Intelligent charging method and device for low-voltage battery pack and electric vehicle

Abstract

The present invention provides a method and device for intelligently charging a low-voltage battery pack, and an electric vehicle. The method is used to intelligently charge the low-voltage battery pack based on an external power supply. The low-voltage battery pack includes a low-voltage battery circuit composed of a low-voltage battery, a battery management system, and a circuit on-off control unit provided on the low-voltage battery circuit. The method includes: determining whether the low-voltage battery needs to be charged. When charging is required, connecting the external power supply to the positive and negative poles of the low-voltage battery; determining whether the battery management system is in an awake state or a dormant state; when the battery management system is in a dormant state, waiting to be awakened; when the battery management system is in an awake state, determining whether the low-voltage battery pack meets the charging conditions; when the low-voltage battery pack meets the charging conditions, the circuit on-off control unit is turned on to charge the low-voltage battery. The present invention can charge a low-voltage battery when the low-voltage battery main output circuit is disconnected, and can also charge a separately placed low-voltage battery.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage battery pack power replenishment, and in particular to an intelligent power replenishment method and device for a low-voltage battery pack and an electric vehicle. Background Art

[0002] In the low-voltage battery field, to prevent battery depletion, the battery management system disconnects the main output circuit of the low-voltage battery to reduce external power consumption. At the same time, to reduce power consumption within the low-voltage battery management system, the low-voltage battery management system enters sleep mode. Therefore, if recharging is needed at this time, the low-voltage battery management system must first be awakened and then control the main output circuit of the low-voltage battery to recharge.

[0003] The existing invention patent CN1145863804A discloses a method and system for intelligently charging a 12V battery of a pure electric vehicle. It proposes that when the battery needs to be recharged, the entire vehicle system is awakened by the telematics processor Tbox, thereby achieving battery recharge. It has the following technical problems: when the low-voltage battery is powered off, other electronic control units (ECUs) of the vehicle are not powered, and recharging cannot be achieved; and when the low-voltage battery is placed externally, there is no environment of the entire vehicle and no other wake-up source, and recharging is also impossible. The existing invention patent CN112677766A discloses a method and system for intelligently charging an electric vehicle based on a BMS, and proposes a solution for recharging the low-voltage battery through a power battery (high-voltage battery). However, there are the following technical problems: when the main output circuit of the low-voltage battery is disconnected, the high-voltage battery cannot be powered on, and the low-voltage battery cannot be replenished by the high-voltage battery; and similarly, when the low-voltage battery is placed externally and there is no complete vehicle environment where both high-voltage and low-voltage batteries exist, the low-voltage battery cannot be replenished.

[0004] Therefore, there is an urgent need to propose an intelligent charging method, device and electric vehicle for a low-voltage battery pack to solve the technical problems in the prior art that when the main output circuit of the low-voltage battery is disconnected, the low-voltage battery cannot be charged, and the low-voltage battery placed alone without a complete vehicle environment cannot be charged. Summary of the Invention

[0005] In view of this, it is necessary to provide an intelligent charging method, device and electric vehicle for a low-voltage battery pack to solve the technical problems in the prior art that when the main output circuit of the low-voltage battery is disconnected, the low-voltage battery cannot be charged, and the low-voltage battery placed alone without a complete vehicle environment cannot be charged.

[0006] In one aspect, the present invention provides an intelligent charging method for a low-voltage battery pack, which is used to intelligently charge a low-voltage battery pack based on an external power supply. The low-voltage battery pack includes a low-voltage battery circuit composed of a low-voltage battery, a battery management system, and a circuit on / off control unit provided on the low-voltage battery circuit. The intelligent charging method for the low-voltage battery pack includes:

[0007] Determine whether the low-voltage battery needs to be recharged, and when the low-voltage battery needs to be recharged, connect the external power supply to the positive and negative electrodes of the low-voltage battery;

[0008] Determining whether the battery management system is in an awake state or a dormant state;

[0009] When the battery management system is in a dormant state, waiting to be awakened; when the battery management system is in an awakened state, determining whether the low-voltage battery pack meets the recharging condition;

[0010] When the low-voltage battery pack meets the charging condition, the battery management system controls the circuit on-off control unit to be turned on to charge the low-voltage battery.

