Multi-battery pack equalization circuit

Abstract

The invention belongs to the related technical field of multi-battery pack charging, and particularly relates to a multi-battery pack equalization circuit. The equalization circuit is arranged between the battery pack and the power supply positive electrode, so that mutual power supply equalization between the battery packs is realized according to the voltage of the battery packs. In the traditional charge-discharge equalization, mutual equalization of the battery packs is also provided, so that the voltage of the battery packs can be kept relatively consistent, the problem that voltage equalization cannot be realized between the battery packs when charge and discharge are not performed is avoided, and the electric quantity change of the battery packs is more flexible.

Description

Technical Field

[0001] The present invention belongs to the technical field related to charging of multiple battery packs, and in particular relates to a multiple battery pack balancing circuit. Background Art

[0002] As the demand for lithium battery packs with long battery life and high current discharge becomes more and more vigorous in various industries, generally speaking, the battery pack capacity needs to be increased to meet the demand for battery life and high current discharge. Increasing the battery pack capacity is mainly achieved by increasing the number of parallel cells in a single pack and reducing the volume of the battery pack.

[0003] Among them, multiple single-pack battery cells are connected in parallel, hereinafter referred to as a multi-pack parallel solution. Although it can effectively increase the capacity of the battery pack, it is inevitable that there will be voltage differences between the battery packs during the use of the battery pack, resulting in different remaining battery capacities during charging and discharging. It is often necessary to balance the power between the battery packs to avoid abnormal charging and discharging caused by different power capacities.

[0004] In the existing balancing technology, the power of the battery pack is often detected during charging and discharging, and partial charging and discharging are performed to achieve a balanced power of the battery pack. However, this technology can only achieve balancing during charging and discharging, and the power of the battery pack cannot be balanced when not charging or discharging. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a multi-battery pack balancing circuit, in which a device is provided to enable the battery packs to charge each other when not being charged or discharged, thereby achieving an active balancing effect between the battery packs, thereby avoiding the need for charging and discharging for balancing the battery packs.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a multi-battery pack balancing circuit, which is applied to a battery module, wherein the battery module comprises at least a first battery pack and a second battery pack, wherein the positive electrodes of the first battery pack and the second battery pack are connected to the positive power supply electrode of the battery module, and comprises:

[0008] A first balancing circuit, used to be connected to the positive electrode of the first battery pack and the positive electrode of the power supply;

[0009] A second balancing circuit, used to be connected to the positive electrode of the second battery pack and the positive power supply electrode; and

[0010] The main control circuit is connected to the first balancing circuit and the second balancing circuit, and is used to control the high-voltage battery pack to supply power to the low-voltage battery pack through the first balancing circuit or the second balancing circuit according to the voltage of the first battery pack and the second battery pack.

[0011] By setting a balancing circuit between the battery pack and the positive power supply electrode, the mutual power supply balance between the battery packs can be achieved according to the voltage of the battery pack. In the traditional charge and discharge balance, the battery packs are also balanced to keep the voltages relatively consistent between the battery packs, so as to avoid the voltage balance between the battery packs when not charging or discharging, so as to make the power change of the battery pack more flexible.

[0012] In some implementations, the first balancing circuit and the second balancing circuit both include a first switch circuit, a monitoring control circuit, an auxiliary control circuit, and a voltage reduction circuit;

[0013] The first switch circuit is arranged between the first battery pack and the positive power supply electrode, or the first switch circuit is arranged between the second battery pack and the positive power supply electrode, and the monitoring control circuit is provided with a first control end; the first control end controls the on and off of the first switch circuit, and the two ends of the step-down circuit are connected in parallel to the positive electrode of the battery pack and the positive power supply electrode, so as to realize the high-voltage battery pack to supply power to the low-voltage battery pack by stepping down the voltage; the auxiliary control circuit is connected between the monitoring control circuit and the main control circuit, and is provided with a second control end, and the second control end is connected to the step-down circuit, so that the second control end controls the on and off of the step-down circuit.

