Charging device, method, electronic device and vehicle for battery pack

Abstract

The present disclosure relates to a charging device, method, electronic device and vehicle for a battery pack. The battery pack (10) includes a first battery pack (1) and a second battery pack (2) connected in series. The charging device (100) includes: a charging circuit (20) connected to the positive and negative electrodes of the battery pack and connected to the node between the first battery pack and the second battery pack; a charging system (200) connected to the first battery pack and the second battery pack through the charging circuit; and a controller (30) connected to the charging circuit and the charging system, respectively, for controlling the charging system and the charging circuit when determining that the first battery pack and the second battery pack are unbalanced during the charging process of the battery pack, so that the charging system charges one of the first battery pack and the second battery pack. In this way, the battery pack is balanced during the charging process, avoiding the situation where the entire battery pack is prematurely charged due to the imbalance of the battery pack, and some battery packs are not fully charged.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle charging, and in particular, to a charging device, method, electronic device and vehicle for a battery pack. Background Art

[0002] The battery pack may include multiple interconnected battery groups. During the use of the vehicle-mounted battery pack, due to factors such as control deviation and actual system deviation, the remaining capacity of each battery group may be uneven, which may easily lead to the premature charging termination of the entire battery pack, while some battery groups are not fully charged. Summary of the invention

[0003] An object of the present disclosure is to provide a charging device, method, electronic device and vehicle for a battery pack, which can balance the battery pack during the charging process.

[0004] In order to achieve the above-mentioned object, the present disclosure provides a charging device for a battery pack, wherein the battery pack includes a first battery group and a second battery group connected in series, and the charging device includes a charging circuit and a controller. The charging circuit is connected to the positive and negative electrodes of the battery pack, and is connected to the node between the first battery group and the second battery group, and the charging system is connected to the first battery group and the second battery group respectively through the charging circuit. The controller is connected to the charging circuit and the charging system respectively, and the controller is used to control the charging system and the charging circuit when it is determined that the first battery group and the second battery group are unbalanced during the charging process of the battery pack, so that the charging system charges one of the first battery group and the second battery group.

[0005] Optionally, the charging circuit includes a first switch, a second switch, a third switch and a transmission module;

[0006] The positive electrode of the first battery group is connected to the negative electrode of the second battery group, the positive electrode of the second battery group is connected to the first end of the transmission module through the second switch, the negative electrode of the first battery group is connected to the second end of the transmission module through the first switch, and the node between the first battery group and the second battery group is connected to the third end of the transmission module through the third switch;

[0007] The transmission module is used for transmitting or reducing the voltage output by the charging system to one of the first battery pack and the second battery pack.

[0008] Optionally, the transmission module includes a first switch tube, a second switch tube and an inductor;

[0009] The first switch tube and the second switch tube are connected to form a phase bridge arm, the first end of the phase bridge arm serves as the first end of the transmission module, the second end of the phase bridge arm serves as the second end of the transmission module, the midpoint of the phase bridge arm is connected to one end of the inductor, and the other end of the inductor serves as the third end of the transmission module.

[0010] Optionally, the transmission module includes a three-phase bridge arm sharing a first bus terminal and a second bus terminal and three inductors;

[0011] The first bus terminal serves as the first end of the transmission module, the second bus terminal serves as the second end of the transmission module, the midpoint of the three-phase bridge arm is connected to one end of the three inductors one by one, and the other ends of the three inductors serve as the third end of the transmission module.

[0012] Optionally, the three-phase bridge arm reuses the bridge arm in the motor controller, and the three inductors reuse the inductors in the motor.

[0013] Optionally, the transmission module further includes a capacitor, and two ends of the capacitor are respectively connected to a first end of the transmission module and a second end of the transmission module.

[0014] The present disclosure also provides a charging method for a battery pack, the battery pack comprising a first battery group and a second battery group connected in series, the method comprising:

[0015] During the battery pack charging process, when it is determined that the first battery group and the second battery group are unbalanced, controlling the charging system and the charging circuit so that the charging system charges one of the first battery group and the second battery group;

[0016] The charging circuit is connected to the positive and negative electrodes of the battery pack and to the node between the first battery pack and the second battery pack. The charging system is connected to the first battery pack and the second battery pack respectively through the charging circuit.

[0017] Optionally, controlling the charging system and the charging circuit so that the charging system charges one of the first battery group and the second battery group includes: when one of the first battery group and the second battery group reaches a charging cut-off voltage, controlling the charging system and the charging circuit so that the charging system charges the other of the first battery group and the second battery group until the other reaches a charging cut-off voltage.

[0018] Optionally, the charging circuit includes a first switch, a second switch, a third switch and a transmission module;

[0019] The positive electrode of the first battery group is connected to the negative electrode of the second battery group, the positive electrode of the second battery group is connected to the first end of the transmission module through the second switch, the negative electrode of the first battery group is connected to the second end of the transmission module through the first switch, and the node between the first battery group and the second battery group is connected to the third end of the transmission module through the third switch;

[0020] Controlling a charging system and a charging circuit so that the charging system charges the other of the first battery pack and the second battery pack until the other reaches a charging cut-off voltage, including: controlling the charging system, a first switch, a second switch, a third switch and a transmission module so that the voltage output by the charging system is transmitted or stepped down and transmitted to the other of the first battery pack and the second battery pack.

[0021] Optionally, the transmission module includes a first switch tube, a second switch tube and an inductor;

[0022] The first switch tube and the second switch tube are connected to form a phase bridge arm, the first end of the phase bridge arm serves as the first end of the transmission module, the second end of the phase bridge arm serves as the second end of the transmission module, the midpoint of the phase bridge arm is connected to one end of the inductor, and the other end of the inductor serves as the third end of the transmission module;

[0023] Controlling the charging system, the first switch, the second switch, the third switch and the transmission module so that the voltage output by the charging system is transmitted or stepped down and transmitted to the other of the first battery pack and the second battery pack, including:

[0024] When only the second battery pack reaches the charging cut-off voltage, requesting the charging system to output a charging current that is less than a current threshold;

[0025] Keep the first switch and the second switch closed, and control the third switch to close;

[0026] Periodically controlling a phase bridge arm, in one cycle, controlling the first switch tube to be turned on and the second switch tube to be turned off, so that the first battery group and the second battery group charge the inductor; then controlling the second switch tube to be turned on and the first switch tube to be turned off, so that the inductor discharges to the first battery group;

[0027] When the duty cycle of the first switch tube or the second switch tube reaches the target duty cycle, the second switch is controlled to be disconnected, and the charging system is requested to output the first charging current until the first battery group reaches the charging cut-off voltage.