[0011] In some possible implementations, when the battery management system is in a dormant state, waiting to be awakened includes:

[0012] When the battery management system is in a dormant state, obtaining a preset timer wake-up time and the time the battery management system is in the dormant state;

[0013] Determine whether the battery management system has been in a dormant state for a period of time that reaches the preset timed wake-up time;

[0014] When the time for which the battery management system is in the dormant state reaches the preset timed awakening time, the battery management system is automatically awakened.

[0015] In some possible implementations, the low-voltage battery includes multiple strings of single cells; and the recharging conditions include:

[0016] The cell voltage of each cell in the plurality of strings of cells is greater than a preset cell voltage;

[0017] The outer voltage of the circuit on-off control unit is greater than the inner voltage of the circuit on-off control unit;

[0018] The external voltage of the loop on-off control unit is within a preset voltage range.

[0019] In some possible implementations, the circuit on-off control unit is a relay or a MOS tube.

[0020] In some possible implementations, when the charging condition is met, the battery management system controls the circuit on / off control unit to be turned on to charge the low-voltage battery, and further includes:

[0021] Determining whether the low-voltage battery meets the conditions for stopping charging;

[0022] When the low-voltage battery meets the condition for stopping charging, the battery management system controls the circuit on-off control unit to be disconnected, and stops charging the low-voltage battery.

[0023] In some possible implementations, the condition for stopping the power replenishment includes:

[0024] The maximum cell voltage in the plurality of strings of single cells is greater than a cell voltage threshold;

[0025] or,

[0026] The remaining power of the low-voltage battery reaches 100%.

[0027] In some possible implementations, the preset cell voltage is 1.5V, the preset voltage range is 12V-15V, and the cell voltage threshold is 3.65V.

[0028] In some possible implementations, determining whether the low-voltage battery needs to be recharged includes:

[0029] Obtaining the remaining power of the low-voltage battery and determining whether the remaining power is less than a preset power;

[0030] When the remaining power is less than the preset power, the low-voltage battery needs to be recharged; when the remaining power is greater than or equal to the preset power, the low-voltage battery does not need to be recharged.

[0031] On the other hand, the present invention also provides an intelligent charging device for a low-voltage battery pack, which is used to intelligently charge the low-voltage battery pack based on an external power supply. The low-voltage battery pack includes a low-voltage battery circuit composed of a low-voltage battery and a battery management system, and a circuit on-off control unit provided on the low-voltage battery circuit; the intelligent charging device for the low-voltage battery pack includes:

[0032] a power replenishment judgment unit, configured to judge whether the low-voltage battery needs to be replenished, and when the low-voltage battery needs to be replenished, connect the external power supply to the positive and negative electrodes of the low-voltage battery;

[0033] A state determination unit, configured to determine whether the battery management system is in an awake state or a dormant state;

[0034] A recharging condition judgment unit, configured to wait for awakening when the battery management system is in a dormant state; and to judge whether the low-voltage battery pack meets the recharging condition when the battery management system is in an awakened state;

[0035] The charging unit is used to control the circuit on-off control unit to be turned on by the battery management system when the low-voltage battery pack meets the charging conditions, so as to charge the low-voltage battery.

[0036] On the other hand, the present invention also provides an electric vehicle, comprising a memory and a processor, wherein:

[0037] The memory is used to store computer programs;

[0038] The processor is coupled to the memory and is used to execute a computer program to implement the steps in the intelligent power replenishment method for a low-voltage battery pack described in any one of the possible implementations above.

[0039] The beneficial effect of adopting the above embodiment is: the intelligent power charging method for the low-voltage battery pack provided by the present invention can control the circuit on-off control unit to be turned on when the low-voltage battery pack meets the power charging conditions, that is: when the low-voltage battery pack meets the power charging conditions, no external wake-up source is required, and the low-voltage battery main output circuit is controlled to be closed, thereby achieving the technical effect of charging the low-voltage battery even when the low-voltage battery main output circuit is disconnected.