[0014] By providing a first switch circuit, the on-off of charging and discharging of the battery pack is realized, the high-voltage battery pack is stepped down to charge the low-voltage battery pack through the step-down circuit, the first switch circuit and the step-down circuit of the battery pack are selectively turned on and off through the monitoring control circuit, and the data of the battery pack is monitored. The auxiliary control circuit receives the signal of the main control circuit to achieve on-off balance among multiple battery packs.

[0015] In some embodiments, the buck circuit is further provided with a second switch circuit; the buck circuits in parallel are switched on and off through the second control terminal.

[0016] The second switch circuit is used to switch the step-down circuit on and off, thereby preventing the step-down circuit from interfering with the charging and discharging voltage during external charging and discharging.

[0017] In some implementations, the step-down circuit is a DC-DC module, the second switch circuit is a first MOS transistor, and the gate of the first MOS transistor is controlled by the second control terminal.

[0018] The voltage is reduced by a DC-DC module so that the high-voltage battery pack can charge the low-voltage battery pack.

[0019] In some embodiments, the first switch circuit is provided with a plurality of switch elements, and each of the switch elements is switched on and off by the first control terminal.

[0020] The on and off of the first switch circuit is realized through a plurality of switch components, so as to realize the on and off of charging and discharging. The plurality of switch components can enhance the charging and discharging overcurrent capacity of the main circuit.

[0021] In some embodiments, the switch element is a second MOS tube, the second MOS tube is an N-channel MOS tube, a plurality of second MOS tubes are connected in parallel, and the first control end is connected to the gate of the second MOS tube, the source and drain of the second MOS tube are connected between the first battery pack and the positive power supply electrode, or the source and drain of the second MOS tube are connected between the first battery pack and the positive power supply electrode.

[0022] The on-off of the first switch circuit is realized by the second MOS tube, and a plurality of second MOS tubes are arranged in parallel to realize the capability of the plurality of second MOS tubes to increase the overcurrent.

[0023] In some embodiments, the monitoring control circuit also includes a third control terminal, the switch element also includes a third MOS tube, the third MOS tube is an N-channel MOS tube, multiple third MOS tubes are connected in parallel, and the third control terminal is connected to the gate of the third MOS tube, the source and drain of the second MOS tube are connected between the first battery pack and the positive power supply electrode, or the source and drain of the second MOS tube are connected between the second battery pack and the positive power supply electrode.

[0024] By dividing into the second control end and the third control end to control the on and off of the two groups of switches respectively, the on and off stability can be achieved and the protection capability of the circuit can be improved.

[0025] In some embodiments, the monitoring control circuit is provided with an analog front-end chip, and the analog front-end chip is also provided with a monitoring terminal, a first current test terminal, a second current test terminal, a charging monitoring terminal, and a first communication terminal; a current measuring resistor is provided between the negative electrode of the first battery pack and the negative power supply electrode, or a current measuring resistor is provided between the negative electrode of the second battery pack and the negative power supply electrode;

[0026] The monitoring end is connected to the positive electrode of the first battery pack, or the monitoring end is connected to the positive electrode of the second battery pack, the first current testing end and the second current testing end are connected to the two ends of the current measuring resistor; the charging detection end is connected between the positive power supply electrode and the positive electrode of the first battery pack, or the charging detection end is connected between the positive power supply electrode and the positive electrode of the second battery pack; the first communication end is connected to the auxiliary control circuit.

[0027] Through the analog front-end chip, the data of the battery pack, such as voltage and current, is monitored and fed back to the auxiliary control circuit, and the on and off of the first switch circuit is controlled.

[0028] In some embodiments, the auxiliary control circuit is provided with an auxiliary control chip, the main control circuit is provided with a main control chip, the auxiliary control chip is also provided with a first ID verification terminal, a second communication terminal and a third communication terminal; the main control chip is provided with a fourth communication terminal and a second ID verification terminal; the first ID verification terminal is connected to the second ID verification terminal, the second communication terminal is connected to the fourth communication terminal, and the third communication terminal is connected to the first communication terminal.

[0029] The battery pack ID is confirmed through the auxiliary control circuit, and the data of the corresponding battery pack is transmitted to the main control chip.

