A multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit

Abstract

This invention discloses a multi-cell lithium battery charging and discharging port overcurrent detection circuit, comprising a battery pack voltage acquisition circuit, a charging control circuit, a discharge control circuit, a detection loop current circuit, a single-cell lithium battery protection IC power supply circuit, and a charge overcurrent detection circuit. By adding a separate charge overcurrent detection circuit, this invention limits the charging current when it exceeds a set value, protecting the battery cells. This circuit meets the requirements for high-current discharge applications and is suitable for widespread adoption.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit. Background Art

[0002] A lithium-ion battery BMS with the same charging and discharging ports uses the same charging and discharging paths. Detecting overcurrent in both charging and discharging is done by detecting the voltage across the same sense resistor in the circuit. In typical applications, discharge currents are relatively high (often reaching over 10 or even several dozen amperes), while charge currents are relatively low (typically only a few amperes, and most applications do not exceed 2 amperes).

[0003] Currently, the charging current of lithium-ion batteries cannot exceed the charging current specified in the battery cell specification. Charging with a current exceeding the specified charging current will pose a safety risk. Therefore, for safety reasons, lithium-ion battery management systems will limit the charging overcurrent. Because the charging overcurrent protection detection voltage and the discharge overcurrent detection voltage of multi-string lithium-ion battery protection ICs are generally half, in practice, the charging overcurrent is often larger to meet the discharge current, which can easily lead to safety risks.

[0004] Therefore, there is a need to improve the existing technology.

[0005] The above information is presented as background information only to assist with an understanding of the present disclosure and is not a determination or admission that any of the above may be applicable as prior art with respect to the present disclosure. Summary of the Invention

[0006] The present invention provides a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit to solve the deficiencies of the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, including a battery pack voltage acquisition circuit, a charging control circuit, a discharge control circuit, a detection loop current circuit, a single-cell lithium battery protection IC power supply circuit and a charging overcurrent detection circuit; wherein,

[0009] The battery pack voltage acquisition circuit includes a multi-string lithium battery protection IC U1 and a battery pack voltage acquisition line; the multi-string lithium battery protection IC U1 is connected to each string of cells in the battery pack through the battery pack voltage acquisition line;

[0010] The charging control circuit includes a first MOS transistor QC1; the G pole of the first MOS transistor QC1 is connected to the CO pin of the multi-string lithium battery protection IC U1, the S pole of the first MOS transistor QC1 is connected to the negative output terminal OP-, and the D pole of the first MOS transistor QC1 is connected to the negative electrode of the battery pack;

[0011] The discharge control circuit includes a second MOS transistor QD1; the G pole of the second MOS transistor QD1 is connected to the DO pin of the multi-string lithium battery protection IC U1, the D pole of the second MOS transistor QD1 is connected to the D pole of the first MOS transistor QC1, and the S pole of the second MOS transistor QD1 is connected to the negative pole of the battery pack;

[0012] The detection loop current circuit includes a sampling resistor RS1; the sampling resistor RS1 is connected in series between the S pole of the second MOS transistor QD1 and the negative electrode of the battery pack; the CS pin of the multi-string lithium battery protection IC U1 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1;

[0013] The charging overcurrent detection circuit includes an overcurrent monitoring chip U2, a first transistor Q1, and a third transistor Q3; the VSS pin of the overcurrent monitoring chip U2 is connected to the negative electrode of the battery pack and to ground, and the VM pin of the overcurrent monitoring chip U2 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; the b pole of the third transistor Q3 is connected to the CO pin of the overcurrent monitoring chip U2, the c pole of the third transistor Q3 is connected to the b pole of the first transistor Q1, the c pole of the first transistor Q1 is connected between the G pole of the first MOS transistor QC1 and the CO pin of the multi-string lithium battery protection IC U1, and the e pole of the first transistor Q1 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-;

[0014] The single-cell lithium battery protection IC power supply circuit includes a second transistor Q2; the c-pole of the second transistor Q2 is connected to the positive electrode of the battery pack, the e-pole of the second transistor Q2 is connected to the e-pole of the third transistor Q3, and the b-pole of the second transistor Q2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

[0015] Furthermore, the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit also includes a multi-string lithium battery protection circuit, and the multi-string lithium battery protection circuit includes a first resistor R1 and a first capacitor C1;

[0016] One end of the first resistor R1 is connected to the positive electrode of the battery pack, and the other end of the first resistor R1 is connected to the VDD pin of the multi-string lithium battery protection IC U1;

[0017] One end of the first capacitor C1 is connected to the VDD pin of the multi-string lithium battery protection IC U1, and the other end of the first capacitor C1 is grounded.

