Battery cell charging protection failure additional overcharge detection circuit and battery pack

Abstract

The utility model provides a battery cell charging protection failure additional overcharge detection circuit and a battery pack. The circuit comprises a battery cell module, a secondary protection chip, an analog front-end chip, a discharge control module, a primary protection module, a secondary protection module, an activation module, an overcharge detection module and a main control chip. The battery cell module is respectively connected with the secondary protection module, the secondary protection chip, the activation module, the analog front-end chip and the discharge control module, the secondary protection chip is further respectively connected with the activation module, the secondary protection module and the overcharge detection module, and the analog front-end chip is further respectively connected with the primary protection module, the activation module and the discharge control module. The discharge control module is connected with the activation module, the primary protection module is also connected with the secondary protection module, and the main control chip is connected with the overcharge detection module. According to the utility model, the overcharge identification circuit is added through improvement, after overcharge protection fails, it is identified that the battery pack is still charged, and overcharge safety accidents are reduced by inviting the main machine to close the charging switch.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery pack circuit technical field, specifically, relate to a kind of electric core charging protection failure to add overcharge detection circuit and battery pack. BACKGROUND

[0002] The role of battery pack is to provide power for the whole machine and needs to have charging function, battery pack is configured with three interfaces (P+, C+, P- / C-) to the outside, as is known, battery pack overcharge will be on fire or even explosion, there is huge security risk, so developers usually involve multiple overcharge protection between P+ and C+ in charging loop to ensure charging safety, but if the external P+ and C+ of battery pack are short-circuited, or P+ port is mistakenly charged as C+ port, all overcharge protection circuits will be short-circuited, when charging protection circuit is short-circuited, charging protection function will be invalid, battery pack will be on fire or even explosion during charging, causing safety accident. SUMMARY

[0003] Therefore, the utility model aims at providing a kind of electric core charging protection failure to add overcharge detection circuit and battery pack, by adding the identification protection circuit in the case where primary protection and secondary protection are both invalid, activate BMS system when identifying that battery pack overcharges, close charging switch by communication invitation host, to achieve the effect of charging protection, to a certain extent, avoid safety accident after overcharge.

[0004] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0005] A kind of electric core charging protection failure to add overcharge detection circuit, including electric core module, secondary protection chip, analog front-end chip, discharge control module, primary protection module, secondary protection module and activation module;It is characterized by further comprising: overcharge detection module and main control chip.

[0006] Electric core module is connected with the positive pole end P+ of secondary protection module, secondary protection chip, activation module, analog front-end chip, discharge control module and charging loop respectively, secondary protection chip is connected with the first end of secondary protection module, activation module and overcharge detection module respectively, overcharge detection module is connected with the first end of main control chip, the third end of secondary protection module is connected with the third end of primary protection module, the second end of primary protection module is connected with the positive pole end C+ of charging loop, activation module is connected with analog front-end chip, the second end of analog front-end chip is connected with the second end of main control chip, analog front-end chip is connected with the first end of primary protection module, discharge control module is connected with the negative pole end P- of charging loop or the negative pole end C- of charging loop.

[0007] The overcharge detection module at least includes a resistor R2 and a field effect tube Q4.

[0008] The G pole of the secondary protection chip is connected with the field effect tube Q4, the D pole of the field effect tube Q4 is connected with the main control chip, the resistor R2 is further connected in the middle, the S pole of the field effect tube Q4 is connected to a ground end, and the other end of the resistor R2 is connected with the main control chip.

[0009] The secondary protection chip at least includes a CO pin of the secondary protection chip and a VDD pin of the secondary protection chip.

[0010] The CO pin of the secondary protection chip is connected with an activation module, a secondary protection module and the field effect tube Q4, and the VDD pin of the main control chip is connected with the resistor R2.

[0011] The second end of the main control chip includes an SDA1 pin of a control chip U2 and an SCL1 pin of the control chip U2, and the second end of the analog front end module includes an SDA2 pin and an SCL2 pin.

