Battery heating circuit, battery system, and electrical apparatus

Abstract

A battery heating circuit, a battery system, and an electrical apparatus, relating to the technical field of batteries. The battery comprises a first battery pack (11) and a second battery pack (12) connected in series. The battery heating circuit comprises a first switch circuit (101), a first energy storage circuit (102), a second energy storage circuit (103), and a controller. The first switch circuit (101) is configured to connect the first energy storage circuit (102), the second energy storage circuit (103), and the first battery pack (11) to form a first heating loop, and is configured to connect the first energy storage circuit (102), the second energy storage circuit (103), and the second battery pack (12) to form a second heating loop. The battery heating circuit can improve battery heating efficiency.

Description

Battery heating circuit, battery system and electrical device

[0001] Cross-references

[0002] This application incorporates Chinese Patent Application No. 202411729699.5, filed on November 28, 2024, entitled “Battery Heating Circuit, Battery System and Electrical Device”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery heating circuit, a battery system, and an electrical device. Background Technology

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0005] To address the issue of low battery charging efficiency in low-temperature environments, the battery can be preheated, and then charged once the battery temperature reaches the required level. However, current methods typically employ external heating devices, resulting in relatively low heating efficiency. Summary of the Invention

[0006] This application aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of this application is to provide a battery heating circuit, a battery system, and an electrical device to solve the aforementioned problems existing in the related art.

[0007] An embodiment of the first aspect of this application provides a battery heating circuit. The battery includes a first battery pack and a second battery pack connected in series. The battery heating circuit includes: a first switching circuit, which includes a first connection point, a second connection point, and a third connection point interconnected by a switching element. The first connection point is connected to the positive terminal of the battery, and the second connection point is connected to the negative terminal of the battery; a first energy storage circuit, with a first terminal connected to the third connection point; and a second energy storage circuit, with a first terminal connected to a second terminal of the first energy storage circuit, and the second terminal of the second energy storage circuit electrically connected to the midpoint between the first battery pack and the second battery pack. The first switching circuit is configured to connect the first energy storage circuit, the second energy storage circuit, and the first battery pack to form a first heating circuit, and to connect the first energy storage circuit, the second energy storage circuit, and the second battery pack to form a second heating circuit.

[0008] In the technical solution of this application embodiment, the first terminal of the second energy storage circuit is connected to the second terminal of the first energy storage circuit, that is, the first energy storage circuit and the second energy storage circuit are connected in series. In the first heating circuit, the first energy storage circuit and the second energy storage circuit, due to their energy storage function, can exchange energy with the first battery pack, thereby heating the first battery pack. Similarly, in the second heating circuit, the first energy storage circuit and the second energy storage circuit exchange energy with the second battery pack, thereby heating the second battery pack. Since the first energy storage circuit and the second energy storage circuit are connected in series, the energy storage capacity can be increased, thereby improving the energy exchange efficiency between the first battery pack or the second battery pack and the first energy storage circuit and the second energy storage circuit, and improving the heating efficiency of the first battery pack and the second battery pack.

[0009] In some embodiments, the battery heating circuit further includes a controller configured to control the first switching circuit to switch between the first heating circuit and the second heating circuit. This enables multiple heating modes for the battery to meet different heating requirements.

[0010] In some embodiments, the first switching circuit includes at least one first switching branch, with its two ends connected to a first connection point and a second connection point, respectively. The first switching branch includes a first switching element and a second switching element connected in series, and the midpoint between the first and second switching elements serves as a third connection point connected to the first energy storage circuit. Through the first and second switching elements, the first connection point, the second connection point, and the third connection point can be interconnected, allowing the first energy storage circuit to selectively connect to either a first battery pack or a second battery pack. This enables the first and second energy storage circuits to be connected to the first and second battery packs, respectively, to form a first heating circuit and a second heating circuit for heating the battery.

[0011] In some embodiments, there are multiple first switching branches connected in parallel. The first energy storage circuit includes multiple first energy storage elements connected in parallel, and each of the multiple first energy storage elements is connected to the midpoint between the first switching element and the second switching element of the first switching branch. This allows the multiple first switching branches to connect the corresponding first and second energy storage elements to a first battery pack or a second battery pack, forming multiple first heating circuits or multiple second heating circuits, thereby improving heating efficiency.

[0012] In some embodiments, the first switching branch is a first bridge arm, which includes a first upper bridge arm and a first lower bridge arm connected in series. The switching element of the first upper bridge arm serves as a first switching element, and the switching element of the first lower bridge arm serves as a second switching element. The first bridge arm has a simple structure and is easy to control, which simplifies the circuit while improving the reliability of battery heating control.

[0013] In some embodiments, the first energy storage element is an inductor. An inductor can store a large amount of electricity, thereby improving the efficiency of energy transfer between the first battery pack, the second battery pack, and the first energy storage element, and thus improving the heating efficiency of the first and second battery packs.

[0014] In some embodiments, the first switching circuit further includes a second switching branch, the two ends of which are connected to the first connection point and the second connection point, respectively. The second switching branch includes a third switching element and a fourth switching element connected in series. The second switching branch can serve as a backup to replace the first switching branch if the first switching branch fails.

[0015] In some embodiments, the battery heating circuit further includes a second switching circuit. The first terminal of the second switching circuit is connected to the second terminal of the second energy storage circuit and the midpoint between the third and fourth switching elements. The second terminal of the second switching circuit is connected to the midpoint between the first and second battery packs. The first and second switching circuits are configured to connect the first energy storage circuit, the second energy storage circuit, the first battery pack, and the second battery pack to form a third heating circuit. In the third heating circuit, energy transfer between the first and second battery packs and the first and second energy storage circuits is realized, increasing the amount of energy transfer and thus increasing the energy stored in the first and second energy storage circuits. Therefore, when the third heating circuit switches to the first or second heating circuit, the amount of energy transfer between the first and second energy storage circuits and the first or second battery pack is increased, thereby improving energy transfer efficiency and further enhancing heating efficiency. Furthermore, by providing the second switching branch and the second switching circuit, a heating circuit for the battery pack can be added, allowing for the selection of the appropriate heating circuit according to different heating requirements to improve the heating effect.

[0016] In some embodiments, the second switching branch is a second bridge arm, which includes a second upper bridge arm and a second lower bridge arm connected in series. The switching element of the second upper bridge arm serves as a third switching element, and the switching element of the second lower bridge arm serves as a fourth switching element. The second bridge arm has a simple structure and is easy to control, which simplifies the circuit while improving the reliability of battery heating control.

[0017] In some embodiments, the second energy storage circuit includes one or more inductors, wherein the inductors are connected in series and / or parallel. Inductors can store a large amount of electricity, which can improve the energy transfer efficiency between the first and second battery packs and the second energy storage element, thereby improving the heating efficiency of the first and second battery packs. Furthermore, when multiple inductors are connected in parallel, high-frequency noise in the circuit can be suppressed, resulting in a more stable circuit current and further improving the battery heating efficiency. When multiple inductors are connected in series, the energy that the second energy storage circuit can store can be increased, thereby improving the energy transfer efficiency between the first and second battery packs and the second energy storage circuit, further enhancing the battery heating efficiency.

[0018] In some embodiments, the first switching circuit and the first energy storage circuit are motors connected to the battery, the first bridge arm is a multi-phase bridge arm in the motor, and the first energy storage circuit is a motor winding in the motor. In this way, if the battery is used in an electrical device and the electrical device has a motor, the motor in the electrical device can be directly reused, which can reduce the cost of the electrical device and keep the complexity of the circuit wiring in the electrical device from being too great.

[0019] In some embodiments, the first switching circuit, the first energy storage circuit, and the second energy storage circuit are motors connected to the battery, and the first switching branch and the second switching branch are multi-phase bridge arms in the motor. The first energy storage circuit and the second energy storage circuit are motor windings in the motor. In this way, while increasing the heating efficiency of the battery by adding a heating circuit through the first switching branch and the second switching branch, the first switching branch and the second switching branch, as well as the first energy storage circuit and the second energy storage circuit, can reuse the motor in the electrical device, reducing the cost of the electrical device, and without excessively increasing the complexity of the circuit wiring in the power supply device.

[0020] In some embodiments, the battery heating circuit further includes a third energy storage circuit, wherein a first terminal of the third energy storage circuit is connected to the positive terminal of the battery, and a second terminal of the third energy storage circuit is connected to the negative terminal of the battery. The third energy storage circuit connects the positive and negative terminals of the battery and can also form a circuit with the battery to achieve energy exchange, thereby further improving the battery's heating efficiency.

[0021] In some embodiments, the third energy storage circuit includes a capacitor. The capacitor has charging and discharging capabilities, is small in size, and can achieve rapid charging and discharging, thereby improving the heating efficiency of the battery while keeping the battery heating circuit small in size.

