge circuit is controlled to be disconnected to avoid over-discharge of the lithium battery and safety problems.

[0021] According to a second aspect of an embodiment of the present application, a battery controller is provided, comprising: one or more processors, working individually or collectively, and the processors are used to execute the steps of the circuit control method as described above.

[0022] According to a third aspect of an embodiment of the present application, a battery management system is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to implement the steps of the circuit control method as described above.

[0023] According to a fourth aspect of an embodiment of the present application, a battery is provided, comprising: the battery controller as described above, or the battery management system as described above.

[0024] According to a fifth aspect of an embodiment of the present application, there is provided an electrical device comprising the battery as described above, wherein the battery is used to provide electrical energy.

[0025] According to the sixth aspect of an embodiment of the present application, a vehicle is provided, comprising a lithium battery, a generator and a vehicle wake-up switch; wherein the lithium battery and the generator are connected to form a charging circuit, and the lithium battery includes a battery management system, and the battery management system is used to: obtain a vehicle wake-up signal; determine whether the power supply terminal voltage of the charging circuit of the lithium battery on the vehicle is greater than a first threshold value, and whether the rate of change within a first time period is less than a second threshold value, the charging circuit is a circuit connecting the lithium battery on the vehicle and the generator, and the power supply terminal voltage is the output voltage of the generator; when the power supply terminal voltage of the charging circuit of the battery on the vehicle is greater than the first threshold value, and the rate of change within a first time period is less than the second threshold value, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

[0026] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0028] Figure 1 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0029] Figure 2 It is an application Figure 1 A block diagram of a power system structure of an electric device of the method;

[0030] Figure 3 It is an application Figure 1 A circuit diagram of a battery according to the method;

[0031] Figure 4 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0032] Figure 5 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0033] Figure 6 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0034] Figure 7 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0035] Figure 8is a flow chart of a circuit control method provided in some embodiments of the present application;

[0036] Figure 9 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0037] Figure 10 is a flow chart of a circuit control method provided in some embodiments of the present application;

[0038] Figure 11 is a schematic structural diagram of a battery controller provided in some embodiments of the present application;

[0039] Figure 12 is a schematic structural diagram of a battery management system provided by some embodiments of the present application;

[0040] Figure 13 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0041] Figure 14 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0042] Figure 15 is a schematic structural diagram of an electrical device provided in some embodiments of the present application;

[0043] Figure 16 It is a schematic structural diagram of a vehicle provided in some embodiments of the present application. DETAILED DESCRIPTION

[0044] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned figures are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In the description of this application, unless otherwise specified, "multiple" means two or more.

[0046] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0047] As mentioned above, it should be emphasized that when the term "include / comprise" is used in this specification, it is used to clearly indicate the existence of the features, integers, steps or components, but does not exclude the existence or addition of one or more other features, integers, steps, components or groups of features, integers, steps, components. As used in this application, the singular forms "a", "an" and "the" also include the plural forms, unless the context clearly indicates otherwise.

[0048] The terms "a" and "an" used in this specification may mean one, but may also have the same meaning as "at least one" or "one or more." The term "about" generally means plus or minus 10%, or more specifically, plus or minus 5%, of the referenced value. The term "or" used in the claims means "and / or" unless it is expressly stated that it refers only to alternatives.

[0049] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0050] Batteries mentioned in this field can be divided into disposable batteries and rechargeable batteries based on whether they are rechargeable. Disposable batteries (primary batteries) are commonly known as "disposable" batteries or original batteries because they cannot be recharged and used once their power is exhausted and must be discarded. Rechargeable batteries are also called secondary batteries or secondary batteries, or storage batteries. Rechargeable batteries are made of different materials and processes than disposable batteries. Their advantage is that they can be recycled multiple times after charging, and their output current load capacity is higher than that of most disposable batteries. Currently, common types of rechargeable batteries include: lead-acid batteries, nickel-metal hydride batteries, and lithium-ion batteries. Lithium-ion batteries have the advantages of light weight, large capacity (1.5 to 2 times the capacity of nickel-metal hydride batteries of the same weight), no memory effect, and a very low self-discharge rate. Therefore, despite their relatively high price, they are still widely used.

[0051] The batteries described in the embodiments of this application are rechargeable batteries. The concepts of this application will be described below primarily using lead-acid batteries and lithium-ion batteries as examples. It should be understood that any other suitable type of rechargeable battery is applicable. The batteries mentioned in the embodiments of this application refer to a single physical module that includes one or more battery cells (also referred to as battery cells) to provide higher voltage and capacity. For example, the batteries mentioned in this application may include battery modules or battery packs. Battery cells include positive electrode sheets, negative electrode sheets, electrolytes, and separators, and are the basic structural units that make up battery modules and battery packs. Commonly used positive electrode materials for lithium-ion batteries include lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium iron phosphate, and ternary materials (such as lithium nickel cobalt manganese oxide). Commonly used negative electrode materials include carbon materials (such as graphite) and silicon-based materials. Commonly used separator materials include polyolefin materials based on polyethylene (PE) or polypropylene (PP). Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells.

[0052] Multiple battery cells can be connected in series and / or in parallel via electrode terminals for use in various applications. In some high-power applications such as electric vehicles, battery applications include three levels: battery cells, battery modules, and battery packs. The battery module is formed by electrically connecting a certain number of battery cells together and placing them in a frame in order to protect the battery cells from external impact, heat, vibration, etc. The battery pack is the final state of the battery system installed in the car. Most of the current battery packs are made by assembling various control and protection systems such as the Battery Management System (BMS) and thermal management components on one or more battery modules. With the development of technology, the battery module level can be omitted, that is, the battery pack is directly formed from battery cells. This improvement has improved the weight energy density and volume energy density of the battery system while significantly reducing the number of components. The batteries mentioned in this application include battery modules or battery packs.

[0053] Currently, vehicle power supplies are primarily used for engine starting, typically using lead-acid batteries or lithium batteries. With rising socioeconomic levels, demands for environmental protection, energy conservation, and comfort in vehicles are also increasing, leading to the emergence of corresponding onboard devices. For example, parking air conditioners address user comfort requirements for ambient air temperature, humidity, and air flow rate. Therefore, the vehicle's power supply must not only meet the requirements for engine starting in various environments, but also provide power for onboard electrical devices such as the parking air conditioner when the vehicle is parked.