[0012] The SDA1 pin of the control chip U2 is connected with the SDA2 pin, and the SCL1 pin of the control chip U2 is connected with the SCL2 pin.

[0013] The first protection module at least includes a field effect tube Q1, the secondary protection module at least includes a field effect tube Q2, a three-terminal fuse F1 and a secondary protection chip.

[0014] The S pole of the field effect tube Q2 is grounded, the G pole of the field effect tube Q2 is connected with the CO pin of the secondary protection chip and is further connected with an activation module, the D pole of the field effect Q2 is connected with the first end of the three-terminal fuse F1, the third end of the three-terminal fuse F1 is connected with the battery module, and the second end of the three-terminal fuse F1 is connected with the D pole of the field effect tube Q1.

[0015] The activation module at least includes a field effect tube Q3 and a triode Q5.

[0016] The D pole of the field effect tube Q3 is connected with the battery module, the S pole of the field effect tube Q3 is connected with the VCC pin of the analog front end chip, the G pole of the field effect tube Q3 is connected with the c pole of the triode Q5, the b pole of the triode Q5 is connected with the co pin of the secondary protection chip, and the e pole of the triode Q5 is connected to a ground end.

[0017] The analog front end chip at least includes a CHG pin of the analog front end chip and a DSG pin of the analog front end chip.

[0018] The DSG pin of the analog front-end chip is connected to the discharge control module, and the CHG pin of the analog front-end chip is connected to the primary protection module.

[0019] To achieve the above objectives, the present invention also adopts the following technical solution:

[0020] A battery pack, the battery pack including at least one of the cell charging protection failure additional overcharge detection circuits as described above. Compared with the prior art, the beneficial effects of this utility model are:

[0021] This invention proposes an additional overcharge detection circuit for cell charging protection failure and a battery pack. By adding an activation module and an overcharge detection module, the main circuit can be promptly disconnected even in the event of primary or secondary protection failure, effectively preventing cell overcharging and reducing the risk of safety accidents. This invention adds an additional overcharge detection circuit to the cell charging / discharging port circuit of the battery pack. The activation module activates the analog front-end chip and main control chip, activating the BMS system. Communication with the host computer invites the charging switch to disconnect, promptly cutting off the circuit and preventing safety accidents caused by battery pack overcharging. This invention, by improving the battery management system, provides a reliable, flexible cell charging protection system with enhanced overcharge protection, significantly reducing the safety risks caused by battery overcharging and extending product lifespan. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an additional overcharge detection circuit for battery cell charging protection failure.

[0023] Figure 2 This is a circuit diagram of an overcharge detection circuit added to the battery cell charging protection failure.

[0024] Figure 3 This is a circuit flowchart for adding an overcharge detection circuit to the battery cell charging protection failure. Detailed Implementation

[0025] To facilitate understanding of this invention, a more comprehensive description will be provided below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the invention. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein. Example

[0026] Please refer to Figure 1In the embodiment, the battery cell charging protection failure additional overcharge detection circuit comprises a battery cell module, a secondary protection chip, an analog front-end chip, a discharge control module, a primary protection module, a secondary protection module and an activation module.

[0027] Compared with the prior art Figure 2 In the prior art, a battery cell charging protection circuit is added to the existing technology, and when overcharging of the battery pack is identified, the BMS system is activated, the host computer is invited to close the charging switch through communication, so that the charging protection function is achieved, and safety accidents after overcharging are avoided to a certain extent.

[0028] The battery cell module is connected with the secondary protection module, the secondary protection chip, the activation module, the analog front-end chip, the discharge control module and the positive electrode end P+ of the charging circuit, the secondary protection chip is connected with the first end of the secondary protection module, the activation module and the overcharge detection module, the overcharge detection module is connected with the first end of the main control chip, the third end of the secondary protection module is connected with the third end of the primary protection module, the second end of the primary protection module is connected with the positive electrode end C+ of the charging circuit, the activation module is connected with the analog front-end chip, the second end of the analog front-end chip is connected with the second end of the main control chip, the analog front-end chip is connected with the first end of the primary protection module, and the discharge control module is connected with the negative electrode end P- of the charging circuit or the negative electrode end C- of the charging circuit.