[0022] An embodiment of the second aspect of this application provides a battery system including a battery comprising a first battery pack and a second battery pack connected in series; and the battery heating circuit described in the above embodiment.

[0023] An embodiment of the third aspect of this application provides an electrical device that includes the battery system described in the above embodiments, the battery system being used to provide electrical energy.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0025] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0026] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0027] Figure 2 is a functional block diagram of a battery heating circuit according to some embodiments of this application;

[0028] Figure 3 is one of the schematic diagrams of the current path forming the first heating circuit in the battery heating circuit of some embodiments of this application;

[0029] Figure 4 is one of the schematic diagrams of the current path for forming a second heating circuit in the battery heating circuit of some embodiments of this application;

[0030] Figure 5 is a second schematic diagram of the current path for forming a second heating circuit in the battery heating circuit of some embodiments of this application;

[0031] Figure 6 is a second schematic diagram of the current path forming the first heating circuit in the battery heating circuit of some embodiments of this application;

[0032] Figure 7 is a functional block diagram of a battery heating circuit according to some other embodiments of this application;

[0033] Figure 8 is a schematic diagram of the battery heating circuit of some embodiments of this application;

[0034] Figure 9 is a schematic diagram of the current path for performing the first step to put the battery into a first heating stage according to some embodiments of this application;

[0035] Figure 10 is a schematic diagram of the current path for performing the second step to put the battery into the first heating stage according to some embodiments of this application;

[0036] Figure 11 is a schematic diagram of the current path for performing the second step to put the battery into a second heating stage according to some embodiments of this application;

[0037] Figure 12 is a schematic diagram of the current path for performing the first step to put the battery into the second heating stage according to some embodiments of this application;

[0038] Figure 13 is a functional block diagram of a battery heating circuit according to some embodiments of this application;

[0039] Figure 14 is one of the current paths of the battery heating circuit forming the third heating circuit in some embodiments of this application;

[0040] Figure 15 is a schematic diagram of the current path for forming a second heating circuit in a battery heating circuit according to some embodiments of this application;

[0041] Figure 16 is a second schematic diagram of the current path for forming a third heating circuit in a battery heating circuit according to some embodiments of this application;

[0042] Figure 17 is a schematic diagram of the current path forming the first heating circuit in a battery heating circuit according to some embodiments of this application;

[0043] Figure 18 is a schematic diagram of the battery heating circuit of some other embodiments of this application;

[0044] Figure 19 is a schematic diagram of the current path for performing the third step to put the battery into the first heating stage according to some embodiments of this application;

[0045] Figure 20 is a schematic diagram of the current path for performing the fourth step to put the battery into the first heating stage according to some embodiments of this application;

[0046] Figure 21 is a schematic diagram of the current path for performing the fifth step to put the battery into the second heating stage according to some embodiments of this application;

[0047] Figure 22 is a schematic diagram of the current path for performing the sixth step to put the battery into the second heating stage in some embodiments of this application.

[0048] Explanation of reference numerals in the attached drawings: Vehicle 1000, first switching element 1011, second switching element 1012, third switching element 1013, fourth switching element 1014, first energy storage element 1021; Battery 100, first switching circuit 101, first switching branch 101a, second switching branch 101b, first energy storage circuit 102, second energy storage circuit 103, second switching circuit 105, third energy storage circuit 106; Vehicle controller 200; Motor 300; First battery pack 11, second battery pack 12, first bridge arm 20, current sensor 21, first connector 22, second connector 23; Second bridge arm 30; First freewheeling diode D1, second freewheeling diode D2, third freewheeling diode D3, fourth freewheeling diode D4, first switch K1, second switch K2, third switch K3, fifth switching element K5, first connection point P1, second connection point P2, third connection point P3, first resistor R1, first upper bridge arm switch V1, first lower bridge arm switch V2, second upper bridge arm switch V3, second upper bridge arm switch V4. Detailed Implementation

[0049] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0051] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0052] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0053] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0054] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0055] To address the issue of low charging efficiency of batteries in low-temperature environments, batteries are typically heated until their temperature reaches the required level before charging.

[0056] In related technologies, external heating devices are typically used to heat the battery, such as PTC (Positive Temperature Coefficient) thermistors. This heating method relies on the principle of heat transfer to achieve heat exchange between the external heating device and the battery. However, this method has low heating efficiency and can easily lead to uneven temperatures between the outside and inside of the battery.

[0057] Based on the above considerations, a battery heating circuit is designed, including: a first switching circuit, a first energy storage circuit, and a second energy storage circuit. The first switching circuit includes a first connection point, a second connection point, and a third connection point interconnected by switching elements. The first connection point is connected to the positive terminal of the battery, and the second connection point is connected to the negative terminal of the battery. The first terminal of the first energy storage circuit is connected to the third connection point. The first terminal of the second energy storage circuit is connected to the second terminal of the first energy storage circuit, and the second terminal of the second energy storage circuit is electrically connected to the midpoint between the first battery pack and the second battery pack.

[0058] The first switching circuit is configured to connect the first energy storage circuit, the second energy storage circuit, and the first battery pack to form a first heating circuit. In the first heating circuit, the first energy storage circuit and the second energy storage circuit, due to their energy storage function, can exchange energy with the first battery pack, thereby heating the first battery pack.

[0059] The first switching circuit is also configured to connect the first energy storage circuit, the second energy storage circuit, and the second battery pack to form a second heating circuit. In the second heating circuit, the first energy storage circuit, the second energy storage circuit, and the second battery pack exchange energy, thereby heating the second battery pack.

[0060] By using energy transfer, the battery can be self-heated, achieving a uniform and rapid increase in battery temperature without the need for external heating equipment, thus reducing costs.

[0061] The first terminal of the second energy storage circuit is connected to the second terminal of the first energy storage circuit, that is, the first energy storage circuit and the second energy storage circuit are connected in series, which can increase the energy storage capacity, thereby improving the energy exchange efficiency between the first battery pack or the second battery pack and the first energy storage circuit and the second energy storage circuit, and improving the heating efficiency of the first battery pack and the second battery pack.

[0062] The battery heating circuit disclosed in this application can be used, but is not limited to, for heating batteries in electrical devices such as vehicles, ships, or aircraft.

[0063] Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0065] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a vehicle controller 200 and a motor 300. The vehicle controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0066] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Referring to Figure 2, this application embodiment provides a battery heating circuit. The battery includes a first battery pack 11 and a second battery pack 12 connected in series. The battery heating circuit includes a first switching circuit 101, which includes a first connection point P1, a second connection point P2, and a third connection point P3 interconnected by switching elements. The first connection point P1 is connected to the positive terminal of the battery, and the second connection point P2 is connected to the negative terminal of the battery. The battery heating circuit also includes a first energy storage circuit 102, the first terminal of which is connected to the third connection point P3. The battery heating circuit further includes: a second energy storage circuit 103, the first end of the second energy storage circuit 103 being connected to the second end of the first energy storage circuit 102, the second end of the second energy storage circuit 103 being electrically connected to the midpoint between the first battery pack 11 and the second battery pack 12, and the first switching circuit 101 being configured to connect the first energy storage circuit 102, the second energy storage circuit 103 and the first battery pack 11 to form a first heating circuit, and to connect the first energy storage circuit 102, the second energy storage circuit 103 and the second battery pack 12 to form a second heating circuit.

[0068] When the positive terminal of the first battery pack 11 is connected to the negative terminal of the second battery pack 12, the positive terminal of the battery is the positive terminal of the second battery pack 12, and the negative terminal of the battery is the negative terminal of the first battery pack 11. When the negative terminal of the first battery pack 11 is connected to the positive terminal of the second battery pack 12, the positive terminal of the battery is the positive terminal of the first battery pack 11, and the negative terminal of the battery is the negative terminal of the second battery pack 12.

[0069] The first connection point P1 can be the node connecting the first switching circuit 101 and the positive terminal of the battery, the second connection point P2 can be the node connecting the first switching circuit 101 and the negative terminal of the battery, and the third connection point P3 can be the node connecting the first energy storage circuit 102 and the first switching circuit 101.

[0070] The first connection point P1, the second connection point P2, and the third connection point P3 are interconnected by a switching element. That is, any two of the first connection point P1, the second connection point P2, and the third connection point P3 can be connected by a switching element. For example, when the first connection point P1 and the second connection point P2 are connected by a switching element, a path is formed between the first connection point P1 and the second connection point P2.

[0071] It is understandable that the first connection point P1, the second connection point P2, and the third connection point P3 can all be connected.

[0072] In some embodiments, the switching element may include, but is not limited to, a MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT transistor (Insulated-Gate Bipolar Transistor), or a relay, or other elements capable of controlling the on / off state of a circuit.