[0040] Furthermore, the intelligent charging method for the low-voltage battery pack provided by the present invention can charge the low-voltage battery only by monitoring and controlling the low-voltage battery, battery management system, and circuit on-off control unit in the low-voltage battery pack itself. It does not require a complete vehicle environment and can charge low-voltage batteries that are placed separately without a complete vehicle environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A schematic structural diagram of an embodiment of a low-voltage battery pack provided by the present invention;

[0043] Figure 2 A schematic flow chart of an embodiment of the intelligent charging method for a low-voltage battery pack provided by the present invention;

[0044] Figure 3 For the present invention Figure 2A flowchart of an embodiment of waiting for wake-up in S203;

[0045] Figure 4 A schematic diagram of a flow chart of an embodiment of stopping charging a low-voltage battery provided by the present invention;

[0046] Figure 5 For the present invention Figure 2 A schematic flow chart of an embodiment of S201;

[0047] Figure 6 A schematic structural diagram of an embodiment of an intelligent charging device for a low-voltage battery pack provided by the present invention;

[0048] Figure 7 This is a schematic structural diagram of an embodiment of an electric vehicle provided by the present invention. DETAILED DESCRIPTION

[0049] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] It should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present invention illustrate operations implemented according to some embodiments of the present invention. It should be understood that the operations in the flowcharts may be implemented out of sequence, and steps that do not have a logical contextual relationship may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the present disclosure, may add one or more additional operations to the flowcharts or remove one or more operations from the flowcharts.

[0051] Some of the blocks shown in the accompanying drawings are functional entities that do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0052] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute a separate 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 herein may be combined with other embodiments.

[0053] The embodiments of the present invention provide a method and device for intelligently charging a low-voltage battery pack, and an electric vehicle, which are described below.

[0054] Figure 1 A schematic structural diagram of an embodiment of a low-voltage battery pack provided by the present invention is shown in FIG. Figure 1 As shown, the low-voltage battery pack 10 is recharged by an external power supply 20. The low-voltage battery pack 10 includes a low-voltage battery circuit composed of a low-voltage battery 11, a battery management system 12, and a circuit on-off control unit 13 arranged on the low-voltage battery circuit.

[0055] Figure 2 A flow chart of an embodiment of the intelligent charging method for a low-voltage battery pack provided by the present invention is shown as follows: Figure 2 As shown in the figure, the intelligent charging method for low-voltage battery packs includes:

[0056] S201, determining whether the low-voltage battery 11 needs to be recharged. If the low-voltage battery 11 needs to be recharged, connecting the external power supply 20 to the positive and negative electrodes of the low-voltage battery 11;

[0057] S202, determining whether the battery management system 12 is in an awake state or a dormant state;

[0058] S203, when the battery management system 12 is in a dormant state, waiting to be awakened; when the battery management system 12 is in an awakened state, determining whether the low-voltage battery pack 10 meets the recharging condition;

[0059] S204 , when the low-voltage battery pack 10 meets the charging condition, the battery management system 12 controls the circuit on-off control unit 13 to be turned on, and charges the low-voltage battery 11 .

[0060] Compared with the prior art, the intelligent charging method for a low-voltage battery pack provided in an embodiment of the present invention can control the circuit on-off control unit 13 to be turned on when the low-voltage battery pack 10 meets the charging conditions. That is, when the low-voltage battery pack 10 meets the charging conditions, no external wake-up source is required, and the low-voltage battery main output circuit is controlled to be closed, thereby achieving the technical effect of charging the low-voltage battery 11 even when the low-voltage battery main output circuit is disconnected.

[0061] Furthermore, the intelligent charging method for the low-voltage battery pack provided by the present invention can charge the low-voltage battery 11 only by monitoring and controlling the low-voltage battery 11, the battery management system 12, and the circuit on-off control unit 13 in the low-voltage battery pack 10. It does not require a complete vehicle environment and can charge a low-voltage battery 11 that is placed separately without a complete vehicle environment.

[0062] In some embodiments of the present invention, Figure 3As shown, when the battery management system 12 is in a dormant state in step S203, waiting for awakening specifically includes:

[0063] S301, when the battery management system 12 is in a dormant state, obtaining a preset timer wake-up time and the time the battery management system 12 is in the dormant state;

[0064] S302, determining whether the battery management system 12 has been in a dormant state for a predetermined time to wake up;

[0065] S303 : When the time the battery management system 12 has been in the dormant state reaches the preset timer wake-up time, the battery management system 12 is automatically woken up.