[0030] In some embodiments, the positive electrode of the first battery pack and the positive electrode of the second battery pack are both provided with fuses.

[0031] A fuse is used to protect the battery pack from overcharging.

[0032] The beneficial effects of a multi-battery pack balancing circuit of the present invention are:

[0033] By setting a balancing circuit between the battery pack and the positive power supply electrode, the mutual power supply balance between the battery packs can be achieved according to the voltage of the battery pack. In the traditional charge and discharge balance, the battery packs are also balanced to keep the voltages relatively consistent between the battery packs, so as to avoid the voltage balance between the battery packs when not charging or discharging, so as to make the power change of the battery pack more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a main frame diagram of a multi-battery pack balancing circuit of the present invention;

[0035] Figure 2 A framework diagram of an equalizing circuit for a multi-battery pack equalizing circuit according to the present invention;

[0036] Figure 3 A schematic diagram of an equalizing circuit for a multi-battery pack equalizing circuit according to the present invention;

[0037] Figure 4 This is a main circuit schematic diagram of a multi-battery pack balancing circuit of the present invention;

[0038] Figure 5 This is the charge and discharge control process proposed in Embodiment 3 of a multi-battery pack balancing circuit of the present invention.

[0039] Reference numerals:

[0040] 1. First balancing circuit; 2. Second balancing circuit; 3. Main control circuit; 4. First battery pack; 5. Second battery pack;

[0041] 11. First switch circuit; 12. Monitoring control circuit; 13. Auxiliary control circuit; 14. Step-down circuit; 15. Second switch circuit; 16. Third switch circuit;

[0042] Q1, the first MOS tube; Q2, the second MOS tube; Q3, the third MOS tube;

[0043] U1, analog front-end chip; U1_1, monitoring terminal; U1_2, first current test terminal; U1_3, second current test terminal; U1_4, charging monitoring terminal; U1_5, first communication terminal; U1_6, first control terminal; U1_7, second control terminal;

[0044] U2, auxiliary control chip; U2_1, first ID verification terminal; U2_2, second communication terminal; U2_3, third communication terminal; U2_4, third control terminal;

[0045] U3, main control chip; U3_1, second ID verification terminal; U3_2, fourth communication terminal;

[0046] R1, current measuring resistor; F1, fuse;

[0047] C+, positive power supply electrode; C-, negative power supply electrode; V+, positive electrode of battery pack; V-, negative electrode of battery pack. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present application are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present application can be more easily understood by those skilled in the art, thereby making a clearer definition of the protection scope of the present application.

[0049] Please refer to the drawings, where the same component symbols represent the same components, and the principles of the present application are illustrated by implementing them in an appropriate computing environment. The following description is based on the illustrated specific embodiments of the present application, which should not be considered as limiting other specific embodiments of the present application that are not described in detail herein.

[0050] The term "module" as used herein may be a software or hardware object executed on the computing system. The different components, modules, engines, and services described herein may be implementation objects on the computing system. The apparatus and methods described herein may be implemented in software, or in hardware, and all are within the scope of protection of this application.

[0051] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] Embodiment 1:

[0054] like Figure 1 As shown, this embodiment proposes a multi-battery pack balancing circuit, which is applied to a battery module. The battery module at least includes a first battery pack 4 and a second battery pack 5. The first battery pack 4 and the second battery pack 5 are connected to the positive power supply electrode C+ of the battery module, including:

[0055] A first balancing circuit 1, used to be connected to the positive electrode of the first battery pack 4 and the positive power supply electrode C+;

[0056] A second balancing circuit 2, used to be connected to the positive electrode of the second battery pack 5 and the positive power supply electrode C+;

[0057] And the main control circuit 3 is connected to the first balancing circuit 1 and the second balancing circuit 2, and is used to control the high-voltage battery pack to supply power to the low-voltage battery pack through the first balancing circuit 1 or the second balancing circuit 2 according to the voltage of the first battery pack 4 and the second battery pack 5.