[0029] It should be noted that in the primary protection module, when the charging in the circuit reaches the primary overvoltage protection threshold V1, the analog front-end chip controls the primary protection module to be disconnected, so that the charging is stopped, and the protection circuit is protected. However, if the battery pack external C+ and P+ are short-circuited or P+ is mistakenly used as a charging port, or when the primary protection module fails, the primary protection function will be invalid. The charger continues to charge the battery cell, and when the charging in the circuit reaches the secondary overvoltage protection threshold V2, the secondary protection chip controls the field effect tube of the secondary protection module to be in a conductive state, and the fuse is blown, so that the charging is stopped, and the protection circuit is protected. At the same time, the activation module activates the analog front-end chip, and then activates the main control chip. The main control chip identifies the secondary overcharge state through the overcharge detection module. If the battery pack external C+ and P+ are short-circuited or P+ is mistakenly used as a charging port, or when the secondary protection module fails, the secondary protection function will be invalid.

[0030] If the external fault is not eliminated or the secondary protection module also fails at this time, the corresponding protection function may fail, and the functions of the overcharge detection module and the activation module are particularly important at this time. The overcharge detection module and the activation module are preferably connected with the main control chip.

[0031] The embodiment provides a safer and more reliable battery charging protection system by means of careful circuit design and multiple protection mechanisms, and effectively reduces the safety risk in overcharging.

[0032] In the embodiment, the primary protection module at least comprises a field effect transistor Q1. The secondary protection module at least comprises a field effect transistor Q2, a three-terminal fuse F1 and a secondary protection chip.

[0033] The S pole of the field effect transistor Q2 is connected to the ground, the G pole of the field effect transistor Q2 is connected to the CO pin of the secondary protection chip and also connected to an activation module, the D pole of the field effect transistor Q2 is connected to the first end of the three-terminal fuse F1, the third end of the three-terminal fuse F1 is connected to the battery module, and the second end of the three-terminal fuse F1 is connected to the D pole of the field effect transistor Q1.

[0034] It should be noted that the field effect transistor Q1 plays a key role in the primary protection module and is mainly used for controlling the on-off of the circuit and realizing the primary protection of the battery. When the charging voltage in the circuit reaches the first overvoltage protection threshold V1, the analog front-end chip controls the field effect transistor Q1 to be switched off, thereby cutting off the circuit and stopping the charging, and achieving the protection effect.

[0035] The field effect transistor Q2 and the three-terminal fuse F1 also play a key role in the secondary protection circuit and are used for controlling the on-off of the circuit and realizing the secondary protection of the battery. When the charging voltage in the circuit reaches the second overvoltage protection threshold V2, the secondary protection circuit outputs a high level through the CO pin of the secondary protection chip, so that the field effect transistor Q2 is turned on, thereby fusing the three-terminal fuse F1, stopping the charging, and achieving a higher level of protection effect.

[0036] The secondary protection chip is used for providing additional protection functions and can generally monitor more battery state parameters to realize more accurate protection control. When the battery charging state is abnormal, the secondary protection chip can trigger corresponding protection actions and activation actions, and cooperates with the analog front-end chip to ensure the safe disconnection of the circuit and avoid the safety problems caused by overcharging.

[0037] When the primary protection module fails, the secondary protection module still plays a secondary protection role, thereby providing multiple levels of safety protection. The control of the field effect transistor Q1 is completed by the analog front-end chip, and the control of the field effect transistor Q2 is completed by the secondary protection chip, thereby ensuring the cooperative work of the entire protection system and providing more reliable battery management and safety protection functions. The introduction of the secondary protection chip enhances the intelligence of the system and can more accurately monitor the battery state and make corresponding protection decisions.

