Battery cell low temperature heating circuit

Abstract

The utility model discloses a kind of low temperature heating circuit of battery cell, including battery cell group, battery cell group protection circuit, BMS communication transmission circuit, temperature acquisition circuit, LED indicator light circuit, heating control circuit, heating film, charger circuit, low-voltage linear voltage stabilizing circuit;The utility model synchronizes multipoint temperature data in real time through BMS communication transmission circuit, dynamically controls heating film work, significantly improves low temperature heating efficiency and temperature uniformity;Adopt charger direct supply heating film and low-voltage linear voltage stabilizing dual power supply architecture, reduce battery cell electric energy loss;Combined with battery cell group protection circuit, effectively avoid over-temperature, overcurrent and signal interference risk, substantially improve system security and reliability.

Description

Technical Field

[0001] This utility model relates to the field of battery cell heating technology, specifically to a low-temperature heating circuit for battery cells. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage systems, and portable electronic devices, lithium batteries have become the mainstream power source due to their high energy density and long cycle life. However, lithium batteries experience problems such as a sharp drop in capacity, a surge in internal resistance, and deterioration in charging efficiency at low temperatures (usually below 0°C), which can even lead to lithium plating accidents and threaten battery safety in severe cases. To solve this problem, low-temperature heating technology has become a key component of the battery management system (BMS).

[0003] Traditional heating solutions mainly rely on resistance wires or PTC heaters powered directly by batteries, resulting in ineffective energy loss and exacerbating capacity decay at low temperatures. The separate design of functional modules such as heating control, temperature acquisition, and BMS communication increases system power consumption and failure risk. The lack of multi-level linkage protection mechanisms may lead to thermal runaway due to overvoltage, overcurrent, or temperature runaway during the heating process. Utility Model Content

[0004] In view of this, the main objective of this utility model is to provide a low-temperature heating circuit for battery cells.

[0005] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0006] This utility model embodiment provides a low-temperature heating circuit for battery cells, including a battery cell assembly, a battery cell assembly protection circuit, a BMS communication transmission circuit, a temperature acquisition circuit, an LED indicator circuit, a heating control circuit, a heating film, a charger circuit, and a low-voltage linear regulator circuit. The BMS communication transmission circuit is communicatively connected to the battery cell assembly. The signal output terminal of the temperature acquisition circuit is connected to the signal input terminal of the BMS communication transmission circuit for acquiring the temperature of the battery cell assembly. The signal output terminal of the BMS communication transmission circuit is connected to the signal input terminals of the LED indicator circuit and the heating control circuit, respectively. The power input terminal of the heating controller is connected to the power output terminal of the charger. The power output terminal of the heating control circuit is connected to the power input terminal of the heating film. The heating film is disposed on the battery cell assembly for heating the battery cell assembly. The low-voltage linear regulator circuit supplies power to the heating control circuit.

[0007] In the above scheme, the battery cell assembly includes a first battery cell, a second battery cell, a third battery cell, a fourth battery cell, a first inductor, a second inductor, a third inductor, a first resistor, a second resistor, a twenty-fifth resistor, a ninth resistor, a first capacitor, a second capacitor, a fourth capacitor, a fifth capacitor, an eighteenth capacitor, a nineteenth capacitor, a thirteenth capacitor, and a twenty-fifth capacitor. The positive terminal of the first battery cell is connected to the first terminal of the first inductor and the negative terminal of the second battery cell. The second terminal of the first inductor, after being connected in series with the first resistor, is connected to the first terminal of the first capacitor, the first terminal of the second capacitor, the first terminal of the fourth capacitor, the first terminal of the fifth capacitor, and the VC1 terminal of the BMS controller. The second terminal of the second battery cell is connected to the negative terminal of the third battery cell and the negative terminal of the second inductor. The first terminal is connected, and the second terminal of the second inductor is connected in series with the second resistor and then connected to the second terminal of the second capacitor, the second terminal of the fifth capacitor, the first terminal of the eighteenth capacitor, the first terminal of the nineteenth capacitor, and the VC2 terminal of the BMS controller. The positive terminal of the third cell is connected to the negative terminal of the fourth cell and the first terminal of the third inductor. The second terminal of the third inductor is connected in series with the twenty-fifth resistor and then connected to the second terminal of the eighteenth capacitor, the second terminal of the nineteenth capacitor, the first terminal of the thirteenth capacitor, the first terminal of the twenty-fifth capacitor, and the VC3 terminal of the BMS controller. The positive terminal of the fourth cell is connected in series with the fourth inductor and the ninth resistor and then connected to the second terminal of the thirteenth capacitor, the second terminal of the twenty-fifth capacitor, and the VC4 terminal of the BMS controller.

[0008] In the above scheme, the BMS communication transmission circuit includes a BMS controller, an eleventh capacitor, a seventeenth capacitor, a seventh capacitor, a ninth capacitor, a fifteenth capacitor, an eighth capacitor, a sixth inductor, a seventh inductor, a third resistor, a fifth resistor, a fourth resistor, a thirty-eighth resistor, a forty-third resistor, a thirty-seventh resistor, a fourteenth capacitor, a forty-seventh capacitor, a sixth capacitor, a third capacitor, a fifth inductor, a first diode, an eleventh inductor, a tenth resistor, an eleventh resistor, a seventeenth resistor, a twelfth resistor, a fourteenth resistor, a third transistor, a second transistor, a first transistor, a fourth transistor, a fifth transistor, a sixth resistor, a nineteenth resistor, and a thirteenth resistor. The following are listed: sixteenth resistor, eighth resistor, twentieth resistor, twelfth capacitor, twenty-fourth capacitor, twenty-sixth capacitor, thirty-third capacitor, twenty-second resistor, twenty-first resistor, sixteenth capacitor, forty-eighth capacitor, fifty-third resistor, twenty-third resistor, ninth inductor, tenth inductor, Zener diode, second TVS diode, third TVS diode, fourth TVS diode, first bidirectional diode, second bidirectional diode, third bidirectional diode, twentieth capacitor, twenty-first capacitor, twenty-second capacitor, and twenty-third capacitor. The first terminal of the eleventh capacitor is connected to the first terminal of the seventh capacitor, the first terminal of the fifteenth capacitor, the first terminal of the eighth capacitor, and the first terminal of the sixth inductor. The first terminal of the seventeenth capacitor is connected to the first terminal of the ninth capacitor, the second terminal of the fifteenth capacitor, the second terminal of the eighth capacitor, the first terminal of the seventh inductor, and the SRN terminal of the BMS controller. The second terminal of the eleventh capacitor is connected to the second terminals of the seventeenth capacitor, the seventh capacitor, and the fifteenth capacitor, and then grounded. The second terminal of the sixth inductor is connected in series with the third resistor and then to the first terminal of the fourth resistor, the first terminal of the forty-third resistor, and the negative terminal of the first cell. The second terminal of the seventh inductor is connected in series with the fifth resistor and then to the second terminal of the fourth resistor, the second terminal of the forty-third resistor, the first terminal of the thirty-eighth resistor, and the... The first terminal of the thirty-seventh resistor is connected. The second terminal of the thirty-eighth resistor is connected to the second terminal of the thirty-seventh resistor, the first terminal of the fourth TVS diode, the first terminal of the twentieth capacitor, the first terminal of the twenty-second capacitor, and the first terminal of the third bidirectional diode. The second terminal of the third bidirectional diode is connected to the second terminal of the fourth TVS diode, the second terminal of the twentieth capacitor, the second terminal of the twenty-second capacitor, the first terminal of the nineteenth resistor, the collector of the fifth transistor, the first terminal of the twentieth resistor, the collector of the fourth transistor, the first terminal of the twenty-sixth capacitor, and the first terminal of the thirty-third capacitor. The second terminal of the nineteenth resistor is connected to the base of the fifth transistor and the first terminal of the fourteenth resistor.The second terminal of the fourteenth resistor is connected in series with the sixteenth resistor and then to the base of the fourth transistor and the second terminal of the twentieth resistor. The emitter of the fifth transistor is connected to the emitters of the fourth transistor, the first transistor, and the second transistor. The base of the second transistor is connected to the first terminals of the sixth and twelfth resistors. The second terminal of the twelfth resistor is connected in series with the thirteenth resistor and then to the base of the first transistor and the first terminal of the eighth resistor. The second terminal of the sixth resistor is connected to the collector of the second transistor and the third transistor. The collector of the first transistor, the collector of the first transistor, the second terminal of the eighth resistor, the first terminal of the tenth resistor, the positive terminal of the first diode, the positive terminal of the fourth cell, the first terminal of the twelfth capacitor, and the first terminal of the twenty-fourth capacitor are connected. The second terminal of the twelfth capacitor is connected to the second terminal of the twenty-sixth capacitor, the second terminal of the twenty-fourth capacitor is connected to the second terminal of the thirty-third capacitor, and the second terminal of the eleventh resistor is connected to the second terminal of the twelfth resistor. The second terminal of the eleventh inductor is connected in series with the eleventh resistor and then connected to the PACK terminal of the BMS controller and the first terminal of the fourteenth capacitor. The first terminal of the fourteenth capacitor and the second terminal of the forty-seventh capacitor are both grounded. The cathode of the first diode is connected in series with the fifth inductor and then connected to the BAT terminal of the BMS controller, the first terminal of the third capacitor, and the first terminal of the sixth capacitor. The second terminals of the third capacitor and the sixth capacitor are both grounded. The SMBC terminal of the BMS controller is connected in series with the twenty-second resistor and then connected to the first terminal of the Zener diode, the first terminal of the forty-eighth capacitor, and the first terminal of the fifty-third resistor. The second terminal of the fifty-third resistor is connected in series with the ninth inductor and then connected to the first terminal of the second bidirectional diode and the first terminal of the third TVS diode. The SMBD terminal of the BMS controller is connected in series with the twenty-first resistor and then connected to the second terminal of the Zener diode, the first terminal of the sixteenth capacitor, and the first terminal of the twenty-third resistor. The second terminal of the twenty-third resistor is connected in series with the tenth inductor and then connected to the first terminal of the first bidirectional diode and the first terminal of the second TVS diode. The second terminals of the first bidirectional diode, the second bidirectional diode, the second TVS diode, the third TVS diode, and the third Zener diode are all grounded.