[0054] Lead-acid batteries are relatively inexpensive and offer consistent quality, but they are heavy, have a high self-discharge rate, and a short lifespan. Lithium batteries are lightweight, compact, have a low self-discharge rate, and offer a long lifespan. However, high-capacity, high-rate lithium batteries are expensive and cannot meet the requirements for engine starting in low temperatures. Therefore, lead-acid batteries are often used in parallel with lithium batteries as starting and parking power sources for vehicles, with the lead-acid battery primarily used for engine starting and the lithium battery primarily used to power the parking air conditioner.

[0055] However, when using a lead-acid battery in parallel with a lithium battery as a vehicle starting and parking power source, if the vehicle is started when the lithium battery charging circuit switch is closed, a large current discharge will occur in the lithium battery charging circuit, causing the switch on the charging circuit (such as a relay) to stick, thereby causing the lithium battery to overcharge, resulting in thermal runaway of the battery, and causing safety accidents such as battery fire.

[0056] In view of this, the present application provides a circuit control method, a battery controller, a battery management system, a battery, an electrical device, and a vehicle, and will specifically describe their design below. It is understood that the circuit control method, battery controller, battery management system, and battery described in the embodiments of the present application are applicable to various devices using batteries, especially vehicles. For the sake of convenience, the following embodiments are described using the application in a vehicle as an example.

[0057] Figure 1 This is a flow chart of a circuit control method provided in some embodiments of the present application. The circuit control method 100 can be applied to batteries in electrical devices, and further, can be applied to battery BMSs. The following describes the concept of the present application using the method applied to a battery BMS in a vehicle as an example. The circuit control method includes the following steps:

[0058] S101: Obtaining a device wake-up signal;

[0059] S102: Determine whether a voltage at a power supply terminal of a charging circuit of a battery on the device is greater than a first threshold and whether a rate of change within a first period of time is less than a second threshold, wherein the charging circuit is a circuit connecting the battery on the device to a generator, and the voltage at the power supply terminal is the output voltage of the generator;

[0060] S103: When the voltage at the power supply terminal of the charging circuit of the battery on the device is greater than a first threshold and the rate of change within a first time period is less than a second threshold, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

[0061] Figure 2 It is an application Figure 1 The power system structure diagram of the power consumption device of the method. Please refer to Figure 2As shown, the power-consuming device includes a parking power supply (a lithium battery is used as an example in this embodiment), a lead-acid battery, a generator, an engine, a vehicle wake-up switch, and an electrical device. The first port P11 of the lithium battery is connected to the generator and the first port P21 of the lead-acid battery, respectively, to form a charging circuit A. The second port P12 of the lithium battery is connected to the electrical device, forming a discharge circuit B between the lithium battery and the electrical device. The first port P21 of the lead-acid battery is also connected to the engine, forming a circuit C that provides power for engine starting. The third port P13 of the lithium battery is connected to the vehicle wake-up switch to receive the device wake-up signal.

[0062] The charging circuit is a circuit connecting the battery on the device and the generator. Specifically, it can be Figure 2 The charging circuit A connects the lithium battery with the generator and the lead-acid battery. Figure 3 It is an application Figure 1 The circuit structure diagram of the battery of the method, the charging circuit can be Figure 3 Charging circuit A1 in.

[0063] The device wake-up signal is an electrical signal used to start the device. For example, in a vehicle, the keyhole is in the ON position (KL15), with one end connected to the vehicle's power supply and the other to the BMS. Before ignition, the KL15 switch is open, resulting in no signal input and the BMS being inoperative. After ignition, the KL15 switch closes, enabling the power management chip and sending a KL15 hard-wired wake-up signal to the BMS, waking it up and starting the vehicle. Therefore, the device wake-up signal in the vehicle can be a KL15 hard-wired wake-up signal, which the BMS receives after the vehicle ignition is started.

[0064] The presence of a device wake-up signal is a first condition for the charging circuit to be turned on, the presence of a device wake-up signal is a second condition for the charging circuit to be turned on, and the presence of a device wake-up signal is a first threshold voltage at the power supply terminal of the charging circuit of the battery on the device is a third condition for the charging circuit to be turned on, and the presence of a device wake-up signal is a first threshold voltage at the power supply terminal of the charging circuit of the battery on the device ... third condition for the charging circuit to be turned on.

[0065] If the device wake-up signal is absent and the first condition is not met, indicating the vehicle is not started, turning on the charging circuit may cause the aforementioned high-current discharge in the lithium battery charging circuit, leading to overcharging and thermal runaway of the lithium battery. If the device wake-up signal is present and the first condition is met, indicating the vehicle is started, the charging circuit can be turned on.

[0066] In order to further avoid the charging circuit being turned on when the vehicle is not started, the BMS also collects some battery parameters and makes corresponding judgments. For example, the power supply terminal voltage of the battery charging circuit can be collected. The power supply terminal voltage is the output voltage of the generator, for example Figure 3The voltage at point a connected to the first port of the generator. Point a is located outside the first switch unit K1 on the charging circuit A1 ("outside" here means connected to the outside of the battery), and the voltage at point a is the outside voltage of the first switch unit K1 on the charging circuit A1. It can be understood that since point a is also connected to the first port of the lead-acid battery, the external measured voltage is also the voltage of the lead-acid battery. The voltage at point a can be sampled by connecting point a to the sampling port of the BMS. The first switch unit K1 can be an element such as a relay that can realize the conduction and disconnection of the circuit. It can be understood that the first switch unit is located inside the lithium battery.

[0067] A first threshold can be set for the voltage at the power supply terminal of the battery charging circuit. If the voltage is less than or equal to the first threshold, the second condition is not met, indicating that the vehicle has not been started and the charging circuit cannot be turned on. If the voltage is greater than the first threshold, the second condition is met, indicating that the vehicle has been started and the charging circuit can be turned on.