[0038] When neither the primary protection module nor the secondary protection module is effective, the circuit will easily cause a safety accident in the case of overcharging. By adding a battery overcharge detection circuit, the battery voltage is monitored in real time by the overcharge detection module. In the case of primary protection and secondary protection failure, the analog front-end chip is activated by the activation module, and then the main control chip is activated. The host computer is invited to close the charging switch to stop charging, ensuring that the circuit can be cut off in time in various abnormal conditions to avoid safety accidents caused by battery overcharging. This mechanism plays a key role in ensuring battery safety.

[0039] In the embodiment, the second end of the main control chip includes the SDA1 pin of the control chip U2 and the SCL1 pin of the control chip U2, and the second end of the analog front-end module includes the SDA2 pin and the SCL2 pin.

[0040] The SDA1 pin of the main control chip U2 is connected with the SDA2 pin, and the SCL1 pin of the control chip U2 is connected with the SCL2 pin.

[0041] It should be noted that SDA (Serial Data Line) and SCL (Serial Clock Line) are two signal lines in the bus communication protocol, and data transmission and communication between the main control chip and the analog front-end chip are realized through the two lines.

[0042] Through this connection configuration, the main control chip can obtain the monitoring data of the analog front-end chip in real time and make corresponding control decisions as needed. The main control chip controls the primary protection module and the secondary protection module through communication with the analog front-end chip, ensures that the circuit can be cut off in time when the battery state is abnormal, and achieves the protection effect. The introduction of the main control chip improves the stability and controllability of the entire system, and through programming, the components work cooperatively to ensure the reliable operation of the battery charging protection system.

[0043] In summary, as the core, the main control chip realizes effective control and cooperative work of various components in the system through pin connection configuration and communication protocol, improving the intelligence and stability of the battery charging protection system.

[0044] Further, as shown in the accompanying Figure 3 In the embodiment, a battery pack integrates a battery overcharge detection circuit mentioned in a preferred embodiment, which includes a battery module, a secondary protection module, a secondary protection chip, an activation module, an analog front-end chip, a discharge control module, a primary protection module, an overcharge detection module, a main control chip, and other components.

[0045] When the battery pack is connected to the charger, the charger begins to provide power to the battery pack, and the overcharge detection circuit for the battery pack with the failed battery cell charging protection exists three working states:

[0046] State one: the charger is inserted when the battery cell voltage is lower than the first overvoltage protection threshold V1, and the host opens the charging switch. At this time, the CO pin of the secondary protection chip outputs a low level, the field effect tube Q2, the field effect tube Q4 and the transistor Q5 are in the off state, the CHG pin of the analog front-end chip outputs a low level, the field effect tube Q1 is in the on state, the charger charges the battery pack, and the battery cell voltage continues to rise.

[0047] State two: the battery cell voltage reaches the first overvoltage protection threshold V1, at which time the CHG pin of the analog front-end chip outputs a high level, the field effect tube Q1 is in the off state, the charging loop is disconnected, and the charging stops. However, if the external P+ and C+ are short-circuited, or the P+ is mistakenly used as a charging port, or the primary protection module fails, the charger will continue to charge the battery pack, and the battery cell voltage continues to rise.

[0048] State three: the battery cell voltage reaches the second overvoltage protection threshold V2, at which time the CO pin of the secondary protection chip outputs a high level, and the following three actions are performed simultaneously:

[0049] Action one: the transistor Q5 is turned on, then the field effect tube Q3 is turned on, B+ begins to supply power to the analog front-end chip, the analog front-end chip begins to supply power to the main control chip, and the main control system is activated.

[0050] Action two: the field effect tube Q2 is turned on, the three-terminal fuse F1 is blown, the charging loop is disconnected, and the charging stops. If the external P+ and C+ are short-circuited, or the P+ is mistakenly used as a charging port, or the secondary protection module fails, the charger will continue to charge the battery pack.

