Battery equalization circuit and battery protection board

Abstract

The utility model provides a battery equalization circuit and a battery protection board, and belongs to the technical field of battery control. The battery equalization circuit comprises a first battery, a second battery, a first group of switch units, a second group of switch units and an energy storage assembly, one end of the first battery is connected with one end of the second battery, the first group of switch units are respectively connected with two ends of the first battery, and the second group of switch units are respectively connected with two ends of the second battery. The energy storage assembly comprises a first end and a second end, the first end is connected with the first group of switch units, and the second end is connected with the second group of switch units. On the basis of the first group of switch units and the second group of switch units, energy between the first battery and the second battery can be transferred from a high-voltage single battery to a low-voltage single battery through the energy storage assembly, so that the problem that the voltage of each single battery in the battery system is unbalanced is solved; therefore, the energy storage capacity of the battery pack can be fully utilized, and the energy utilization efficiency of the whole system is improved.

Description

Technical Field

[0001] This application belongs to the technical field of battery control, and particularly relates to a battery equalization circuit and a battery protection board. Background Art

[0002] With the rapid development of batteries towards high energy density and large current charge and discharge, the charge and discharge current of the battery is large and the time is short. Voltage imbalance may occur among individual cells inside the battery system, and the battery system may not be able to output normal power, limiting its application performance. Utility Model Content

[0003] In view of the above problems, this application provides a battery equalization circuit and a battery protection board, which solve the technical problem of voltage imbalance among individual cells inside the battery system.

[0004] This application provides a battery equalization circuit. The battery equalization circuit includes: a first battery and a second battery, one end of the first battery is connected to one end of the second battery, a first group of switch units, the first group of switch units are respectively connected to both ends of the first battery, a second group of switch units, the second group of switch units are respectively connected to both ends of the second battery, and an energy storage component, the energy storage component includes a first end and a second end, the first end is connected to the first group of switch units, and the second end is connected to the second group of switch units.

[0005] In some embodiments, the first battery has a first voltage V1, the second battery has a second voltage V2, and the first battery is configured to charge the second battery through the energy storage component when the first voltage V1 is greater than the second voltage V2.

[0006] In some embodiments, the first group of switch units includes a first switch and a second switch connected in series, and the second group of switch units includes a third switch and a fourth switch connected in series; the first end is connected between the first switch and the second switch, and the second end is connected between the third switch and the fourth switch.

[0007] In some embodiments, when the first battery charges the second battery through the energy storage component, the first switch is turned on, the second switch is turned off, the third switch is turned on, and the fourth switch is turned off, so that the first battery and the energy storage component form a closed-loop circuit to enable the first battery to charge the energy storage component; after the first battery charges the energy storage component, the first switch is turned off, the second switch is turned on, the third switch is turned off, and the fourth switch is turned on, so that the second battery and the energy storage component form a closed-loop circuit to enable the energy storage component to charge the second battery.

[0008] In some embodiments, a first switch and a second switch are connected in series between one end and the other end of the first battery, and a third switch and a fourth switch are connected in series between one end and the other end of the second battery.

[0009] In some embodiments, there is a first connection node between the second switch and the third switch, and a second connection node between the first battery and the second battery, and the first connection node is connected to the second connection node.

[0010] In some embodiments, the first switch includes a first MOS transistor and a second MOS transistor, the second switch includes a third MOS transistor and a fourth MOS transistor, and the first MOS transistor, the second MOS transistor, the third MOS transistor, and the fourth MOS transistor are connected in series.

[0011] In some embodiments, the third switch includes a fifth MOS transistor and a sixth MOS transistor, the fourth switch includes a seventh MOS transistor and an eighth MOS transistor, and the fifth MOS transistor, the sixth MOS transistor, the seventh MOS transistor, and the eighth MOS transistor are connected in series.

[0012] In some embodiments, it further includes: a third battery, the third battery is connected in series between the first battery and the second battery; a third group of switch units is connected between the first battery and the third battery, and / or a third group of switch units is connected between the second battery and the third battery.

[0013] Correspondingly, the present application further provides a battery system, including the battery equalization circuit as described in the above embodiments.

[0014] The beneficial effect of the present application is that the present application provides a battery equalization circuit and a battery protection board. The first battery and the second battery of the battery equalization circuit are connected in series. The first group of switch units are respectively connected to both ends of the first battery, and the second group of switch units are respectively connected to both ends of the second battery. Both ends of the energy storage component are respectively connected to the first group of switch units and the second group of switch units; based on the first group of switch units and the second group of switch units, the energy is transferred from the single battery with a higher voltage to the single battery with a lower voltage between the first battery and the second battery through the energy storage component, and a voltage equalization operation is performed on the first battery and the second battery, solving the problem of voltage imbalance of each single battery inside the battery system. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of the overall structure of a battery equalization circuit provided by an embodiment of the present application;

[0017] Figure 2 It is a schematic diagram of an exemplary structure of the battery equalization circuit provided by an embodiment of the present application;

[0018] Figure 3 Another schematic structural diagram of the battery balancing circuit provided by the embodiment of the present application;

[0019] Figure 4 Yet another schematic structural diagram of the battery balancing circuit provided by the embodiment of the present application;

[0020] Figure 5 A schematic diagram of a switch provided by the embodiment of the present application;

[0021] Figure 6 Another schematic diagram of a switch provided by the embodiment of the present application;

[0022] Figure 7 Yet another schematic structural diagram of the battery balancing circuit provided by the embodiment of the present application.