[0068] Typically, after a long period of parking, the voltage of a lead-acid battery after standing still may be higher than that of a lithium battery. After the vehicle is started and the engine speed reaches ≥ idle speed, the generator's output voltage is normal and generally higher than the maximum voltage of the lead-acid battery after standing still. Therefore, the first threshold can be set based on the generator's output voltage and the maximum voltage of the lead-acid battery after standing still. The first threshold can be set to be less than the generator's output voltage and greater than the maximum voltage of the lead-acid battery after standing still for a certain period of time after being fully charged. For example, if the generator's output voltage is 28±0.3V, and the maximum voltage of the lead-acid battery drops from 29V to approximately 26V after standing still for 300 seconds, the first threshold can be set to a value greater than 26V and less than 27.7V, such as 27V. If the voltage at the power supply terminal of the charging circuit is less than or equal to the first threshold, the vehicle has not started. If the voltage is greater than the first threshold, the vehicle has started. The predetermined time period can be set based on the time it takes for the lead-acid battery's voltage to drop to a stable value after standing still. For example, the predetermined time period can be set to the minimum time required for the lead-acid battery's voltage to drop to a stable value after standing still.

[0069] After a full charge and idling, the voltage of a lead-acid battery may be higher than that of a lithium battery. However, if the vehicle is turned off, de-energizing the lead-acid battery's charging circuit, and the battery is left idling for a certain period of time, the voltage of the lead-acid battery will drop slightly. Therefore, a second threshold can be set for the rate of change of the voltage at the power supply terminal of the battery's charging circuit over the first period of time. If this rate of change is greater than or equal to the second threshold, the third condition is not met, indicating that the vehicle is powered off and not started, and the charging circuit cannot be turned on. If the rate of change is less than the second threshold, the third condition is met, indicating that the vehicle is started and the charging circuit can be turned on.

[0070] Based on the acquired power supply terminal voltage, the BMS can calculate the rate of change of the power supply terminal voltage within a first time period and compare it with a second threshold value. The first time period can be determined based on the time range in which the voltage change rate is more obvious after the lead-acid battery is fully charged and the power is disconnected and left at rest. The second threshold value can be set based on the minimum value of the rate of change between the highest voltage after the lead-acid battery is fully charged and the highest voltage after a certain period of time when the power is disconnected and left at rest. The second threshold value can be set to be less than the minimum value of the rate of change between the highest voltage after the lead-acid battery is fully charged and the highest voltage after a certain period of time when the power is disconnected and left at rest. For example, if the time range in which the voltage change rate is more obvious after the lead-acid battery is fully charged is 5 minutes (300 seconds), the first time period can be set to 300 seconds. If the highest voltage of the lead-acid battery after a full charge is 29V and the voltage drops to 26V after 300 seconds of power disconnection and rest, the second threshold value can be set to a value less than (29-26) / 29=10.34%, for example, 10%.

[0071] In summary, S103 controls the first switch unit in the charging circuit to be closed, so that the charging circuit is turned on, only when the first condition, the second condition and the third condition are all satisfied.

[0072] It is understandable that when any of the first, second and third conditions mentioned above is not met, the charging circuit will not be turned on, thereby maintaining the disconnected state of the charging circuit or disconnecting the charging circuit.

[0073] A first instruction may be sent to a first switch unit in the charging circuit via a battery management unit (BMU) interface on the BMS, thereby controlling the first switch unit in the charging circuit to close, thereby turning on the charging circuit. The first instruction may be a high or low level signal.

[0074] The circuit control method of the embodiment of the present application obtains the device wake-up signal and the power supply terminal voltage of the charging circuit, and determines whether the power supply terminal voltage of the charging circuit is greater than a first threshold and whether the rate of change within the first time period is less than a second threshold. Since the device wake-up signal, the power supply terminal voltage of the charging circuit is greater than the first threshold and the rate of change within the first time period is less than the second threshold only exist after the device is started, the method controls the battery charging circuit to be turned on when all the above conditions are met, so that the device is started when the battery charging circuit is turned on, avoiding the battery charging circuit being turned on when the device is not started, and causing a large current discharge in the battery charging circuit when the device is subsequently started, resulting in sticking of the switch on the charging circuit, avoiding overcharging of the lithium battery and causing thermal runaway of the battery, thereby improving the safety of the battery.

[0075] In some embodiments, other conditions for turning on the charging circuit may also be set. Figure 4 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 4 As shown, the circuit control method includes the following steps:

[0076] S101: Obtaining a device wake-up signal;

[0077] S102: Determine whether a voltage at a power supply terminal of a charging circuit of a battery on the device is greater than a first threshold and whether a rate of change within a first period of time is less than a second threshold, wherein the charging circuit is a circuit connecting the battery on the device to a generator, and the voltage at the power supply terminal is the output voltage of the generator;

[0078] S403: Determine whether the battery SOC is greater than a third threshold, whether a battery fault alarm exists, and whether the battery cell temperature is within a first range;

[0079] S404: When the power supply terminal voltage of the charging circuit of the battery on the device is greater than a first threshold, the rate of change within a first time period is less than a second threshold, the SOC of the battery is greater than a third threshold, there is no battery fault alarm, and the battery cell temperature is within a first range, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

[0080] The specific implementation process of S101 and S102 is substantially the same as that of S101 and S102 in the aforementioned embodiment, and the implementation process can refer to the above description.

[0081] The fourth condition for the charging circuit to be turned on is that the battery SOC is greater than the third threshold, the fifth condition for the charging circuit to be turned on is that there is no battery fault alarm, and the sixth condition for the charging circuit to be turned on is that the battery cell temperature is within the first range.

[0082] SOC refers to the state of charge. The BMS obtains the SOC of the lithium battery and determines whether the SOC is greater than a third threshold. The third threshold can be determined based on the value after the lithium battery is fully charged and its charging circuit is disconnected, and the battery cell depolarization causes the lithium battery cell voltage to drop. For example, the third threshold is 95%. Because after the lithium battery is fully charged and its charging circuit is disconnected, the battery cell depolarization will cause the lithium battery cell voltage to drop. If the charging circuit is closed at this time, it will cause floating charge. Therefore, the SOC greater than the third threshold is used as the fourth condition for the charging circuit to be turned on. Only when the SOC is greater than the third threshold can the charging circuit be controlled to be turned on to avoid the above-mentioned floating charge problem.

[0083] If the battery has a fault alarm, the battery cannot be charged, otherwise it may easily lead to safety problems. Only when the battery does not have a fault alarm and the fifth condition is met, can the charging circuit be controlled to conduct to avoid safety problems.