[0066] The embodiment of the present invention can realize automatic awakening of the battery management system 12 based on the preset timer awakening time without the need for an external awakening source, thereby further ensuring the charging reliability of the low-voltage battery pack 10 in the absence of a complete vehicle environment.

[0067] It should be understood that the preset timer wake-up time can be set according to actual application scenarios or empirical values. In a specific embodiment of the present invention, the preset timer wake-up time is 8 minutes. That is, when the battery management system 12 is in the dormant state for 8 minutes, the battery management system 12 will be automatically awakened.

[0068] In some embodiments of the present invention, the low-voltage battery 11 includes multiple strings of single cells, and the charging conditions include:

[0069] Recharge condition 1: The cell voltage of each cell in a string of cells is greater than the preset cell voltage;

[0070] Second power supply condition: the voltage outside the circuit on-off control unit 13 is greater than the voltage inside the circuit on-off control unit 13;

[0071] Power replenishment condition three: the external voltage of the circuit on-off control unit 13 is within a preset voltage range.

[0072] When the cell voltage of a single cell is lower than the preset cell voltage, it indicates that the low-voltage battery 11 is damaged. Therefore, by setting the charging condition 1, ineffective charging of the damaged low-voltage battery 11 can be avoided, thereby improving the rationality of charging.

[0073] Furthermore, since the external power supply 20 is connected only when the external voltage of the circuit on-off control unit 13 is greater than the internal voltage of the circuit on-off control unit 13, the reliability of the power replenishment process can be improved by setting the second power replenishment condition.

[0074] Furthermore, the embodiment of the present invention can improve the charging effect and charging safety during the charging process of the low-voltage battery 11 by setting the charging condition three.

[0075] It should be noted that: Figure 1 As shown, the external voltage of the circuit on-off control unit 13 is Figure 1 The voltage at position A in the middle, the inner voltage of the circuit on-off control unit 13 is Figure 1 The voltage at position B in the diagram.

[0076] It should also be noted that the preset single cell voltage and the preset voltage range can be set or adjusted according to the actual application scenario. In some embodiments of the present invention, the preset single cell voltage is 1.5V and the preset voltage range is 12V-15V.

[0077] In some embodiments of the present invention, the circuit on / off control unit 13 may be a relay or a MOS tube.

[0078] In order to avoid overcharging the low-voltage battery 11, Figure 4 As shown, after step S204, the following steps are further included:

[0079] S401, determine whether the low-voltage battery 11 meets the conditions for stopping charging;

[0080] S402 : When the low-voltage battery 11 meets the condition for stopping charging, the battery management system 12 controls the circuit on-off control unit 13 to be disconnected, and stops charging the low-voltage battery 11 .

[0081] In the embodiment of the present invention, when the low-voltage battery 11 meets the conditions for stopping charging, the control circuit on-off control unit 13 is disconnected to stop charging the low-voltage battery 11, thereby avoiding overcharging the low-voltage battery 11 and further improving the safety of the low-voltage battery 11 during the charging process.

[0082] In some embodiments of the present invention, the condition for stopping the power replenishment is:

[0083] The maximum cell voltage in a string of cells is greater than the cell voltage threshold;

[0084] or,

[0085] The remaining power of the low-voltage battery 11 reaches 100%.

[0086] When the maximum single cell voltage is greater than the single cell voltage threshold or the remaining power of the low-voltage battery 11 reaches 100%, it means that the low-voltage battery 11 is full or fully charged and cannot be charged anymore. Therefore, by setting the above two conditions for stopping charging, overcharging of the low-voltage battery 11 can be avoided, further improving the safety of the low-voltage battery 11 during the charging process.

[0087] It should be noted that the cell voltage threshold can be set or adjusted according to actual application scenarios. In a specific embodiment of the present invention, the cell voltage threshold is 3.65V.

[0088] In some embodiments of the present invention, Figure 5 As shown, step S201 includes:

[0089] S501, obtaining the remaining power of the low-voltage battery 11, and determining whether the remaining power is less than a preset power;

[0090] S502 : When the remaining power is less than the preset power, the low-voltage battery 11 needs to be recharged. When the remaining power is greater than or equal to the preset power, the low-voltage battery 11 does not need to be recharged.