[0018] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the charging control circuit further includes a fourth resistor R4 and a seventh resistor R7;

[0019] The fourth resistor R4 is connected in series between the G terminal of the first MOS tube QC1 and the CO pin of the multi-string lithium battery protection IC U1;

[0020] The seventh resistor R7 is connected in parallel between the G pole and the S pole of the first MOS transistor QC1.

[0021] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the discharge control circuit further includes a third resistor R3 and a sixth resistor R6;

[0022] The third resistor R3 is connected in series between the G terminal of the second MOS transistor QD1 and the DO pin of the multi-string lithium battery protection IC U1;

[0023] The sixth resistor R6 is connected in parallel between the G electrode and the S electrode of the second MOS transistor QD1.

[0024] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the detection loop current circuit further includes a second resistor R2 and a second capacitor C2;

[0025] The CS pin of the multi-string lithium battery protection IC U1 is connected in series with the second resistor R2 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1;

[0026] One end of the second capacitor C2 is connected between the CS pin of the multi-string lithium battery protection IC U1 and the second resistor R2, and the other end of the second capacitor C2 is grounded.

[0027] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the charging overcurrent detection circuit further includes a twelfth resistor R12, a second voltage stabilizing diode Z2, a fourth capacitor C4, an eighth resistor R8, an eleventh resistor R11, a fourteenth resistor R14 and a thirteenth resistor R13;

[0028] One end of the twelfth resistor R12 is connected to the VDD pin of the overcurrent monitoring chip U2, and the other end of the twelfth resistor R12 is connected between the e-pole of the second transistor Q2 and the e-pole of the third transistor Q3;

[0029] The cathode of the second voltage stabilizing diode Z2 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the anode of the second voltage stabilizing diode Z2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0030] One end of the fourth capacitor C4 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the other end of the fourth capacitor C4 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0031] The eighth resistor R8 is connected in series between the c-pole of the third transistor Q3 and the b-pole of the first transistor Q1;

[0032] The eleventh resistor R11 is connected in parallel between the b-pole and the e-pole of the third transistor Q3;

[0033] The fourteenth resistor R14 is connected in series between the b-pole of the third transistor Q3 and the CO pin of the overcurrent monitoring chip U2;

[0034] The VM pin of the overcurrent monitoring chip U2 is connected in series with the thirteenth resistor R13 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1.

[0035] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the single-cell lithium battery protection IC power supply circuit includes a ninth resistor R9, a tenth resistor R10, a first voltage stabilizing diode Z1 and a third capacitor C3;

[0036] The ninth resistor R9 is connected in series between the C-pole of the second transistor Q2 and the positive electrode of the battery pack;

[0037] The tenth resistor R10 is connected in parallel between the c-pole and the b-pole of the second transistor Q2;

[0038] The cathode of the first voltage stabilizing diode Z1 is connected to the b-pole of the second transistor Q2, and the anode of the first voltage stabilizing diode Z1 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0039] One end of the third capacitor C3 is connected to the b-pole of the second transistor Q2 , and the other end of the third capacitor C3 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

[0040] Furthermore, in the multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, the battery pack voltage acquisition circuit further includes a fifth resistor R5;

[0041] One end of the fifth resistor R5 is connected to the VM pin of the multi-string lithium battery protection IC U1, and the other end of the fifth resistor R5 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-.

[0042] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0043] An embodiment of the present invention provides a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit. By adding a separate charging overcurrent detection circuit, the charging current can be limited when the charging current exceeds a set value to protect the safety of the battery cells, meeting the application scenario of high-current discharge and being suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 This is a schematic diagram of the circuit principle of a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit provided by Example 1 of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purposes, features, and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be understood that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a centrally located component. When a component is considered to be "disposed on" another component, it can be directly disposed on the other component or there may be a centrally located component.