[0084] When charging a battery, it is necessary to ensure that the temperature of the battery cells within it is within the allowable charging range, otherwise safety issues may occur. The first range is the allowable charging range, for example, 0-55°C. Only when the battery cell temperature is within the first range and the sixth condition is met, can the charging circuit be controlled to conduct, avoiding safety issues.

[0085] The fourth, fifth, and sixth conditions, along with the first, second, and third conditions described above, are necessary to determine whether the charging circuit can be turned on. Therefore, in S404, the first switch unit in the charging circuit is controlled to close, turning the charging circuit on, only when all of the above conditions are met.

[0086] It is understandable that when any of the above conditions is not met, the charging circuit will not be turned on, thereby maintaining the disconnected state of the charging circuit or disconnecting the charging circuit.

[0087] In the above embodiment, by judging whether the SOC of the battery is greater than the third threshold, whether the battery has a fault alarm, and whether the battery cell temperature is within the first range, the battery charging circuit is controlled to be turned on only when the SOC of the battery is greater than the third threshold, there is no battery fault alarm, and the battery cell temperature is within the first range, thereby avoiding battery floating charge and safety problems.

[0088] In some embodiments, a technical solution is also provided for controlling the disconnection of the charging circuit of the battery after it is turned on. Figure 5 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 5 As shown, the circuit control method includes the following steps:

[0089] S501: After the charging circuit of the battery is turned on, determining whether a rate of change of the battery charging current within a second time period is greater than a fourth threshold, or whether a voltage of a battery cell in the battery is greater than or equal to a fifth threshold, or whether a battery fault alarm is issued, or whether a temperature of the battery cell is not within a first range;

[0090] S502: When the rate of change of the battery's charging current within the second time period is greater than a fourth threshold, or the voltage of a battery cell in the battery is greater than or equal to a fifth threshold, or there is a battery fault alarm, or the temperature of the battery cell is not within the first range, a second instruction is issued, and the second instruction is used to control the first switch unit in the charging circuit to disconnect, so that the charging circuit is disconnected.

[0091] Among them, the first condition for disconnecting the charging circuit is that the rate of change of the battery's charging current within the second time period is greater than the fourth threshold value, the second condition for disconnecting the charging circuit is that the voltage of the battery cell in the battery is greater than or equal to the fifth threshold value, the third condition for disconnecting the charging circuit is that the battery fault alarm exists, and the fourth condition for disconnecting the charging circuit is that the temperature of the battery cell is not within the first range.

[0092] Normally, after the vehicle is started, the battery's charging circuit is turned on and the generator charges the lithium battery. If the voltage of the lead-acid battery is greater than a first threshold value (for example, >27V) after the vehicle is turned off, the lead-acid battery will charge the lithium battery and the charging circuit will remain turned on. When the vehicle is started immediately after being turned off, if the charging circuit is turned on, a large current discharge will occur in the charging circuit, causing the switch (such as a relay) on the charging circuit to stick, thereby causing the lithium battery to overcharge, causing thermal runaway of the battery, and causing safety accidents such as battery fire. Therefore, it is necessary to set conditions for disconnecting the charging circuit of the control battery that are applicable to this situation. For example, if the vehicle is turned off (not started), the battery's charging circuit needs to be disconnected.

[0093] After the vehicle is started, the generator charges the lithium battery, and the battery's charging current is normal. If the vehicle suddenly stalls, the charging current will quickly drop to 0. Therefore, the first condition for disconnecting the charging circuit can be set as the rate of change of the battery's charging current within the second time period being greater than a fourth threshold. If the rate of change of the battery's charging current within the second time period is less than or equal to the fourth threshold, the first condition is not met, indicating that the vehicle has been started and stalled, and there is no need to disconnect the charging circuit; the charging circuit can remain on. If the rate of change of the battery's charging current within the second time period is greater than the fourth threshold, the first condition is met, indicating that the vehicle has been stalled, and the charging circuit needs to be disconnected to avoid the aforementioned problem of lithium battery overcharging.

[0094] Based on the acquired battery charging current, the BMS can calculate the rate of change of the charging current over the second time period and compare it with the fourth threshold. Because it takes a certain amount of time for the generator output current to change from a normal value to no output, the second time period and the fourth threshold can be set based on this time period and the rate of change from a normal value to no output. For example, if the generator output current takes approximately 1 second to change from a normal value of 110A to a zero output of 0A, the second time period can be set to 1 second and the fourth threshold to 110A.

[0095] When charging a battery, overcharge protection is required to prevent overcharging. Therefore, overcharge protection can be implemented by setting a fifth threshold. The fifth threshold can be set according to the battery's overcharge protection mechanism, for example, the fifth threshold can be set to 3.65V. If the voltage of a battery cell in the battery is greater than or equal to the fifth threshold, the second condition is met, and in this case, the charging circuit needs to be disconnected to prevent the lithium battery from overcharging. If the voltage of a battery cell in the battery is less than the fifth threshold, the second condition is not met, and in this case, the charging circuit does not need to be disconnected and can remain on.

[0096] If the battery has a fault alarm, the battery cannot be charged, otherwise it may cause safety problems. At this time, the third condition is met and the charging circuit needs to be disconnected to avoid safety problems.

[0097] When charging a battery, it is necessary to ensure that the temperature of the battery cells within it is within the allowable charging range, otherwise safety issues may occur. The first range is the allowable charging range, for example, 0-55°C. If the battery cell temperature is not within the first range, the fourth condition is met and the charging circuit needs to be disconnected to avoid safety issues.

[0098] The first, second, third, and fourth conditions are sufficient to determine whether the charging circuit needs to be disconnected after the battery charging circuit is turned on. Therefore, if any of the above conditions is met in S502, the first switch unit in the charging circuit can be controlled to be disconnected, thereby disconnecting the charging circuit.

[0099] A second instruction can be sent to the first switch unit in the charging circuit through the BMU interface on the BMS, thereby controlling the first switch unit in the charging circuit to be disconnected, so that the charging circuit is disconnected. The second instruction can be a high or low level signal.

[0100] It is understood that, in some embodiments, the circuit control method may further include: Figures 1-4 The steps in any one of the embodiments, or a combination of the steps in these embodiments.