[0058] Specifically, in a multi-battery pack module, at least two battery packs are included to balance the voltages. The positive poles of the first battery pack 4 and the second battery pack 5 are connected to the positive power supply pole C+, and further, the negative poles of the first battery pack 4 and the second battery pack 5 are connected to the negative power supply pole C- to form a charging closed loop. An equalization circuit is provided between the positive pole V+ of each battery pack and the positive power supply pole C+, that is, a first equalization circuit 1 for connecting to the positive pole of the first battery pack 4 and the positive power supply pole C+, and a second equalization circuit 2 for connecting to the positive pole of the second battery pack 5 and the positive power supply pole C+. The charging and discharging of the battery packs and the mutual charging of the battery packs are controlled by the equalization circuit to control the voltage of each battery pack so that the voltage of the battery packs is kept as consistent as possible. The main control circuit 3 obtains data of the first battery pack 4 and the second battery pack 5, such as voltage, current, temperature and other data, and through the voltage data, the main control chip U3 determines and controls the first equalization circuit 1 or the second equalization circuit 2 to control the high-voltage battery pack to supply power to the low-voltage battery pack.

[0059] By setting a balancing circuit between the battery pack and the positive power supply C+, the mutual power supply balance between the battery packs can be achieved according to the voltage of the battery pack. In the traditional charge and discharge balance, the battery packs are also balanced to keep the voltages relatively consistent between the battery packs, so as to avoid the voltage balance between the battery packs when not charging or discharging, so as to make the power change of the battery pack more flexible.

[0060] Embodiment 2:

[0061] like Figure 2 to Figure 4 As shown, this embodiment further optimizes and illustrates the circuit structure proposed in Embodiment 1, and the difference is that:

[0062] In some embodiments, the first balancing circuit 1 and the second balancing circuit 2 both include a first switch circuit 11, a monitoring control circuit 12, an auxiliary control circuit 13, or a voltage reduction circuit 14;

[0063] The first switch circuit 11 is arranged between the first battery pack 4 and the positive power supply electrode C+, or the first switch circuit 11 is arranged between the second battery pack 5 and the positive power supply electrode C+, and the monitoring control circuit 12 is provided with a first control terminal U1_6; the first control terminal U1_6 controls the on and off of the first switch circuit 11, and the two ends of the step-down circuit 14 are connected in parallel to the positive pole V+ of the battery pack and the positive power supply electrode C+, so as to reduce the voltage and realize that the high-voltage battery pack supplies power to the low-voltage battery pack; the auxiliary control circuit 13 is connected between the monitoring control circuit 12 and the main control circuit 3, and is provided with a second control terminal U2_4, and the second control terminal U2_4 is connected to the step-down circuit 14, so that the second control terminal U2_4 controls the on and off of the step-down circuit 14.

[0064] Specifically, the first balancing circuit 1 and the second balancing circuit 2 both include a first switch circuit 11, a monitoring control circuit 12, an auxiliary control circuit 13, and a step-down circuit 14; wherein the first switch circuit 11 is arranged between the positive electrode V+ of each battery pack and the positive power supply electrode C+, and the first switch circuit 11 is used to realize the on-off of the battery pack and the positive power supply electrode C+, and the implementation method thereof can be through a high-voltage switch, a relay, a triode, a MOS tube, etc. The first switch circuit 11 is used to realize that the battery pack with high voltage is discharged first and the battery pack with low voltage is charged first during external charging and discharging, so as to realize the passive balancing of the battery pack. The monitoring control circuit 12 collects data from the battery pack and controls the on-off of the first switch circuit 11, and the control method thereof can be the gate control of the MOS tube, the control end control of the relay, the high-voltage switch control, etc. The auxiliary control circuit 13 is used to receive the control information of the main control circuit 3, or to send the voltage information of the battery pack. A step-down circuit 14 is also provided, and both ends of the step-down circuit 14 are connected in parallel to the positive electrode V+ of the battery pack and the positive electrode C+ of the power supply, and a second control terminal U2_4 is provided, and the second control terminal U2_4 is used to control the on-off of the step-down circuit 14, so as to reduce the voltage of the high-voltage battery pack through the step-down circuit 14, and charge the low-voltage battery pack to achieve active balancing between the battery packs. The first switch circuit 11 and the second control terminal U2_4 are used to switch the active balancing between the battery packs and the passive balancing achieved by charging and discharging.