[0048] In addition, terms such as "long", "short", "inside", and "outside" indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings and are only used to facilitate the description of the present invention. They do not indicate or imply that the device or component referred to must have this specific orientation or operate in a specific orientation structure, and should not be understood as a limitation of the present invention.

[0049] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0050] Example 1

[0051] In view of the aforementioned deficiencies in the prior art, the applicant, drawing upon years of extensive practical experience and expertise in design and manufacturing in this field, combined with the application of scientific knowledge, has actively engaged in research and innovation, hoping to create a technology that can address these deficiencies. Through continuous research and design, and through repeated trial production and refinement, the present invention has been developed, which possesses truly practical value.

[0052] Please refer to Figure 1 The embodiment of the present invention provides a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit, which is characterized by including a battery pack voltage acquisition circuit, a charging control circuit, a discharge control circuit, a detection loop current circuit, a single-cell lithium battery protection IC power supply circuit and a charging overcurrent detection circuit; wherein,

[0053] The battery pack voltage acquisition circuit includes a multi-string lithium battery protection IC U1 and a battery pack voltage acquisition line; the multi-string lithium battery protection IC U1 is connected to each string of battery cells in the battery pack through the battery pack voltage acquisition line; the multi-string lithium battery protection IC U1 collects the voltage of each string of battery cells through the battery pack voltage acquisition line, and determines whether the battery cells are overcharged or over-discharged based on the collected voltage.

[0054] The charging control circuit includes a first MOS transistor QC1; the G pole of the first MOS transistor QC1 is connected to the CO pin of the multi-string lithium battery protection IC U1, the S pole of the first MOS transistor QC1 is connected to the negative output terminal OP-, and the D pole of the first MOS transistor QC1 is connected to the negative pole of the battery pack; when charging or discharging, the CO pin of the multi-string lithium battery protection IC U1 is high, and the first MOS transistor QC1 is turned on; when the voltage of a single battery cell exceeds the set overcharge protection voltage or the charging overcurrent protection current exceeds the set value, the CO pin level of the multi-string lithium battery protection IC U1 becomes low, the first MOS transistor QC1 is turned off, and charging stops.

[0055] The discharge control circuit includes a second MOS transistor QD1; the G pole of the second MOS transistor QD1 is connected to the DO pin of the multi-string lithium battery protection IC U1, the D pole of the second MOS transistor QD1 is connected to the D pole of the first MOS transistor QC1, and the S pole of the second MOS transistor QD1 is connected to the negative pole of the battery pack; during charging or discharging, the CO pin of the multi-string lithium battery protection IC U1 is high, and the second MOS transistor QD1 is turned on; when the voltage of a single battery cell is lower than the set over-discharge protection voltage or the discharge overcurrent protection current exceeds the set value, the DO pin level of the multi-string lithium battery protection IC U1 becomes low, the second MOS transistor QD1 is turned off, and discharging stops.

[0056] The detection loop current circuit includes a sampling resistor RS1; the sampling resistor RS1 is connected in series between the S pole of the second MOS transistor QD1 and the negative pole of the battery pack; the CS pin of the multi-string lithium battery protection IC U1 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; the multi-string lithium battery protection IC U1 detects the voltage across the sampling resistor RS1 through the CS pin to detect the charge and discharge current.

[0057] The charging overcurrent detection circuit includes an overcurrent monitoring chip U2, a first transistor Q1, and a third transistor Q3; the VSS pin of the overcurrent monitoring chip U2 is connected to the negative electrode of the battery pack and to ground, and the VM pin of the overcurrent monitoring chip U2 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; the b pole of the third transistor Q3 is connected to the CO pin of the overcurrent monitoring chip U2, the c pole of the third transistor Q3 is connected to the b pole of the first transistor Q1, the c pole of the first transistor Q1 is connected between the G pole of the first MOS transistor QC1 and the CO pin of the multi-string lithium battery protection IC U1, and the e pole of the first transistor Q1 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-;

[0058] The single-cell lithium battery protection IC power supply circuit includes a second transistor Q2; the c-pole of the second transistor Q2 is connected to the positive electrode of the battery pack, the e-pole of the second transistor Q2 is connected to the e-pole of the third transistor Q3, and the b-pole of the second transistor Q2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

[0059] It should be noted that the sampling resistor RS1 can be a 10mR resistor, the first transistor Q1 can be a transistor of model MMBT5551, the third transistor Q3 can be a transistor of model MMBT5401, and the second transistor Q2 can be a transistor of model MMBT5551.