[0101] In some embodiments, if there is no device wake-up signal, it means that the vehicle is not started, and in this case, the charging circuit needs to be disconnected.

[0102] In the above embodiment, by judging whether the rate of change of the battery charging current within the second time period is greater than the fourth threshold, or whether the voltage of the battery cell in the battery is greater than or equal to the fifth threshold, or whether there is a battery fault alarm, or whether the temperature of the battery cell is not within the first range, the charging circuit is controlled to be disconnected when the rate of change of the battery charging current within the second time period is greater than the fourth threshold, or the voltage of the battery cell in the battery is greater than or equal to the fifth threshold, or there is a battery fault alarm, or the temperature of the battery cell is not within the first range, thereby ensuring that the charging circuit is disconnected when the vehicle is not started, thereby avoiding overcharging of the lithium battery and safety problems.

[0103] In the above embodiment, by judging whether the SOC of the battery is greater than the third threshold, whether the battery has a fault alarm, and whether the battery cell temperature is within the first range, the battery charging circuit is controlled to be turned on only when the SOC of the battery is greater than the third threshold, there is no battery fault alarm, and the battery cell temperature is within the first range, thereby avoiding battery floating charge and safety problems.

[0104] Lead-acid batteries are heavy and have a high self-discharge rate of 20% to 30% per month, resulting in a short lifespan. When a vehicle is left unused for an extended period, the battery may lose charge, rendering it unable to start. Therefore, some embodiments provide a technical solution for controlling the charging circuit after a battery has been unused for an extended period. Figure 6 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 6 As shown, the circuit control method includes the following steps:

[0105] S601: Determine whether there is a device wake-up signal and whether the power supply voltage is less than a sixth threshold;

[0106] S602: When there is a device wake-up signal and the voltage at the power supply end is less than a sixth threshold, a third instruction is issued, where the third instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on and the charging circuit is in a first conduction state.

[0107] The sixth threshold can be set based on the maximum voltage of the lead-acid battery when it is low on power. For example, if the voltage of a low-power lead-acid battery is approximately 16V-22V, the sixth threshold can be set to 22V. When the power supply terminal voltage is less than this value, the lead-acid battery is low on power, and the charging circuit can be turned on to charge the lead-acid battery. This provides power for subsequent vehicle starts, extending the service life of the lead-acid battery and extending the vehicle's storage time.

[0108] The presence of a device wake-up signal is a first condition for enabling the charging circuit, and the power supply voltage being less than a sixth threshold is a second condition for enabling the charging circuit. These first and second conditions together serve as necessary conditions for determining whether the charging circuit can be enabled. Therefore, in S602, only when both of these conditions are met does the first switch unit in the charging circuit close, thereby enabling the charging circuit.

[0109] It is understandable that when any of the above conditions is not met, the charging circuit will not be turned on, thereby maintaining the disconnected state of the charging circuit or disconnecting the charging circuit.

[0110] A third instruction may be sent to the first switch unit in the charging circuit via the BMU interface on the BMS, thereby controlling the first switch unit in the charging circuit to close, thereby turning on the charging circuit. The third instruction may be a high or low level signal.

[0111] In some embodiments, a delay condition can also be added to step S602. For example, if a device wake-up signal is present and the power supply voltage is less than a sixth threshold, a third instruction is issued after a delay of t to turn on the charging circuit. When the key is inserted into the vehicle keyhole and turned, it is initially in the ACC position. At this point (before the ignition ON position), the BMS detects the device wake-up signal (KL15). If the power supply voltage is also less than the sixth threshold, the BMS issues a third instruction to turn on the charging circuit. Starting the vehicle with the charging circuit on will discharge the lithium battery into the engine, potentially causing the aforementioned battery thermal runaway, leading to safety hazards such as battery fire. Therefore, by setting a certain delay of t before turning on the charging circuit, the vehicle can be started when the battery charging circuit is turned on. This prevents the battery charging circuit from being turned on when the vehicle is not started, which would cause a large current discharge in the battery charging circuit during subsequent vehicle startup, leading to sticking of the charging circuit switch. This prevents overcharging of the lithium battery and thermal runaway, thereby improving battery safety. The delay time t is set to meet the operation time of the key from the ACC gear to the ON gear, for example, it can be set to 10s, 30s or 60s. It is understood that in some embodiments, the circuit control method can also include Figure 1-Figure 5 The steps in any one of the embodiments, or a combination of the steps in these embodiments.

[0112] In the above embodiment, by judging whether there is a device wake-up signal and whether the voltage at the power supply end is less than the sixth threshold, the charging circuit is controlled to be turned on when there is a device wake-up signal and the voltage at the power supply end is less than the sixth threshold, and the lithium battery charges the lead-acid battery, thereby avoiding the problem of the vehicle being unable to start due to depletion of the lead-acid battery when the vehicle is parked for a long time.

[0113] In some embodiments, Figure 6 On the basis of the illustrated embodiment, other conditions for conducting the charging circuit may also be set. Figure 7 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 7 As shown, the circuit control method includes the following steps:

[0114] S701: Determine whether there is a device wake-up signal and whether the power supply voltage is less than a sixth threshold;

[0115] S702: Determine whether the battery SOC is greater than a seventh threshold and whether there is a battery fault alarm;

[0116] S703: When there is a device wake-up signal, the power supply voltage is less than the sixth threshold, the battery SOC is greater than the seventh threshold, and there is no battery fault alarm, a third instruction is issued. The third instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on and the charging circuit is in the first conduction state.

[0117] The specific implementation process of S701 is substantially the same as that of S601 in the aforementioned embodiment, and the implementation process may refer to the above description.

[0118] The third condition for the charging circuit to be turned on is that the battery SOC is greater than the seventh threshold, and the fourth condition for the charging circuit to be turned on is that there is no battery fault alarm.

[0119] When a vehicle is parked for a long time, if the lithium battery continues to charge the lead-acid battery, it may cause the lithium battery to over-discharge. Over-discharge will increase the internal pressure of the lithium battery, destroy the reversibility of the positive and negative active materials, and significantly attenuate the capacity. Therefore, a seventh threshold can be set. If the battery's SOC is less than or equal to the seventh threshold, it means that the battery is no longer suitable for discharge. At this time, the third condition is not met and the charging circuit cannot be turned on, thereby avoiding the lithium battery over-discharge caused by the lithium battery continuously charging the lead-acid battery when the vehicle is parked for a long time. Only when the battery's SOC is greater than the seventh threshold is the charging circuit turned on and the lithium battery charges the lead-acid battery. The seventh threshold can be set according to the discharge cut-off SOC value of the lithium battery. For example, the seventh threshold is set to 15%.