[0009] In the above scheme, the cell pack protection circuit includes a lithium battery protection chip, an eighteenth resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-ninth resistor, a fortieth resistor, a forty-first resistor, a forty-second resistor, a thirty-fourth capacitor, a thirty-fifth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a thirty-eighth capacitor, a thirty-ninth capacitor, a fortieth capacitor, a forty-first capacitor, a forty-second capacitor, a forty-third capacitor, a forty-fourth capacitor, a forty-fifth capacitor, a switch, a thirteenth inductor, and a fourteenth inductor. The first terminal of the thirty-fourth capacitor is connected to the first terminal of the fourth cell and the first terminal of the thirty-fifth capacitor, respectively. The first terminals of the 36th, 37th, 38th, and 39th capacitors, the first terminal of the 40th resistor, and the VDD terminal of the lithium battery protection chip are connected. The second terminal of the 40th resistor is connected to the SEL terminal of the lithium battery protection chip. The first terminal of the 33rd resistor is connected to the positive terminal of the first battery cell. The second terminal of the 33rd resistor is connected to the VC4 terminal of the lithium battery protection chip and the second terminal of the 39th capacitor. The first terminal of the 34th resistor is connected to the positive terminal of the second battery cell. The second terminal of the 34th resistor is connected to the VC3 terminal of the lithium battery protection chip and the first terminal of the 38th capacitor. The first terminal of resistor 15 is connected to the positive terminal of the third battery cell. The second terminal of resistor 35 is connected to the VC2 terminal of the lithium battery protection chip and the second terminal of capacitor 37. The first terminal of resistor 36 is connected to the positive terminal of the fourth battery cell. The second terminal of resistor 36 is connected to the VC1 terminal of the lithium battery protection chip and the second terminal of capacitor 36. The second terminal of capacitor 34 is connected to the second terminal of capacitor 35, the first terminal of resistor 18, the first terminal of resistor 39, the VSS terminal of the lithium battery protection chip, the first terminal of capacitor 40, the first terminal of capacitor 42, the first terminal of capacitor 44, and the first terminal of capacitor 45. The second terminal of the eighteenth resistor is grounded; the second terminal of the thirty-ninth resistor is connected in series with a switch and then connected to the CTL terminal of the lithium battery protection chip; the second terminal of the fortieth capacitor is connected to the CCT terminal of the lithium battery protection chip; the second terminal of the forty-second capacitor is connected to the CDT terminal of the lithium battery protection chip; the second terminal of the forty-fourth capacitor is connected to the VINI terminal of the lithium battery protection chip, the second terminal of the forty-fifth capacitor, and the first terminal of the fourteenth inductor, respectively; the second terminal of the fourteenth inductor is connected in series with the forty-second resistor and then grounded; and the VMP terminal of the lithium battery protection chip is connected to the first terminal of the forty-first resistor, the first terminal of the forty-first capacitor, and the first terminal of the forty-third capacitor, respectively.The second terminal of the forty-first resistor is connected in series with the thirteenth inductor and then connected to the second terminal of the third bidirectional diode.

[0010] In the above scheme, the temperature acquisition circuit includes a first sliding rheostat, a second sliding rheostat, a third sliding rheostat, and a fourth sliding rheostat. The first end of the first sliding rheostat is connected to the TS1 terminal of the BMS controller, the first end of the second sliding rheostat is connected to the TS2 terminal of the BMS controller, the first end of the third sliding rheostat is connected to the TS3 terminal of the BMS controller, and the first end of the fourth sliding rheostat is connected to the TS4 terminal of the BMS controller. The second end of the first sliding rheostat is connected to the second ends of the second, third, and fourth sliding rheostats respectively and then grounded.

[0011] In the above scheme, the low-voltage linear regulator circuit includes a twelfth inductor, a twenty-ninth resistor, a regulator, a twenty-seventh capacitor, a thirtieth capacitor, a thirtieth capacitor, and a thirty-second capacitor. The first end of the twelfth inductor is connected to the first end of the third bidirectional diode. The second end of the twelfth inductor is connected in series with the twenty-ninth resistor and then connected to the first end of the twenty-seventh capacitor, the first end of the thirtieth capacitor, and the VIN terminal of the regulator. The second end of the twenty-seventh capacitor is connected to the second end of the thirtieth capacitor, the GND terminal of the regulator, the first end of the thirty-first capacitor, and the first end of the thirty-second capacitor. The second end of the thirty-first capacitor is connected to the second end of the thirty-second capacitor and the OUT terminal of the regulator.

[0012] In the above scheme, the heating control circuit includes a heating control chip, a 31st resistor, a 44th resistor, a 6th transistor, a 28th capacitor, a 29th capacitor, and an 8th inductor. The collector of the 6th transistor is connected to the DISP terminal of the BMS controller, and the emitter of the 6th transistor is grounded. The base of the 6th transistor is connected in series with the 31st resistor and then connected to the first terminal of the 44th resistor and the fifth terminal of the heating control chip. The first terminal of the heating control chip is connected to the first terminal of the 8th inductor, the first terminal of the 28th capacitor, and the first terminal of the 29th capacitor. The second terminal of the 28th capacitor is connected to the second terminal of the 29th capacitor and the 14th terminal of the heating control chip and then grounded. The second terminal of the 8th inductor is connected to the OUT terminal of the voltage regulator.