[0060] Please refer again Figure 1 In this embodiment, a multi-string lithium battery protection circuit is further included, and the multi-string lithium battery protection circuit includes a first resistor R1 and a first capacitor C1;

[0061] One end of the first resistor R1 is connected to the positive electrode of the battery pack, and the other end of the first resistor R1 is connected to the VDD pin of the multi-string lithium battery protection IC U1;

[0062] One end of the first capacitor C1 is connected to the VDD pin of the multi-string lithium battery protection IC U1, and the other end of the first capacitor C1 is grounded.

[0063] It should be noted that the first resistor R1 can be a 1K resistor, and the first capacitor C1 can be a 1uF capacitor. The first resistor R1 provides power for multi-string lithium battery protection; the first capacitor C1 serves as a power decoupling capacitor to reduce power supply noise.

[0064] Please refer again Figure 1 In this embodiment, the charging control circuit further includes a fourth resistor R4 and a seventh resistor R7;

[0065] The fourth resistor R4 is connected in series between the G terminal of the first MOS tube QC1 and the CO pin of the multi-string lithium battery protection IC U1;

[0066] The seventh resistor R7 is connected in parallel between the G pole and the S pole of the first MOS transistor QC1.

[0067] It should be noted that the fourth resistor R4 can be a 1K resistor, and the seventh resistor R7 can be a 3.3M resistor.

[0068] Please refer again Figure 1 In this embodiment, the discharge control circuit further includes a third resistor R3 and a sixth resistor R6;

[0069] The third resistor R3 is connected in series between the G terminal of the second MOS transistor QD1 and the DO pin of the multi-string lithium battery protection IC U1;

[0070] The sixth resistor R6 is connected in parallel between the G electrode and the S electrode of the second MOS transistor QD1.

[0071] It should be noted that the third resistor R3 can be a 1K resistor, and the sixth resistor R6 can be a 3.3M resistor.

[0072] Please refer again Figure 1 In this embodiment, the detection loop current circuit further includes a second resistor R2 and a second capacitor C2;

[0073] The CS pin of the multi-string lithium battery protection IC U1 is connected in series with the second resistor R2 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1;

[0074] One end of the second capacitor C2 is connected between the CS pin of the multi-string lithium battery protection IC U1 and the second resistor R2, and the other end of the second capacitor C2 is grounded.

[0075] It should be noted that the second resistor R2 can be a 1K resistor, and the second capacitor C2 can be a 0.1uF capacitor.

[0076] Please refer again Figure 1 In this embodiment, the charging overcurrent detection circuit further includes a twelfth resistor R12, a second voltage stabilizing diode Z2, a fourth capacitor C4, an eighth resistor R8, an eleventh resistor R11, a fourteenth resistor R14 and a thirteenth resistor R13;

[0077] One end of the twelfth resistor R12 is connected to the VDD pin of the overcurrent monitoring chip U2, and the other end of the twelfth resistor R12 is connected between the e-pole of the second transistor Q2 and the e-pole of the third transistor Q3;

[0078] The cathode of the second voltage stabilizing diode Z2 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the anode of the second voltage stabilizing diode Z2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0079] One end of the fourth capacitor C4 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the other end of the fourth capacitor C4 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0080] The eighth resistor R8 is connected in series between the c-pole of the third transistor Q3 and the b-pole of the first transistor Q1;

[0081] The eleventh resistor R11 is connected in parallel between the b-pole and the e-pole of the third transistor Q3;

[0082] The fourteenth resistor R14 is connected in series between the b-pole of the third transistor Q3 and the CO pin of the overcurrent monitoring chip U2;

[0083] The VM pin of the overcurrent monitoring chip U2 is connected in series with the thirteenth resistor R13 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1.