[0065] By providing a first switch circuit 11, the on-off of charging and discharging of the battery pack is realized, and the high-voltage battery pack is stepped down to charge the low-voltage battery pack through the step-down circuit 14. The first switch circuit 11 and the step-down circuit 14 of the battery pack are selectively turned on and off through the monitoring control circuit 12, and the data of the battery pack is monitored. The auxiliary control circuit 13 receives the signal of the main control circuit 3 to achieve on-off balance among multiple battery packs.

[0066] In some embodiments, the buck circuit 14 is further provided with a second switch circuit 15; the buck circuits 14 connected in parallel are switched on and off through the second control terminal U2_4.

[0067] Specifically, the second control terminal U2_4 controls the on / off of the parallel buck circuit 14 through the second switch circuit 15, so as to switch from the passive balancing mode of charge and discharge to the active balancing mode between the battery pack voltages. More specifically, the second switch circuit 15 can be a device with on / off capability such as a relay switch or a high-side switch, or a switch circuit with on / off capability such as a multi-stage transistor switch circuit.

[0068] The second switch circuit 15 is used to switch the step-down circuit 14 on and off, so as to prevent the step-down circuit 14 from interfering with the charging and discharging voltage during external charging and discharging.

[0069] In some embodiments, the step-down circuit 14 is a DC-DC module, the second switch circuit 15 is a first MOS transistor Q1 , and the gate of the first MOS transistor Q1 is controlled by the second control terminal U2_4 .

[0070] Specifically, the step-down circuit 14 may be a DC-DC module, and may be composed of a specific IC chip. More specifically, the optional step-down IC may be Southchip, SC8002, and other related models. The second switch circuit 15 may be a MOS tube, and the gate of the first MOS tube Q1 is controlled to be on and off by the second control terminal U2_4.

[0071] The voltage is reduced by a DC-DC module so that the high-voltage battery pack can charge the low-voltage battery pack.

[0072] In some embodiments, the first switch circuit 11 is provided with a plurality of switch elements, and all of them are switched on and off by the first control terminal U1_6.

[0073] The first switch circuit 11 is provided with a switch element, which can be turned on and off by the first control terminal U1_6. The switch element can be a device with on-off capability such as a relay switch, a high-side switch, or a switch circuit with on-off capability such as a multi-stage transistor switch circuit.

[0074] The first switch circuit 11 is turned on and off by a plurality of switch components, so as to further turn on and off the charge and discharge. The plurality of switch components can enhance the charge and discharge overcurrent capability of the main circuit.

[0075] In some embodiments, the switch element is a second MOS tube Q2, the second MOS tube Q2 is an N-channel MOS tube, a plurality of second MOS tubes Q2 are connected in parallel, and the first control terminal U1_6 is connected to the gate of the second MOS tube Q2, the source and drain of the second MOS tube Q2 are connected between the first battery pack 4 and the positive power supply electrode C+, or the source and drain of the second MOS tube Q2 are connected between the first battery pack 4 and the positive power supply electrode C+

[0076] Specifically, the switch element is a second MOS tube Q2, which is an N-channel MOS tube. Multiple second MOS tubes Q2 are connected in parallel, and the on and off of the second MOS tube Q2 are uniformly controlled through the first control terminal U1_6, so that the current can be conducted through multiple paths, thereby increasing the overcurrent capacity of the main circuit. Among them, the source of the second MOS tube Q2 can be connected to the positive electrode of the first battery pack 4, or the source of the second MOS tube Q2 is connected to the positive electrode of the second battery pack 5, and the drain of the second MOS tube Q2 can be connected to the positive power supply electrode C+.

[0077] The first switch circuit 11 is turned on and off by the second MOS transistor Q2 , and a plurality of second MOS transistors Q2 are arranged in parallel to achieve the capability of increasing overcurrent.