[0120] If the battery has a fault alarm, the battery cannot be charged, otherwise it may easily lead to safety problems. Only when the battery does not have a fault alarm and the fourth condition is met, can the charging circuit be controlled to be turned on to avoid safety problems.

[0121] The third and fourth conditions, together with the first and second conditions in S601, are necessary conditions for determining whether the charging circuit can be turned on. Therefore, in S703, only when all the above conditions are met does the first switch unit in the charging circuit close, turning on the charging circuit.

[0122] It is understandable that when any of the above conditions is not met, the charging circuit will not be turned on, thereby maintaining the disconnected state of the charging circuit or disconnecting the charging circuit.

[0123] In the above embodiment, by judging whether the SOC of the battery is greater than the seventh threshold and whether the battery has a fault alarm, the charging circuit is controlled to be turned on when the SOC of the battery is greater than the seventh threshold and no battery fault alarm exists, thereby avoiding over-discharge of the lithium battery and safety problems.

[0124] In some embodiments, a technical solution is also provided for controlling the disconnection of the charging circuit after the battery has been left for a long time and its charging circuit is turned on. Figure 8 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 8 As shown, the circuit control method includes the following steps:

[0125] S801: In the first conduction state, determining whether the charging circuit conduction time is greater than an eighth threshold;

[0126] S802: If the charging circuit conduction time is greater than an eighth threshold, issue a fourth instruction, where the fourth instruction is used to control the first switch unit in the charging circuit to be disconnected, so that the charging circuit is disconnected.

[0127] The first condition for the charging circuit to be disconnected is that the charging circuit is turned on for a time greater than the eighth threshold. Figure 6 or Figure 7 In the embodiment shown, the first conduction state, i.e., the

[0128] After the battery is placed for a long time, the charging circuit of the battery is turned on. At this time, the charging circuit is in a conductive state to distinguish it from the Figure 1-Figure 5 The charging circuit is in the conductive state in the illustrated embodiment.

[0129] After the vehicle has been parked for a long time, in order to solve the problem of the lead-acid battery being depleted and causing the vehicle to be unable to start, the above Figure 6-Figure 7 In the illustrated embodiment, a lithium battery can charge a lead-acid battery. Charging can be stopped once the lithium battery has charged the lead-acid battery to the point where it can meet the vehicle's one-time starting energy requirements. Therefore, an eighth threshold can be set. When the charging circuit conduction time exceeds this eighth threshold, it indicates that the lead-acid battery has reached the required energy for a single start, and the charging circuit can be disconnected, halting charging. The eighth threshold can be set based on the time it takes for the lead-acid battery to charge to the required energy for a single start.

[0130] A fourth instruction may be sent to the first switch unit in the charging circuit via the BMU interface on the BMS, thereby controlling the first switch unit in the charging circuit to be disconnected, thereby disconnecting the charging circuit. The fourth instruction may be a high or low level signal.

[0131] In some embodiments, other conditions for disconnecting the charging circuit can also be set, such as the absence of a device wake-up signal as a second condition for disconnecting the charging circuit, and the absence of a battery fault alarm as a third condition for disconnecting the charging circuit. These first, second, and third conditions are sufficient to determine whether the charging circuit needs to be disconnected after the battery charging circuit is turned on. When any of these conditions is met, the first switch unit in the charging circuit can be controlled to disconnect, disconnecting the charging circuit.

[0132] In the above embodiment, by determining whether the charging circuit is on for longer than the eighth threshold, the charging circuit is controlled to be disconnected when the charging circuit is on for longer than the eighth threshold, thereby ensuring that the lithium battery charges the lead-acid battery to a level sufficient to meet the electrical energy required for one start of the vehicle and preventing the lithium battery from being over-discharged.

[0133] In some embodiments, a technical solution for controlling the conduction of a discharge circuit of a battery is also provided. Figure 9 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 9 As shown, the circuit control method includes the following steps:

[0134] S901: Determine whether the battery SOC is greater than a seventh threshold;

[0135] S902: If the SOC of the battery is greater than the seventh threshold, a fifth instruction is issued. The fifth instruction is used to control the second switch unit in the discharge circuit of the battery to close, so that the discharge circuit is turned on. The discharge circuit is a circuit connecting the battery on the device and the electrical equipment.

[0136] The discharge circuit is a circuit connecting the battery on the device and the electrical equipment. Specifically, it can be Figure 2 The discharge circuit B that connects the lithium battery and the electrical equipment, Figure 3 The discharge circuit B1 in the second switch unit can be Figure 2 K2 can be a relay or other element that can realize the conduction and disconnection of the circuit. It can be understood that the second switch unit is located inside the lithium battery.

[0137] The first condition for the discharge circuit to be turned on is that the SOC of the battery is greater than the seventh threshold.

[0138] Lithium batteries are power sources for electrical devices, such as batteries that power parking air conditioners. When electrical devices are operating for long periods of time, if lithium batteries continue to power the devices, it may cause the lithium batteries to over-discharge. Over-discharge will increase the internal pressure of the lithium battery, damage the reversibility of the positive and negative active materials, and significantly reduce the capacity. Therefore, a seventh threshold can be set. If the battery's SOC is less than or equal to the seventh threshold, it means that the battery is not suitable for discharge. At this time, the first condition is not met and the discharge circuit cannot be turned on, thereby avoiding the lithium battery over-discharge caused by the lithium battery continuously powering the electrical device. Only when the battery's SOC is greater than the seventh threshold is the discharge circuit turned on and the lithium battery powers the electrical device. The seventh threshold can be set according to the lithium battery's discharge cut-off SOC value. For example, the seventh threshold can be set to 15%.

[0139] A fifth instruction may be sent to the second switch unit in the discharge circuit via the BMU interface on the BMS, thereby controlling the second switch unit in the discharge circuit to close, thereby turning on the discharge circuit. The fifth instruction may be a high or low level signal.