[0073] Since the first end of the first energy storage circuit 102 is connected to the third connection point P3, the first end of the second energy storage circuit 103 is connected to the second end of the first energy storage circuit 102, and the second end of the second energy storage circuit 103 is electrically connected to the midpoint between the first battery pack 11 and the second battery pack 12, the first energy storage circuit 102 and the second energy storage circuit 103 are connected in series between the first end of the first energy storage circuit 102 and the midpoint between the first battery pack 11 and the second battery pack 12.

[0074] The first heating circuit and the second heating circuit will be described in detail below, taking the example of connecting the negative terminal of the first battery pack 11 to the positive terminal of the second battery pack 12.

[0075] As shown in Figures 3 and 6, when the first connection point P1 and the third connection point P3 are connected through a switching element, the first end of the first energy storage circuit 102 can be connected to the positive terminal of the battery through the first switching circuit 101, that is, connected to the positive terminal of the first battery pack 11. The second end of the second energy storage circuit 103 is electrically connected to the negative terminal of the first battery pack 11. The first battery pack 11, the first energy storage circuit 102 and the second energy storage circuit 103 constitute the first heating circuit.

[0076] As shown in Figure 3, if the first energy storage circuit 102 and the second energy storage circuit 103 do not store energy, the first battery pack 11 charges the first energy storage circuit 102 and the second energy storage circuit 103, realizing the transfer of energy from the first battery pack 11 to the first energy storage circuit 102 and the second energy storage circuit 103. During the energy transfer process, current is transmitted in the first battery pack 11, thereby heating the first battery pack 11. The solid lines with arrows in Figure 3 show the current path of the first battery pack charging the first and second energy storage circuits in the first heating circuit.

[0077] As shown in Figure 6, if the first energy storage circuit 102 and the second energy storage circuit 103 store energy, after forming the first heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the first battery pack 11, realizing the transfer of energy from the first energy storage circuit 102 and the second energy storage circuit 103 to the second battery pack 12. The solid lines with arrows in Figure 6 show the current paths of the first energy storage circuit and the second energy storage circuit releasing energy to the first battery pack in the first heating circuit.

[0078] As shown in Figures 4 and 5, when the second connection point P2 and the third connection point P3 are connected through a switching element, the first end of the first energy storage circuit 102 can be connected to the negative terminal of the battery through the first switching circuit 101, that is, connected to the negative terminal of the second battery pack 12, and the second end of the second energy storage circuit 103 is electrically connected to the positive terminal of the second battery pack 12.

[0079] As shown in Figure 4, if the first energy storage circuit 102 and the second energy storage circuit 103 store energy, after forming the second heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the second battery pack 12, realizing the transfer of energy from the first energy storage circuit 102 and the second energy storage circuit 103 to the second battery pack 12. During the energy transfer process, current is transmitted in the second battery pack 12, thereby achieving heating of the second battery pack 12. The solid lines with arrows in Figure 4 show the current path of the first energy storage circuit and the second energy storage circuit releasing energy to the second battery pack in the second heating circuit.

[0080] As shown in Figure 5, if the first energy storage circuit 102 and the second energy storage circuit 103 do not store energy, the second battery pack 12 charges the first energy storage circuit 102 and the second energy storage circuit 103, realizing the transfer of energy from the first battery pack 11 to the first energy storage circuit 102 and the second energy storage circuit 103. The solid lines with arrows in Figure 5 show the current path of the second battery pack charging the first and second energy storage circuits in the second heating circuit.

[0081] As can be seen from the above, the current flow direction in the first heating circuit can be from the first battery pack 11 to the first energy storage circuit 102 and the second energy storage circuit 103, or from the first energy storage circuit 102 and the second energy storage circuit 103 to the first battery pack 11. Regardless of how the current is transmitted, it will flow through the first battery pack 11, thereby enabling the heating of the first battery pack 11.

[0082] Similarly, the current flow in the second heating circuit can be either from the second battery pack 12 to the first energy storage circuit 102 and the second energy storage circuit 103, or from the first energy storage circuit 102 and the second energy storage circuit 103 to the second battery pack 12. Regardless of how the current is transmitted, it will flow through the first battery pack 11, thereby enabling the heating of the first battery pack 11.

[0083] Since the first energy storage circuit 102 and the second energy storage circuit 103 are connected in series, the amount of energy transferred between the first battery pack 11 or the second battery pack 12 and the first energy storage circuit 102 and the second energy storage circuit 103 is relatively large, thereby increasing the current and improving the heating efficiency of the first battery pack 11 and the second battery pack 12.

[0084] In some embodiments, the first energy storage circuit 102 may include, but is not limited to, energy storage elements such as inductors and capacitors that can store and release energy, and the second energy storage circuit 103 may include, but is not limited to, energy storage elements such as inductors and capacitors that can store and release energy.

[0085] In the above technical solution, in the first heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103, due to their energy storage function, can exchange energy with the first battery pack 11, thereby heating the first battery pack 11. Similarly, in the second heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 exchange energy with the second battery pack 12, thereby heating the second battery pack 12. Through energy transfer, the battery can achieve self-heating, resulting in a uniform and rapid increase in battery temperature, without the need for external heating equipment, thus reducing costs.

[0086] Since the first energy storage circuit 102 and the second energy storage circuit 103 are connected in series, the energy storage capacity can be increased, thereby improving the energy exchange efficiency between the first battery pack 11 or the second battery pack 12 and the first energy storage circuit 102 and the second energy storage circuit 103, and improving the heating efficiency of the first battery pack 11 and the second battery pack 12.

[0087] According to some embodiments of this application, the battery heating circuit further includes a controller configured to control the first switching circuit 101 to switch between the first heating circuit and the second heating circuit.

[0088] The controller can achieve different conduction modes between the first connection point P1, the second connection point P2, and the third connection point P3 by controlling the switching mode of the switching elements, thereby realizing the switching between the first heating circuit and the second heating circuit.

[0089] In some embodiments, the controller may control the first switching circuit 101 to switch between the first heating circuit and the second heating circuit in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value, so as to heat the first battery pack 11 and the second battery pack 12.

[0090] In some embodiments, the controller may include, but is not limited to, the vehicle's MCU (Microcontroller Unit) or the controller in the battery's BMS (Battery Management System).

[0091] In some embodiments, the battery also includes a temperature sensor for detecting the temperature of the first battery pack 11 and the second battery pack 12. The temperature sensor is communicatively connected to the BMS, and the controller in the BMS can receive the temperature information of the first battery pack 11 and the second battery pack 12 detected by the temperature sensor, and in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value, control the first switching circuit 101 to switch between the first heating circuit and the second heating circuit.

[0092] The first heating circuit and the second heating circuit will be described in detail below, taking the example of connecting the negative terminal of the first battery pack 11 to the positive terminal of the second battery pack 12.

[0093] As shown in Figure 3, when the controller controls the first connection point P1 and the third connection point P3 to be connected through the switching element, the first battery pack 11, the first energy storage circuit 102 and the second energy storage circuit 103 constitute the first heating circuit. If the first energy storage circuit 102 and the second energy storage circuit 103 do not store energy, the first battery pack 11 charges the first energy storage circuit 102 and the second energy storage circuit 103.

[0094] As shown in Figure 4, when the controller connects the second connection point P2 and the third connection point P3 through a switching element, the second battery pack 12, the first energy storage circuit 102, and the second energy storage circuit constitute the second heating circuit. That is, the controller controls the first heating circuit to switch to the second heating circuit. Since the first energy storage circuit 102 and the second energy storage circuit 103 have stored energy in the aforementioned first heating circuit, after forming the second heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the second battery pack 12, realizing the transfer of energy from the first energy storage circuit 102 and the second energy storage circuit 103 to the second battery pack 12.

[0095] As can be seen from the above process, the controller can realize the transfer of energy from the first battery pack 11 to the second battery pack 12 by sequentially and alternately executing the operation of turning on the first connection point P1 and the third connection point P3, as well as the operation of turning on the second connection point P2 and the third connection point P3.

[0096] It is understood that the controller can also achieve the transfer of energy from the second battery pack 12 to the first battery pack 11 by sequentially and alternately executing the operation of turning on the second connection point P2 and the third connection point P3, as well as the operation of turning on the first connection point P1 and the third connection point P3. For example, battery heating may include alternating first and second heating stages. In the first heating stage, the first battery pack 11 transfers energy to the second battery pack 12, and in the second heating stage, the second battery pack 12 transfers energy to the first battery pack 11, thereby achieving energy balance between the first battery pack 11 and the second battery pack 12.

[0097] The process of transferring energy from the second battery pack 12 to the first battery pack 11 is described below.

[0098] As shown in Figure 5, when the controller controls the second connection point P2 and the third connection point P3 to be connected through the switching element, the second battery pack 12, the first energy storage circuit 102 and the second energy storage circuit 103 constitute the second heating circuit. If the first energy storage circuit 102 and the second energy storage circuit 103 do not store energy, the second battery pack 12 charges the first energy storage circuit 102 and the second energy storage circuit 103, realizing the transfer of energy from the first battery pack 11 to the first energy storage circuit 102 and the second energy storage circuit 103.