[0013] In the above scheme, the charger circuit includes a charger interface, a 71st capacitor, a 72nd capacitor, a 73rd capacitor, a 74th capacitor, an 11th transistor, a 12th transistor, a 71st resistor, a 72nd resistor, a 73rd resistor, and a 74th resistor. The positive terminal of the charger interface is connected to the first end of the heating film and then grounded. The negative terminal of the charger interface is connected to the first end of the 71st capacitor, the first end of the 72nd capacitor, the emitter of the 11th transistor, the emitter of the 12th transistor, and the positive terminal of the third bidirectional diode. The second end of the 71st capacitor is connected to the first end of the 73rd capacitor, and the second end of the 72nd capacitor... The first terminal of the 74th capacitor is connected to the second terminal of the 73rd capacitor, the first terminal of the 71st resistor, the collector of the 11th transistor, the first terminal of the 73rd resistor, the collector of the 12th transistor, and the second terminal of the heating film. The second terminal of the 71st resistor is connected to the base of the 11th transistor and the first terminal of the 72nd resistor. The second terminal of the 72nd resistor is connected to the CO1 terminal of the heating control chip. The second terminal of the 73rd resistor is connected to the base of the 12th transistor and the first terminal of the 74th resistor. The second terminal of the 74th resistor is connected to the CO1 terminal of the heating control chip.

[0014] In the above scheme, the LED indicator circuit includes a first optocoupler, a second optocoupler, a third optocoupler, a fourth optocoupler, a fifth optocoupler, a twenty-fourth resistor, a thirty-second resistor, a twenty-sixth resistor, a twenty-seventh resistor, and a twenty-eighth resistor. The first terminal of the first optocoupler is connected to the LEDCNTLA terminal of the BMS controller, the second terminal of the first optocoupler is connected to the LEDCNTLB terminal of the BMS controller, the third terminal of the first optocoupler is grounded, and the fourth terminal of the first optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the twenty-eighth resistor. The first terminal of the second optocoupler is connected to the LEDCNTLB terminal of the BMS controller, the second terminal of the second optocoupler is connected to the LEDCNTLA terminal of the BMS controller, the third terminal of the second optocoupler is grounded, and the fourth terminal of the second optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the twenty-seventh resistor. The third optocoupler's first terminal ...LA terminal of the BMS controller, the second terminal of the second optocoupler is connected to the LEDCNTLA terminal of the BMS controller, the third terminal of the second optocoupler is grounded, and the fourth terminal of the second optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the twenty-seventh resistor. The third optocoupler's first terminal is connected to the LEDCNTLB terminal of the BMS controller, the second One end of the third optocoupler is connected to the LEDCNTLB terminal of the BMS controller. The second end of the third optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The third end of the third optocoupler is grounded. The fourth end of the third optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 26th resistor. The first end of the fourth optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The second end of the fourth optocoupler is connected to the LEDCNTLB terminal of the BMS controller. The third end of the fourth optocoupler is grounded. The fourth end of the fourth optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 32nd resistor. The first end of the fifth optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The second end of the fifth optocoupler is connected to the LEDCNTLA terminal of the BMS controller. The third end of the fifth optocoupler is grounded. The fourth end of the fifth optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 24th resistor.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] This invention uses a BMS communication transmission circuit to synchronize multi-point temperature data in real time and dynamically control the operation of the heating film, significantly improving the low-temperature heating efficiency and temperature uniformity. It adopts a dual power supply architecture of direct charger supply to the heating film and low-voltage linear regulated power supply to reduce battery cell power loss. Combined with the battery cell protection circuit, it effectively avoids the risks of over-temperature, over-current and signal interference, greatly improving the system safety and reliability. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this invention, illustrate exemplary embodiments of the present invention and, together with their description, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of the structure of a low-temperature heating circuit for a battery cell according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the BMS communication transmission circuit in a low-temperature heating circuit for a battery cell according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the battery cell assembly protection circuit in a low-temperature heating circuit for battery cells according to an embodiment of the present invention.

[0021] Figure 4 This is a schematic diagram of the heating control circuit in a low-temperature heating circuit for a battery cell according to an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram of the LED indicator circuit in a low-temperature heating circuit for a battery cell according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the charger circuit in a low-temperature heating circuit for a battery cell according to an embodiment of the present invention;

[0024] Figure 7 This is a schematic diagram of the low-voltage linear voltage regulator circuit in a low-temperature heating circuit for battery cells according to an embodiment of this utility model. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0027] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0028] This utility model embodiment provides a low-temperature heating circuit for battery cells, such as... Figure 1-7 As shown, the device includes a battery cell assembly, a battery cell assembly protection circuit, a BMS communication transmission circuit, a temperature acquisition circuit, an LED indicator circuit, a heating control circuit, a heating film, a charger circuit, and a low-voltage linear regulator circuit. The BMS communication transmission circuit is connected to the battery cell assembly. The signal output terminal of the temperature acquisition circuit is connected to the signal input terminal of the BMS communication transmission circuit to acquire the temperature of the battery cell assembly. The signal output terminal of the BMS communication transmission circuit is connected to the signal input terminals of the LED indicator circuit and the heating control circuit, respectively. The power input terminal of the heating controller is connected to the power output terminal of the charger. The power output terminal of the heating control circuit is connected to the power input terminal of the heating film. The heating film is disposed on the battery cell assembly and is used to heat the battery cell assembly. The low-voltage linear regulator circuit supplies power to the heating control circuit.

[0029] like Figure 1 and Figure 2As shown, the battery cell assembly includes a first battery cell BAT1, a second battery cell BAT2, a third battery cell BAT3, a fourth battery cell BAT4, a first inductor L1, a second inductor L2, a third inductor L3, a first resistor R1, a second resistor R2, a twenty-fifth resistor R25, a ninth resistor R9, a first capacitor C1, a second capacitor C2, a fourth capacitor C4, a fifth capacitor C5, an eighteenth capacitor C18, a nineteenth capacitor C19, a thirteenth capacitor C13, and a twenty-fifth capacitor C25. The positive terminal of the first battery cell BAT1 is connected to the first terminal of the first inductor L1 and the negative terminal of the second battery cell BAT2. The second terminal of the first inductor L1 is connected in series with the first resistor R1 and then connected to the first terminal of the first capacitor C1, the first terminal of the second capacitor C2, the first terminal of the fourth capacitor C4, the first terminal of the fifth capacitor C5, and the VC1 terminal of the BMS controller U1. The second terminal of the second battery cell BAT2 is connected to the first terminal of the third battery cell BAT3. The negative terminal is connected to the first end of the second inductor L2. The second end of the second inductor L2 is connected in series with the second resistor R2 and then connected to the second end of the second capacitor C2, the second end of the fifth capacitor C5, the first end of the eighteenth capacitor C18, the first end of the nineteenth capacitor C19, and the VC2 terminal of the BMS controller U1. The positive terminal of the third cell BAT3 is connected to the negative terminal of the fourth cell BAT4 and the first end of the third inductor L3. The second end of the third inductor L3 is connected in series with the twenty-fifth resistor R25 and then connected to the second end of the eighteenth capacitor C18, the second end of the nineteenth capacitor C19, the first end of the thirteenth capacitor C13, the first end of the twenty-fifth capacitor C25, and the VC3 terminal of the BMS controller U1. The positive terminal of the fourth cell BAT4 is connected in series with the fourth inductor L4 and the ninth resistor R9 and then connected to the second end of the thirteenth capacitor C13, the second end of the twenty-fifth capacitor C25, and the VC4 terminal of the BMS controller U1.