[0028] Optionally, controlling the charging system, the first switch, the second switch, the third switch and the transmission module so that the voltage output by the charging system is transmitted or stepped down and transmitted to the other of the first battery pack and the second battery pack includes:

[0029] When only the first battery pack reaches the charging cut-off voltage, requesting the charging system to output a charging current that is less than a current threshold;

[0030] Keep the first switch and the second switch closed, and control the third switch to close;

[0031] Periodically controlling a phase bridge arm, in one cycle, controlling the second switch tube to be turned on and the first switch tube to be turned off, so that the first battery group and the second battery group charge the inductor; then controlling the first switch tube to be turned on and the second switch tube to be turned off, so that the inductor discharges to the second battery group;

[0032] When the duty cycle of the first switch tube or the second switch tube reaches the target duty cycle, the first switch is controlled to be disconnected, and the charging system is requested to output a second charging current until the second battery pack reaches a charging cut-off voltage.

[0033] Optionally, controlling the charging system, the first switch, the second switch, the third switch and the transmission module so that the voltage output by the charging system is transmitted or stepped down and transmitted to the other of the first battery pack and the second battery pack includes:

[0034] When only the second battery pack reaches the charging cut-off voltage, requesting the charging system to output a charging current that is less than a current threshold;

[0035] Keep the first switch closed and control the second switch to open;

[0036] Requesting the charging voltage output by the charging system to be reduced to a first charging voltage;

[0037] The third switch is controlled to be closed, the first switch tube is turned on, and the second switch tube is turned off, and the charging system is requested to output a first charging current so that the charging system charges the first battery pack until the first battery pack reaches a charging cut-off voltage.

[0038] Optionally, controlling the charging system, the first switch, the second switch, the third switch and the transmission module so that the voltage output by the charging system is transmitted or stepped down and transmitted to the other of the first battery pack and the second battery pack includes:

[0039] When only the first battery pack reaches the charging cut-off voltage, requesting the charging system to output a charging current that is less than a current threshold;

[0040] Keep the second switch closed and control the first switch to open;

[0041] Requesting the charging voltage output by the charging system to be reduced to a second charging voltage;

[0042] The third switch is controlled to be closed, the second switch tube is turned on, and the first switch tube is turned off, and the charging system is requested to output a first charging current so that the charging system charges the second battery pack until the second battery pack reaches a charging cut-off voltage.

[0043] Optionally, the method further includes: when a difference between the remaining capacities of the first battery group and the second battery group is greater than a difference threshold, determining that the first battery group and the second battery group are unbalanced.

[0044] The present disclosure also provides an electronic device, the electronic device comprising a processor and a memory for storing instructions executable by the processor, wherein the processor is configured to execute the above-mentioned charging method for a battery pack provided by the present disclosure.

[0045] The present disclosure also provides a vehicle, which includes the above-mentioned charging device provided by the present disclosure or the above-mentioned electronic device provided by the present disclosure.

[0046] Through the above technical solution, during the battery pack charging process, if it is determined that the two battery packs connected in series are unbalanced, the charging system and the charging circuit are controlled to charge one of the battery packs to achieve balance. The charging circuit is connected to the positive and negative electrodes of the battery pack, and is also connected to the node between the first battery pack and the second battery pack. In this way, by controlling the circuit structure of the charging system and the charging circuit, the charging system can charge one of the two battery packs through the charging circuit, thereby achieving balance of the battery pack. In this way, it is avoided that the entire battery pack is prematurely charged due to the imbalance of the battery pack, and some battery packs are not fully charged.

[0047] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0049] Figure 1 is a structural block diagram of a charging device for a battery pack provided by an exemplary embodiment.

[0050] Figure 2 is a structural block diagram of a charging device for a battery pack provided by another exemplary embodiment.

[0051] Figure 3 1 is a circuit diagram of a charging device for a battery pack provided by an exemplary embodiment.

[0052] Figure 4 is a circuit diagram of a charging device for a battery pack provided by another exemplary embodiment.

[0053] Figure 5 yes Figure 4 Schematic diagram of the connection relationship between the charging device and the charging system.

[0054] Figure 6 is a flow chart of a charging method for a battery pack provided by an exemplary embodiment.

[0055] Figure 7 is a flow chart of a charging method for a battery pack provided by another exemplary embodiment.

[0056] Figure 8 is a flow chart of a charging method for a battery pack provided by yet another exemplary embodiment.

[0057] Description of Reference Numerals

[0058] 100. Charging device; 200. Charging system; 10. Battery pack;

[0059] 20. Charging circuit; 30. Controller; 1. First battery pack;

[0060] 2. Second battery pack; 21. Transmission module; K1. First switch;

[0061] K2, second switch; K3, third switch; a, first end of the transmission module;

[0062] b, the second end of the transmission module; c, the third end of the transmission module; T1, the first switch tube;

[0063] T2, the second switch tube; L, inductor; C1, capacitor;

[0064] L1, first inductor; L2, second inductor; L3, third inductor;

[0065] 201, vehicle-mounted AC charger; 202, DC charging port; K4, fourth switch;

[0066] K5, the fifth switch. DETAILED DESCRIPTION

[0067] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0068] Figure 1 FIG. 1 is a structural block diagram of a charging device for a battery pack provided by an exemplary embodiment. Figure 1 As shown, the battery pack 10 includes a first battery group 1 and a second battery group 2 connected in series. The charging device 100 includes a charging circuit 20 and a controller 30.

[0069] The charging circuit 20 is connected to the positive and negative electrodes of the battery pack 10 and to the node between the first battery group 1 and the second battery group 2 . The charging system 200 is connected to the first battery group 1 and the second battery group 2 respectively through the charging circuit 20 .

[0070] The controller 30 is connected to the charging circuit 20 and the charging system 200 respectively, and is used to control the charging system 200 and the charging circuit 20 when it is determined that the first battery group 1 and the second battery group 2 are unbalanced during the charging process of the battery pack 10, so that the charging system 200 charges one of the first battery group 1 and the second battery group 2.