[0023] Explanation of reference numerals:

[0024] 10 - First battery, 11 - First positive electrode, 12 - First negative electrode, 20 - Second battery, 21 - Second positive electrode, 22 - Second negative electrode, 30 - Energy storage component, 31 - First end, 32 - Second end, 40 - First group of switch units, 41 - First switch, 411 - First MOS transistor, 412 - Second MOS transistor, 42 - Second switch, 421 - Third MOS transistor, 422 - Fourth MOS transistor, 50 - Second group of switch units, 51 - Third switch, 511 - Fifth MOS transistor, 512 - Sixth MOS transistor, 52 - Fourth switch, 521 - Seventh MOS transistor, 522 - Eighth MOS transistor, 60 - Third battery, 70 - Third group of switch units, 71 - Fifth switch, 72 - Sixth switch, 73 - Seventh switch, 80 - First connection node, 90 - Second connection node, G - Gate, S - Source, D - Drain. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation terms such as "upper", "lower", "left", and "right" generally refer to the upper, lower, left, and right in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings.

[0026] The present application provides a battery balancing circuit and a battery protection board, which will be described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. And in the following embodiments, each embodiment has its own emphasis. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0027] The battery system of the product is a battery pack composed of multiple single cells. Due to the differences in the manufacturing and use processes, and with the rapid development of batteries towards high energy density and large current charging and discharging, the charging and discharging current of the battery is large and the time is short. Voltage imbalance may occur among the single cells inside the battery system, which limits its application performance and leads to a decline in battery performance, a decrease in stored energy, and a shortening of the lifespan.

[0028] In view of this, the embodiment of the present application provides a battery balancing circuit. By transferring energy from the single cell with a higher voltage to the single cell with a lower voltage between the first battery and the second battery through an energy storage component, a voltage balancing operation is performed on the first battery and the second battery to solve the problem of voltage imbalance among each single cell inside the battery system.

[0029] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the overall structure of a battery balancing circuit provided by an embodiment of the present application. The embodiment of the present application provides a battery balancing circuit. The battery balancing circuit includes: a first battery 10 and a second battery 20, one end of the first battery 10 is connected to one end of the second battery 20, a first group of switch units 40, the first group of switch units 40 are respectively connected to both ends of the first battery 10, a second group of switch units 50, the second group of switch units 50 are respectively connected to both ends of the second battery 20, an energy storage component 30, the energy storage component 30 includes a first end 31 and a second end 32, the first end 31 is connected to the first group of switch units 40, and the second end 32 is connected to the second group of switch units 50.

[0030] Exemplarily, the first battery 10 includes a first positive electrode 11 and a first negative electrode 12, the second battery 20 includes a second positive electrode 21 and a second negative electrode 22, and the first negative electrode 12 is connected to the second positive electrode 21. One end of the first battery 10 is the first negative electrode 12, the other end of the first battery 10 is the first positive electrode 11, one end of the second battery 20 is the second positive electrode 21, the other end of the second battery 20 is the second negative electrode 22, the first negative electrode 12 is connected to the second positive electrode 21, the first group of switching units are respectively connected to both ends of the first battery 10 to form a loop with the first battery, and the second group of switching units are respectively connected to both ends of the second battery 20 to form a loop with the second battery. Specifically, the first positive electrode 11 is connected to one end of the first group of switching units 40, the other end of the first group of switching units 40 is connected to the first negative electrode 12, the second negative electrode 22 is connected to one end of the second group of switching units 50, and the other end of the second group of switching units 50 is connected to the second positive electrode 21.

[0031] In some embodiments, the energy storage component 30 may include a capacitor.

[0032] It should be understood that the energy storage component 30 includes, but is not limited to, energy storage devices such as capacitors and inductors.

[0033] Through the above technical solution, based on the first group of switching units 40 and the second group of switching units 50, the energy is transferred from the single battery with a higher voltage between the first battery 10 and the second battery 20 to the single battery with a lower voltage through the energy storage component 30, and a voltage equalization operation is performed on the first battery 10 and the second battery 20, thereby solving the problem of voltage imbalance of each single battery inside the battery system. Moreover, the circuit in the battery equalization circuit will flow current into the energy storage component 30 to charge the energy storage component 30, and these energy storage components 30 can release the stored energy when needed to provide energy to the single battery with a lower voltage, thereby reducing the difference between each battery and ensuring the consistency of the overall performance of each battery, which helps to improve the overall energy storage and release efficiency of the battery pack and enhance the power output ability.