[0099] As shown in Figure 6, when the controller controls the first connection point P1 and the third connection point P3 to be connected through the switching element, the first battery pack 11, the first energy storage circuit 102 and the second energy storage circuit 103 constitute the first heating circuit. Since the first energy storage circuit 102 and the second energy storage circuit 103 have stored energy in the aforementioned second heating circuit, after the first heating circuit is formed, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the first battery pack 11, realizing the transfer of energy from the first energy storage circuit 102 and the second energy storage circuit 103 to the second battery pack 12.

[0100] In the above technical solution, by switching the first heating circuit and the second heating circuit by the controller, multiple heating modes for the battery can be realized to meet the different heating needs of the battery.

[0101] Referring to FIG7, according to some embodiments of the present application, the first switching circuit 101 includes at least one first switching branch 101a, the two ends of the first switching branch 101a are respectively connected to a first connection point P1 and a second connection point P2, the first switching branch 101a includes a first switching element 1011 and a second switching element 1012 connected in series, and the midpoint between the first switching element 1011 and the second switching element 1012 is connected to the first energy storage circuit 102 as a third connection point P3.

[0102] The end of the first switching element 1011 that is away from the second switching element 1012 can be connected to the first connection point P1, and the end of the second switching element 1012 that is away from the first switching element 1011 can be connected to the second connection point P2.

[0103] By controlling the on and off states of the first switching element 1011, the connection and disconnection between the first connection point P1 and the third connection point P3 can be controlled respectively. By controlling the on and off states of the second switching element 1012, the connection and disconnection between the second connection point P2 and the third connection point P3 can be controlled respectively.

[0104] In some embodiments, the first switching element 1011 may include, but is not limited to, elements capable of controlling the on / off state of a circuit, such as a relay, a MOSFET, or an IGBT. The second switching element 1012 may include, but is not limited to, elements capable of controlling the on / off state of a circuit, such as a relay, a MOSFET, or an IGBT.

[0105] The first switching element 1011 and the second switching element 1012 can be of the same type. This makes it easy to control the current in the first heating circuit and the second heating circuit to be the same, so that the heating effect of the first battery pack 11 and the second battery pack 12 is the same or close, which is beneficial to maintaining the temperature balance of the entire battery.

[0106] In the above technical solution, the first switching element 1011 and the second switching element 1012 can realize the mutual connection between the first connection point P1, the second connection point P2 and the third connection point P3, so that the first energy storage circuit 102 can be selectively connected to the first battery pack 11 or the second battery pack 12, thereby realizing that the first energy storage circuit 102 and the second energy storage circuit 103 are respectively connected to the first battery pack 11 and the second battery pack 12 to form a first heating circuit and a second heating circuit to heat the battery.

[0107] According to some embodiments of this application, there are multiple first switch branches 101a, and the multiple first switch branches 101a are connected in parallel. The first energy storage circuit 102 includes multiple first energy storage elements connected in parallel. The multiple first energy storage elements are connected one-to-one to the midpoint between the first switch element 1011 and the second switch element 1012 of the first switch branch 101a.

[0108] The first end of each first energy storage element is connected to the midpoint between the first switching element 1011 and the second switching element 1012 of the corresponding first switching branch 101a, and the second end of each first energy storage element is connected to the first end of the second energy storage circuit 103. When the controller controls the first switching element 1011 to be turned on, each first energy storage element is connected to the second energy storage circuit 103 and the first battery pack 11 to form multiple first heating circuits. When the second switching element 1012 is turned on, each first energy storage element is connected to the second energy storage circuit 103 and the second battery pack 12 to form multiple second heating circuits.

[0109] In some embodiments, the number of first switch branches 101a can be two, three, or more. The number of first switch branches 101a can be adjusted according to different heating requirements to achieve better heating results.

[0110] The first energy storage element may include, but is not limited to, inductors or capacitors and other elements capable of storing energy.

[0111] In the above technical solution, multiple first switch branches 101a respectively connect the corresponding first energy storage element and second energy storage element to the first battery pack 11 or the second battery pack 12 to form multiple first heating circuits or multiple second heating circuits, thereby improving heating efficiency.

[0112] Referring to FIG8, according to some embodiments of the present application, the first switch branch 101a is a first bridge arm 20. The first bridge arm 20 includes a first upper bridge arm and a first lower bridge arm connected in series. The switching element of the first upper bridge arm serves as a first switching element, and the switching element of the first lower bridge arm serves as a second switching element.

[0113] The first upper bridge arm may include a first upper bridge arm switch V1, and the first lower bridge arm may include a first lower bridge arm switch V2. The first upper bridge arm switch V1 serves as a first switching element 1011, and the first lower bridge arm switch V2 serves as a second switching element 1012. By turning the first upper bridge arm switch V1 and the first lower bridge arm switch V2 on or off, the first upper bridge arm and the first lower bridge arm can be turned on or off. The types of the first upper bridge arm switch V1 and the first lower bridge arm switch V2 include, but are not limited to, MOSFETs or IGBTs.

[0114] The controller can control the first upper bridge arm to be turned on and the first lower bridge arm to be turned off to form a first heating circuit, and control the first upper bridge arm to be turned off and the first lower bridge arm to be turned on to form a second heating circuit.

[0115] In some embodiments, the controller may control the batteries to alternate between a first heating phase and a second heating phase in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value.

[0116] The controller is configured to alternately execute the first step and the second step to control the battery in a first heating stage, and alternately execute the second step and the first step to control the battery pack in a second heating stage. The first step includes controlling the first upper bridge arm to be turned on and the first lower bridge arm to be turned off, and the second step includes controlling the first lower bridge arm to be turned on and the first upper bridge arm to be turned off.

[0117] In the first heating stage, the first step is executed to form a first heating circuit, as shown in Figure 9. The first battery pack 11, the first upper bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 constitute the first heating circuit. Current flows out from the positive terminal of the first battery pack 11 and sequentially through the first upper bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 before flowing back to the negative terminal of the first battery pack 11. The first energy storage circuit 102 and the second energy storage circuit 103 store energy. The solid lines with arrows in Figure 9 show the current path in the first heating circuit during the first heating stage.

[0118] Next, the second step is executed to form a second heating circuit, as shown in Figure 10. The second battery pack 12, the first lower bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 constitute the second heating circuit. The first energy storage circuit 102 and the second energy storage circuit 103 release energy, and the current flows out from the first energy storage circuit 102 and the second energy storage circuit 103 and flows sequentially through the positive terminal, the negative terminal, and the first lower bridge arm of the second battery pack 12 before flowing back to the first energy storage circuit 102 and the second energy storage circuit 103. The first energy storage circuit 102 and the second energy storage circuit 103 charge the second battery pack 12. The solid lines with arrows in Figure 10 show the current path in the second heating circuit during the first heating stage.

[0119] In the second heating stage, the second step is executed first to form a second heating circuit, as shown in Figure 11. The second battery pack 12, the first lower bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 constitute the second heating circuit. Current flows out from the positive terminal of the second battery pack 12 and sequentially through the first lower bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 before flowing back to the negative terminal of the second battery pack 12. The first energy storage circuit 102 and the second energy storage circuit 103 store energy. The solid lines with arrows in Figure 11 show the current path in the second heating circuit during the second heating stage.

[0120] Next, the first step is executed to form the first heating circuit, as shown in Figure 12. The first battery pack 11, the first upper bridge arm, the first energy storage circuit 102, and the second energy storage circuit 103 constitute the first heating circuit. The first energy storage circuit 102 and the second energy storage circuit 103 release energy, and the current flows out from the first energy storage circuit 102 and the second energy storage circuit 103, flows through the positive terminal of the first battery pack 11, the negative terminal of the first battery pack 11, and the first upper bridge arm, and then flows back to the first energy storage circuit 102 and the second energy storage circuit 103. The first energy storage circuit 102 and the second energy storage circuit 103 charge the first battery pack 11. The solid lines with arrows in Figure 12 show the current path in the first heating circuit during the second heating stage.

[0121] In some embodiments, the first upper bridge arm switch V1 is correspondingly provided with a first freewheeling diode D1, and the first lower bridge arm switch V2 is correspondingly provided with a second freewheeling diode D2. During the switching between the first and second steps, current can freewheel from either the corresponding first freewheeling diode D1 or the second freewheeling diode D2, ensuring that current always flows through the first energy storage circuit 102 and the second energy storage circuit 103 during the switching process. Throughout the heating phase, current always flows through the first energy storage circuit 102 and the second energy storage circuit 103, resulting in a small rate of change of current through the first and second energy storage circuits 102 and 103, and maintaining a low current frequency. This significantly improves the problem of excessive circuit noise caused by excessive current flowing through the circuit, maintaining relatively stable circuit performance and improving the heating efficiency of the battery.