[0030] like Figure 1 and Figure 2As shown, the BMS communication transmission circuit includes a BMS controller U1, an eleventh capacitor C11, a seventeenth capacitor C17, a seventh capacitor C7, a ninth capacitor C9, a fifteenth capacitor C15, an eighth capacitor C8, a sixth inductor L6, a seventh inductor L7, a third resistor R3, a fifth resistor R5, a fourth resistor R4, a thirty-eighth resistor R38, a forty-third resistor R43, a thirty-seventh resistor R37, a fourteenth capacitor C14, a forty-seventh capacitor C47, a sixth capacitor C6, a third capacitor C3, a fifth inductor L5, a first diode D1, an eleventh inductor L11, a tenth resistor R10, an eleventh resistor R11, a seventeenth resistor R17, and a twelfth... Resistor R12, fourteenth resistor R14, third transistor Q3, second transistor Q2, first transistor Q1, fourth transistor Q4, fifth transistor Q5, sixth resistor R6, nineteenth resistor R19, thirteenth resistor R13, sixteenth resistor R16, eighth resistor R8, twentieth resistor R20, twelfth capacitor C12, twenty-fourth capacitor C24, twenty-sixth capacitor C26, thirty-third capacitor C33, twenty-second resistor R22, twenty-first resistor R21, sixteenth capacitor C16, forty-eighth capacitor C48, fifty-third resistor R53, twenty-third resistor R23, ninth inductor L9, tenth inductor L10, Zener diode Z1 The system comprises: a second TVS diode Z2, a third TVS diode Z3, a fourth TVS diode Z4, a first bidirectional diode ESD1, a second bidirectional diode ESD2, a third bidirectional diode ESD3, a twentieth capacitor C20, a twenty-first capacitor C21, a twenty-second capacitor C22, and a twenty-third capacitor C23. The first terminal of the eleventh capacitor C11 is connected to the first terminals of the seventh capacitor C7, the fifteenth capacitor C15, the eighth capacitor C8, the sixth inductor L6, and the SRP terminal of the BMS controller U1. The first terminal of the seventeenth capacitor C17 is connected to the first terminal of the ninth capacitor C9, the second terminal of the fifteenth capacitor C15, and the first terminal of the eighth capacitor C8. The first terminal of the seventh inductor L7 is connected to the SRN terminal of the BMS controller U1. The second terminal of the eleventh capacitor C11 is connected to the second terminals of the seventeenth capacitor C17, the seventh capacitor C7, and the fifteenth capacitor C15, and then grounded. The second terminal of the sixth inductor L6 is connected in series with the third resistor R3 and then to the first terminal of the fourth resistor R4, the first terminal of the forty-third resistor R43, and the negative terminal of the first cell BAT1. The second terminal of the seventh inductor L7 is connected in series with the fifth resistor R5 and then to the second terminal of the fourth resistor R4, the second terminal of the forty-third resistor R43, the first terminal of the thirty-eighth resistor R38, and the first terminal of the thirty-seventh resistor R37.The second terminal of the thirty-eighth resistor R38 is connected to the second terminal of the thirty-seventh resistor R37, the first terminal of the fourth TVS diode Z4, the first terminal of the twentieth capacitor C20, the first terminal of the twenty-second capacitor C22, and the first terminal of the third bidirectional diode ESD3. The second terminal of the third bidirectional diode ESD3 is connected to the second terminal of the fourth TVS diode Z4, the second terminal of the twentieth capacitor C20, the second terminal of the twenty-second capacitor C22, the first terminal of the nineteenth resistor R19, the collector of the fifth transistor Q5, the first terminal of the twentieth resistor R20, the collector of the fourth transistor Q4, the first terminal of the twenty-sixth capacitor C26, and the first terminal of the thirty-third capacitor C33. The nineteenth resistor R19... The second end of resistor 9 is connected to the base of the fifth transistor Q5 and the first end of the fourteenth resistor R14. The second end of the fourteenth resistor R14 is connected in series with the sixteenth resistor R16 and then to the base of the fourth transistor Q4 and the second end of the twentieth resistor R20. The emitter of the fifth transistor Q5 is connected to the emitter of the fourth transistor Q4, the emitter of the first transistor Q1, and the emitter of the second transistor Q2. The base of the second transistor Q2 is connected to the first end of the sixth resistor R6 and the first end of the twelfth resistor R12. The second end of the twelfth resistor R12 is connected in series with the thirteenth resistor R13 and then to the base of the first transistor Q1 and the first end of the eighth resistor R8. The sixth resistor... The second terminal of resistor R6 is connected to the collector of the second transistor Q2, the collector of the third transistor Q3, the collector of the first transistor Q1, the second terminal of the eighth resistor R8, the first terminal of the tenth resistor R10, the positive terminal of the first diode D1, the positive terminal of the fourth battery cell BAT4, the first terminal of the twelfth capacitor C12, and the first terminal of the twenty-fourth capacitor C24. The second terminal of the twelfth capacitor C12 is connected to the second terminal of the twenty-sixth capacitor C26, the second terminal of the twenty-fourth capacitor C24 is connected to the second terminal of the thirty-third capacitor C33, and the second terminal of the eleventh resistor R11 is connected to the second terminal of the twelfth resistor R12. The second terminal of the eleventh inductor L11 is connected in series with the eleventh resistor R11 and then... The first diode D1 is connected to the PACK terminal of BMS controller U1, the first terminal of the fourteenth capacitor C14, and the first terminal of the forty-seventh capacitor C47. The second terminals of the fourteenth capacitor C14 and the forty-seventh capacitor C47 are both grounded. The cathode of the first diode D1 is connected in series with the fifth inductor L5 and then connected to the BAT terminal of BMS controller U1, the first terminal of the third capacitor C3, and the first terminal of the sixth capacitor C6. The second terminals of the third capacitor C3 and the sixth capacitor C6 are both grounded. The SMBC terminal of BMS controller U1 is connected in series with the twenty-second resistor R22 and then connected to the first terminal of the Zener diode Z1, the first terminal of the forty-eighth capacitor C48, and the first terminal of the fifty-third resistor R53.The second terminal of the fifty-third resistor R53 is connected in series with the ninth inductor L9 and then to the first terminal of the second bidirectional diode ESD2 and the first terminal of the third TVS diode Z3. The SMBD terminal of the BMS controller U1 is connected in series with the twenty-first resistor R21 and then to the second terminal of the Zener diode Z1, the first terminal of the sixteenth capacitor C16, and the first terminal of the twenty-third resistor R23. The second terminal of the twenty-third resistor R23 is connected in series with the tenth inductor L10 and then to the first terminal of the first bidirectional diode ESD1 and the first terminal of the second TVS diode Z2. The second terminals of the first bidirectional diode ESD1, the second bidirectional diode ESD2, the second TVS diode Z2, the third TVS diode Z3, and the third terminal of the Zener diode Z1 are all grounded.