[0071] The charging system 200 may include a DC charging pile for DC charging, and may also include an onboard charger (OBC) for AC charging.

[0072] The charging system 200 can charge the first battery pack 1 and the second battery pack 2 at the same time through the charging circuit 20, that is, charge the battery pack as a whole, or can charge the first battery pack 1 or the second battery pack 2 separately through the charging circuit 20 to balance the battery pack. The charging circuit 20 can be provided with switching devices, and the controller 30 controls these switching devices to realize the charging system 200 to realize a separate charging circuit for either the first battery pack 1 or the second battery pack 2. In addition, the controller 30 can match the charging parameters (current, voltage, electric power) of the charging system 200 and the battery pack to be charged by requesting the charging current or charging voltage of the charging system 200.

[0073] The controller 30 may be one or more controllers in the vehicle. For example, a battery manager and a motor controller may communicate to jointly complete the control method of the present solution.

[0074] Through the above technical solution, during the battery pack charging process, if it is determined that the two battery packs connected in series are unbalanced, the charging system and the charging circuit are controlled to charge one of the battery packs to achieve balance. The charging circuit is connected to the positive and negative electrodes of the battery pack, and is also connected to the node between the first battery pack and the second battery pack. In this way, by controlling the circuit structure of the charging system and the charging circuit, the charging system can charge one of the two battery packs through the charging circuit, thereby achieving balance of the battery pack. In this way, it is avoided that the entire battery pack is prematurely charged due to the imbalance of the battery pack, and some battery packs are not fully charged.

[0075] Figure 2 FIG. 1 is a structural block diagram of a charging device for a battery pack provided by another exemplary embodiment. Figure 2 As shown, the charging circuit 20 includes a first switch K1 , a second switch K2 , a third switch K3 and a transmission module 21 .

[0076] The positive electrode of the first battery group 1 is connected to the negative electrode of the second battery group 2, the positive electrode of the second battery group 2 is connected to the first end a of the transmission module 21 through the second switch K2, the negative electrode of the first battery group 1 is connected to the second end b of the transmission module 21 through the first switch K1, and the node between the first battery group 1 and the second battery group 2 is connected to the third end c of the transmission module 21 through the third switch K3.

[0077] The transmission module 21 is used to transmit or reduce the voltage output by the charging system 200 to one of the first battery pack 1 and the second battery pack 2 .

[0078] Figure 2 In the embodiment, the two ends of the charging system 200 are connected to the first end a of the transmission module 21 and the second end b of the transmission module 21 respectively. Figure 2(not shown) by controlling the on and off of the first switch K1, the second switch K2, and the third switch K3, the connection relationship between the positive and negative electrodes of the first battery group 1 and the second battery group 2 and the charging system 200 and the transmission module 21 is controlled.

[0079] The first switch K1 , the second switch K2 , and the third switch K3 may be contactors, relays, etc. The second switch K2 may be reused as the main positive relay of the battery pack 10 , and the first switch K1 may be reused as the main negative relay of the battery pack 10 .

[0080] Figure 3 FIG. 1 is a circuit diagram of a charging device for a battery pack provided by an exemplary embodiment. Figure 3 As shown, the transmission module 21 may include a first switch tube T1 , a second switch tube T2 and an inductor L.

[0081] The first switch tube T1 and the second switch tube T2 are connected to form a phase bridge arm. The first end of the phase bridge arm serves as the first end a of the transmission module 21, the second end of the phase bridge arm serves as the second end b of the transmission module 21, the midpoint of the phase bridge arm is connected to one end of the inductor L, and the other end of the inductor L serves as the third end c of the transmission module 21.

[0082] This article Figure 3 The embodiment of the present invention is taken as an example, and a control method of the controller 30 in the charging device 100, that is, a method of using the charging device 100, is described in detail.

[0083] During the process of charging the battery pack 10 as a whole by the charging device 100, the controller 30 can calculate the remaining capacity of the first battery group 1 and the second battery group 2 in real time. The amount of electricity charged in this charge can be calculated according to the ampere-hour integration method, and the remaining capacity can be calculated according to the rated capacity, the amount of electricity before charging and the amount of electricity charged in this charge. When the difference between the remaining capacity of the first battery group 1 and the second battery group 2 is greater than the difference threshold, it can be determined that the first battery group 1 and the second battery group 2 are unbalanced. The difference threshold can be determined in advance based on experiments and experience, or it can be determined in real time.

[0084] The method of comparing the difference threshold is used to determine whether the balance is achieved. The method is simple and has good accuracy.

[0085] Next, it is determined whether the triggering condition for balancing is met. One of the battery packs can reach the cut-off voltage as the triggering condition for balancing.

[0086] Specifically, when one of the first battery pack 1 and the second battery pack 2 reaches the charge cut-off voltage, the controller 30 can control the charging system 200 and the charging circuit 20 so that the charging system 200 charges the other of the first battery pack 1 and the second battery pack 2 until the other reaches the charge cut-off voltage.

[0087] That is, when one of the first battery pack 1 and the second battery pack 2 reaches the charging cut-off voltage, it is easy to trigger the charging system 200 to terminate prematurely in the related art, while the other one is not fully charged.

[0088] At this time, the controller 30 can control the charging circuit 20 to operate so that the charging system 200 only charges the battery packs that have not reached the charging cutoff. In addition, the controller 30 can request the charging system 200 to output a current and voltage that matches charging a group of battery packs alone to avoid overvoltage, overcurrent, etc. in the battery pack.

[0089] Charging the battery pack that has not reached the charging cut-off voltage separately can achieve a balancing effect. The separate charging can be performed until the battery pack reaches the charging cut-off voltage. In this way, both battery packs reach the charging cut-off voltage, and the balancing effect is good.

[0090] In one embodiment, the controller 30 can control the charging system 200, the first switch K1, the second switch K2, the third switch K3 and the transmission module 21 so that the voltage output by the charging system 200 is transmitted or stepped down to the other of the first battery pack 1 and the second battery pack 2.

[0091] That is, under different control strategies, the transmission module 21 can play different roles. The transmission module 21 can step down the voltage output by the charging system 200 and transmit it to the first battery pack 1 or the second battery pack 2 (the first control method below), or the transmission module 21 can directly transmit the voltage output by the charging system 200 to the first battery pack 1 or the second battery pack 2 (the second control method below).