[0078] In other embodiments, the monitoring control circuit 12 also includes a third control terminal U1_7, the switch element also includes a third MOS tube Q3, the third MOS tube Q3 is an N-channel MOS tube, multiple third MOS tubes Q3 are connected in parallel, and the third control terminal U1_7 is connected to the gate of the third MOS tube Q3, the source and drain of the second MOS tube Q2 are connected between the first battery pack 4 and the positive power supply electrode C+, or the source and drain of the second MOS tube Q2 are connected between the second battery pack 5 and the positive power supply electrode C+.

[0079] Specifically, another group of second MOS transistors Q2 controlled by the third control terminal U1_7 is further provided, and the source and drain of the second MOS transistor Q2 are connected between the first battery pack 4 and the second MOS transistor Q2, or the source and drain of the third MOS transistor Q3 are connected between the second battery pack 5 and the second MOS transistor Q2. More specifically, the source of the third MOS transistor Q3 is connected to the positive power supply electrode C+, and the drain of the third MOS transistor Q3 is connected to the drain of the second MOS transistor Q2. In the above manner, the two groups of switches can be used to turn on and off the first switch circuit 11, thereby improving the circuit protection capability.

[0080] By respectively controlling the on and off of the two groups of switches through the second control terminal U2_4 and the third control terminal U1_7, the on and off stability can be achieved and the protection capability of the circuit can be improved.

[0081] In some embodiments, the monitoring control circuit 12 is provided with an analog front-end chip U1, and the analog front-end chip U1 is also provided with a monitoring terminal U1_1, a first current test terminal U1_2, a second current test terminal U1_3, a charging monitoring terminal U1_4, and a first communication terminal U1_5; a current measuring resistor R1 is provided between the negative electrode of the first battery pack 4 and the negative power supply electrode C-, or a current measuring resistor R1 is provided between the negative electrode of the second battery pack 5 and the negative power supply electrode C-;

[0082] The monitoring terminal U1_1 is connected to the positive pole of the first battery pack 4, or the monitoring terminal U1_1 is connected to the positive pole of the second battery pack 5, the first current testing terminal U1_2 and the second current testing terminal U1_3 are connected to the two ends of the current measuring resistor R1; the charging detection terminal is connected between the power supply positive pole C+ and the positive pole of the first battery pack 4, or the charging detection terminal is connected between the power supply positive pole C+ and the positive pole of the second battery pack 5; the first communication terminal U1_5 is connected to the auxiliary control circuit 13.

[0083] Specifically, the monitoring control circuit 12 is composed of an analog front-end chip U1 such as AFE, which can be a TI BQ76942 or BQ76952 or other related models, wherein two current test terminals are respectively connected to the two ends of the measuring resistor to detect the current size. The monitoring terminal U1_1 is connected to the positive pole of the battery pack to monitor the size of the battery pack and provide data, which is sent to the auxiliary control circuit 13 by the first communication terminal U1_5 for control. The charging monitoring terminal U1_4 is used to detect whether the charging main circuit of the battery pack is in a charging or discharging state. The first communication terminal U1_5 is a pin for the monitoring control circuit 12 to transmit the battery pack current and voltage to the auxiliary control circuit 13, and further includes data such as the temperature of the battery pack. The battery pack negative electrode V- and the power supply negative electrode C-, that is, a current measuring resistor R1 is provided between the negative electrode of the first battery pack 4 and the power supply negative electrode C-, or a current measuring resistor R1 is provided between the negative electrode of the second battery pack 5 and the power supply negative electrode C-.

[0084] The data of the battery pack, such as voltage and current, is monitored through the analog front-end chip U1 and fed back to the auxiliary control circuit to control the on and off of the first switch circuit 11.

[0085] In some embodiments, the auxiliary control circuit 13 is provided with an auxiliary control chip U2, the main control circuit 3 is provided with a main control chip U3, and the auxiliary control chip U2 is also provided with a first ID verification terminal U2_1, a second communication terminal U2_2 and a third communication terminal U2_3; the main control chip U3 is provided with a fourth communication terminal U3_2 and a second ID verification terminal U3_1; the first ID verification terminal U2_1 is connected to the second ID verification terminal U3_1, the second communication terminal U2_2 is connected to the fourth communication terminal U3_2, and the third communication terminal U2_3 is connected to the first communication terminal U1_5.