[0031] like Figures 1-3As shown, the battery cell protection circuit includes a lithium battery protection chip U9, an eighteenth resistor R18, a thirty-third resistor R33, a thirty-fourth resistor R34, a thirty-fifth resistor R35, a thirty-sixth resistor R36, a thirty-ninth resistor R39, a fortieth resistor R40, a forty-first resistor R41, a forty-second resistor R42, a thirty-fourth capacitor C34, a thirty-fifth capacitor C35, a thirty-sixth capacitor C36, a thirty-seventh capacitor C37, a thirty-eighth capacitor C38, a thirty-ninth capacitor C39, a fortieth capacitor C40, a forty-first capacitor C41, a forty-second capacitor C42, a forty-third capacitor C43, a forty-fourth capacitor C44, and a... The system includes a 45th capacitor (C45), a switch (TS1), a 13th inductor (L13), a 14th inductor (L14), a 34th capacitor (C34), a 35th capacitor (C35), a 36th capacitor (C36), a 37th capacitor (C37), a 38th capacitor (C38), a 39th capacitor (C39), a 40th resistor (R40), and the VDD terminal of the lithium battery protection chip U9. The system also includes a 45th capacitor (C45), a 35th capacitor (TS1), a 36th capacitor (C36), a 37th capacitor (C37), a 38th capacitor (C38), a 39th capacitor (C39), a 40th resistor (R40), and the VDD terminal of the lithium battery protection chip U9. The system also includes a 33rd resistor (R33), a 35th capacitor (C45), a 36th capacitor (C36), a 37th capacitor (C37), a 38th capacitor (C38), a 39th capacitor (C39), a 40th resistor (R40), and the VDD terminal of the lithium battery protection chip U9. The system further includes a 33rd capacitor (C45), a 34th capacitor (TS1), a 35th capacitor (TS1), a 36th capacitor (C36), a 37th capacitor (C37), a 38th capacitor (C38), a 39th capacitor (C39), a 30th resistor (R33), and the VDD terminal of the lithium battery protection chip U9. The second terminal of resistor R33 is connected to the VC4 terminal of lithium battery protection chip U9 and the second terminal of the thirty-ninth capacitor C39, respectively. The first terminal of the thirty-fourth resistor R34 is connected to the positive terminal of the second cell BAT2. The second terminal of the thirty-fourth resistor R34 is connected to the VC3 terminal of lithium battery protection chip U9 and the first terminal of the thirty-eighth capacitor C38, respectively. The first terminal of the thirty-fifth resistor R35 is connected to the positive terminal of the third cell BAT3, and the second terminal of the thirty-fifth resistor R35 is connected to the VC2 terminal of lithium battery protection chip U9 and the second terminal of the thirty-seventh capacitor C37, respectively. The first terminal of the thirty-sixth resistor R36 is connected to the positive terminal of the fourth cell BAT4, and the third... The second terminal of resistor R36 (sixteenth resistor) is connected to the VC1 terminal of lithium battery protection chip U9 and the second terminal of capacitor C36 (thirty-sixth capacitor). The second terminal of capacitor C34 (thirty-fourth capacitor) is connected to the second terminal of capacitor C35 (thirty-fifth capacitor), the first terminal of resistor R18 (eighteenth resistor), resistor R39 (thirty-ninth resistor), the VSS terminal of lithium battery protection chip U9, the first terminal of capacitor C40 (fortieth capacitor), capacitor C42 (forty-second capacitor), capacitor C44 (forty-fourth capacitor), and capacitor C45 (forty-fifth capacitor). The second terminal of resistor R18 (eighteenth resistor) is grounded. The second terminal of resistor R39 (thirty-ninth resistor) is connected to the CTL terminal of lithium battery protection chip U9 after being connected in series with a switch.The second terminal of the 40th capacitor C40 is connected to the CCT terminal of the lithium battery protection chip U9. The second terminal of the 42nd capacitor C42 is connected to the CDT terminal of the lithium battery protection chip U9. The second terminal of the 44th capacitor C44 is connected to the VINI terminal of the lithium battery protection chip U9, the second terminal of the 45th capacitor C45, and the first terminal of the 14th inductor L14. The second terminal of the 14th inductor L14 is connected to ground after being connected in series with the 42nd resistor R42. The VMP terminal of the lithium battery protection chip U9 is connected to the first terminal of the 41st resistor R41, the first terminal of the 41st capacitor C41, and the first terminal of the 43rd capacitor C43. The second terminal of the 41st resistor R41 is connected to the second terminal of the 13th inductor L13 after being connected in series with the 13th inductor L13.

[0032] like Figure 1 and Figure 2 As shown, the temperature acquisition circuit includes a first sliding rheostat RT1, a second sliding rheostat RT2, a third sliding rheostat RT3, and a fourth sliding rheostat RT4. The first end of the first sliding rheostat RT1 is connected to the TS1 terminal of the BMS controller U1, the first end of the second sliding rheostat RT2 is connected to the TS2 terminal of the BMS controller U1, the first end of the third sliding rheostat RT3 is connected to the TS3 terminal of the BMS controller U1, and the first end of the fourth sliding rheostat RT4 is connected to the TS4 terminal of the BMS controller U1. The second end of the first sliding rheostat RT1 is connected to the second ends of the second sliding rheostat RT2, the third sliding rheostat RT3, and the fourth sliding rheostat RT4, respectively, and then grounded.

[0033] like Figure 1 and Figure 7 As shown, the low-voltage linear regulator circuit includes a twelfth inductor L12, a twenty-ninth resistor R29, a regulator U3, a twenty-seventh capacitor C27, a thirtieth capacitor C30, a thirty-first capacitor C31, and a thirty-second capacitor C32. The first terminal of the twelfth inductor L12 is connected to the first terminal of the third bidirectional diode ESD3. The second terminal of the twelfth inductor L12 is connected in series with the twenty-ninth resistor R29 and then connected to the first terminal of the twenty-seventh capacitor C27, the first terminal of the thirtieth capacitor C30, and the VIN terminal of the regulator U3. The second terminal of the twenty-seventh capacitor C27 is connected to the second terminal of the thirtieth capacitor C30, the GND terminal of the regulator U3, the first terminal of the thirty-first capacitor C31, and the first terminal of the thirty-second capacitor C32. The second terminal of the thirty-first capacitor C31 is connected to the second terminal of the thirty-second capacitor C32 and the OUT terminal of the regulator U3.

[0034] like Figures 1-4As shown, the heating control circuit includes a heating control chip U2, a 31st resistor R31, a 44th resistor R44, a 6th transistor Q6, a 28th capacitor C28, a 29th capacitor C29, and an 8th inductor L8. The collector of the 6th transistor Q6 is connected to the DISP terminal of the BMS controller U1, and the emitter of the 6th transistor Q6 is grounded. The base of the 6th transistor Q6 is connected in series with the 31st resistor R31 and then connected to the first terminal of the 44th resistor R44 and the fifth terminal of the heating control chip U2. The first terminal of the heating control chip U2 is connected to the first terminal of the 8th inductor L8, the first terminal of the 28th capacitor C28, and the first terminal of the 29th capacitor C29. The second terminal of the 28th capacitor C28 is connected to the second terminal of the 29th capacitor C29 and the 14th terminal of the heating control chip U2 and then grounded. The second terminal of the 8th inductor L8 is connected to the OUT terminal of the voltage regulator U3.

[0035] like Figure 1 , Figure 2 , Figure 3 and Figure 6 As shown, the charger circuit includes a charger interface, a seventy-first capacitor C71, a seventy-second capacitor C72, a seventy-third capacitor C73, a seventy-fourth capacitor C74, an eleventh transistor Q11, a twelfth transistor Q12, a seventy-first resistor R71, a seventy-second resistor R72, a seventy-third resistor R73, and a seventy-fourth resistor R74. The positive terminal of the charger interface is connected to the first end of the heating film U4 and then grounded. The negative terminal of the charger interface is connected to the first end of the seventy-first capacitor C71, the first end of the seventy-second capacitor C72, the emitter of the eleventh transistor Q11, the emitter of the twelfth transistor Q12, and the positive terminal of the third bidirectional diode ESD3. The second end of the seventy-first capacitor C71 is connected to the first end of the seventy-third capacitor C73. The seventh end of the seventy-second capacitor C72... The second terminal of the seventy-fourth capacitor C74 is connected to the first terminal of the seventy-third capacitor C73. The second terminal of the seventy-third capacitor C73 is connected to the second terminal of the seventy-fourth capacitor C74, the first terminal of the seventy-first resistor R71, the collector of the eleventh transistor Q11, the first terminal of the seventy-third resistor R73, the collector of the twelfth transistor Q12, and the second terminal of the heating film U4. The second terminal of the seventy-first resistor R71 is connected to the base of the eleventh transistor Q11 and the first terminal of the seventy-second resistor R72. The second terminal of the seventy-second resistor R72 is connected to the CO1 terminal of the heating control chip U2. The second terminal of the seventy-third resistor R73 is connected to the base of the twelfth transistor Q12 and the first terminal of the seventy-fourth resistor R74. The second terminal of the seventy-fourth resistor R74 is connected to the CO1 terminal of the heating control chip U2.