[0084] It should be noted that the twelfth resistor R12 can be a 330R resistor, the second voltage-stabilizing diode Z2 can be a 4.3V voltage-stabilizing diode, the fourth capacitor C4 can be a 0.1uF capacitor, the eighth resistor R8 can be a 100K resistor, the eleventh resistor R11 can be a 200K resistor, the fourteenth resistor R14 can be a 100K resistor, and the thirteenth resistor R13 can be a 2K resistor.

[0085] Please refer again Figure 1 In this embodiment, the single-cell lithium battery protection IC power supply circuit includes a ninth resistor R9, a tenth resistor R10, a first voltage stabilizing diode Z1 and a third capacitor C3;

[0086] The ninth resistor R9 is connected in series between the C-pole of the second transistor Q2 and the positive electrode of the battery pack;

[0087] The tenth resistor R10 is connected in parallel between the c-pole and the b-pole of the second transistor Q2;

[0088] The cathode of the first voltage stabilizing diode Z1 is connected to the b-pole of the second transistor Q2, and the anode of the first voltage stabilizing diode Z1 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack;

[0089] One end of the third capacitor C3 is connected to the b-pole of the second transistor Q2 , and the other end of the third capacitor C3 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

[0090] It should be noted that the ninth resistor R9 can be a 1K resistor, the tenth resistor R10 can be a 3.3M resistor, the first voltage regulator diode Z1 can be a 1.3V voltage regulator diode, and the third capacitor C3 can be a 0.1uF capacitor.

[0091] As the input voltage increases, the output voltage tends to rise. Since the potential of the b-pole of the second transistor Q2 is fixed at 4.3V by the first Zener diode Z1, the increase in output voltage reduces the forward bias voltage at the transistor's e-pole, decreasing the b-pole current. This increases the resistance between the transistor's c- and e-pole terminals, increasing the CE voltage. This offsets the increase in output voltage, keeping the output voltage essentially constant. The supply voltage of a single-cell lithium battery protection IC is the voltage of the first Zener diode Z1 minus the transistor voltage drop: 4.3V - 0.6V = 3.6V.

[0092] Please refer again Figure 1 In this embodiment, the battery pack voltage acquisition circuit further includes a fifth resistor R5;

[0093] One end of the fifth resistor R5 is connected to the VM pin of the multi-string lithium battery protection IC U1, and the other end of the fifth resistor R5 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-.

[0094] It should be noted that the fifth resistor R5 can be a 10K resistor.

[0095] Working principle:

[0096] During charging, the CO pin of the multi-string lithium battery protection IC U1 is at a high level, the G and S poles of the first MOS tube QC1 are at a high level, the first MOS tube QC1 is turned on, and the overcurrent monitoring chip U2 detects the voltage of the sampling resistor RS1 through the VSS pin and the VM pin. When the VM pin voltage is greater than the charging overcurrent detection voltage of the overcurrent monitoring chip U2, the CO pin outputs a low level, the third transistor Q3 is turned on, and the C pole voltage of the third transistor Q3 is high. The b pole of the first transistor Q1 is pulled high through the eighth resistor R8, the first transistor Q is turned on, and the G and S pole voltages of the first MOS tube QC1 are pulled to 0V, and charging is turned off.

[0097] Although terms such as battery pack, current, overcurrent, and protection are frequently used herein, the use of other terms is not excluded. These terms are used solely to more conveniently describe and explain the essence of the present invention; interpreting them as any additional limitations is contrary to the spirit of the present invention.

[0098] An embodiment of the present invention provides a multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit. By adding a separate charging overcurrent detection circuit, the charging current can be limited when the charging current exceeds a set value to protect the safety of the battery cells, meeting the application scenario of high-current discharge and being suitable for large-scale promotion and application.

[0099] In summary, after reading this detailed disclosure, those skilled in the art will appreciate that the foregoing detailed disclosure may be presented by way of example only and may not be limiting. Although not explicitly stated herein, those skilled in the art will understand that this application is intended to encompass various reasonable changes, improvements, and modifications to the embodiments. Such changes, improvements, and modifications are intended to be proposed by this application and are within the spirit and scope of the exemplary embodiments of this application.