[0092] In the first control method, two cases 1) and 2) are described below.

[0093] 1) When it is determined that only the second battery pack 2 has reached the charge cut-off voltage (the first battery pack 1 has not reached the charge cut-off voltage), the controller 30 performs the following control steps 1a to 1e:

[0094] 1a. Request the charging system 200 to output a charging current that is smaller than a current threshold.

[0095] A current threshold can be set so that when the charging current output by the charging system 200 is less than the current threshold, the second battery pack 2 that has reached the charging cut-off voltage in a short time will not be overcharged due to continued charging. The charging current output by the charging system 200 can also be directly requested to be zero.

[0096] 1b. Keep the first switch K1 and the second switch K2 closed, and control the third switch K3 to be closed.

[0097] When the battery pack 10 is being charged as a whole, the first switch K1 and the second switch K2 are closed, and the third switch K3 is opened. In step 1b, the third switch K3 may be controlled to be closed.

[0098] 1c. Periodically control the one-phase bridge arm. In one cycle, control the first switch tube T1 to be turned on and the second switch tube T2 to be turned off, so that the first battery group 1 and the second battery group 2 charge the inductor L; then control the second switch tube T2 to be turned on and the first switch tube T1 to be turned off, so that the inductor L discharges to the first battery group 1.

[0099] The transmission module 21 serves to reduce the voltage output by the charging system 200 .

[0100] Steps 1a to 1c are a first step-down mode step-down process.

[0101] 1d. When the duty cycle of the first switch tube T1 or the second switch tube T2 reaches the target duty cycle, the second switch K2 is controlled to be disconnected, and the charging system 200 is requested to output the first charging current (charging voltage remains unchanged) until the first battery pack 1 reaches the charging cut-off voltage.

[0102] When the duty cycle reaches the target duty cycle, it can be considered that the charging voltage output by the charging system 200 applied to the first battery pack 1 through the voltage reduction effect of the transmission module 21 will not cause overcurrent and overvoltage of the first battery pack 1. The charging system 200 is requested to output a first charging current, which should not be greater than the maximum allowable charging current of the first battery pack 1. The charging power output by the charging system 200 is requested to be less than the maximum allowable charging power of the first battery pack 1.

[0103] Step 1d is the first buck mode charging process.

[0104] 1e. When the first battery pack 1 reaches the charging cut-off voltage, the first switch tube T1 and the second switch tube T2 can be turned off, and the third switch K3 can be disconnected to end the charging process.

[0105] Step 1e is the first step-down mode exit process.

[0106] 2) When only the first battery pack 1 reaches the charge cut-off voltage (the second battery pack does not reach the charge cut-off voltage), the controller 30 performs the following control steps 2a to 2e:

[0107] 2a. Request the charging system 200 to output a charging current that is smaller than a current threshold.

[0108] A current threshold can be set so that when the charging current output by the charging system 200 is less than the current threshold, the first battery pack 1 that has reached the charging cut-off voltage in a short time will not be overcharged due to continued charging. The charging current output by the charging system 200 can also be directly requested to be zero.

[0109] 2b. Keep the first switch K1 and the second switch K2 closed, and control the third switch K3 to be closed.

[0110] 2c. Periodically control the one-phase bridge arm. In one cycle, control the second switch tube T2 to be turned on and the first switch tube T1 to be turned off, so that the first battery group 1 and the second battery group 2 charge the inductor L; then control the first switch tube T1 to be turned on and the second switch tube T2 to be turned off, so that the inductor L discharges to the second battery group 2.

[0111] The transmission module 21 serves to reduce the voltage output by the charging system 200 .

[0112] Steps 2a to 2c are the voltage reduction process in the second voltage reduction mode.

[0113] 2d. When the duty cycle of the first switch tube T1 or the second switch tube T2 reaches the target duty cycle, the first switch K1 is controlled to be disconnected, and the charging system 200 is requested to output a second charging current (with the charging voltage unchanged) until the second battery pack 2 reaches the charging cut-off voltage.

[0114] When the duty cycle reaches the target duty cycle, it can be considered that the charging voltage output by the charging system 200 applied to the second battery pack 2 through the voltage reduction effect of the transmission module 21 will not cause overcurrent and overvoltage of the second battery pack 2. The charging system 200 is requested to output a second charging current that should not be greater than the maximum allowable charging current of the second battery pack 2. The charging power output by the charging system 200 is requested to be less than the maximum allowable charging power of the second battery pack 2.

[0115] Step 2d is the second step-down mode charging process.

[0116] 2e. When the second battery pack 2 reaches the charging cut-off voltage, the first switch tube T1 and the second switch tube T2 can be turned off, and the third switch K3 can be disconnected to end the charging process.

[0117] Step 2e is the second step-down mode exit process.

[0118] In the second control method, two cases 3) and 4) are described below.

[0119] 3) When only the second battery pack 2 reaches the charge cut-off voltage (the first battery pack 1 does not reach the charge cut-off voltage), the controller 30 performs the following control steps 3a to 3e:

[0120] 3a. Request the charging system 200 to output a charging current that is smaller than a current threshold.

[0121] A current threshold can be set so that when the charging current output by the charging system 200 is less than the current threshold, the second battery pack 2 that has reached the charging cut-off voltage in a short time will not be overcharged due to continued charging. The charging current output by the charging system 200 can also be directly requested to be zero.

[0122] 3b. Keep the first switch K1 closed and control the second switch K2 to open.

[0123] When the battery pack 10 is being charged as a whole, the first switch K1 and the second switch K2 are closed, and the third switch K3 is opened. In step 3b, the second switch K2 may be controlled to be opened.

[0124] 3c. Request the charging system 200 to reduce the charging voltage output to the first charging voltage.

[0125] The first charging voltage may be determined according to the voltage of the first battery pack 1 , so that the first charging voltage does not exceed the voltage of the first battery pack 1 .

[0126] Steps 3a to 3c are the first charging mode jump process.

[0127] 3d. Control the third switch K3 to close, the first switch tube T1 to turn on, and the second switch tube T2 to turn off, and request the charging system 200 to output the first charging current, so that the charging system 200 charges the first battery pack 1 until the first battery pack 1 reaches the charging cut-off voltage.