[0036] like Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, the LED indicator circuit includes a first optocoupler LED1, a second optocoupler LED2, a third optocoupler LED3, a fourth optocoupler LED4, a fifth optocoupler LED5, a twenty-fourth resistor R24, a thirty-second resistor R32, a twenty-sixth resistor R26, a twenty-seventh resistor R27, and a twenty-eighth resistor R28. The first terminal of the first optocoupler LED1 is connected to the LEDCNT1A terminal of the BMS controller U1, and the second terminal of the first optocoupler LED1 is connected to the LEDCNT1B terminal of the BMS controller U1. The third terminal of the first optocoupler LED1 is grounded. The fourth terminal of the first optocoupler LED1 is connected in series with the 28th resistor R28 and then connected to the OUT terminal of the voltage regulator U3. The first terminal of the second optocoupler LED2 is connected to the LEDCNTLB terminal of the BMS controller U1, and the second terminal of the second optocoupler LED2 is connected to the LEDCNTLA terminal of the BMS controller U1. The third terminal of the second optocoupler LED2 is grounded. The fourth terminal of the second optocoupler LED2 is connected in series with the 27th resistor R27 and then connected to the OUT terminal of the voltage regulator U3. The third optocoupler... The first terminal of the third optocoupler LED3 is connected to the LEDCNTLB terminal of the BMS controller U1. The second terminal of the third optocoupler LED3 is connected to the LEDCNTLC terminal of the BMS controller U1. The third terminal of the third optocoupler LED3 is grounded. The fourth terminal of the third optocoupler LED3 is connected to the OUT terminal of the voltage regulator U3 after being connected in series with the 26th resistor R26. The first terminal of the fourth optocoupler LED4 is connected to the LEDCNTLC terminal of the BMS controller U1. The second terminal of the fourth optocoupler LED4 is connected to the LEDCNTLB terminal of the BMS controller U1. The fourth optocoupler LED4 has its third terminal grounded, and its fourth terminal is connected to the OUT terminal of the voltage regulator U3 via a series connection of the thirty-second resistor R32. The first terminal of the fifth optocoupler LED5 is connected to the LEDCNTLC terminal of the BMS controller U1, and its second terminal is connected to the LEDCNTLA terminal of the BMS controller U1. The third terminal of the fifth optocoupler LED5 is grounded, and its fourth terminal is connected to the OUT terminal of the voltage regulator U3 via a series connection of the twenty-fourth resistor R24.

[0037] The working principle of this utility model is as follows:

[0038] like Figure 1-7As shown, the low-temperature heating circuit for the battery cells achieves efficient and safe heating through multi-module collaborative closed-loop control. The sliding rheostat in the temperature acquisition circuit senses the surface temperature of the battery cell assembly in real time, generating a resistance signal that is input to the TS1-TS4 ports of the BMS communication transmission circuit. The BMS controller U1 internally uses an RC filter network (such as the fourteenth capacitor C14 and the forty-seventh capacitor C47) and a TVS diode to suppress noise and protect against electrostatic discharge, accurately analyzing the temperature data at each point. When the temperature is below the set threshold, the BMS controller U1 outputs a decision command through the SMBC / SMBD communication line: on one hand, a PWM signal is sent from the DISP terminal to drive the sixth transistor Q6 to conduct, triggering the heating control chip U2 to start; on the other hand, the optocoupler of the LED indicator circuit is controlled through the LEDCNTLA-C terminal to display the working status.

[0039] After the heating control chip U2 is activated, it outputs a drive current from the CO1 terminal, turning on the eleventh transistor Q11 and the twelfth transistor Q12 in the charger circuit. This allows the external charger's power to be directly delivered to the heating film U4 attached to the battery cell assembly, avoiding the consumption of the battery cell's own stored energy. Simultaneously, the low-voltage linear regulator circuit generates an isolated and stable voltage through an inductor-capacitor network (such as the twelfth inductor L12 and the twenty-seventh capacitor C27) to power the heating control chip U2, eliminating the risk of control instability caused by charger input ripple.

[0040] The cell protection circuit monitors the cell voltage status throughout the process (sampled via VC1-VC4 ports). The lithium battery protection chip U9 and the BMS controller U1 form a dual protection mechanism: if overvoltage, overcurrent, or temperature exceeding the limit is detected, the heating control signal is immediately shut off and an LED alarm is triggered. During the heating process, temperature data is continuously fed back to the BMS controller U1. When the set temperature is reached, heating is automatically terminated, forming a complete process control of "temperature sensing, BMS controller decision-making, direct heating from the charger, cell protection circuit, and feedback closed loop," achieving a balance between energy efficiency and safety.

[0041] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A low-temperature heating circuit for battery cells, characterized in that, The device includes a battery cell assembly, a battery cell assembly protection circuit, a BMS communication transmission circuit, a temperature acquisition circuit, an LED indicator circuit, a heating control circuit, a heating film, a charger circuit, and a low-voltage linear regulator circuit. The BMS communication transmission circuit is connected to the battery cell assembly. The signal output terminal of the temperature acquisition circuit is connected to the signal input terminal of the BMS communication transmission circuit to acquire the temperature of the battery cell assembly. The signal output terminal of the BMS communication transmission circuit is connected to the signal input terminals of the LED indicator circuit and the heating control circuit, respectively. The power input terminal of the heating controller is connected to the power output terminal of the charger. The power output terminal of the heating control circuit is connected to the power input terminal of the heating film. The heating film is disposed on the battery cell assembly and is used to heat the battery cell assembly. The low-voltage linear regulator circuit supplies power to the heating control circuit.

2. The low-temperature heating circuit for a battery cell according to claim 1, characterized in that, The battery cell assembly includes a first battery cell, a second battery cell, a third battery cell, a fourth battery cell, a first inductor, a second inductor, a third inductor, a first resistor, a second resistor, a twenty-fifth resistor, a ninth resistor, a first capacitor, a second capacitor, a fourth capacitor, a fifth capacitor, an eighteenth capacitor, a nineteenth capacitor, a thirteenth capacitor, and a twenty-fifth capacitor. The positive terminal of the first battery cell is connected to the first terminal of the first inductor and the negative terminal of the second battery cell. The second terminal of the first inductor, connected in series with the first resistor, is connected to the first terminal of the first capacitor, the first terminal of the second capacitor, the first terminal of the fourth capacitor, the first terminal of the fifth capacitor, and the VC1 terminal of the BMS controller. The second terminal of the second battery cell is connected to the negative terminal of the third battery cell and the first terminal of the second inductor. The second inductor is connected in series with a second resistor and then connected to the second terminal of the second capacitor, the second terminal of the fifth capacitor, the first terminal of the eighteenth capacitor, the first terminal of the nineteenth capacitor, and the VC2 terminal of the BMS controller. The positive terminal of the third cell is connected to the negative terminal of the fourth cell and the first terminal of the third inductor. The second terminal of the third inductor is connected in series with a twenty-fifth resistor and then connected to the second terminal of the eighteenth capacitor, the second terminal of the nineteenth capacitor, the first terminal of the thirteenth capacitor, the first terminal of the twenty-fifth capacitor, and the VC3 terminal of the BMS controller. The positive terminal of the fourth cell is connected in series with a fourth inductor and a ninth resistor and then connected to the second terminal of the thirteenth capacitor, the second terminal of the twenty-fifth capacitor, and the VC4 terminal of the BMS controller.