[0091] The embodiment of the present invention determines whether the low-voltage battery 11 needs to be recharged based on the remaining power of the low-voltage battery 11, and can recharge the low-voltage battery 11 only when it is low on power, avoiding redundant recharge of the low-voltage battery 11 when the low-voltage battery 11 is not low on power, thereby improving the rationality of the recharge timing.

[0092] In order to better implement the intelligent charging method of the low-voltage battery pack in the embodiment of the present invention, based on the intelligent charging method of the low-voltage battery pack, the embodiment of the present invention also provides an intelligent charging device for a low-voltage battery pack, which is used to intelligently charge the low-voltage battery pack based on an external power supply. The low-voltage battery pack includes a low-voltage battery circuit composed of a low-voltage battery and a battery management system, and a circuit on-off control unit provided on the low-voltage battery circuit; Figure 6 As shown, the intelligent charging device 600 for the low-voltage battery pack includes:

[0093] The power replenishment judgment unit 601 is used to judge whether the low-voltage battery needs to be replenished. When the low-voltage battery needs to be replenished, the external power supply is connected to the positive and negative electrodes of the low-voltage battery;

[0094] A state determination unit 602 is used to determine whether the battery management system is in an awake state or a dormant state;

[0095] The recharging condition judgment unit 603 is used to wait for awakening when the battery management system is in a dormant state; when the battery management system is in an awake state, judge whether the low-voltage battery pack meets the recharging condition;

[0096] The charging unit 604 is used to control the battery management system to control the circuit on-off control unit to conduct when the low-voltage battery pack meets the charging conditions, so as to charge the low-voltage battery.

[0097] The intelligent charging device 600 for a low-voltage battery pack provided in the above embodiment can implement the technical solution described in the above embodiment of the intelligent charging method for a low-voltage battery pack. The specific implementation principles of the above modules or units can be found in the corresponding contents in the above embodiment of the intelligent charging method for a low-voltage battery pack, which will not be repeated here.

[0098] like Figure 7 As shown, the present invention also provides an electric vehicle 700. The electric vehicle 700 includes a processor 701, a memory 702 and a display 703. Figure 7 Only some of the components of the electric vehicle 700 are shown, but it should be understood that implementation of all of the shown components is not required, and more or fewer components may be implemented instead.

[0099] In some embodiments, the memory 702 may be an internal storage unit of the electric vehicle 700, such as a hard disk or memory of the electric vehicle 700. In other embodiments, the memory 702 may also be an external storage device of the electric vehicle 700, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electric vehicle 700.

[0100] In some embodiments, the processor 701 can be a central processing unit (CPU), a microprocessor, or other data processing chip, used to run program codes or process data stored in the memory 702, such as the intelligent charging program of the low-voltage battery pack in the present invention.

[0101] The display 703 is used to display information on the electric vehicle 700 and to display a visual user interface. The components 701-703 of the electric vehicle 700 communicate with each other via a system bus.

[0102] In one embodiment, when the processor 701 executes the intelligent charging program for the low-voltage battery pack in the memory 702 , the steps in step S201 to step S204 may be implemented.

[0103] It should be understood that, when the processor 701 executes the intelligent charging program for the low-voltage battery pack in the memory 702 , in addition to the above functions, it can also implement other functions. For details, please refer to the description of the corresponding method embodiment above.

[0104] Those skilled in the art will appreciate that all or part of the process steps of the above-described embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a magnetic disk, an optical disk, a read-only memory, or a random access memory.