[0128] At this time, the first switch tube T1 and the inductor L in the transmission module 21 play a role in connecting the charging system 200 and the first battery pack 1. The first charging current requested to be output by the charging system 200 can be determined according to the maximum allowable charging current of the first battery pack 1. For example, the first charging current requested to be output by the charging system 200 can be the maximum allowable charging current of the first battery pack 1.

[0129] Step 3d is the charging process of the first charging mode.

[0130] 3e. When the first battery pack 1 reaches the charging cut-off voltage, the first switch tube T1 and the second switch tube T2 can be turned off, and the third switch K3 can be disconnected to end the charging process.

[0131] Step 3e is the first charging mode exit process.

[0132] 4) When only the first battery pack 1 reaches the charge cut-off voltage (the second battery pack 2 does not reach the charge cut-off voltage), the controller 30 performs the following control steps 4a to 4e:

[0133] 4a. Request the charging system 200 to output a charging current that is smaller than a current threshold.

[0134] A current threshold can be set so that when the charging current output by the charging system 200 is less than the current threshold, the first battery pack 1 that has reached the charging cut-off voltage in a short time will not be overcharged due to continued charging. The charging current output by the charging system 200 can also be directly requested to be zero.

[0135] 4b. Keep the second switch K2 closed and control the first switch K1 to open.

[0136] When the battery pack 10 is being charged as a whole, the first switch K1 and the second switch K2 are closed, and the third switch K3 is opened. In step 4b, the first switch K1 may be controlled to be opened.

[0137] 4c. Request the charging system 200 to reduce the charging voltage output to the second charging voltage.

[0138] The second charging voltage may be determined according to the voltage of the second battery pack 2 , so that the second charging voltage does not exceed the voltage of the second battery pack 2 .

[0139] Steps 4a to 4c are the second charging mode jump process.

[0140] 4d. Control the third switch K3 to close, the second switch tube T2 to turn on, and the first switch tube T1 to turn off, and request the charging system 200 to output a second charging current so that the charging system 200 charges the second battery pack 2 until the second battery pack 2 reaches the charging cut-off voltage.

[0141] At this time, the second switch tube T2 and the inductor L in the transmission module 21 play a role in connecting the charging system 200 and the second battery pack 2. The second charging current requested to be output by the charging system 200 can be determined according to the maximum allowable charging current of the second battery pack 2. For example, the second charging current requested to be output by the charging system 200 can be the maximum allowable charging current of the second battery pack 2.

[0142] Step 4d is the charging process of the second charging mode.

[0143] 4e. When the second battery pack 2 reaches the charging cut-off voltage, the first switch tube T1 and the second switch tube T2 can be turned off, and the third switch K3 can be disconnected to end the charging process.

[0144] Step 4e is the second charging mode exit process.

[0145] Figure 4 FIG. 1 is a circuit diagram of a charging device for a battery pack provided by another exemplary embodiment. Figure 4 As shown, the transmission module 21 includes a three-phase bridge arm sharing a first bus terminal and a second bus terminal and three inductors (a first inductor L1 , a second inductor L2 , and a third inductor L3 ).

[0146] The first bus terminal serves as the first terminal a of the transmission module 21, the second bus terminal serves as the second terminal b of the transmission module 21, the midpoints of the three-phase bridge arms are connected to one end of the three inductors one by one, and the other ends of the three inductors serve as the third terminal c of the transmission module 21.

[0147] Figure 4 and Figure 3 The control principle of the two is similar, the difference between them is that Figure 3 There is only one bridge arm or inductor in the Figure 4 In addition to one path, two or three paths can be used to transmit current in parallel. When one path fails, the other path serves as a redundancy.

[0148] In another embodiment, the three-phase bridge arm can reuse the bridge arm in the motor controller, and the three inductors can reuse the inductors in the motor. Since the motor does not work when the battery pack is charging, reusing the motor controller and the devices in the motor can save space in the vehicle.

[0149] exist Figure 3 and Figure 4 In the embodiment of the present invention, the transmission module 21 may further include a capacitor C1, and two ends of the capacitor C1 are respectively connected to a first end a of the transmission module 21 and a second end b of the transmission module 21. The capacitor C1 may play a role in voltage stabilization.

[0150] Figure 5 yes Figure 4 Schematic diagram of the connection relationship between the charging device and the charging system. Figure 5 In the embodiment, the charging system 200 includes an on-board AC charger 201, a DC charging port 202, a fourth switch K4 and a fifth switch K5. The on-board AC charger 201 can be connected to an external AC power source, and is used to convert the AC power transmitted by the external AC power source into DC power and then charge the battery pack 10. The DC charging port 202 can be connected to a DC charging gun, and is used to charge the battery pack 10 after receiving the DC power transmitted by the DC charging pile. The two ends of the on-board AC charger 201 are respectively connected to the first end a of the transmission module 21 and the second end b of the transmission module 21. The first end a of the transmission module 21 is connected to the positive pole of the DC charging port 202 through the fourth switch K4, and the second end b of the transmission module 21 is connected to the negative pole of the DC charging port 202 through the fifth switch K5.

[0151] Based on the same inventive concept, the present disclosure also provides a charging method for a battery pack. Figure 6 FIG. 1 is a flow chart of a method for charging a battery pack provided by an exemplary embodiment. Figure 6 As shown, the charging method for the battery pack includes step S11.

[0152] Step S11 , during the charging process of the battery pack 10 , when it is determined that the first battery group 1 and the second battery group 2 are unbalanced, the charging system 200 and the charging circuit 20 are controlled so that the charging system 200 charges one of the first battery group 1 and the second battery group 2 .

[0153] Among them, the battery pack 10 includes a first battery group 1 and a second battery group 2 connected in series, the charging circuit 20 is connected to the positive and negative electrodes of the battery pack 10, and connects the node between the first battery group 1 and the second battery group 2, and the charging system 200 is connected to the first battery group 1 and the second battery group 2 respectively through the charging circuit 20.