3. The low-temperature heating circuit for a battery cell according to claim 2, characterized in that, The BMS communication transmission circuit includes a BMS controller, an eleventh capacitor, a seventeenth capacitor, a seventh capacitor, a ninth capacitor, a fifteenth capacitor, an eighth capacitor, a sixth inductor, a seventh inductor, a third resistor, a fifth resistor, a fourth resistor, a thirty-eighth resistor, a forty-third resistor, a thirty-seventh resistor, a fourteenth capacitor, a forty-seventh capacitor, a sixth capacitor, a third capacitor, a fifth inductor, a first diode, an eleventh inductor, a tenth resistor, an eleventh resistor, a seventeenth resistor, a twelfth resistor, a fourteenth resistor, a third transistor, a second transistor, a first transistor, a fourth transistor, a fifth transistor, a sixth resistor, a nineteenth resistor, a thirteenth resistor, and a sixteenth resistor. Resistor, eighth resistor, twentieth resistor, twelfth capacitor, twenty-fourth capacitor, twenty-sixth capacitor, thirty-third capacitor, twenty-second resistor, twenty-first resistor, sixteenth capacitor, forty-eighth capacitor, fifty-third resistor, twenty-third resistor, ninth inductor, tenth inductor, Zener diode, second TVS diode, third TVS diode, fourth TVS diode, first bidirectional diode, second bidirectional diode, third bidirectional diode, twentieth capacitor, twenty-first capacitor, twenty-second capacitor, and twenty-third capacitor, wherein the first terminal of the eleventh capacitor is respectively connected to the first terminal of the seventh capacitor, the first terminal of the fifteenth capacitor, the first terminal of the eighth capacitor, the first terminal of the sixth inductor, and BM. The SRP terminal of the S controller is connected. The first terminal of the seventeenth capacitor is connected to the first terminal of the ninth capacitor, the second terminal of the fifteenth capacitor, the second terminal of the eighth capacitor, the first terminal of the seventh inductor, and the SRN terminal of the BMS controller. The second terminal of the eleventh capacitor is connected to the second terminals of the seventeenth capacitor, the seventh capacitor, and the fifteenth capacitor, and then grounded. The second terminal of the sixth inductor is connected in series with the third resistor and then to the first terminal of the fourth resistor, the first terminal of the forty-third resistor, and the negative terminal of the first cell. The second terminal of the seventh inductor is connected in series with the fifth resistor and then to the second terminal of the fourth resistor, the second terminal of the forty-third resistor, the first terminal of the thirty-eighth resistor, and the third... The first terminal of the seventeenth resistor is connected. The second terminal of the thirty-eighth resistor is connected to the second terminal of the thirty-seventh resistor, the first terminal of the fourth TVS diode, the first terminal of the twentieth capacitor, the first terminal of the twenty-second capacitor, and the first terminal of the third bidirectional diode. The second terminal of the third bidirectional diode is connected to the second terminal of the fourth TVS diode, the second terminal of the twentieth capacitor, the second terminal of the twenty-second capacitor, the first terminal of the nineteenth resistor, the collector of the fifth transistor, the first terminal of the twentieth resistor, the collector of the fourth transistor, the first terminal of the twenty-sixth capacitor, and the first terminal of the thirty-third capacitor. The second terminal of the nineteenth resistor is connected to the base of the fifth transistor and the first terminal of the fourteenth resistor.The second terminal of the fourteenth resistor is connected in series with the sixteenth resistor and then to the base of the fourth transistor and the second terminal of the twentieth resistor. The emitter of the fifth transistor is connected to the emitters of the fourth transistor, the first transistor, and the second transistor. The base of the second transistor is connected to the first terminals of the sixth and twelfth resistors. The second terminal of the twelfth resistor is connected in series with the thirteenth resistor and then to the base of the first transistor and the first terminal of the eighth resistor. The second terminal of the sixth resistor is connected to the collector of the second transistor and the third transistor. The collector of the first transistor, the collector of the first transistor, the second terminal of the eighth resistor, the first terminal of the tenth resistor, the positive terminal of the first diode, the positive terminal of the fourth cell, the first terminal of the twelfth capacitor, and the first terminal of the twenty-fourth capacitor are connected. The second terminal of the twelfth capacitor is connected to the second terminal of the twenty-sixth capacitor, the second terminal of the twenty-fourth capacitor is connected to the second terminal of the thirty-third capacitor, and the second terminal of the eleventh resistor is connected to the second terminal of the twelfth resistor. The second terminal of the eleventh inductor is connected in series with the eleventh resistor and then connected to the PACK terminal of the BMS controller and the first terminal of the fourteenth capacitor. The first terminal of the fourteenth capacitor and the second terminal of the forty-seventh capacitor are both grounded. The cathode of the first diode is connected in series with the fifth inductor and then connected to the BAT terminal of the BMS controller, the first terminal of the third capacitor, and the first terminal of the sixth capacitor. The second terminals of the third capacitor and the sixth capacitor are both grounded. The SMBC terminal of the BMS controller is connected in series with the twenty-second resistor and then connected to the first terminal of the Zener diode, the first terminal of the forty-eighth capacitor, and the first terminal of the fifty-third resistor. The second terminal of the fifty-third resistor is connected in series with the ninth inductor and then connected to the first terminal of the second bidirectional diode and the first terminal of the third TVS diode. The SMBD terminal of the BMS controller is connected in series with the twenty-first resistor and then connected to the second terminal of the Zener diode, the first terminal of the sixteenth capacitor, and the first terminal of the twenty-third resistor. The second terminal of the twenty-third resistor is connected in series with the tenth inductor and then connected to the first terminal of the first bidirectional diode and the first terminal of the second TVS diode. The second terminals of the first bidirectional diode, the second bidirectional diode, the second TVS diode, the third TVS diode, and the third Zener diode are all grounded.

