A self-temperature maintaining device applied to a battery pack

Abstract

The utility model discloses a kind of self-thermal insulation devices applied to battery pack, it is related to battery thermal management technical field.The device aims to solve the problem that lithium battery etc. in prior art cannot be charged under low temperature environment, or need to rely on complex battery management system to realize heating problem.The technical scheme of the utility model is: provide a kind of self-thermal insulation device containing independent heating control module.The module can work independently, when it detects that battery temperature is lower than preset threshold and there is charging current satisfying condition simultaneously, heating unit will be automatically started to heat battery;Once temperature is up to standard or charging stops, heating is automatically closed.The beneficial effects of the utility model are: simple structure, low cost, without BMS, can independently realize intelligent charging heating function under low temperature environment, effectively improve the use performance and safety of battery in cold region, and can be widely adapted to various battery packs.

Description

Technical Field

[0001] This utility model relates to the field of battery thermal management technology, and in particular to a self-heating device for battery packs. Background Technology

[0002] Currently, lithium-ion batteries, lead-acid batteries, and other chemical batteries are widely used in various industries. However, the electrochemical performance of these batteries is significantly affected by temperature. In low-temperature environments, especially below 0°C, the internal resistance of the battery increases sharply, the activity of the active materials decreases, leading to a significant reduction in its charge acceptance and discharge capacity. Forcibly charging lithium-ion batteries at low temperatures may also induce the precipitation of lithium dendrites, which can puncture the separator and cause an internal short circuit, posing a serious safety hazard.

[0003] To address this issue, the industry's common solution is to integrate a heating system within the battery pack. In existing technologies, the start / stop control of the heating system largely relies on the Battery Management System (BMS). The BMS collects battery temperature data through its temperature sensors. When the temperature is too low, the BMS's main control unit issues a command to close a relay, activating the heating film to raise the battery temperature. While this approach is feasible, it has the following drawbacks: First, it requires a complex BMS, increasing the cost and size of the entire battery system; second, for some battery systems without a BMS or with a simple BMS, low-temperature heating is not possible, limiting its application scenarios.

[0004] Therefore, this application provides a self-heating device for battery packs to meet the need for intelligent charging heating of batteries at low temperatures without the need for a complex BMS. Utility Model Content

[0005] The purpose of this application is to provide a self-heating device for battery packs, which aims to solve the technical problems in the prior art where battery charging is limited at low temperatures and the heating function is heavily dependent on the battery management system.

[0006] To achieve the above objectives, this application provides the following technical solution: a self-heating device for a battery pack, comprising a battery module 6; a heating unit 5 thermally coupled to the battery module 6; and a low-temperature heating management control module, the module being configured to operate independently of a battery management system, and comprising: one or more temperature switch interfaces for connecting a temperature switch 3 disposed on the battery module 6; a current detection unit 1 for detecting the charging current flowing through the main circuit of the battery module 6; and a control switch unit 2; wherein the opening and closing of the control switch unit 2 is controlled by the on / off state of the temperature switch 3 and the output signal of the current detection unit 1, and the control switch unit 2 is activated to connect the power supply to the heating unit 5 when and only when the temperature switch 3 is turned on due to low temperature and the charging current detected by the current detection unit 1 is greater than or equal to a preset current threshold.

[0007] Preferably, the current detection unit 1 is a current transformer. A current transformer can accurately sense the main circuit current in a non-contact manner, offering high reliability and having no impact on the main circuit.

[0008] Preferably, the control switch unit 2 is a DC relay. As a mature switching element, the DC relay has strong switching capability and reliable operation.

[0009] Preferably, the low-temperature heating management control module further includes a potentiometer for adjusting the preset current threshold. This potentiometer allows the user to flexibly set the charging current for initiating heating according to different battery specifications or charging devices, thus broadening the module's applicability. The adjustable current range is, for example, DC 0.5A to 40A.

[0010] Preferably, the preset temperature threshold of the temperature switch 3 is one of -20℃, -15℃, -10℃, -5℃, 0℃, 5℃, or 10℃. These fixed temperature thresholds are typical critical points where the battery needs to start heating in low-temperature environments, and users can select appropriate specifications according to battery type and application environment.

[0011] Preferably, the low-temperature heating management and control module is entirely encapsulated within a structural injection-molded shell 4, forming a compact, well-insulated, and easy-to-install independent module.

[0012] In summary, the technical effects and advantages of this utility model are as follows: In this invention, the heating circuit is controlled by combining the signals of the temperature switch and the current detection unit with an AND logic. This ensures that heating is only activated when both conditions are met: "the battery temperature is indeed low" and "there is indeed charging behavior". This avoids the accidental activation of heating when the battery is stationary or discharging, thus preventing the waste of electrical energy.

[0013] In this invention, all control logic is completed within an independent module, without the need for external BMS or central processing unit intervention. This greatly simplifies the design of the battery system, reduces costs, and makes the self-heating function easily applicable to various battery systems without BMS, exhibiting strong versatility and economic benefits. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a circuit schematic diagram of one embodiment of the present invention.