[0086] Specifically, the auxiliary control chip U2 is an MCU, and further specifically, Eastsoft, ES8P5066 and other related chips, so as to control each battery pack, and the auxiliary control circuit 13 can also be the control core circuit in each battery pack. And further, the first ID verification terminal U2_1 and the second ID verification terminal U3_1 are set to perform ID verification, so that the main control chip U3 can wake up the MCU through the ID correspondence, and can further achieve the purpose of closing or hibernating the battery pack that is not necessarily turned on, avoiding the uncontrolled external charging of the battery pack, and through the connection between the second communication terminal U2_2 and the fourth communication terminal U3_2, to collect the voltage, current and other signals of the battery pack where the MCU is located, so as to globally control the power of the battery pack through the main control chip U3.

[0087] Embodiment 3:

[0088] like Figure 5As shown, based on the circuit structures proposed in Embodiments 1 and 2, this embodiment proposes a battery pack charge and discharge control process. After the main control chip U3 obtains the power of all battery packs, the following three processes are set according to the current state:

[0089] Among them, the first process S1 includes: if it is in the charging state at this time, turning on the second MOS tube Q2 and the third MOS tube Q3 in the balancing circuit of the low-power battery pack, so that the positive power supply electrode C+ of the low-power battery pack can be connected to the positive electrode of the low-power battery pack.

[0090] The second process S2 includes: if it is in the discharging state at this time, turning on the second MOS transistor Q2 and the third MOS transistor Q3 in the balancing circuit of the battery pack with high power, so that the battery pack with high power is discharged first.

[0091] The third process S3 includes: if it is in a non-charging and discharging state at this time, turning on the first MOS tube Q1 in the balancing circuit of the battery pack with high power, and turning on the second MOS tube Q2 and the third MOS tube Q3 in the balancing circuit of the battery pack with low power, so that the battery pack with high power can charge the battery pack with low power.

[0092] The battery pack ID is confirmed by the auxiliary control circuit 13, and the data of the corresponding battery pack is transmitted to the main control chip U3.

[0093] The implementation modes of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present application.

Claims

1. A multi-battery pack balancing circuit, characterized in that: Applied to a battery module, the battery module at least comprising a first battery pack (4) and a second battery pack (5), the positive electrodes of the first battery pack (4) and the second battery pack (5) being connected to a positive power supply electrode (C+) of the battery module, comprising: A first balancing circuit (1), used for connecting to the positive electrode of the first battery pack (4) and the positive power supply electrode (C+); a second balancing circuit (2), configured to be connected to the positive electrode of the second battery pack (5) and the positive power supply electrode (C+); and The main control circuit (3) is connected to the first balancing circuit (1) and the second balancing circuit (2) so as to control the high-voltage battery pack to supply power to the low-voltage battery pack through the first balancing circuit (1) or the second balancing circuit (2) according to the voltage of the first battery pack (4) and the second battery pack (5).

2. A multi-battery pack balancing circuit according to claim 1, characterized in that: The first balancing circuit (1) and the second balancing circuit (2) both comprise a first switch circuit (11), a monitoring control circuit (12), an auxiliary control circuit (13), and a voltage reduction circuit (14); The first switch circuit (11) is arranged between the first battery pack (4) and the positive power supply electrode (C+), or the first switch circuit (11) is arranged between the second battery pack (5) and the positive power supply electrode (C+), and the monitoring control circuit (12) is provided with a first control terminal (U1_6); the first control terminal (U1_6) controls the on and off of the first switch circuit (11), and the two ends of the step-down circuit (14) are connected in parallel to the positive pole (V+) of the battery pack and the positive power supply electrode (C+), so as to reduce the voltage so that the high-voltage battery pack supplies power to the low-voltage battery pack; the auxiliary control circuit (13) is connected between the monitoring control circuit (12) and the main control circuit (3), and is provided with a second control terminal (U2_4), and the second control terminal (U2_4) is connected to the step-down circuit (14), so that the second control terminal (U2_4) controls the on and off of the step-down circuit (14).