[0034] In some embodiments, the first battery 10 has a first voltage V1, the second battery 20 has a second voltage V2, and the first battery 10 is configured to charge the second battery 20 through the energy storage component 30 when the first voltage V1 is greater than the second voltage V2. Wherein, the first voltage V1 is the voltage across the first battery 10, and the second voltage V2 is the voltage across the second battery 20. Exemplarily, the first voltage V1 and the second voltage V2 are the voltages across the first battery 10 and the second battery 20 respectively measured before the voltage equalization operation is performed on the first battery 10 and the second battery 20, and then the corresponding voltage equalization operation is performed based on the measured voltages across the first battery 10 and the second battery 20.

[0035] Specifically, based on the first group of switching units 40 and the second group of switching units 50, the on-off states at both ends of the first battery 10 and the second battery 20 are adjusted respectively, so that the first battery 10 and the energy storage assembly 30 form a closed-loop circuit, enabling the first battery 10 to charge the energy storage assembly 30. After the first battery 10 charges the energy storage assembly 30, based on the first group of switching units 40 and the second group of switching units 50, the on-off states at both ends of the first battery 10 and the second battery 20 are adjusted respectively, so that the second battery 20 and the energy storage assembly 30 form a closed-loop circuit, enabling the energy storage assembly 30 to charge the second battery 20. Thus, the first battery 10 charges the second battery 20 through the energy storage assembly 30.

[0036] Exemplarily, taking the case where the first battery 10 charges the second battery 20 through the energy storage assembly 30 as an example, first, the first battery 10 releases energy to the energy storage assembly 30, and the energy storage assembly 30 stores the energy released by the first battery 10, that is, the first battery 10 charges the energy storage assembly 30. Specifically, by the on-off states of the first group of switching units 40 and the second group of switching units 50, the first battery 10 and the energy storage assembly 30 form a closed-loop circuit. Specifically, through the on-off state of the first group of switching units 40, the route connecting the first positive electrode 11 of the first battery 10 and the first group of switching units 40 is made conductive, and the route connecting the first negative electrode 12 of the first battery 10 and the first group of switching units 40 is made disconnected; through the on-off state of the second group of switching units 50, the route connecting the second positive electrode 21 of the second battery 20 and the second group of switching units 50 is made conductive, and the route connecting the second positive electrode 21 of the second battery 20 and the second group of switching units 50 is made disconnected, thereby enabling the first battery 10 and the energy storage assembly 30 to form a closed-loop circuit.

[0037] Then, the energy storage assembly 30 releases energy to the second battery 20, and the second battery 20 receives the energy released by the energy storage assembly 30, that is, the energy storage assembly 30 charges the second battery 20. Specifically, by the on-off states of the first group of switching units 40 and the second group of switching units 50, the second battery 20 and the energy storage assembly 30 form a closed-loop circuit. Specifically, through the on-off state of the first group of switching units 40, the route connecting the first positive electrode 11 of the first battery 10 and the first group of switching units 40 is made disconnected, and the route connecting the first negative electrode 12 of the first battery 10 and the first group of switching units 40 is made conductive; through the on-off state of the second group of switching units 50, the route connecting the second positive electrode 21 of the second battery 20 and the second group of switching units 50 is made disconnected, and the route connecting the second positive electrode 21 of the second battery 20 and the second group of switching units 50 is made conductive, thereby enabling the second battery 20 and the energy storage assembly 30 to form a closed-loop circuit.

[0038] When the energy storage component 30 stores battery energy and releases the stored energy, that is, during the charging and discharging processes of the energy storage component 30, it is usually necessary to form a closed-loop circuit between the corresponding battery and the energy storage component 30. The energy storage component 30 stores battery energy and releases energy to the battery by accumulating and releasing charges. When the voltage across the battery is higher than the voltage across the energy storage component 30, current will flow into the energy storage component 30, causing positive charges to accumulate at the end of the energy storage component 30 connected to the positive electrode of the battery and negative charges to accumulate at the end connected to the negative electrode of the battery. This results in an increase in the electric field energy of the energy storage component 30, and the energy is stored in the electric field. However, when the voltage across the energy storage component 30 is higher than the voltage across the battery, current will flow out of the energy storage component 30, and the energy storage component 30 begins to release the stored electric field energy. In this way, the energy storage component 30 provides energy to the battery.

[0039] Through the above technical solution, the first battery 10 charges the second battery 20 through the energy storage component 30 to realize the redistribution of energy among the batteries, reduce the energy loss during the equalization process, improve the energy utilization rate of the battery pack, and extend the duration of a single charge of the battery system.

[0040] Please refer to Figure 2 , Figure 2 , which is a schematic structural diagram of an example of the battery equalization circuit provided by the embodiment of the present application. In some embodiments, the first group of switch units 40 includes a first switch 41 and a second switch 42 connected in series, and the second group of switch units 50 includes a third switch 51 and a fourth switch 52 connected in series; the first end 31 is connected between the first switch 41 and the second switch 42, and the second end 32 is connected between the third switch 51 and the fourth switch 52.