[0154] Through the above technical solution, during the battery pack charging process, if it is determined that the two battery packs connected in series are unbalanced, the charging system and the charging circuit are controlled to charge one of the battery packs to achieve balance. The charging circuit is connected to the positive and negative electrodes of the battery pack, and is also connected to the node between the first battery pack and the second battery pack. In this way, by controlling the circuit structure of the charging system and the charging circuit, the charging system can charge one of the two battery packs through the charging circuit, thereby achieving balance of the battery pack. In this way, it is avoided that the entire battery pack is prematurely charged due to the imbalance of the battery pack, and some battery packs are not fully charged.

[0155] In yet another embodiment, controlling the charging system 200 and the charging circuit 20 so that the charging system 200 charges one of the first battery pack 1 and the second battery pack 2 includes:

[0156] When one of the first battery pack 1 and the second battery pack 2 reaches the charge cutoff voltage, the charging system 200 and the charging circuit 20 are controlled so that the charging system 200 charges the other of the first battery pack 1 and the second battery pack 2 until the other reaches the charge cutoff voltage.

[0157] In yet another embodiment, the charging circuit 20 includes a first switch K1, a second switch K2, a third switch K3 and a transmission module 21;

[0158] The positive electrode of the first battery group 1 is connected to the negative electrode of the second battery group 2, the positive electrode of the second battery group 2 is connected to the first end a of the transmission module 21 through the second switch K2, the negative electrode of the first battery group 1 is connected to the second end b of the transmission module 21 through the first switch K1, and the node between the first battery group 1 and the second battery group 2 is connected to the third end c of the transmission module 21 through the third switch K3.

[0159] Controlling the charging system 200 and the charging circuit 20 so that the charging system 200 charges the other of the first battery pack 1 and the second battery pack 2 until the other reaches a charging cut-off voltage, including:

[0160] The charging system 200 , the first switch K1 , the second switch K2 , the third switch K3 and the transmission module 21 are controlled so that the voltage output by the charging system 200 is transmitted or stepped down to be transmitted to the other of the first battery pack 1 and the second battery pack 2 .

[0161] In another embodiment, the transmission module 21 includes a first switch tube T1 , a second switch tube T2 and an inductor L.

[0162] The first switch tube T1 and the second switch tube T2 are connected to form a one-phase bridge arm, the first end of the one-phase bridge arm serves as the first end a of the transmission module 21, the second end of the one-phase bridge arm serves as the second end b of the transmission module 21, the midpoint of the one-phase bridge arm is connected to one end of the inductor L, and the other end of the inductor L serves as the third end c of the transmission module 21.

[0163] Controlling the charging system 200, the first switch K1, the second switch K2, the third switch K3 and the transmission module 21 so that the voltage output by the charging system 200 is transmitted or stepped down to the other of the first battery pack 1 and the second battery pack 2, including:

[0164] When only the second battery pack 2 reaches the charging cut-off voltage, the charging current output by the charging system 200 is requested to be less than the current threshold;

[0165] Keep the first switch K1 and the second switch K2 closed, and control the third switch K3 to be closed;

[0166] The one-phase bridge arm is periodically controlled. In one cycle, the first switch tube T1 is controlled to be turned on and the second switch tube T2 is controlled to be turned off, so that the first battery group 1 and the second battery group 2 charge the inductor L; then the second switch tube T2 is controlled to be turned on and the first switch tube T1 is controlled to be turned off, so that the inductor L discharges to the first battery group 1;

[0167] When the duty cycle of the first switch tube T1 or the second switch tube T2 reaches the target duty cycle, the second switch K2 is controlled to be disconnected, and the charging system 200 is requested to output the first charging current until the first battery pack 1 reaches the charging cut-off voltage.

[0168] In another embodiment, controlling the charging system 200, the first switch K1, the second switch K2, the third switch K3 and the transmission module 21 so that the voltage output by the charging system 200 is transmitted or stepped down to the other of the first battery pack 1 and the second battery pack 2 includes:

[0169] When only the first battery pack 1 reaches the charging cut-off voltage, the charging current output by the charging system 200 is requested to be less than the current threshold;

[0170] Keep the first switch K1 and the second switch K2 closed, and control the third switch K3 to be closed;

[0171] The one-phase bridge arm is periodically controlled. In one cycle, the second switch tube T2 is controlled to be turned on and the first switch tube T1 is turned off, so that the first battery group 1 and the second battery group 2 charge the inductor L; then the first switch tube T1 is controlled to be turned on and the second switch tube T2 is turned off, so that the inductor L discharges to the second battery group 2;

[0172] When the duty cycle of the first switch tube T1 or the second switch tube T2 reaches the target duty cycle, the first switch K1 is controlled to be disconnected, and the charging system 200 is requested to output the second charging current until the second battery pack 2 reaches the charging cut-off voltage.

[0173] In another embodiment, controlling the charging system 200, the first switch K1, the second switch K2, the third switch K3 and the transmission module 21 so that the voltage output by the charging system 200 is transmitted or stepped down to the other of the first battery pack 1 and the second battery pack 2 includes:

[0174] When only the second battery pack 2 reaches the charging cut-off voltage, the charging current output by the charging system 200 is requested to be less than the current threshold;

[0175] Keep the first switch K1 closed and control the second switch K2 to open;

[0176] Requesting the charging voltage output by the charging system 200 to be reduced to a first charging voltage;

[0177] The third switch K3 is controlled to be closed, the first switch tube T1 is turned on, and the second switch tube T2 is turned off, and the charging system 200 is requested to output a first charging current so that the charging system 200 charges the first battery pack 1 until the first battery pack 1 reaches the charging cut-off voltage.

[0178] In another embodiment, controlling the charging system 200, the first switch K1, the second switch K2, the third switch K3 and the transmission module 21 so that the voltage output by the charging system 200 is transmitted or stepped down to the other of the first battery pack 1 and the second battery pack 2 includes:

[0179] When only the first battery pack 1 reaches the charging cut-off voltage, the charging current output by the charging system 200 is requested to be less than the current threshold;

[0180] Keep the second switch K2 closed and control the first switch K1 to open;

[0181] Requesting the charging voltage output by the charging system 200 to be reduced to a second charging voltage;

[0182] The third switch K3 is controlled to be closed, the second switch tube T2 is turned on, and the first switch tube T1 is turned off, and the charging system 200 is requested to output a second charging current so that the charging system 200 charges the second battery pack 2 until the second battery pack 2 reaches the charging cut-off voltage.