[0122] In some embodiments, the battery heating circuit further includes a first switch K1 and a second switch K2. The first end of the first switch K1 is connected to the positive terminal of the battery, and the second end of the first switch K1 is connected to the first upper bridge arm, used to control the connection or disconnection between the positive terminal of the battery and the first upper bridge arm. The first end of the second switch K2 is connected to the negative terminal of the battery, and the second end of the second switch K2 is connected to the first lower bridge arm, used to control the connection or disconnection between the negative terminal of the battery and the first lower bridge arm. Thus, when the battery needs to be heated, the connection between the battery and the bridge arm can be controlled by the first switch K1 and the second switch K2; when the battery does not need to be heated, the connection between the battery and the bridge arm can be controlled by the first switch K1 and the second switch K2, thereby not affecting the normal performance of the battery.

[0123] In some embodiments, the first switch K1 can be connected to the upper bridge arm via the first connector 22, and the second switch K2 can be connected to the lower bridge arm via the second connector 23.

[0124] In some embodiments, the battery heating circuit further includes a third switch K3 connected in parallel with the second switch K2 and a first resistor R1. The third switch and the first resistor are connected in series to provide current limiting protection.

[0125] In some embodiments, the battery heating circuit further includes a current sensor 21, which is connected between the positive terminal of the battery and the first switch to detect the current output by the battery, so as to regulate the current used for battery heating in the battery heating circuit to produce a better heating effect on the battery.

[0126] In some embodiments, the first switch K1, the second switch K2, and the third switch K3 may include, but are not limited to, relays.

[0127] In the above technical solution, the structure of the first bridge arm 20 is simple and easy to control, which simplifies the circuit and improves the reliability of battery heating control.

[0128] Referring to Figure 8, according to some embodiments of this application, the first energy storage element 1021 is an inductor.

[0129] Inductors can store energy and also release energy.

[0130] In some embodiments, the first energy storage circuit 102 may include a plurality of inductors.

[0131] In one example, multiple inductors can be connected in parallel. When multiple inductors are connected in parallel, high-frequency noise in the circuit can be suppressed, making the current in the circuit more stable and further increasing the heating efficiency of the battery.

[0132] In another example, multiple inductors can also be connected in series, which can increase the overall storage capacity of the first energy storage circuit 102, thereby improving the efficiency of energy transfer between the first battery pack 11 or the second battery pack 12 and the first energy storage circuit 102, so as to further enhance the heating efficiency of the battery.

[0133] In some embodiments, the second energy storage circuit 103 also includes one or more inductors, wherein the multiple inductors are connected in series and / or in parallel.

[0134] In the above technical solution, the inductor can store a large amount of electricity, which can improve the efficiency of energy transfer between the first battery pack 11 and the second battery pack 12 and the first energy storage element, thereby improving the heating efficiency of the first battery pack 11 and the second battery pack 12.

[0135] According to some embodiments of this application, the first switching circuit 101 further includes a second switching branch, the two ends of which are respectively connected to the first connection point P1 and the second connection point P2. The second switching branch includes a third switching element and a fourth switching element connected in series.

[0136] In some embodiments, the third switching element may include, but is not limited to, elements capable of controlling the switching on and off of a circuit, such as relays, MOSFETs, or IGBTs. The fourth switching element may include, but is not limited to, elements capable of controlling the switching on and off of a circuit, such as relays, MOSFETs, or IGBTs.

[0137] It is not difficult to see that the two ends of the second switch branch are connected to the first connection point P1 and the second connection point P2 respectively, and the two ends of the first switch branch are also connected to the first connection point P1 and the second connection point P2 respectively. That is, the connection method between the second switch branch and the battery is the same as the connection method between the first switch branch and the battery.

[0138] In the above technical solution, the second switch branch can be used as a backup to replace the first switch branch when the first switch branch fails.

[0139] Referring to FIG13, according to some embodiments of the present application, the battery heating circuit further includes: a second switching circuit 105, the first end of the second switching circuit 105 being connected to the second end of the second energy storage circuit 103 and the midpoint between the third switching element 1013 and the fourth switching element 1014, the second end of the second switching circuit 105 being connected to the midpoint between the first battery pack 11 and the second battery pack 12, and the first switching circuit 101 and the second switching circuit 105 being configured to connect the first energy storage circuit 102, the second energy storage circuit 103, the first battery pack 11, and the second battery pack 12 to form a third heating circuit.

[0140] The second switching circuit 105 may include a fifth switching element K5, which may include, but is not limited to, a relay, a MOSFET, or an IGBT, or other components capable of controlling the switching on and off of the circuit.

[0141] In some embodiments, the controller is configured to control the first switching circuit 101 and the second switching circuit 105 to switch between at least two of the first heating circuit, the second heating circuit and the third heating circuit.

[0142] The controller can control the switching between the first heating circuit and the second heating circuit, as well as the switching between the third heating circuit and the first heating circuit, and the switching between the third heating circuit and the second heating circuit. Alternatively, when the heating of the battery includes a first heating stage and a second heating stage, the controller can control the switching between the third heating circuit and the first heating circuit during the first heating stage, and the controller can control the switching between the third heating circuit and the second heating circuit during the second heating stage.

[0143] It is understood that the first energy storage circuit 102, the second energy storage circuit 103, and the first battery pack 11 are connected to form a first heating circuit; the first energy storage circuit 102, the second energy storage circuit 103, and the second battery pack 12 are connected to form a second heating circuit; and the first energy storage circuit 102, the second energy storage circuit 103, the first battery pack 11, and the second battery pack 12 are connected to form a third heating circuit. There can be various connection methods, as long as the aforementioned heating circuits can be formed.

[0144] The controller can form a first heating circuit, a second heating circuit, and a third heating circuit by controlling the different conduction modes of the first switching element 1011, the second switching element 1012, the third switching element 1013, and the fourth switching element 1014.

[0145] The following describes the method of forming the first heating circuit, the second heating circuit, and the third heating circuit, taking the example of connecting the negative terminal of the first battery pack 11 to the positive terminal of the second battery pack 12.

[0146] The end of the third switching element 1013 away from the fourth switching element 1014 is connected to the first connection point P1, and the end of the fourth switching element 1014 away from the third switching element 1013 is connected to the second connection point P2.

[0147] In some embodiments, the method of implementing the first heating circuit through the first switching circuit 101 and the second switching circuit 105 may include: turning on the first switching element 1011 and the second switching circuit 105, and turning off the second switching element 1012, the third switching element 1013 and the fourth switching element 1014, so that the first end of the first energy storage circuit 102 is connected to the positive terminal of the first battery pack 11 through the first switching element 1011, and the second end of the second energy storage circuit 103 is connected to the negative terminal of the first battery pack 11 through the second switching circuit 105, thereby forming the first heating circuit.

[0148] The method of realizing the second heating circuit through the first switching circuit 101 and the second switching circuit 105 may include: turning on the second switching element 1012 and the second switching circuit 105, and turning off the first switching element 1011, the third switching element 1013 and the fourth switching element 1014, so that the first end of the first energy storage circuit 102 is connected to the negative terminal of the second battery pack 12 through the second switching element 1012, and the second end of the second energy storage circuit 103 is connected to the positive terminal of the second battery pack 12 through the second switching circuit 105, thereby forming the second heating circuit.

[0149] In one example, the method of implementing the third heating circuit through the first switching circuit 101 and the second switching circuit 105 may include: turning on the first switching element 1011 and the fourth switching element 1014, and turning off the second switching element 1012, the third switching element 1013 and the second switching circuit 105, so that the first end of the first energy storage circuit 102 is connected to the positive terminal of the first battery pack 11 through the first switching element 1011, and the second end of the second energy storage circuit 103 is connected to the negative terminal of the second battery pack 12 through the fourth switching element 1014, thus forming the third heating circuit.

[0150] In another example, the method of implementing the third heating circuit through the first switching circuit 101 and the second switching circuit 105 may also include: turning on the second switching element 1012 and the third switching element 1013, and turning off the first switching element 1011, the fourth switching element 1014 and the second switching circuit 105, so that the first end of the first energy storage circuit 102 is connected to the negative terminal of the second battery pack 12 through the second switching element 1012, and the second end of the second energy storage circuit 103 is connected to the positive terminal of the first battery pack 11 through the third switching element 1013, thus forming the third heating circuit.

[0151] In some embodiments, the controller may control the batteries to alternate between a first heating phase and a second heating phase in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value.

[0152] In some embodiments, during the first heating stage, a third heating circuit and a second heating circuit may be formed alternately in sequence.

[0153] As shown in Figure 14, a third heating circuit is first formed so that the first battery pack 11 and the second battery pack 12 jointly charge the first energy storage circuit 102 and the second energy storage circuit 103.

[0154] As shown in Figure 15, a second heating circuit is then formed. In the second heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the second battery pack 12 and charge the second battery pack 12. This cycle continues until the first heating stage ends.