3. A multi-battery pack balancing circuit according to claim 2, characterized in that: The step-down circuit (14) is also provided with a second switch circuit (15); the parallel step-down circuit (14) is switched on and off via the second control terminal (U2_4).

4. A multi-battery pack balancing circuit according to claim 3, characterized in that: The step-down circuit (14) is a DC-DC module, the second switch circuit (15) is a first MOS transistor (Q1), and the gate of the first MOS transistor (Q1) is controlled by the second control terminal (U2_4).

5. A multi-battery pack balancing circuit according to claim 2, characterized in that: The first switch circuit (11) is provided with a plurality of switch elements, all of which are switched on and off by the first control terminal (U1_6).

6. A multi-battery pack balancing circuit according to claim 3, characterized in that: The switch element is a second MOS tube (Q2), the second MOS tube (Q2) is an N-channel MOS tube, a plurality of the second MOS tubes (Q2) are connected in parallel, the first control end (U1_6) is connected to the gate of the second MOS tube (Q2), the source and drain of the second MOS tube (Q2) are connected between the first battery pack (4) and the positive power supply electrode (C+), or the source and drain of the second MOS tube (Q2) are connected between the second battery pack (5) and the positive power supply electrode (C+).

7. A multi-battery pack balancing circuit according to claim 4, characterized in that: The monitoring control circuit (12) further comprises a third control terminal (U1_7), the switch element further comprises a third MOS tube (Q3), the third MOS tube (Q3) is an N-channel MOS tube, a plurality of the third MOS tubes (Q3) are connected in parallel, and the third control terminal (U1_7) is connected to the gate of the third MOS tube (Q3), the source and drain of the third MOS tube (Q3) are connected between the first battery pack (4) and the positive power supply electrode (C+), or the source and drain of the third MOS tube (Q3) are connected between the second battery pack (5) and the positive power supply electrode (C+).

8. A multi-battery pack balancing circuit according to claim 2, characterized in that: The monitoring control circuit (12) is provided with an analog front-end chip (U1), and the analog front-end chip (U1) is also provided with a monitoring terminal (U1_1), a first current testing terminal (U1_2), a second current testing terminal (U1_3), a charging monitoring terminal (U1_4), and a first communication terminal (U1_5); a current measuring resistor (R1) is provided between the negative electrode of the first battery pack (4) and the negative power supply electrode (C-), or a current measuring resistor (R1) is provided between the negative electrode of the second battery pack (5) and the negative power supply electrode (C-); The monitoring terminal (U1_1) is connected to the positive electrode of the first battery pack (4), or the monitoring terminal (U1_1) is connected to the positive electrode of the second battery pack (5); the first current test terminal (U1_2) and the second current test terminal (U1_3) are connected to both ends of the current measuring resistor (R1); the charging detection terminal is connected between the power supply positive electrode (C+) and the positive electrode of the first battery pack (4), or the charging detection terminal is connected between the power supply positive electrode (C+) and the positive electrode of the second battery pack (5); and the first communication terminal (U1_5) is connected to the auxiliary control circuit (13).

9. The multi-battery pack balancing circuit according to claim 2, characterized in that: The auxiliary control circuit (13) is provided with an auxiliary control chip (U2), the main control circuit (3) is provided with a main control chip (U3), the auxiliary control chip (U2) is also provided with a first ID verification terminal (U2_1), a second communication terminal (U2_2) and a third communication terminal (U2_3); the main control chip (U3) is provided with a fourth communication terminal (U3_2) and a second ID verification terminal (U3_1); the first ID verification terminal (U2_1) is connected to the second ID verification terminal (U3_1), the second communication terminal (U2_2) is connected to the fourth communication terminal (U3_2), and the third communication terminal (U2_3) is connected to the first communication terminal (U1_5).

10. The multi-battery pack balancing circuit according to claim 1, characterized in that: The positive electrode of the first battery pack (4) and the positive electrode of the second battery pack (5) are both provided with a fuse (F1).

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