[0041] Taking the example of the first battery 10 charging the second battery 20 through the energy storage component 30. When the first battery 10 charges the second battery 20 through the energy storage component 30, first, the first battery 10 releases energy to the energy storage component 30, then the first switch 41 is turned on, the second switch 42 is turned off, the third switch 51 is turned on, and the fourth switch is turned off, so that the first battery 10 and the energy storage component 30 form a closed-loop circuit to enable the first battery 10 to charge the energy storage component 30;

[0042] After the first battery 10 charges the energy storage component 30, the energy storage component 30 releases energy to the second battery 20, then the first switch 41 is turned off, the second switch 42 is turned on, the third switch 51 is turned off, and the fourth switch is turned on, so that the second battery 20 and the energy storage component 30 form a closed-loop circuit to enable the energy storage component 30 to charge the second battery 20.

[0043] Through the above technical solution, the current flow direction of the batteries in the circuit of the battery equalization circuit is restricted by the first switch 41, the second switch 42, the third switch 51 and the fourth switch 52, so that when the first battery 10 and the second battery 20 have unequal voltages, the battery with a higher voltage charges the battery with a lower voltage through the energy storage component 30, and a voltage equalization operation is performed on the first battery 10 and the second battery 20.

[0044] Please refer to Figure 3 , Figure 3 which is another schematic structural diagram of the battery equalization circuit provided by the embodiment of the present application. In some embodiments, a first switch 41 and a second switch 42 are connected in series between one end and the other end of the first battery 10, and a third switch 51 and a fourth switch 52 are connected in series between one end and the other end of the second battery 20. Exemplarily, one end of the first battery 10 is the first negative electrode 12, the other end of the first battery 10 is the first positive electrode 11, one end of the second battery 20 is the second positive electrode 21, the other end of the second battery 20 is the second negative electrode 22, the first negative electrode 12 is connected to the second positive electrode 21, and a first switch 41 and one end of the second switch 42 are connected in series between the first positive electrode 11 and the first negative electrode 12, and a third switch 51 and a fourth switch 52 are connected in series between the second negative electrode 22 and the second positive electrode 21.

[0045] In some embodiments, there is a first connection node 80 between the second switch 42 and the third switch 51, and there is a second connection node 90 between the first battery 10 and the second battery 20, and the first connection node 80 is connected to the second connection node 90.

[0046] Exemplarily, one end of the second switch 42 connected to the first negative electrode 12 and one end of the third switch 51 connected to the second positive electrode 21 are connected, and the connection node is the first connection node 80; the first negative electrode 12 and the second positive electrode are connected, and the connection node is the second connection node 90.

[0047] Specifically, taking the charging of the second battery 20 by the first battery 10 through the energy storage component 30 as an example, first, a closed-loop circuit is formed by the first battery 10 and the energy storage component 30. Specifically, through the closed state of the first switch 41, the open state of the second switch 42, the closed state of the third switch 51, and the open state of the fourth switch 52, the first battery 10 releases energy to the energy storage component 30, and the energy storage component 30 stores the energy released by the first battery 10.

[0048] Then, a closed-loop circuit is formed by the second battery 20 and the energy storage component 30. Specifically, through the open state of the first switch 41, the closed state of the second switch 42, the open state of the third switch 51, and the closed state of the fourth switch 52, the energy storage component 30 releases energy to the second battery 20, and the second battery 20 receives the energy released by the energy storage component 30.

[0049] Through the above technical solution, during the voltage equalization process of the first battery 10 and the second battery 20, by the on / off states of the first switch 41, the second switch 42, the third switch 51, and the fourth switch 52, the battery with a higher voltage is first connected in series with the energy storage component 30, and the battery with a higher voltage charges the energy storage component 30 first; then the energy storage component 30 is connected in series with the battery with a lower voltage, and the energy storage component 30 charges the battery with a lower voltage; thus, the voltage equalization operation of the first battery 10 and the second battery 20 is achieved.

[0050] Please refer to Figure 4 , Figure 4 which is another exemplary structural schematic diagram of the battery equalization circuit provided by the embodiment of the present application. In the figure, G is the gate of the MOS transistor, S is the source of the MOS transistor, and D is the drain of the MOS transistor. In some embodiments, the first switch 41 includes a first MOS transistor 411 and a second MOS transistor 412, the second switch 42 includes a third MOS transistor 421 and a fourth MOS transistor 422, and the first MOS transistor 411, the second MOS transistor 412, the third MOS transistor 421, and the fourth MOS transistor 422 are connected in series.

[0051] In some embodiments, the third switch 51 includes a fifth MOS transistor 511 and a sixth MOS transistor 512, the fourth switch 52 includes a seventh MOS transistor 521 and an eighth MOS transistor 522, and the fifth MOS transistor 511, the sixth MOS transistor 512, the seventh MOS transistor 521, and the eighth MOS transistor 522 are connected in series.