[0140] In some embodiments, other conditions for turning on the discharge circuit can also be set, such as the presence of a device wake-up signal as a second condition for turning on the discharge circuit, and the absence of a battery fault alarm as a third condition for turning on the discharge circuit. The first, second, and third conditions together serve as necessary conditions for determining whether the discharge circuit can be turned on. Only when all of the above conditions are met is the second switch unit in the discharge circuit controlled to close, turning on the discharge circuit.

[0141] It is understandable that when any of the above conditions is not met, the discharge circuit will not be turned on, thereby maintaining the disconnected state of the discharge circuit or disconnecting the discharge circuit.

[0142] In the above embodiment, by determining whether the SOC of the battery is greater than the seventh threshold, when the SOC of the battery is greater than the seventh threshold, the discharge circuit of the battery is controlled to be turned on to avoid over-discharge of the lithium battery.

[0143] In some embodiments, a technical solution is also provided for controlling the disconnection of the discharge circuit of the battery after it is turned on. Figure 10 This is a flow chart of the circuit control method provided by some embodiments of the present application. Figure 10 As shown, the circuit control method includes the following steps:

[0144] S1001: After the discharge circuit of the battery is turned on, determine whether there is no device wake-up signal, whether there is a battery fault alarm, or whether the battery SOC is less than or equal to a seventh threshold;

[0145] S1002: When there is no device wake-up signal, or there is a battery fault alarm, or the battery SOC is less than or equal to the seventh threshold, a sixth instruction is issued, and the sixth instruction is used to control the second switch unit in the discharge circuit to disconnect, so that the discharge circuit is disconnected.

[0146] Among them, the absence of a device wake-up signal is the first condition for the discharge circuit to be disconnected, the presence of a battery fault alarm is the second condition for the discharge circuit to be disconnected, and the battery SOC is less than or equal to the seventh threshold value is the third condition for the discharge circuit to be disconnected.

[0147] If there is no device wake-up signal, it means that the vehicle has not started. At this time, the lithium battery does not need to power the electrical equipment, and the first condition is not met, so there is no need to control the discharge circuit to be turned on.

[0148] If the battery has a fault alarm, the battery cannot be discharged, otherwise it may cause safety problems. At this time, the second condition is met and the discharge circuit needs to be disconnected to avoid safety problems.

[0149] When electrical equipment is working for a long time, if it is continuously powered by a lithium battery, it may cause the lithium battery to over-discharge. Over-discharge will increase the internal pressure of the lithium battery, destroy the reversibility of the positive and negative active materials, and significantly reduce the capacity. Therefore, a seventh threshold can be set. If the battery SOC is less than or equal to the seventh threshold, it means that the battery is not suitable for discharge. At this time, the first and third conditions are met, and the discharge circuit needs to be disconnected to avoid over-discharge of the lithium battery caused by the continuous use of the lithium battery to power the electrical equipment. The seventh threshold can be set according to the discharge cut-off SOC value of the lithium battery. For example, the seventh threshold is set to 15%.

[0150] The first, second, and third conditions are sufficient to determine whether the discharge circuit needs to be disconnected after the discharge circuit of the battery is turned on. Therefore, when any of the above conditions is met in S1002, the second switch unit in the discharge circuit can be controlled to be disconnected, thereby disconnecting the discharge circuit.

[0151] A sixth instruction may be sent to the second switch unit in the discharge circuit via the BMU interface on the BMS, thereby controlling the second switch unit in the discharge circuit to be disconnected, thereby disconnecting the discharge circuit. The sixth instruction may be a high or low level signal.

[0152] It is understood that, in some embodiments, the circuit control method may further include: Figure 9 Steps in the illustrated embodiment.

[0153] In the above embodiment, by judging whether there is no device wake-up signal, whether there is a battery fault alarm, or whether the battery SOC is less than or equal to the seventh threshold, when there is no device wake-up signal, or there is a battery fault alarm, or the battery SOC is less than or equal to the seventh threshold, the discharge circuit is controlled to be disconnected to avoid over-discharge of the lithium battery and safety problems.

[0154] Combined with the above Figures 1 to 10 The circuit control method of the embodiment of the present application is described below. Figure 11 The battery controller of the embodiment of the present application is described. For parts not described in detail, please refer to the aforementioned embodiments. Figure 11 is a schematic diagram of the structure of the battery controller provided by some embodiments of the present application, such as Figure 11 As shown, the battery controller 1100 includes: one or more processors 1101, working individually or collectively, and the processor 1101 is used to execute the steps of the circuit control method in the above embodiment.

[0155] The following will be combined Figure 12 The battery management system of the embodiment of the present application is described. For parts not described in detail, reference can be made to the aforementioned embodiments. Figure 12 is a schematic diagram of the structure of the battery management system provided by some embodiments of the present application, such as Figure 12 As shown, the battery management system 1200 includes: at least one processor 1201; and a memory 1202 communicatively connected to the at least one processor 1201; wherein the memory 1202 stores instructions that can be executed by the at least one processor 1201, and the instructions are executed by the at least one processor 1201 to enable the at least one processor 1201 to implement the steps of the circuit control method in the above embodiment.

[0156] The following will be combined Figure 13 The battery of the embodiment of the present application is described. For parts not described in detail, reference can be made to the aforementioned embodiments. Figure 13 is a schematic diagram of the structure of the battery provided by some embodiments of the present application, such as Figure 13 As shown, the battery 1300 includes Figure 11 The battery controller 1100 is shown.

[0157] The following will be combined Figure 14 The battery of the embodiment of the present application is described. For parts not described in detail, reference can be made to the aforementioned embodiments. Figure 14 is a schematic diagram of the structure of the battery provided by some embodiments of the present application, such as Figure 14 As shown, the battery 1400 includes Figure 12 The battery management system 1200 is shown.

[0158] The following will be combined Figure 15 The electrical device of the embodiment of the present application is described. For parts not described in detail, reference can be made to the aforementioned embodiments. Figure 15 is a schematic diagram of the structure of the electrical device provided in some embodiments of the present application, such as Figure 15 As shown, the electric device 1500 includes the battery 1300 or the battery 1400 of the above embodiment.