[0105] The above is a detailed introduction to the intelligent charging method, device and electric vehicle for the low-voltage battery pack provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An intelligent charging method for a low-voltage battery pack, characterized in that: Used to intelligently recharge a low-voltage battery pack based on an external power supply, the low-voltage battery pack comprising a low-voltage battery, a battery management system, and a circuit on-off control unit provided on the low-voltage battery circuit; The intelligent charging method for the low-voltage battery pack includes: Determine whether the low-voltage battery needs to be recharged, and when the low-voltage battery needs to be recharged, connect the external power supply to the positive and negative electrodes of the low-voltage battery; Determining whether the battery management system is in an awake state or a dormant state; When the battery management system is in a dormant state, waiting to be awakened; when the battery management system is in an awakened state, determining whether the low-voltage battery pack meets the recharging condition; When the low-voltage battery pack meets the charging condition, the battery management system controls the circuit on-off control unit to be turned on to charge the low-voltage battery; When the battery management system is in a dormant state, waiting to be awakened includes: When the battery management system is in a dormant state, obtaining a preset timer wake-up time and the time the battery management system is in the dormant state; Determine whether the battery management system has been in a dormant state for a period of time that reaches the preset timed wake-up time; When the time for which the battery management system is in the dormant state reaches the preset timed awakening time, the battery management system is automatically awakened.

2. The intelligent charging method for a low-voltage battery pack according to claim 1, characterized in that: The low-voltage battery includes multiple strings of single cells; the charging conditions include: The cell voltage of each cell in the plurality of strings of cells is greater than a preset cell voltage; The outer voltage of the circuit on-off control unit is greater than the inner voltage of the circuit on-off control unit; The external voltage of the loop on-off control unit is within a preset voltage range.

3. The intelligent charging method for a low-voltage battery pack according to any one of claims 1-2, characterized in that: The circuit on-off control unit is a relay or a MOS tube.

4. The intelligent charging method for a low-voltage battery pack according to claim 2, characterized in that: When the charging condition is met, the battery management system controls the circuit on-off control unit to be turned on to charge the low-voltage battery, and further includes: Determining whether the low-voltage battery meets the conditions for stopping charging; When the low-voltage battery meets the condition for stopping charging, the battery management system controls the circuit on-off control unit to be disconnected, and stops charging the low-voltage battery.

5. The intelligent charging method for a low-voltage battery pack according to claim 4, characterized in that: The conditions for stopping the power replenishment include: The maximum cell voltage in the plurality of strings of single cells is greater than a cell voltage threshold; or, The remaining power of the low-voltage battery reaches 100%.

6. The intelligent charging method for a low-voltage battery pack according to claim 5, characterized in that: The preset cell voltage is 1.5V, the preset voltage range is 12V-15V, and the cell voltage threshold is 3.65V.

7. The intelligent charging method for a low-voltage battery pack according to claim 1, characterized in that: The determining whether the low-voltage battery needs to be recharged includes: Obtaining the remaining power of the low-voltage battery and determining whether the remaining power is less than a preset power; When the remaining power is less than the preset power, the low-voltage battery needs to be recharged; when the remaining power is greater than or equal to the preset power, the low-voltage battery does not need to be recharged.

8. An intelligent charging device for a low-voltage battery pack, characterized in that: Used to intelligently recharge a low-voltage battery pack based on an external power supply, the low-voltage battery pack comprising a low-voltage battery, a battery management system, and a circuit on-off control unit provided on the low-voltage battery circuit; The intelligent charging device of the low-voltage battery pack includes: a power replenishment judgment unit, configured to judge whether the low-voltage battery needs to be replenished, and when the low-voltage battery needs to be replenished, connect the external power supply to the positive and negative electrodes of the low-voltage battery; A state determination unit, configured to determine whether the battery management system is in an awake state or a dormant state; A recharging condition judgment unit, configured to wait for awakening when the battery management system is in a dormant state; and to judge whether the low-voltage battery pack meets the recharging condition when the battery management system is in an awakened state; A charging unit, configured to, when the low-voltage battery pack meets the charging condition, control the circuit on-off control unit to be turned on by the battery management system, so as to charge the low-voltage battery pack; When the battery management system is in a dormant state, waiting to be awakened includes: When the battery management system is in a dormant state, obtaining a preset timer wake-up time and the time the battery management system is in the dormant state; Determine whether the battery management system has been in a dormant state for a period of time that reaches the preset timed wake-up time; When the time for which the battery management system is in the dormant state reaches the preset timed awakening time, the battery management system is automatically awakened.

9. An electric vehicle, characterized in that: comprising a memory and a processor, wherein, The memory is used to store computer programs; The processor is coupled to the memory and is used to execute a computer program to implement the steps in the intelligent charging method for a low-voltage battery pack as described in any one of claims 1 to 7.

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