[0052] Exemplarily, the drain of the first MOS transistor 411 is connected to the first positive electrode 11, the source of the first MOS transistor 411 is connected to the source of the second MOS transistor 412, the drain of the second MOS transistor 412 is connected to the drain of the third MOS transistor 421, the source of the third MOS transistor 421 is connected to the source of the fourth MOS transistor 422, the drain of the fourth MOS transistor 422 is connected to the drain of the fifth MOS transistor 511, the source of the fifth MOS transistor 511 is connected to the source of the sixth MOS transistor 512, the drain of the sixth MOS transistor 512 is connected to the source of the seventh MOS transistor 521, the drain of the seventh MOS transistor 521 is connected to the drain of the eighth MOS transistor 522, and the source of the eighth MOS transistor 522 is connected to the second positive electrode 21; the first end 31 is connected between the second MOS transistor 412 and the third MOS transistor 421, and the second end 32 is connected between the sixth MOS transistor 512 and the seventh MOS transistor 521; there is a first connection node 80 between the fourth MOS transistor 422 and the fifth MOS transistor 511, and there is a second connection node 90 between the first negative electrode 12 and the second positive electrode 21.

[0053] To simplify the control of the on / off states of each switch, specifically, the gate of the first MOS transistor 411 is connected to the gate of the second MOS transistor 412, the gate of the third MOS transistor 421 is connected to the gate of the fourth MOS transistor 422, the gate of the fifth MOS transistor 511 is connected to the gate of the sixth MOS transistor 512, and the gate of the seventh MOS transistor 521 is connected to the gate of the eighth MOS transistor 522. The on / off states of the first MOS transistor 411 and the second MOS transistor 412 are the same, the on / off states of the third MOS transistor 421 and the fourth MOS transistor 422 are the same, the on / off states of the fifth MOS transistor 511 and the sixth MOS transistor 512 are the same, and the on / off states of the seventh MOS transistor 521 and the eighth MOS transistor 522 are the same.

[0054] Specifically, taking the example of the first battery 10 charging the second battery 20 through the energy storage module 30, first, the first battery 10 releases energy to the energy storage module 30, and the energy storage module 30 stores the energy released by the first battery 10. Specifically, the first MOS transistor 411 and the second MOS transistor 412 are both in the saturation state, the third MOS transistor 421 and the fourth MOS transistor 422 are both in the cut-off state; the fifth MOS transistor 511 and the sixth MOS transistor 512 are both in the saturation state, and the seventh MOS transistor 521 and the eighth MOS transistor 522 are both in the cut-off state, so that the first battery 10 and the energy storage module 30 form a closed-loop circuit.

[0055] Then, the energy storage module 30 releases energy to the second battery 20, and the second battery 20 receives the energy released by the energy storage module 30. Specifically, the first MOS transistor 411 and the second MOS transistor 412 are both in the cut-off state, the third MOS transistor 421 and the fourth MOS transistor 422 are both in the saturation state; the fifth MOS transistor 511 and the sixth MOS transistor 512 are both in the cut-off state, and the seventh MOS transistor 521 and the eighth MOS transistor 522 are both in the saturation state, so that the second battery 20 and the energy storage module 30 form a closed-loop circuit.

[0056] In some embodiments, when a voltage imbalance occurs between the first battery 10 and the second battery 20, the voltages of the first battery 10 and the second battery 20 are obtained through a fuel gauge in the static state of the host end of the device where the battery system is located, and then the MOS transistors are controlled to perform voltage equalization between the first battery 10 and the second battery 20.

[0057] The fuel gauge is respectively connected in parallel across the two ends of the first battery 10 and the second battery 20 to obtain the voltages of the first battery 10 and the second battery 20; then, based on the voltages at both ends of the first battery 10 and the second battery 20, the on / off states of the first MOS transistor 411, the second MOS transistor 412, the third MOS transistor 421, the fourth MOS transistor 422, the fifth MOS transistor 511, the sixth MOS transistor 512, the seventh MOS transistor 521, and the eighth MOS transistor 522 are configured. The specific control process is as follows:

[0058] Based on the voltage difference obtained by the fuel gauge between the first battery 10 and the second battery 20, if the voltage difference is greater than the voltage difference threshold, the balancing process is started to balance the voltages of the first battery 10 and the second battery 20. Specifically, taking the example where the first battery 10 has a first voltage V1 greater than the second battery 20 having a second voltage V2, the first MOS transistor 411 and the second MOS transistor 412 are turned on, the third MOS transistor 421 and the fourth MOS transistor 422 are turned off, the fifth MOS transistor 511 and the sixth MOS transistor 512 are turned on, and the seventh MOS transistor 521 and the eighth MOS transistor 522 are turned off. This enables the first battery 10 to charge the energy storage component 30. Based on the time threshold, when the charging time of the energy storage component 30 reaches the time threshold, the first MOS transistor 411 and the second MOS transistor 412 are turned off, the third MOS transistor 421 and the fourth MOS transistor 422 are turned on, the fifth MOS transistor 511 and the sixth MOS transistor 512 are turned off, and the seventh MOS transistor 521 and the eighth MOS transistor 522 are turned on. This allows the energy storage component 30 to charge the second battery 20, transferring the energy obtained from the first battery 10 to the second battery 20. Based on the time threshold, when the discharging time of the energy storage component 30 reaches the time threshold, the first MOS transistor 411, the second MOS transistor 412, the third MOS transistor 421, the fourth MOS transistor 422, the fifth MOS transistor 511, the sixth MOS transistor 512, the seventh MOS transistor 521, and the eighth MOS transistor 522 are all turned off. The above steps are repeated until the voltage difference is not greater than the voltage difference threshold or the host end of the device where the battery system is located is in an operating state, achieving voltage balance between the first battery 10 and the second battery 20 and keeping the voltages of each battery as close as possible.