[0183] In yet another embodiment, the method further includes: when the difference between the remaining capacities of the first battery group 1 and the second battery group 2 is greater than a difference threshold, determining that the first battery group 1 and the second battery group 2 are unbalanced.

[0184] The method of comparing the difference threshold is used to determine whether the balance is achieved. The method is simple and has good accuracy.

[0185] Figure 7 FIG. 1 is a flow chart of a method for charging a battery pack provided by another exemplary embodiment. Figure 7 As shown, the charging method for the battery pack may include the following steps:

[0186] 1. When the battery pack is being charged, determine whether the difference between the remaining capacity of the first battery pack and the second battery pack is greater than a difference threshold.

[0187] 2. If the difference is greater than the difference threshold, determine whether an active balancing start condition is met. The active balancing start condition includes that one of the first battery group and the second battery group reaches a charging cut-off voltage.

[0188] 3. If the active balancing start condition is met, determine which battery pack needs to be charged separately. If one of the first battery pack and the second battery pack reaches the charging cut-off voltage, the other needs to be charged separately.

[0189] 4. If the first battery pack needs to be charged separately, the first step-down mode step-down process control is executed; when the first step-down mode step-down process is completed, the first step-down mode charging process control is executed; when the exit condition is met, the first step-down mode exit process control is executed. The exit condition is that the battery pack charged separately reaches the charging cut-off voltage.

[0190] 5. If the second battery pack needs to be charged separately, the second step-down mode step-down process control is executed; when the second step-down mode step-down process is completed, the second step-down mode charging process control is executed; when the exit condition is met, the second step-down mode exit process control is executed.

[0191] Figure 8 FIG. 1 is a flow chart of a method for charging a battery pack provided by another exemplary embodiment. Figure 8 As shown, the charging method for the battery pack may include the following steps:

[0192] 1. When the battery pack is being charged, determine whether the difference between the remaining capacity of the first battery pack and the second battery pack is greater than a difference threshold.

[0193] 2. If the difference is greater than the difference threshold, determine whether an active balancing start condition is met. The active balancing start condition includes that one of the first battery group and the second battery group reaches a charging cut-off voltage.

[0194] 3. If the active balancing start condition is met, determine which battery pack needs to be charged separately. If one of the first battery pack and the second battery pack reaches the charging cut-off voltage, the other needs to be charged separately.

[0195] 4. If the first battery pack needs to be charged separately, the first charging mode jump process control is executed; when the first charging mode jump process is completed, the first charging mode charging process control is executed; when the exit condition is met, the first charging mode exit process control is executed.

[0196] 5. If the second battery pack needs to be charged separately, the second charging mode jump process control is executed; when the second charging mode jump process is completed, the second charging mode charging process control is executed; when the exit condition is met, the second charging mode exit process control is executed.

[0197] Regarding the method in the above embodiment, the specific manner of performing the operation in each step has been described in detail in the embodiment of the device, and will not be elaborated here.

[0198] The present disclosure also provides an electronic device, which includes a processor and a memory for storing instructions executable by the processor, wherein the processor is configured to execute the above-mentioned charging method for a battery pack provided by the present disclosure.

[0199] The present disclosure also provides a vehicle, which includes the above-mentioned charging device provided by the present disclosure or the above-mentioned electronic device provided by the present disclosure.

[0200] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0201] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0202] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A charging device (100) for a battery pack, characterized in that: The battery pack (10) comprises a first battery group (1) and a second battery group (2) connected in series, and the charging device (100) comprises: A charging circuit (20) connected to the positive electrode and the negative electrode of the battery pack (10) and connected to the node between the first battery pack (1) and the second battery pack (2); the charging system (200) is connected to the first battery pack (1) and the second battery pack (2) respectively through the charging circuit (20); The charging circuit (20) comprises a first switch (K1), a second switch (K2), a third switch (K3) and a transmission module (21); The positive electrode of the first battery group (1) and the negative electrode of the second battery group (2) are connected, the positive electrode of the second battery group (2) is connected to the first end (a) of the transmission module (21) through the second switch (K2), the negative electrode of the first battery group (1) is connected to the second end (b) of the transmission module (21) through the first switch (K1), and the node between the first battery group (1) and the second battery group (2) is connected to the third end (c) of the transmission module (21) through the third switch (K3); The transmission module (21) comprises a first switch tube (T1), a second switch tube (T2) and an inductor (L); The first switch tube (T1) and the second switch tube (T2) are connected to form a phase bridge arm, the first end of the phase bridge arm serves as the first end (a) of the transmission module (21), the second end of the phase bridge arm serves as the second end (b) of the transmission module (21), the midpoint of the phase bridge arm is connected to one end of the inductor (L), and the other end of the inductor (L) serves as the third end (c) of the transmission module (21); A controller (30) connected to the charging circuit (20) and the charging system (200) respectively, and used for determining during the charging process of the battery pack (10) that the first battery group (1) and the second battery group (2) are unbalanced, and when one of the first battery group (1) and the second battery group (2) reaches a charging cut-off voltage, controlling the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery group (1) and the second battery group (2); The controlling of the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery pack (1) and the second battery pack (2) comprises: When only the second battery pack (2) reaches the charging cut-off voltage, requesting the charging system (200) to output a charging current that is less than a current threshold; Keeping the first switch (K1) and the second switch (K2) closed, and controlling the third switch (K3) to close; The one-phase bridge arm is periodically controlled, and in one cycle, the first switch tube (T1) is controlled to be turned on and the second switch tube (T2) is controlled to be turned off, so that the first battery group (1) and the second battery group (2) charge the inductor (L); then the second switch tube (T2) is controlled to be turned on and the first switch tube (T1) is controlled to be turned off, so that the inductor (L) discharges to the first battery group (1); When the duty cycle of the first switch tube (T1) or the second switch tube (T2) reaches a target duty cycle, the second switch (K2) is controlled to be disconnected, and the charging system (200) is requested to output a first charging current until the first battery pack (1) reaches a charging cut-off voltage.

2. The charging device (100) according to claim 1, characterized in that: The transmission module (21) comprises a three-phase bridge arm sharing a first bus terminal and a second bus terminal, and three inductors; The first bus terminal serves as the first end (a) of the transmission module (21), the second bus terminal serves as the second end (b) of the transmission module (21), the midpoints of the three-phase bridge arms are connected to one end of the three inductors in a one-to-one correspondence, and the other ends of the three inductors serve as the third end (c) of the transmission module (21).