[0155] The method for forming the third heating circuit in the first heating stage can be: turning on the first switching element 1011 and the fourth switching element 1014, and turning off the second switching element 1012, the third switching element 1013 and the second switching circuit 105.

[0156] In the second heating stage, the third heating circuit and the first heating circuit can be formed alternately in sequence.

[0157] As shown in Figure 16, a third heating circuit is first formed so that the first battery pack 11 and the second battery pack 12 jointly charge the first energy storage circuit 102 and the second energy storage circuit 103.

[0158] As shown in Figure 17, a first heating circuit is then formed. In the first heating circuit, the first energy storage circuit 102 and the second energy storage circuit 103 release energy to the first battery pack 11 and charge the first battery pack 11. This cycle continues until the second heating stage ends.

[0159] The method for forming the third heating circuit in the second heating stage can be: turning on the second switching element 1012 and the third switching element 1013, and turning off the first switching element 1011, the fourth switching element 1014 and the second switching circuit 105.

[0160] In other embodiments, in the first heating stage, the first heating circuit and the second heating circuit can be formed alternately in sequence, and in the second heating stage, the second heating circuit and the first heating circuit can be formed alternately in sequence. The method can be referred to the relevant description of the above embodiments, and will not be repeated below.

[0161] In the above technical solution, the third heating circuit enables energy transfer between the first and second battery packs and the first and second energy storage circuits, increasing the amount of energy transfer and thus increasing the energy stored in the first and second energy storage circuits. Therefore, when the third heating circuit switches to the first or second heating circuit, the amount of energy transferred between the first and second energy storage circuits and the first or second battery pack is increased, thereby improving energy transfer efficiency and further enhancing heating efficiency. Furthermore, by setting up a second switching branch and a second switching circuit, a heating circuit for the battery pack can be added, allowing for the selection of the appropriate heating circuit according to different heating requirements to improve the heating effect.

[0162] Referring to Figures 8 and 18, according to some embodiments of this application, the second switch branch 101b is a second bridge arm 30, which includes a second upper bridge arm and a second lower bridge arm connected in series. The switching element of the second upper bridge arm is a third switching element 1013, and the switching element of the second lower bridge arm is a fourth switching element 1014.

[0163] The second upper bridge arm may include a second upper bridge arm switch V3, and the second lower bridge arm may include a second lower bridge arm switch V4. The second upper bridge arm switch V3 serves as a third switching element 1013, and the second lower bridge arm switch V4 serves as a fourth switching element 1014. By turning the second upper bridge arm switch V3 and the second lower bridge arm switch V4 on or off, the second upper bridge arm and the second lower bridge arm can be turned on / off. The types of the second upper bridge arm switch V3 and the second lower bridge arm switch V4 include, but are not limited to, MOSFETs or IGBTs.

[0164] In some embodiments, the controller may control the batteries to alternate between a first heating phase and a second heating phase in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value.

[0165] For example, in the first heating stage, the third heating circuit and the second heating circuit can be formed alternately in sequence, and in the second heating stage, the third heating circuit and the first heating circuit can be formed alternately in sequence.

[0166] The first switch branch 101a is the first bridge arm 20, and the controller is configured to execute the third and fourth steps alternately in sequence to put the battery into the first heating stage.

[0167] As shown in Figure 19, the third step includes: controlling the first upper bridge arm and the second lower bridge arm to be turned on, and controlling the first lower bridge arm, the second upper bridge arm and the second switch circuit 105 to be turned off, forming a third heating circuit so that the first battery pack 11 and the second battery pack 12 charge the first energy storage circuit 102 and the second energy storage circuit 103. The solid line with arrows in Figure 19 shows the current path in the third heating circuit of the first heating stage.

[0168] As shown in Figure 20, the fourth step includes: controlling the first lower bridge arm and the second switch circuit 105 to be turned on, and controlling the first upper bridge arm and the second bridge arm 30 to be turned off, forming a second heating circuit so that the first energy storage circuit 102 and the second energy storage circuit 103 charge the second battery pack 12. The solid line with arrows in Figure 20 shows the current path in the second heating circuit during the first heating stage.

[0169] The controller is also configured to execute the fifth and sixth steps alternately in sequence to bring the battery into the second heating stage.

[0170] As shown in Figure 21, the fifth step includes: controlling the first lower bridge arm and the second upper bridge arm to be turned on, controlling the first upper bridge arm, the second lower bridge arm and the second switch circuit 105 to be turned off, forming a third heating circuit so that the first battery pack 11 and the second battery pack 12 charge the first energy storage circuit 102 and the second energy storage circuit 103. The solid line with arrows in Figure 21 shows the current path in the third heating circuit of the second heating stage.

[0171] As shown in Figure 22, the sixth step includes: controlling the first upper bridge arm and the second switch circuit 105 to be turned on, and controlling the first lower bridge arm and the second bridge arm 30 to be turned off, forming a first heating circuit so that the first energy storage circuit 102 and the second energy storage circuit 103 charge the first battery pack 11. The solid line with arrows in Figure 22 shows the current path in the first heating circuit of the first heating stage.

[0172] The above method can achieve the goal of heating the battery while maintaining the energy balance in the first battery pack 11 and the second battery pack 12.

[0173] In some embodiments, the second upper bridge arm switch V3 is provided with a third freewheeling diode D3, and the second lower bridge arm switch V4 is provided with a fourth freewheeling diode D4, so that the current can be kept stable when the third heating circuit switches to the first heating circuit or the second heating circuit.

[0174] In the above technical solution, the structure of the second bridge arm 30 is simple and easy to control, which simplifies the circuit and improves the reliability of battery heating control.

[0175] Referring to Figures 8 and 18, according to some embodiments of this application, the second energy storage circuit 103 includes one or more inductors, wherein the multiple inductors are connected in series and / or in parallel.

[0176] When multiple inductors are connected in parallel, the first end of each inductor is connected to the second end of the first energy storage circuit 102, and the second end of each inductor is connected to the first end of the second switching circuit 105.

[0177] In some embodiments, the first energy storage circuit 102 may also include a first or multiple inductors, which are connected in series and / or in parallel.

[0178] In the above technical solution, the inductors can store a large amount of electricity, which can improve the energy transfer efficiency between the first battery pack 11 and the second battery pack 12 and the second energy storage element, thereby improving the heating efficiency of the first battery pack 11 and the second battery pack 12. Furthermore, when multiple inductors are connected in parallel, high-frequency noise in the circuit can be suppressed, making the circuit current more stable and further improving the battery heating efficiency. When multiple inductors are connected in series, the energy that the second energy storage circuit 103 can store can be increased, thereby improving the energy transfer efficiency between the first battery pack 11 and the second battery pack 12 and the second energy storage circuit 103, further improving the battery heating efficiency.

[0179] According to some embodiments of this application, the first switching circuit and the first energy storage circuit are motors connected to the battery, the first bridge arm is a multi-phase bridge arm in the motor, and the first energy storage circuit is a motor winding in the motor.

[0180] As shown in Figure 18, in some embodiments, the first switching circuit includes multiple first switching branches 101a, each of which is a bridge arm. The first switching circuit 101 includes three parallel bridge arms, which can be multiplexed from the three-phase bridge arms in the motor.

[0181] When the battery is the power-consuming device, such as the battery in a vehicle, and the vehicle has a motor, the three parallel first switch branches 101a can be reused from the motor in the vehicle. That is, the existing motor in the vehicle can be used directly without the need to set up an additional bridge arm.

[0182] The first energy storage circuit 102 may include three first energy storage elements connected in parallel, with the first ends of the three first energy storage elements connected to the three bridge arms one by one.

[0183] In some embodiments, the first end of the second energy storage circuit 103 may be connected to the second end of each first energy storage element, and the second end of the second energy storage circuit 103 may be directly connected to the midpoint between the first battery pack 11 and the second battery pack 12.

[0184] As shown in Figure 18, in some other embodiments, the first switching circuit 101 may further include a second switching branch 101b, the battery heating circuit may further include a second switching circuit 105, the first end of the second energy storage circuit 103 may be connected to the second end of each first energy storage element, the second end of the second energy storage circuit 103 may be connected to the midpoint between the third switching element 1013 and the fourth switching element 1014 in the second switching branch 101b, and the second end of the second energy storage circuit 103 is also connected to the midpoint between the first battery pack 11 and the second battery pack 12 through the second switching circuit 105.

[0185] The first energy storage circuit may include multiple inductors connected in parallel, each inductor serving as a first energy storage element and connected one-to-one with multiple first switching branches. The multiple inductors connected in parallel can be derived from the motor windings in the motor, for example, from the three-phase motor windings in the motor.

[0186] In the above technical solution, if the battery is used in an electrical device and the electrical device has a motor, the motor in the electrical device can be directly reused, which can reduce the cost of the electrical device and make the circuit wiring in the electrical device less complex.