4. The low-temperature heating circuit for a battery cell according to claim 3, characterized in that, The battery cell protection circuit includes a lithium battery protection chip, an eighteenth resistor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a thirty-ninth resistor, a fortieth resistor, a forty-first resistor, a forty-second resistor, a thirty-fourth capacitor, a thirty-fifth capacitor, a thirty-sixth capacitor, a thirty-seventh capacitor, a thirty-eighth capacitor, a thirty-ninth capacitor, a fortieth capacitor, a forty-first capacitor, a forty-second capacitor, a forty-third capacitor, a forty-fourth capacitor, a forty-fifth capacitor, a switch, a thirteenth inductor, and a fourteenth inductor. The first terminal of the thirty-fourth capacitor is connected to the first terminal of the fourth battery cell, the first terminal of the thirty-fifth capacitor, and the first terminal of the thirty-sixth capacitor. The first terminals of the 37th capacitor, the 38th capacitor, the 39th capacitor, and the 40th resistor are connected to the VDD terminal of the lithium battery protection chip. The second terminal of the 40th resistor is connected to the SEL terminal of the lithium battery protection chip. The first terminal of the 33rd resistor is connected to the positive terminal of the first battery cell. The second terminal of the 33rd resistor is connected to the VC4 terminal of the lithium battery protection chip and the second terminal of the 39th capacitor. The first terminal of the 34th resistor is connected to the positive terminal of the second battery cell. The second terminal of the 34th resistor is connected to the VC3 terminal of the lithium battery protection chip and the first terminal of the 38th capacitor. The first terminal of the 35th resistor is connected to the positive terminal of the third battery cell. The second terminal of the thirty-fifth resistor is connected to the VC2 terminal of the lithium battery protection chip and the second terminal of the thirty-seventh capacitor, respectively. The first terminal of the thirty-sixth resistor is connected to the positive terminal of the fourth battery cell. The second terminal of the thirty-sixth resistor is connected to the VC1 terminal of the lithium battery protection chip and the second terminal of the thirty-sixth capacitor, respectively. The second terminal of the thirty-fourth capacitor is connected to the second terminal of the thirty-fifth capacitor, the first terminal of the eighteenth resistor, the first terminal of the thirty-ninth resistor, the VSS terminal of the lithium battery protection chip, the first terminal of the fortieth capacitor, the first terminal of the forty-second capacitor, the first terminal of the forty-fourth capacitor, and the first terminal of the forty-fifth capacitor, respectively. The second terminal of the eighteenth resistor is grounded. The first terminal of the thirty-ninth resistor... The two-terminal series switch is connected to the CTL terminal of the lithium battery protection chip. The second terminal of the 40th capacitor is connected to the CCT terminal of the lithium battery protection chip. The second terminal of the 42nd capacitor is connected to the CDT terminal of the lithium battery protection chip. The second terminal of the 44th capacitor is connected to the VINI terminal of the lithium battery protection chip, the second terminal of the 45th capacitor, and the first terminal of the 14th inductor. The second terminal of the 14th inductor is connected to ground after being connected in series with the 42nd resistor. The VMP terminal of the lithium battery protection chip is connected to the first terminal of the 41st resistor, the first terminal of the 41st capacitor, and the first terminal of the 43rd capacitor. The second terminal of the 41st resistor is connected in series with the 13th inductor and then connected to the second terminal of the third bidirectional diode.

5. A low-temperature heating circuit for a battery cell according to claim 4, characterized in that, The temperature acquisition circuit includes a first sliding rheostat, a second sliding rheostat, a third sliding rheostat, and a fourth sliding rheostat. The first end of the first sliding rheostat is connected to the TS1 terminal of the BMS controller, the first end of the second sliding rheostat is connected to the TS2 terminal of the BMS controller, the first end of the third sliding rheostat is connected to the TS3 terminal of the BMS controller, and the first end of the fourth sliding rheostat is connected to the TS4 terminal of the BMS controller. The second end of the first sliding rheostat is connected to the second ends of the second, third, and fourth sliding rheostats respectively and then grounded.

6. A low-temperature heating circuit for a battery cell according to claim 5, characterized in that, The low-voltage linear regulator circuit includes a twelfth inductor, a twenty-ninth resistor, a voltage regulator, a twenty-seventh capacitor, a thirtieth capacitor, a thirtieth capacitor, and a thirty-second capacitor. The first terminal of the twelfth inductor is connected to the first terminal of the third bidirectional diode. The second terminal of the twelfth inductor is connected in series with the twenty-ninth resistor and then connected to the first terminal of the twenty-seventh capacitor, the first terminal of the thirtieth capacitor, and the VIN terminal of the voltage regulator. The second terminal of the twenty-seventh capacitor is connected to the second terminal of the thirtieth capacitor, the GND terminal of the voltage regulator, the first terminal of the thirty-first capacitor, and the first terminal of the thirty-second capacitor. The second terminal of the thirty-first capacitor is connected to the second terminal of the thirty-second capacitor and the OUT terminal of the voltage regulator.

7. A low-temperature heating circuit for a battery cell according to claim 6, characterized in that, The heating control circuit includes a heating control chip, a 31st resistor, a 44th resistor, a 6th transistor, a 28th capacitor, a 29th capacitor, and an 8th inductor. The collector of the 6th transistor is connected to the DISP terminal of the BMS controller, and the emitter of the 6th transistor is grounded. The base of the 6th transistor is connected in series with the 31st resistor and then connected to the first terminal of the 44th resistor and the fifth terminal of the heating control chip. The first terminal of the heating control chip is connected to the first terminal of the 8th inductor, the first terminal of the 28th capacitor, and the first terminal of the 29th capacitor. The second terminal of the 28th capacitor is connected to the second terminal of the 29th capacitor and the 14th terminal of the heating control chip and then grounded. The second terminal of the 8th inductor is connected to the OUT terminal of the voltage regulator.

8. A low-temperature heating circuit for a battery cell according to claim 7, characterized in that, The charger circuit includes a charger interface, a 71st capacitor, a 72nd capacitor, a 73rd capacitor, a 74th capacitor, an 11th transistor, a 12th transistor, a 71st resistor, a 72nd resistor, a 73rd resistor, and a 74th resistor. The positive terminal of the charger interface is connected to the first end of the heating film and then grounded. The negative terminal of the charger interface is connected to the first end of the 71st capacitor, the first end of the 72nd capacitor, the emitter of the 11th transistor, the emitter of the 12th transistor, and the positive terminal of the third bidirectional diode. The second end of the 71st capacitor is connected to the first end of the 73rd capacitor, and the second end of the 72nd capacitor is connected to the 74th capacitor. The first end of the fourteenth capacitor is connected, and the second end of the seventy-third capacitor is connected to the second end of the seventy-fourth capacitor, the first end of the seventy-first resistor, the collector of the eleventh transistor, the first end of the seventy-third resistor, the collector of the twelfth transistor, and the second end of the heating film. The second end of the seventy-first resistor is connected to the base of the eleventh transistor and the first end of the seventy-second resistor. The second end of the seventy-second resistor is connected to the CO1 terminal of the heating control chip. The second end of the seventy-third resistor is connected to the base of the twelfth transistor and the first end of the seventy-fourth resistor. The second end of the seventy-fourth resistor is connected to the CO1 terminal of the heating control chip.

9. A low-temperature heating circuit for a battery cell according to claim 8, characterized in that, The LED indicator circuit includes a first optocoupler, a second optocoupler, a third optocoupler, a fourth optocoupler, a fifth optocoupler, a twenty-fourth resistor, a thirty-second resistor, a twenty-sixth resistor, a twenty-seventh resistor, and a twenty-eighth resistor. The first terminal of the first optocoupler is connected to the LEDCNTLA terminal of the BMS controller, the second terminal of the first optocoupler is connected to the LEDCNTLB terminal of the BMS controller, the third terminal of the first optocoupler is grounded, and the fourth terminal of the first optocoupler is connected in series with the twenty-eighth resistor and then connected to the OUT terminal of the voltage regulator. The first terminal of the second optocoupler is connected to the LEDCNTLB terminal of the BMS controller, the second terminal of the second optocoupler is connected to the LEDCNTLA terminal of the BMS controller, the third terminal of the second optocoupler is grounded, and the fourth terminal of the second optocoupler is connected in series with the twenty-seventh resistor and then connected to the OUT terminal of the voltage regulator. The first terminal of the third optocoupler is connected to... The LEDCNTLB terminal of the BMS controller is connected. The second terminal of the third optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The third terminal of the third optocoupler is grounded. The fourth terminal of the third optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 26th resistor. The first terminal of the fourth optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The second terminal of the fourth optocoupler is connected to the LEDCNTLB terminal of the BMS controller. The third terminal of the fourth optocoupler is grounded. The fourth terminal of the fourth optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 32nd resistor. The first terminal of the fifth optocoupler is connected to the LEDCNTLC terminal of the BMS controller. The second terminal of the fifth optocoupler is connected to the LEDCNTLA terminal of the BMS controller. The third terminal of the fifth optocoupler is grounded. The fourth terminal of the fifth optocoupler is connected to the OUT terminal of the voltage regulator after being connected in series with the 24th resistor.

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