[0016] In the diagram: 1. Current detection unit; 2. Control switch unit; 3. Temperature switch; 4. Structural injection molded shell; 5. Heating unit; 6. Battery module; 7. Second temperature switch. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example

[0018] refer to Figure 1-2 The device shown is a self-heating device for battery packs. The core of the device is a low-temperature heating management and control module, which mainly consists of an interface circuit of a current detection unit 1, a control switch unit 2, and a temperature switch 3 encapsulated in a structural injection-molded shell 4.

[0019] In one specific embodiment, the current detection unit 1 in the low-temperature heating management control module is a current transformer, and the control switch unit 2 is a DC relay. This module is connected to the battery system via external wiring. Figure 2As shown, the battery symbol on the left represents battery module 6. One end of temperature switch 3 is connected to the positive or negative terminal of battery module 6, and the other end provides power to the power supply pin of current detection unit 1. The central hole of current detection unit 1 is used to pass through the main circuit busbar or wire of battery module 6 to sense the current flowing through it. The signal output terminal of current detection unit 1 is connected to the coil terminal of control switch unit 2. The main contacts of control switch unit 2 are connected in series in the circuit that supplies power to external heating unit 5.

[0020] As a preferred embodiment, such as Figure 2 As shown, a second temperature switch 7 may also be included. This second temperature switch 7 can be directly attached to the surface of the battery cell in the battery module 6 for more accurate sensing of the actual temperature of the cell. In this configuration, temperature switch 3 can be used as a condition for determining low ambient temperature, while the second temperature switch 7 can be used as a condition for determining the core temperature of the battery cell. The heating logic is only allowed to be triggered when both indicate excessively low temperatures, thus providing safer and more precise control.

[0021] In one embodiment of this invention, the heating unit 5 may be a polyimide (PI) heating film thermally coupled to the battery module 6. The battery module 6 may be a lithium iron phosphate battery module, a ternary lithium battery module, a lithium titanate battery module, or a lead-acid battery module.

[0022] The working principle of this device is as follows: When the low-temperature heating management control module of this device is correctly installed in the battery system, and the entire system is in a low-temperature environment, such as -30℃, and the preset opening temperature threshold of the selected temperature switch 3 is -10℃, the temperature switch 3 is in the conducting state because the ambient temperature is below -10℃, providing working power to the current detection unit 1 and putting it in standby mode.

[0023] At this time, if the user starts charging the battery module 6, a charging current is generated in the main circuit. The current detection unit 1 senses this charging current, and when the current value is greater than or equal to its internally set preset current threshold (e.g., 3A), its signal output terminal will output a control voltage or current signal to drive the coil of the control switch unit 2, causing its main contacts to close.

[0024] After the main contacts are closed, the circuit for powering the heating unit 5 is connected, and the heating unit 5 starts to work, heating the battery module 6.

[0025] As heating progresses, when the temperature of battery module 6 rises above -10℃, temperature switch 3 turns off, cutting off the power supply to current detection unit 1. The entire module stops working, the coil of control switch unit 2 is de-energized, the main contacts open, and heating stops. Alternatively, if charging stops during heating and the charging current is less than the preset current threshold, current detection unit 1 will also stop outputting control signals, and control switch unit 2 will also open, stopping heating.

[0026] This enables safe and intelligent charging and heating of low-temperature batteries without relying on a BMS.

[0027] The electromechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments; they are common knowledge.

[0028] Components not described in detail in this article are existing technologies.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A self-heating device for use in battery packs, characterized in that, include: A battery module (6); A heating unit (5) thermally coupled to the battery module (6); And a low-temperature heating management control module, the module being configured to operate independently of the battery management system, and including: One or more temperature switch interfaces are provided for connecting temperature switches (3) disposed on the battery module (6); A current detection unit (1) is used to detect the charging current flowing through the main circuit of the battery module (6); And a control switch unit (2); The opening and closing of the control switch unit (2) is controlled by the on / off state of the temperature switch (3) and the output signal of the current detection unit (1). The control switch unit (2) is activated to connect the power supply of the heating unit (5) when and only when the temperature switch (3) is turned on due to low temperature and the charging current detected by the current detection unit (1) is greater than or equal to the preset current threshold.

2. The self-heating device for a battery pack according to claim 1, characterized in that: The current detection unit (1) is a current transformer.

3. The self-heating device for a battery pack according to claim 2, characterized in that: The control switch unit (2) is a DC relay.

4. A self-heating device for a battery pack according to claim 2, characterized in that: The low-temperature heating management and control module also includes a potentiometer for adjusting the preset current threshold.

5. A self-heating device for a battery pack according to claim 1, characterized in that: The preset temperature threshold of the temperature switch (3) is one of -20℃, -15℃, -10℃, -5℃, 0℃, 5℃ or 10℃.

6. A self-heating device for a battery pack according to claim 3, characterized in that: The low-temperature heating management and control module is housed within a structural injection-molded shell (4).

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