[0100] In addition, certain terms in this application have been used to describe embodiments of the present application. For example, "one embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in conjunction with that embodiment may be included in at least one embodiment of the present application. Therefore, it is emphasized and should be understood that two or more references to "an embodiment," "one embodiment," or "an alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be appropriately combined in one or more embodiments of the present application.

[0101] It should be understood that in the foregoing description of the embodiments of this application, in order to facilitate understanding of a feature and to simplify this application, this application combines various features into a single embodiment, figure, or description thereof. However, this does not mean that the combination of these features is required. When reading this application, it is entirely possible for those skilled in the art to extract some of the features and understand them as separate embodiments. In other words, the embodiments of this application can also be understood as the integration of multiple secondary embodiments. This also applies when the content of each secondary embodiment is less than all the features of a single aforementioned disclosed embodiment.

[0102] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, documents, articles, etc., cited herein is hereby incorporated by reference in its entirety for all purposes, except for any prosecution document history related thereto, any equivalent that may be inconsistent or conflicting with this document, or any equivalent prosecution document history that may have a limiting effect on the broadest scope of the claims now or hereafter associated with this document. For example, if there is any inconsistency or conflict between the description, definition, and / or use of terms associated with any incorporated material and the terminology, description, definition, and / or use associated with this document, the terminology in this document shall control.

[0103] Finally, it should be understood that the embodiments of the application disclosed herein are illustrations of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Therefore, the embodiments disclosed in the present application are merely examples and not limitations. Those skilled in the art can adopt alternative configurations based on the embodiments in the present application to implement the applications in the present application. Therefore, the embodiments of the present application are not limited to the embodiments precisely described in the application.

Claims

1. A multi-string lithium battery charging and discharging same port charging overcurrent detection circuit, characterized in that: It includes battery pack voltage acquisition circuit, charging control circuit, discharge control circuit, detection loop current circuit, single-cell lithium battery protection IC power supply circuit and charging overcurrent detection circuit; Among them, The battery pack voltage acquisition circuit includes a multi-string lithium battery protection IC U1 and a battery pack voltage acquisition line; the multi-string lithium battery protection IC U1 is connected to each string of cells in the battery pack through the battery pack voltage acquisition line; The charging control circuit includes a first MOS transistor QC1; the G pole of the first MOS transistor QC1 is connected to the CO pin of the multi-string lithium battery protection IC U1, the S pole of the first MOS transistor QC1 is connected to the negative output terminal OP-, and the D pole of the first MOS transistor QC1 is connected to the negative electrode of the battery pack; The discharge control circuit includes a second MOS transistor QD1; the G pole of the second MOS transistor QD1 is connected to the DO pin of the multi-string lithium battery protection IC U1, the D pole of the second MOS transistor QD1 is connected to the D pole of the first MOS transistor QC1, and the S pole of the second MOS transistor QD1 is connected to the negative pole of the battery pack; The detection loop current circuit includes a sampling resistor RS1; the sampling resistor RS1 is connected in series between the S pole of the second MOS transistor QD1 and the negative electrode of the battery pack; the CS pin of the multi-string lithium battery protection IC U1 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; The charging overcurrent detection circuit includes an overcurrent monitoring chip U2, a first transistor Q1, and a third transistor Q3; the VSS pin of the overcurrent monitoring chip U2 is connected to the negative electrode of the battery pack and to ground, and the VM pin of the overcurrent monitoring chip U2 is connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; the b pole of the third transistor Q3 is connected to the CO pin of the overcurrent monitoring chip U2, the c pole of the third transistor Q3 is connected to the b pole of the first transistor Q1, the c pole of the first transistor Q1 is connected between the G pole of the first MOS transistor QC1 and the CO pin of the multi-string lithium battery protection IC U1, and the e pole of the first transistor Q1 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-; The single-cell lithium battery protection IC power supply circuit includes a second transistor Q2; the c-pole of the second transistor Q2 is connected to the positive electrode of the battery pack, the e-pole of the second transistor Q2 is connected to the e-pole of the third transistor Q3, and the b-pole of the second transistor Q2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

2. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 1, characterized in that: It also includes a multi-string lithium battery protection circuit, the multi-string lithium battery protection circuit includes a first resistor R1 and a first capacitor C1; One end of the first resistor R1 is connected to the positive electrode of the battery pack, and the other end of the first resistor R1 is connected to the VDD pin of the multi-string lithium battery protection IC U1; One end of the first capacitor C1 is connected to the VDD pin of the multi-string lithium battery protection IC U1, and the other end of the first capacitor C1 is grounded.

3. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 2, characterized in that: The charging control circuit further includes a fourth resistor R4 and a seventh resistor R7; The fourth resistor R4 is connected in series between the G terminal of the first MOS tube QC1 and the CO pin of the multi-string lithium battery protection IC U1; The seventh resistor R7 is connected in parallel between the G pole and the S pole of the first MOS transistor QC1.

4. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 3, characterized in that: The discharge control circuit further includes a third resistor R3 and a sixth resistor R6; The third resistor R3 is connected in series between the G terminal of the second MOS transistor QD1 and the DO pin of the multi-string lithium battery protection IC U1; The sixth resistor R6 is connected in parallel between the G electrode and the S electrode of the second MOS transistor QD1.

5. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 4, characterized in that: The detection loop current circuit further includes a second resistor R2 and a second capacitor C2; The CS pin of the multi-string lithium battery protection IC U1 is connected in series with the second resistor R2 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1; One end of the second capacitor C2 is connected between the CS pin of the multi-string lithium battery protection IC U1 and the second resistor R2, and the other end of the second capacitor C2 is grounded.

6. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 5, characterized in that: The charging overcurrent detection circuit further includes a twelfth resistor R12, a second voltage stabilizing diode Z2, a fourth capacitor C4, an eighth resistor R8, an eleventh resistor R11, a fourteenth resistor R14 and a thirteenth resistor R13; One end of the twelfth resistor R12 is connected to the VDD pin of the overcurrent monitoring chip U2, and the other end of the twelfth resistor R12 is connected between the e-pole of the second transistor Q2 and the e-pole of the third transistor Q3; The cathode of the second voltage stabilizing diode Z2 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the anode of the second voltage stabilizing diode Z2 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack; One end of the fourth capacitor C4 is connected between the twelfth resistor R12 and the VDD pin of the overcurrent monitoring chip U2, and the other end of the fourth capacitor C4 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack; The eighth resistor R8 is connected in series between the c-pole of the third transistor Q3 and the b-pole of the first transistor Q1; The eleventh resistor R11 is connected in parallel between the b-pole and the e-pole of the third transistor Q3; The fourteenth resistor R14 is connected in series between the b-pole of the third transistor Q3 and the CO pin of the overcurrent monitoring chip U2; The VM pin of the overcurrent monitoring chip U2 is connected in series with the thirteenth resistor R13 and then connected between the sampling resistor RS1 and the S pole of the second MOS transistor QD1.

7. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 6, characterized in that: The single-cell lithium battery protection IC power supply circuit includes a ninth resistor R9, a tenth resistor R10, a first voltage stabilizing diode Z1 and a third capacitor C3; The ninth resistor R9 is connected in series between the C-pole of the second transistor Q2 and the positive electrode of the battery pack; The tenth resistor R10 is connected in parallel between the c-pole and the b-pole of the second transistor Q2; The cathode of the first voltage stabilizing diode Z1 is connected to the b-pole of the second transistor Q2, and the anode of the first voltage stabilizing diode Z1 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack; One end of the third capacitor C3 is connected to the b-pole of the second transistor Q2 , and the other end of the third capacitor C3 is connected between the VSS pin of the overcurrent monitoring chip U2 and the negative electrode of the battery pack.

8. The multi-string lithium battery charging and discharging same-port charging overcurrent detection circuit according to claim 7, characterized in that: The battery pack voltage acquisition circuit further includes a fifth resistor R5; One end of the fifth resistor R5 is connected to the VM pin of the multi-string lithium battery protection IC U1, and the other end of the fifth resistor R5 is connected between the S pole of the first MOS transistor QC1 and the negative output terminal OP-.

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