[0059] In some embodiments, the eight MOS transistors, namely the first MOS transistor 411, the second MOS transistor 412, the third MOS transistor 421, the fourth MOS transistor 422, the fifth MOS transistor 511, the sixth MOS transistor 512, the seventh MOS transistor 521, and the eighth MOS transistor 522, can be packaged into an IC (Integrated Circuit), achieving circuit simplification and still being able to meet the voltage balance design requirements between the first battery 10 and the second battery 20.

[0060] Through the above technical solution, due to the existence of the MOS parasitic diode, conduction can still occur through the parasitic diode in the off state of the MOS transistor. Furthermore, by connecting two MOS transistors in series, a controllable conduction path can be provided, avoiding the influence caused by the conduction of the parasitic diode.

[0061] Please refer to Figure 5 , Figure 5 which is a schematic diagram of a switch provided by an embodiment of the present application. In some embodiments, the two MOS transistors included in each switch are connected in series, specifically, the source S is connected to the source S.

[0062] Please refer to Figure 6 , Figure 6 which is another schematic diagram of a switch provided by an embodiment of the present application. In some embodiments, the two MOS transistors included in each switch are connected in series, specifically, the drain D is connected to the drain D.

[0063] It should be understood that the saturation state of the MOS transistor is the on state of the MOS transistor, and the cut-off state of the MOS transistor is the off state of the MOS transistor.

[0064] It should be understood that the first switch 41, the second switch 42, the third switch 51, and the fourth switch 52 in the present application may also adopt other switching devices, including but not limited to relays, transistors, etc.

[0065] In some embodiments, the battery equalization circuit further includes a third battery 60, and the third battery 60 is connected in series between the first battery 10 and the second battery 20; a third group of switch units 70 is connected between the first battery 10 and the third battery 60, and / or a third group of switch units 70 is connected between the second battery 20 and the third battery 60. Exemplarily, the positive electrode of the third battery 60 is connected to the negative electrode of the first battery 10, and the negative electrode of the third battery 60 is connected to the positive electrode of the second battery.

[0066] That is to say, the battery equalization circuit may only have a third group of switch units 70 connected between the first battery 10 and the third battery 60, or may only have a third group of switch units 70 connected between the second battery 20 and the third battery 60, or may also have a third group of switch units 70 connected between the first battery 10 and the third battery 60 and between the second battery 20 and the third battery 60. In some embodiments, a third group of switch units 70 is connected between the first battery 10 and the third battery 60. Exemplarily, the third group of switch units 70 includes a fifth switch 71, one end of the fifth switch 71 is connected to the first connection node 80, and the other end of the fifth switch 71 is connected between the first battery and the third battery. Exemplarily, if the positive electrode of the third battery 60 is connected to the negative electrode of the first battery 10 and the negative electrode of the third battery 60 is connected to the positive electrode of the second battery 20, then the other end of the fifth switch 71 is connected to the connection node between the positive electrode of the third battery 60 and the negative electrode of the first battery 10.

[0067] Specifically, in the case where a third group of switch units 70 is connected between the first battery 10 and the third battery 60, taking the first battery 10 charging the second battery 20 and the third battery 60 through the energy storage component 30 as an example. First, the first battery 10 releases energy to the energy storage component 30, and the energy storage component 30 stores the energy released by the first battery 10. Specifically, through the closed state of the first switch 41, the open state of the second switch 42, the closed state of the third switch 51, the open state of the fourth switch 52, and the closed state of the fifth switch 71, a closed-loop circuit is formed between the first battery 10 and the energy storage component 30.

[0068] Then, the energy storage component 30 releases energy to the connected second battery 20 and third battery 60. The second battery 20 receives the energy released by the energy storage component 30, specifically by the first switch 41 being in the off state, the second switch 42 being in the on state, the third switch 51 being in the off state, the fourth switch 52 being in the on state, and the fifth switch 71 being in the on state, so that the second battery 20 and the third battery 60 are connected in series with the energy storage component 30 to form a closed-loop circuit.