[0159] The following will be combined Figure 16 The vehicle of the embodiment of the present application is described, and parts not described in detail can be referred to the aforementioned embodiments. Figure 16 is a schematic diagram of the structure of a vehicle provided by some embodiments of the present application, such as Figure 16 As shown, the vehicle 1600 includes a lithium battery 1601, a generator 1602, and a vehicle wake-up switch 1603; wherein the lithium battery 1601 and the generator 1602 are connected to form a charging circuit, and the lithium battery 1601 includes a battery management system 1604, and the battery management system 1604 is used to:

[0160] Get vehicle wake-up signal;

[0161] Determining whether a power supply terminal voltage of a charging circuit of a lithium battery on the vehicle is greater than a first threshold and whether a rate of change within a first time period is less than a second threshold, wherein the charging circuit is a circuit connecting the lithium battery on the vehicle and a generator, and the power supply terminal voltage is the output voltage of the generator;

[0162] When the power terminal voltage of the charging circuit of the battery on the vehicle is greater than a first threshold and the rate of change within a first time period is less than a second threshold, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A circuit control method, characterized in that: include: Obtaining a device wake-up signal from the power-consuming device; determining whether a power supply terminal voltage of a charging circuit of a battery on the electrical device is greater than a first threshold and whether a rate of change within a first time period is less than a second threshold, wherein the charging circuit is a circuit connecting the battery on the electrical device and a generator, and the power supply terminal voltage is the output voltage of the generator; When the power supply terminal voltage of the charging circuit of the battery on the electrical device is greater than a first threshold and the rate of change within a first time period is less than a second threshold, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

2. The method according to claim 1, wherein The method further comprises: Determining whether the state of charge (SOC) of the battery is greater than a third threshold, whether a fault alarm has occurred in the battery, and whether a cell temperature of the battery is within a first range; The step of issuing a first instruction when the voltage at the power supply terminal of the charging circuit of the battery on the electrical device is greater than a first threshold and the rate of change within a first time period is less than a second threshold further includes: A first instruction is issued when the power supply terminal voltage of the charging circuit of the battery on the electrical device is greater than a first threshold, the rate of change within a first time period is less than a second threshold, the SOC of the battery is greater than a third threshold, there is no fault alarm of the battery, and the battery cell temperature of the battery is within a first range.

3. The method according to claim 1 or 2, wherein: The method further comprises: After the charging circuit of the battery is turned on, determining whether a rate of change of the charging current of the battery within a second time period is greater than a fourth threshold, or whether a voltage of a battery cell in the battery is greater than or equal to a fifth threshold, or whether a fault alarm is issued for the battery, or whether a temperature of the battery cell is not within a first range; When the rate of change of the charging current of the battery within the second time period is greater than a fourth threshold, or the voltage of a battery cell in the battery is greater than or equal to a fifth threshold, or there is a fault alarm in the battery, or the temperature of the battery cell is not within the first range, a second instruction is issued, and the second instruction is used to control the first switch unit in the charging circuit to disconnect, so that the charging circuit is disconnected.

4. The method according to claim 1, wherein The method further comprises: Determining whether a device wake-up signal exists and whether the power supply terminal voltage is less than a sixth threshold; When there is a device wake-up signal and the power supply terminal voltage is less than a sixth threshold, a third instruction is issued, and the third instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on and the charging circuit is in a first conduction state.

5. The method according to claim 4, wherein The method further comprises: Determining whether the SOC of the battery is greater than a seventh threshold and whether there is a fault alarm for the battery; The issuing of a third instruction when a device wake-up signal is present and the power supply terminal voltage is less than a sixth threshold further includes: In the case where there is a device wake-up signal, the power supply terminal voltage is less than a sixth threshold, the SOC of the battery is greater than a seventh threshold, and there is no fault alarm of the battery, a third instruction is issued.

6. The method according to claim 5, wherein The method further comprises: In the first conduction state, determining whether the conduction time of the charging circuit is greater than an eighth threshold; If the conduction time of the charging circuit is greater than an eighth threshold, a fourth instruction is issued, where the fourth instruction is used to control the first switch unit in the charging circuit to be disconnected, so that the charging circuit is disconnected.

7. The method according to claim 1, wherein The method further comprises: determining whether the SOC of the battery is greater than a seventh threshold; If the SOC of the battery is greater than the seventh threshold, a fifth instruction is issued, and the fifth instruction is used to control the second switch unit in the discharge circuit of the battery to close, so that the discharge circuit is turned on. The discharge circuit is a circuit connecting the battery on the electrical device and the electrical equipment.

8. The method according to claim 7, wherein The method further comprises: After the discharge circuit of the battery is turned on, determining whether there is a device wake-up signal, or whether there is a battery fault alarm, or whether the SOC of the battery is less than or equal to a seventh threshold; When there is a device wake-up signal, or there is a fault alarm in the battery, or the SOC of the battery is less than or equal to the seventh threshold, a sixth instruction is issued, and the sixth instruction is used to control the second switching unit in the discharge circuit to disconnect, so that the discharge circuit is disconnected.

9. A battery controller, characterized in that: include: One or more processors, working individually or collectively, are configured to execute the steps of the circuit control method according to any one of claims 1 to 8.

10. A battery management system, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to implement the steps of the circuit control method according to any one of claims 1 to 8.

11. A battery, characterized in that: include: The battery controller according to claim 9 or the battery management system according to claim 10.

12. An electrical device, characterized in that: The battery of claim 11 is used to provide electrical energy.

13. A vehicle, characterized in that: The vehicle comprises a lithium battery, a generator, and a vehicle wake-up switch; wherein the lithium battery and the generator are connected to form a charging circuit, and the lithium battery includes a battery management system, which is used to: Get vehicle wake-up signal; Determining whether a power supply terminal voltage of a charging circuit of a lithium battery on the vehicle is greater than a first threshold and whether a rate of change within a first time period is less than a second threshold, wherein the charging circuit is a circuit connecting the lithium battery on the vehicle and a generator, and the power supply terminal voltage is the output voltage of the generator; When the power terminal voltage of the charging circuit of the battery on the vehicle is greater than a first threshold and the rate of change within a first time period is less than a second threshold, a first instruction is issued, and the first instruction is used to control the first switch unit in the charging circuit to close, so that the charging circuit is turned on.

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