[0187] Referring to Figures 13 and 8, according to some embodiments of this application, the first switching circuit, the first energy storage circuit, and the second energy storage circuit are motors connected to the battery, the first switching branch and the second switching branch are multi-phase bridge arms in the motor, and the first energy storage circuit and the second energy storage circuit are motor windings in the motor.

[0188] The connection methods of the first switch branch 101a and the second switch branch 101b with the first energy storage circuit 102 and the second energy storage circuit 103, as well as the method of heating the battery, can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0189] In some embodiments, as shown in FIG8, the first switching branch includes two parallel first bridge arms 20, and the second switching branch includes a second bridge arm 30. The first energy storage circuit 102 may include two parallel first energy storage elements, for example, both of which may be inductors. The two first energy storage elements are respectively connected to the two first switching branches 101a. The first terminal of the second energy storage circuit 103 is connected to the second terminal of each first energy storage element, and the second terminal of the second energy storage circuit 103 is connected to the midpoint between the first battery pack 11 and the second battery pack 12 through the second switching circuit 105. The second energy storage circuit 103 may also be an inductor.

[0190] In other words, the inductance of the first energy storage circuit 102 and the inductance of the second energy storage circuit 103 can be reused from the three-phase motor windings in the motor. In this way, when the power device in which the battery is used has a motor, there is no need to set up an additional inductor. Furthermore, the first switch branch 101a and the second switch branch 101b are also reused from the three-phase bridge arm in the motor, so there is no need to set up an additional bridge arm. While achieving self-heating of the battery, the size and cost of the power device are kept small.

[0191] It is understood that in the three-phase bridge arms and three-phase inductors of the motor, each bridge arm and inductor is connected in the same way. Based on this, in some embodiments, the first end of the inductor of the first energy storage circuit 102 is connected to the midpoint of the first bridge arm 20, the first end of the inductor of the second energy storage circuit 103 is connected to the second end of the inductor of the first energy storage circuit 102, the second end of the inductor of the second energy storage circuit 103 can be connected to the midpoint of the second bridge arm 30, and the second end of the inductor of the second energy storage circuit 103 is also connected to the midpoint between the first battery pack 11 and the second battery pack 12 through the second switching circuit 105. In this way, the connection method of the inductor and the first bridge arm 20 of the first energy storage circuit 102 is the same as the connection method of the inductor and the second bridge arm 30 of the second energy storage circuit 103. That is, there is no need to change the connection method between the three-phase bridge arm and the three-phase inductor in the motor. Only the addition of the second switching circuit 105 is needed to connect the connection point of one of the three-phase inductors to the bridge arm to the midpoint between the first battery pack 11 and the second battery pack 12 to realize the scheme of two inductors in the three-phase inductors being connected in parallel and then connected in series with the remaining inductor.

[0192] In the above technical solution, while increasing the heating circuit for the battery by adding the first switch branch 101a and the second switch branch 101b to improve heating efficiency, the first switch branch 101a and the second switch branch 101b, as well as the first energy storage circuit and the second energy storage circuit, can reuse the motor in the power supply device, reduce the cost of the power supply device, and will not increase the complexity of the circuit wiring in the power supply device too much.

[0193] Referring to Figures 8 and 18, according to some embodiments of this application, the battery heating circuit further includes: a third energy storage circuit 106, the first end of the third energy storage circuit 106 being connected to the positive terminal of the battery, and the second end of the third energy storage circuit 106 being connected to the negative terminal of the battery.

[0194] That is, the third energy storage circuit 106 is connected in parallel across the two ends of the battery, enabling the first battery pack 11 or the second battery pack 12 to charge the third energy storage circuit 106 through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103, and the third energy storage circuit 106 to charge the first battery pack 11 or the second battery pack 12 through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103. In other words, the third energy storage circuit 106 can also exchange energy with the first battery pack 11 and the second battery pack 12 respectively, thereby heating the battery.

[0195] For example, the controller may control the batteries to alternate between a first heating phase and a second heating phase in response to the temperature of at least one of the first battery pack 11 and the second battery pack 12 being less than a preset value.

[0196] During the first heating phase, the first battery pack 11 forms a first heating circuit through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103, charging the first battery pack 11 to the first energy storage circuit 102 and the second energy storage circuit 103. During the formation of the first heating circuit, the third energy storage circuit 106 can form a circuit with the second battery pack 12, allowing the third energy storage circuit 106 to charge the second battery pack 12, resulting in current flowing through the second battery pack 12.

[0197] During the first heating phase, the second battery pack 12 forms a second heating circuit through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103. The first energy storage circuit 102 and the second energy storage circuit 103 discharge to the second battery pack 12. During the formation of the second heating circuit, the third energy storage circuit 106 can form a circuit with the first battery pack 11 so that the first battery pack 11 charges the third energy storage circuit 106, and current flows through the first battery pack 11.

[0198] During the second heating stage, the second battery pack 12 forms a second heating circuit through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103, charging the first energy storage circuit 102 and the second energy storage circuit 103. During the formation of the second heating circuit, the third energy storage circuit 106 can form a circuit with the first battery pack 11, allowing the third energy storage circuit 106 to charge the first battery pack 11, resulting in current flowing through the first battery pack 11.

[0199] During the second heating stage, the first battery pack 11 forms a first heating circuit through the first switching circuit 101, the first energy storage circuit 102, and the second energy storage circuit 103. The first energy storage circuit 102 and the second energy storage circuit 103 discharge to the first battery pack 11. During the formation of the first heating circuit, the third energy storage circuit 106 can form a circuit with the second battery pack 12 so that the second battery pack 12 charges the third energy storage circuit 106, and current flows through the second battery pack 12.

[0200] In other words, during the entire heating phase, current always flows through the first battery pack 11 and the second battery pack 12, which helps to maintain the stability of the current flowing through the first battery pack 11 and the second battery pack 12. This improves the heating efficiency of the batteries and makes the performance of the first battery pack 11 and the second battery pack 12 more stable.

[0201] In the above technical solution, the third energy storage circuit 106 is connected to the positive and negative terminals of the battery and can also form a circuit with the battery to realize energy exchange with the battery, thereby further improving the heating efficiency of the battery.

[0202] According to some embodiments of this application, the third energy storage circuit 106 includes a capacitor.

[0203] Both the first energy storage circuit 102 and the second energy storage circuit 103 may include inductors.

[0204] Both inductors and capacitors have charging and discharging functions. The first energy storage circuit 102 and the second energy storage circuit 103 can both include inductors, and the third energy storage circuit 106 includes a capacitor. This enables the following to be achieved in the first heating stage: through the first switching circuit 101, the first battery pack 11 charges the first energy storage circuit 102 and the second energy storage circuit 103, and the third energy storage circuit 106 charges the second battery pack 12; and through the first switching circuit 101, the first energy storage circuit 102 and the second energy storage circuit 103 charge the second battery pack 12, and the first battery pack 11 charges the third energy storage circuit 106.

[0205] The capacitor is connected in parallel across the two ends of the battery. In the first battery pack 11, a circuit is formed through the first switching circuit 101 and the inductor. During the charging of the inductor, the capacitor can act as a substitute for the power source. Since the first switching circuit 101 and the inductor are connected, the capacitor can form a circuit with the second battery pack 12 through the first switching circuit 101 and the inductor. The current in this circuit charges the second battery pack 12 because the current flows in the first switching circuit 101 and the inductor.

[0206] When the second battery pack 12 forms a circuit through the first switching circuit 101 and the inductor, the capacitor can form a circuit with the first battery pack 11 through the first switching circuit 101 and the inductor during the charging of the second battery pack 12 by the inductor. The current in the circuit is in the direction of the current in the first switching circuit 101 and the inductor, so that the first battery pack 11 charges the capacitor.

[0207] Similarly, when the battery is in the second heating stage, the first switching circuit 101 can simultaneously charge the second battery pack 12 for the first energy storage circuit 102 and the second energy storage circuit 103, and charge the third energy storage circuit 106 for the first battery pack 11. The first switching circuit 101 can also simultaneously charge the first energy storage circuit 102 and the second energy storage circuit 103 for the first battery pack 11, and charge the second battery pack 12 for the third energy storage circuit 106.

[0208] During the charging of the inductor, the capacitor can form a circuit with the first battery pack 11 through the first switch circuit 101 and the inductor. The current in the circuit charges the first battery pack 11 because it flows along the direction of the current in the first switch circuit 101 and the inductor.

[0209] The first battery pack 11 forms a circuit through the first switching circuit 101 and the inductor, so that during the charging of the first battery pack 11 by the inductor, the capacitor can form a circuit with the second battery pack 12 through the first switching circuit 101 and the inductor, and the current in the circuit charges the capacitor by the second battery pack 12 because it flows along the direction of the first switching circuit 101 and the inductor.

[0210] In the above technical solution, the capacitor has the function of charging and discharging, the capacitor is small in size, and the capacitor can achieve rapid charging and discharging, which improves the heating efficiency of the battery while keeping the size of the battery heating circuit small.