3. The charging device (100) according to claim 2, characterized in that: The three-phase bridge arm reuses the bridge arm in the motor controller, and the three inductors reuse the inductors in the motor.

4. The charging device (100) according to any one of claims 1 to 3, characterized in that: The transmission module (21) further comprises a capacitor (C1), wherein two ends of the capacitor (C1) are respectively connected to a first end (a) of the transmission module (21) and a second end (b) of the transmission module (21).

5. A charging method for a battery pack, characterized in that: The battery pack (10) comprises a first battery group (1) and a second battery group (2) connected in series, the charging system (200) being connected to the first battery group (1) and the second battery group (2) respectively via a charging circuit (20), the charging circuit (20) being connected to a positive electrode and a negative electrode of the battery pack (10) and connecting a node between the first battery group (1) and the second battery group (2); The charging circuit (20) comprises a first switch (K1), a second switch (K2), a third switch (K3) and a transmission module (21); The positive electrode of the first battery group (1) and the negative electrode of the second battery group (2) are connected, the positive electrode of the second battery group (2) is connected to the first end (a) of the transmission module (21) through the second switch (K2), the negative electrode of the first battery group (1) is connected to the second end (b) of the transmission module (21) through the first switch (K1), and the node between the first battery group (1) and the second battery group (2) is connected to the third end (c) of the transmission module (21) through the third switch (K3); The transmission module (21) comprises a first switch tube (T1), a second switch tube (T2) and an inductor (L); The first switch tube (T1) and the second switch tube (T2) are connected to form a phase bridge arm, the first end of the phase bridge arm serves as the first end (a) of the transmission module (21), the second end of the phase bridge arm serves as the second end (b) of the transmission module (21), the midpoint of the phase bridge arm is connected to one end of the inductor (L), and the other end of the inductor (L) serves as the third end (c) of the transmission module (21); The method comprises: During the charging process of the battery pack (10), when it is determined that the first battery group (1) and the second battery group (2) are unbalanced and one of the first battery group (1) and the second battery group (2) reaches a charging cut-off voltage, the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) are controlled so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery group (1) and the second battery group (2); The controlling of the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery pack (1) and the second battery pack (2) comprises: When only the second battery pack (2) reaches the charging cut-off voltage, requesting the charging system (200) to output a charging current that is less than a current threshold; Keeping the first switch (K1) and the second switch (K2) closed, and controlling the third switch (K3) to close; The one-phase bridge arm is periodically controlled, and in one cycle, the first switch tube (T1) is controlled to be turned on and the second switch tube (T2) is controlled to be turned off, so that the first battery group (1) and the second battery group (2) charge the inductor (L); then the second switch tube (T2) is controlled to be turned on and the first switch tube (T1) is controlled to be turned off, so that the inductor (L) discharges to the first battery group (1); When the duty cycle of the first switch tube (T1) or the second switch tube (T2) reaches a target duty cycle, the second switch (K2) is controlled to be disconnected, and the charging system (200) is requested to output a first charging current until the first battery pack (1) reaches a charging cut-off voltage.

6. The charging method according to claim 5, characterized in that: The controlling of the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery pack (1) and the second battery pack (2), comprises: When only the first battery pack (1) reaches the charging cut-off voltage, requesting the charging system (200) to output a charging current smaller than the current threshold; Keeping the first switch (K1) and the second switch (K2) closed, and controlling the third switch (K3) to close; The one-phase bridge arm is periodically controlled, and in one cycle, the second switch tube (T2) is controlled to be turned on and the first switch tube (T1) is controlled to be turned off, so that the first battery group (1) and the second battery group (2) charge the inductor (L); then the first switch tube (T1) is controlled to be turned on and the second switch tube (T2) is controlled to be turned off, so that the inductor (L) discharges to the second battery group (2); When the duty cycle of the first switch tube (T1) or the second switch tube (T2) reaches a target duty cycle, the first switch (K1) is controlled to be disconnected, and the charging system (200) is requested to output a second charging current until the second battery pack (2) reaches a charging cut-off voltage.

7. The charging method according to claim 5, characterized in that: The controlling of the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery pack (1) and the second battery pack (2), comprises: When only the second battery pack (2) reaches the charging cut-off voltage, requesting the charging system (200) to output a charging current that is less than a current threshold; Keeping the first switch (K1) closed, and controlling the second switch (K2) to open; Requesting the charging voltage output by the charging system (200) to be reduced to a first charging voltage; The third switch (K3) is controlled to be closed, the first switch tube (T1) is controlled to be turned on, and the second switch tube (T2) is controlled to be turned off, and the charging system (200) is requested to output a first charging current, so that the charging system (200) charges the first battery pack (1) until the first battery pack (1) reaches a charging cut-off voltage.

8. The charging method according to claim 5, characterized in that: The controlling of the charging system (200), the first switch (K1), the second switch (K2), the third switch (K3) and the transmission module (21) so that the voltage output by the charging system (200) is transmitted or transmitted after voltage reduction to the other of the first battery pack (1) and the second battery pack (2), comprises: When only the first battery pack (1) reaches the charging cut-off voltage, requesting the charging system (200) to output a charging current that is less than a current threshold; Keeping the second switch (K2) closed, and controlling the first switch (K1) to open; Requesting the charging voltage output by the charging system (200) to be reduced to a second charging voltage; The third switch (K3) is controlled to be closed, the second switch tube (T2) is controlled to be turned on, and the first switch tube (T1) is controlled to be turned off, and the charging system (200) is requested to output a second charging current, so that the charging system (200) charges the second battery group (2) until the second battery group (2) reaches a charging cut-off voltage.

9. The charging method according to any one of claims 5 to 8, characterized in that: The method further comprises: When the difference between the remaining capacities of the first battery group (1) and the second battery group (2) is greater than a difference threshold, it is determined that the first battery group (1) and the second battery group (2) are unbalanced.

10. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to execute the charging method for a battery pack described in any one of claims 5-9.

11. A vehicle, characterized in that: The vehicle comprises the charging device (100) according to any one of claims 1 to 4 or the electronic device according to claim 10.

Images