[0069] In some other examples, a third group of switch units 70 is connected between the second battery 20 and the third battery 60. Exemplarily, the third group of switch units 70 includes a fifth switch 71. One end of the fifth switch 71 is connected to the first connection node 80, and the other end of the fifth switch 71 is connected between the third battery 60 and the second battery 20, that is, the connection node between the negative electrode of the third battery 60 and the positive electrode of the second battery 20.

[0070] Specifically, taking the example of the connected first battery 10 and third battery 60 charging the second battery 20 through the energy storage component 30. First, the connected first battery 10 and third battery 60 release energy to the energy storage component 30, and the energy storage component 30 stores the energy released by the connected first battery 10 and third battery 60. Specifically, by the first switch 41 being in the on state, the second switch 42 being in the off state, the third switch 51 being in the on state, the fourth switch 52 being in the off state, and the fifth switch 71 being in the on state, the first battery 10 and the energy storage component 30 form a closed-loop circuit.

[0071] Then, the energy storage component 30 releases energy to the connected second battery 20, and the second battery 20 receives the energy released by the energy storage component 30. Specifically, by the first switch 41 being in the off state, the second switch 42 being in the on state, the third switch 51 being in the off state, the fourth switch 52 being in the on state, and the fifth switch 71 being in the on state, the second battery 20 and the energy storage component 30 form a closed-loop circuit.

[0072] Through the above technical solution, the present application can enable one or more connected batteries with a relatively high single-cell voltage to transfer energy to the energy storage component 30, and then the energy storage component 30 transfers the energy to one or more connected battery cells with a relatively low single-cell voltage.

[0073] Please refer to Figure 7 , Figure 7 which is another schematic structural diagram of the equalization protection board provided by the embodiment of the present application. In some other examples, a third group of switch units 70 is connected between the first battery 10 and the third battery 60, and a third group of switch units 70 is also connected between the second battery 20 and the third battery 60.

[0074] Exemplarily, the third group of switch units 70 includes a fifth switch 71, a sixth switch 72, and a seventh switch 73. The sixth switch 72 is connected in series between the second switch 42 and the third switch 51. One end of the fifth switch 71 is connected between the first battery 10 and the third battery 60, and the other end of the fifth switch 71 is connected between the second switch 42 and the sixth switch 72. One end of the seventh switch 73 is connected between the second battery 20 and the third battery 60, and the other end of the seventh switch 73 is connected between the sixth switch 72 and the third switch 51.

[0075] Specifically, taking the example of the first battery 10 charging the second battery 20 through the energy storage component 30. First, with the first switch 41 in the closed state, the second switch 42 in the open state, the third switch 51 in the closed state, the fourth switch 52 in the open state, the fifth switch 71 in the closed state, the sixth switch 72 in the closed state, and the seventh switch 73 in the open state, a closed-loop circuit is formed between the first battery 10 and the energy storage component 30, enabling the first battery 10 to release energy to the energy storage component 30, and the energy storage component 30 stores the energy released by the first battery 10.

[0076] Then, with the first switch 41 in the open state, the second switch 42 in the closed state, the third switch 51 in the open state, the fourth switch 52 in the closed state, the fifth switch 71 in the open state, the sixth switch 72 in the closed state, and the seventh switch 73 in the closed state, a closed-loop circuit is formed between the second battery 20 and the energy storage component 30. The energy storage component 30 releases energy to the second battery 20, and the second battery 20 receives the energy released by the energy storage component 30.

[0077] In some embodiments, the fifth switch 71, the sixth switch 72, and the seventh switch 73 each include two MOS transistors connected in series. The on / off states of the two MOS transistors included in each switch are the same.

[0078] Through the above technical solution, when there are more than two batteries in the battery system, through the first group of switch units 40, the second group of switch units 50, and the third group of switch units 70, the energy is transferred from the single battery with a higher voltage to the single battery with a lower voltage between the first battery 10, the second battery 20, and the third battery 60 through the energy storage component 30, and a voltage equalization operation is performed on the three batteries to make the voltages of the multiple batteries as balanced as possible.

[0079] It should be understood that when the number of batteries is greater than two and the multiple batteries are connected in series, one end of a switch is connected between two adjacent batteries, and a switch is connected in series between the other ends of two adjacent switches. Through the on / off states of the switches, a voltage equalization operation between the multiple batteries can be achieved, and the embodiments of the present application will not elaborate on other numbers of batteries.

[0080] Through the above technical solution, when there is voltage imbalance in the battery system, it will cause the voltage of some single cells to be too high or too low, thus increasing the risk of battery failure or damage. The circuit in the battery equalization circuit can adjust the voltage of each single cell to keep it in a relatively balanced state, thereby improving the reliability and safety of the battery. Maintaining battery balance by consuming energy causes the battery power to drop rapidly, and the loss will lead to overheating and energy waste of the battery, which may accelerate the aging process of the battery. Based on the cooperation of the energy storage component 30, the energy between the batteries is transferred, reducing the energy loss of the battery and extending the duration of a single charge. This can make full use of the energy storage capacity of the battery pack and improve the energy utilization efficiency of the entire system.