[0211] This application provides a battery system including a battery, which includes a first battery pack and a second battery pack connected in series; and the battery heating circuit described in the above embodiment.

[0212] The battery is connected to the battery heating circuit. The connection method can be referred to the relevant description of the connection method between the battery and the battery heating circuit in the above embodiment, and will not be repeated below.

[0213] The battery system has the beneficial effects of the battery heating circuit provided in the embodiments of this application. For details, please refer to the specific descriptions of the battery heating circuit in the above embodiments, which will not be repeated here.

[0214] This application provides an electrical device that includes the battery system described in the above embodiments, the battery system being used to provide electrical energy.

[0215] The electrical devices can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0216] This application provides a battery heating circuit. Referring to Figures 8 and 18, the battery includes a first battery pack 11 and a second battery pack 12 connected in series. The negative terminal of the first battery pack 11 and the positive terminal of the second battery pack 12 are connected. The battery heating circuit includes: a first switching circuit, which includes a first connection point P1, a second connection point P2, and a third connection point P3 interconnected by switching elements. The first connection point P1 is connected to the positive terminal of the battery, and the second connection point P2 is connected to the negative terminal of the battery; a first energy storage circuit, whose first terminal is connected to the third connection point P3; and a second energy storage circuit, whose first terminal is connected to the second terminal of the first energy storage circuit, and whose second terminal is electrically connected to the midpoint between the first battery pack 11 and the second battery pack 12. The first switching circuit is configured to connect the first energy storage circuit, the second energy storage circuit, and the first battery pack 11 to form a first heating circuit, and to connect the first energy storage circuit, the second energy storage circuit, and the second battery pack 12 to form a second heating circuit. The battery heating circuit also includes: a controller configured to control the first switching circuit to switch between the first heating circuit and the second heating circuit.

[0217] For example, referring to FIG8, the first switching circuit includes two parallel first bridge arms 20, with the two ends of the first bridge arms 20 connected to a first connection point and a second connection point, respectively, and the midpoint of the first bridge arms serving as a third connection point. The first energy storage circuit includes two parallel inductors, with the two inductors respectively connected to the midpoint of the first bridge arms 20. The first switching circuit also includes a second bridge arm 30, with the two ends of the second bridge arm 30 connected to the positive and negative terminals of the battery, respectively. The second energy storage circuit includes an inductor, with the first end of the inductor of the second energy storage circuit connected to the inductor of the first energy storage circuit, and the second end connected to the midpoint of the second bridge arm 30. The battery heating circuit also includes a second switching circuit 105, which is connected between the second end of the inductor of the second energy storage circuit and the midpoint between the first battery pack 11 and the second battery pack 12.

[0218] The first bridge arm 20 and the second bridge arm 30 are multiplexed from the three-phase bridge arms in the motor, and the inductance of the first energy storage circuit and the inductance of the second energy storage circuit are multiplexed from the three-phase inductance in the motor.

[0219] For example, referring to FIG18, the first switching circuit may also include three parallel first bridge arms 20, with the two ends of the first bridge arms 20 connected to a first connection point and a second connection point, respectively, and the midpoint of the first bridge arms serving as a third connection point. The first energy storage circuit includes three parallel inductors, each connected to the midpoint of the first bridge arm 20. The first switching circuit also includes a second bridge arm 30, with the two ends of the second bridge arm 30 connected to the positive and negative terminals of the battery, respectively. The second energy storage circuit includes an inductor, with the first end of the inductor connected to the inductor of the first energy storage circuit and the second end connected to the midpoint of the second bridge arm 30. The battery heating circuit also includes a second switching circuit 105, which is connected between the second end of the inductor of the second energy storage circuit and the midpoint between the first battery pack 11 and the second battery pack 12. The first and second switching circuits are configured to connect the first bridge arm 20, the second bridge arm 30, the first battery pack 11, and the second battery pack 12 to form a third heating circuit. The controller is also configured to control the first and second switching circuits to switch between at least two of the first, second, and third heating circuits.

[0220] Among them, the three parallel first bridge arms 20 can be multiplexed from the three-phase bridge arms in the motor, and the three inductors of the first energy storage circuit can be multiplexed from the three-phase inductors in the motor.

[0221] The method of connecting an inductor and a first battery pack through the first bridge arm to form a first heating circuit, connecting an inductor and a second battery pack to form a second heating circuit, and connecting an inductor and a first battery pack and a second battery pack through the first bridge arm and the second bridge arm to form a third heating circuit, as well as the control method of the controller, can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0222] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery heating circuit, wherein the battery comprises a first battery pack and a second battery pack connected in series, the battery heating circuit comprising: A first switching circuit includes a first connection point, a second connection point, and a third connection point interconnected by switching elements. The first connection point is connected to the positive terminal of the battery, and the second connection point is connected to the negative terminal of the battery. A first energy storage circuit, wherein a first terminal of the first energy storage circuit is connected to the third connection point; The second energy storage circuit has a first terminal connected to the second terminal of the first energy storage circuit, and the second terminal of the second energy storage circuit is electrically connected to the midpoint between the first battery pack and the second battery pack. The first switching circuit is configured to connect the first energy storage circuit, the second energy storage circuit and the first battery pack to form a first heating circuit, and to connect the first energy storage circuit, the second energy storage circuit and the second battery pack to form a second heating circuit.

2. The battery heating circuit according to claim 1, wherein, The battery heating circuit further includes a controller configured to control the first switching circuit to switch between the first heating circuit and the second heating circuit.

3. The battery heating circuit according to claim 1 or 2, wherein, The first switching circuit includes at least one first switching branch, with its two ends connected to the first connection point and the second connection point, respectively. The first switching branch includes a first switching element and a second switching element connected in series, and the midpoint between the first switching element and the second switching element serves as the third connection point connected to the first energy storage circuit.

4. The battery heating circuit according to claim 3, wherein, The number of the first switch branches is multiple, and the multiple first switch branches are connected in parallel. The first energy storage circuit includes multiple first energy storage elements connected in parallel. The multiple first energy storage elements are connected one-to-one to the midpoint between the first switch element and the second switch element of the first switch branch.

5. The battery heating circuit according to claim 3 or 4, wherein, The first switch branch is the first bridge arm, which includes a first upper bridge arm and a first lower bridge arm connected in series. The switch element of the first upper bridge arm serves as the first switch element, and the switch element of the first lower bridge arm serves as the second switch element.

6. The battery heating circuit according to claim 4 or 5, wherein, The first energy storage element is an inductor.

7. The battery heating circuit according to any one of claims 3-6, wherein, The first switching circuit further includes a second switching branch, the two ends of which are connected to the first connection point and the second connection point respectively. The second switching branch includes a third switching element and a fourth switching element connected in series.

8. The battery heating circuit according to claim 7, wherein, The battery heating circuit further includes: a second switching circuit, the first end of which is connected to the second end of the second energy storage circuit and the midpoint between the third switching element and the fourth switching element, the second end of which is connected to the midpoint between the first battery pack and the second battery pack, and the first switching circuit and the second switching circuit are configured to connect the first energy storage circuit, the second energy storage circuit, the first battery pack, and the second battery pack to form a third heating circuit.

9. The battery heating circuit according to claim 7 or 8, wherein, The second switch branch is the second bridge arm, which includes a second upper bridge arm and a second lower bridge arm connected in series. The switching element of the second upper bridge arm serves as the third switching element, and the switching element of the second lower bridge arm serves as the fourth switching element.

10. The battery heating circuit according to any one of claims 1-9, wherein, The second energy storage circuit includes one or more inductors, wherein the multiple inductors are connected in series and / or in parallel.

11. The battery heating circuit according to claim 5, wherein, The first switching circuit and the first energy storage circuit are motors connected to the battery, the first bridge arm is a multi-phase bridge arm in the motor, and the first energy storage circuit is a motor winding in the motor.

12. The battery heating circuit according to any one of claims 7-9, wherein, The first switching circuit, the first energy storage circuit, and the second energy storage circuit are motors connected to the battery; the first switching branch and the second switching branch are multi-phase bridge arms in the motor; and the first energy storage circuit and the second energy storage circuit are motor windings in the motor.

13. The battery heating circuit according to any one of claims 1-12, wherein, The battery heating circuit also includes: A third energy storage circuit, wherein the first end of the third energy storage circuit is connected to the positive terminal of the battery, and the second end of the third energy storage circuit is connected to the negative terminal of the battery.

14. The battery heating circuit according to claim 13, wherein, The third energy storage circuit includes a capacitor.

15. A battery system, wherein, include: The battery includes a first battery pack and a second battery pack connected in series. as well as The battery heating circuit according to any one of claims 1-14.

16. An electrical appliance, wherein, Includes the battery system according to claim 15, wherein the battery system supplies power to the electrical device.

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