[0081] For balancing among multiple batteries, it is necessary to control the current direction in the battery equalization circuit, so as to achieve that in the case of uneven battery voltages, the battery equalization circuit can meet the current directions under both charging and discharging conditions. Therefore, in this solution, a switch is used to limit the current flow direction of the battery.

[0082] Correspondingly, an embodiment of the present application further provides a battery system, including the equalization protection board as described in the above embodiment.

[0083] Exemplarily, the battery system of the embodiment of the present application is applied to consumer electronic products such as smart phones, computers, and wearable devices, and can be used in products with a battery system including two battery combinations, as well as those with more than two.

[0084] It can be understood that the battery system transfers energy from the single cell with a high voltage to the single cell with a low voltage through the battery equalization circuit, solving the problem of uneven voltage of each single cell inside the battery system. This can make full use of the energy storage capacity of the battery pack and improve the energy utilization efficiency of the entire system.

[0085] In summary, the present application provides a battery equalization circuit and a battery protection board. In the present application, the battery equalization circuit can transfer energy from the single cell with a high voltage to the single cell with a low voltage between the first battery and the second battery through the energy storage component, perform voltage equalization operations on the first battery and the second battery, and solve the problem of uneven voltage of each single cell inside the battery system. And this can make full use of the energy storage capacity of the battery pack and improve the energy utilization efficiency of the entire system.

[0086] The above has provided a detailed introduction to a battery equalization circuit and a battery protection board provided by the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A battery balancing circuit, characterized in that, Comprising: A first battery (10) and a second battery (20), one end of the first battery (10) being connected to one end of the second battery (20), A first set of switch units (40), the first set of switch units (40) being respectively connected to both ends of the first battery (10), A second set of switch units (50), the second set of switch units (50) being respectively connected to both ends of the second battery (20), An energy storage component (30), the energy storage component (30) including a first end (31) and a second end (32), the first end (31) being connected to the first set of switch units (40), and the second end (32) being connected to the second set of switch units (50).

2. A battery equalization circuit according to claim 1, wherein: The first battery (10) has a first voltage V1, the second battery (20) has a second voltage V2, and the first battery (10) is configured to charge the second battery (20) through the energy storage component (30) when the first voltage V1 is greater than the second voltage V2.

3. A battery equalization circuit according to claim 1, wherein: The first set of switch units (40) includes a first switch (41) and a second switch (42) connected in series with each other, and the second set of switch units (50) includes a third switch (51) and a fourth switch (52) connected in series with each other; the first end (31) is connected between the first switch (41) and the second switch (42), and the second end (32) is connected between the third switch (51) and the fourth switch (52).

4. A battery equalization circuit according to claim 3, wherein: When the first battery (10) charges the second battery (20) through the energy storage component (30), the first switch (41) is turned on, the second switch (42) is turned off, the third switch (51) is turned on, and the fourth switch is turned off, so that the first battery (10) and the energy storage component (30) form a closed-loop circuit to enable the first battery (10) to charge the energy storage component (30); After the first battery (10) charges the energy storage component (30), the first switch (41) is turned off, the second switch (42) is turned on, the third switch (51) is turned off, and the fourth switch is turned on, so that the second battery (20) and the energy storage component (30) form a closed-loop circuit to enable the energy storage component (30) to charge the second battery (20).

5. A battery equalization circuit according to claim 3, wherein: The first switch (41) and the second switch (42) are connected in series between one end and the other end of the first battery (10), The third switch (51) and the fourth switch (52) are connected in series between one end and the other end of the second battery (20).

6. A battery equalization circuit according to claim 5, wherein: A first connection node (80) is provided between the second switch (42) and the third switch (51), a second connection node (90) is provided between the first battery (10) and the second battery (20), and the first connection node (80) is connected to the second connection node (90).

7. A battery equalization circuit according to claim 3, wherein: The first switch (41) includes a first MOS transistor (411) and a second MOS transistor (412), the second switch (42) includes a third MOS transistor (421) and a fourth MOS transistor (422), and the first MOS transistor (411), the second MOS transistor (412), the third MOS transistor (421), and the fourth MOS transistor (422) are connected in series.

8. A battery equalization circuit according to claim 3, wherein: The third switch (51) includes a fifth MOS transistor (511) and a sixth MOS transistor (512), the fourth switch (52) includes a seventh MOS transistor (521) and an eighth MOS transistor (522), and the fifth MOS transistor (511), the sixth MOS transistor (512), the seventh MOS transistor (521), and the eighth MOS transistor (522) are connected in series.

9. The battery equalization circuit according to claim 1, wherein Further comprising: A third battery (60) connected in series between the first battery (10) and the second battery (20); A third set of switch units (70) is connected between the first battery (10) and the third battery (60), and / or a third set of switch units (70) is connected between the second battery (20) and the third battery (60).

10. A battery protection board, wherein: It includes the battery equalization circuit according to any one of claims 1-9.

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