[0051] Action three: the field effect tube Q4 is turned on, and the IO1 pin of the main control chip becomes a low level. After the main control chip is activated, it determines whether the charging protection measure is effective. If the main control chip detects that the CO pin of the secondary protection chip has been set high, and the charging loop current greater than the set threshold is read through the analog front-end chip, it is determined that the charging protection function fails, and the host is invited to close the charging switch and record the fault information through communication.

[0052] The overcharge detection circuit for the battery pack with the failed battery cell charging protection integrated in the battery pack provides a multi-level protection mechanism, including the primary protection, the secondary protection and the overcharge detection module, thereby enhancing the reliability of the entire system.

[0053] In summary, the battery pack with the overcharge detection circuit for the battery pack with the failed battery cell charging protection in the preferred embodiment effectively prevents the battery cell from overcharging, and improves the safety and stability of the battery pack.

[0054] In the description of the application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In the description of the application, the illustrative description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0055] In the description of the application, it is understood that the terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0056] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0057] Although the description of the application is made in combination with the above specific embodiments, it is obvious for those skilled in the art to make many substitutions, modifications and changes according to the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.

Claims

1. A battery cell charging protection failure additional overcharge detection circuit, comprising a battery cell module, a secondary protection chip, an analog front-end chip, a discharge control module, a primary protection module, a secondary protection module and an activation module; characterized in that, Also includes: overcharge detection module and main control chip; the positive electrode end P+ of the electric core module is connected with the secondary protection module, the secondary protection chip, the activation module, the analog front-end chip, the discharge control module and the positive electrode end C+ of the charging circuit, the secondary protection chip is connected with the first end of the secondary protection module, the activation module and the overcharge detection module, the first end of the overcharge detection module is connected with the main control chip, the third end of the secondary protection module is connected with the third end of the primary protection module, the second end of the primary protection module is connected with the positive electrode end C+ of the charging circuit, the activation module is connected with the analog front-end chip, the second end of the analog front-end chip is connected with the second end of the main control chip, the analog front-end chip is connected with the first end of the primary protection module, the discharge control module is connected with the negative electrode end P- of the charging circuit or the negative electrode end C- of the charging circuit.

2. The overcharge detection circuit for the failed battery charging protection according to claim 1, wherein the overcharge detection module comprises at least a resistor R2 and a field effect transistor Q4.

3. The overcharge detection circuit for the failed battery charging protection according to claim 2, wherein the secondary protection chip is connected with the G pole of the field effect transistor Q4; the D pole of the field effect transistor Q4 is connected with the main control chip, and the resistor R2 is connected therebetween; the S pole of the field effect transistor Q4 is connected to the ground; and the other end of the resistor R2 is connected with the main control chip.

4. The overcharge detection circuit for the failed battery charging protection according to claim 3, wherein the secondary protection chip comprises at least a CO pin of the secondary protection chip and a VDD pin of the secondary protection chip; the CO pin of the secondary protection chip is connected with the activation module, the secondary protection module and the field effect transistor Q4; and the VDD pin of the main control chip is connected with the resistor R2.

5. The overcharge detection circuit for the failed battery charging protection according to claim 4, wherein the second end of the main control chip comprises an SDA1 pin of a control chip U2 and an SCL1 pin of the control chip U2; the second end of the analog front-end chip comprises an SDA2 pin and an SCL2 pin; the SDA1 pin of the control chip U2 is connected with the SDA2 pin; and the SCL1 pin of the control chip U2 is connected with the SCL2 pin.

6. The overcharge detection circuit for the failed battery charging protection according to claim 5, wherein the primary protection module comprises at least a field effect transistor Q1.

7. The overcharge detection circuit for the failed battery charging protection according to claim 6, wherein the secondary protection module comprises at least a field effect transistor Q2, a three-terminal fuse F1 and a secondary protection chip; the S pole of the field effect transistor Q2 is grounded; the G pole of the field effect transistor Q2 is connected with the CO pin of the secondary protection chip and the activation module; the D pole of the field effect transistor Q2 is connected with the first end of the three-terminal fuse F1; the third end of the three-terminal fuse F1 is connected with the electric core module; and the second end of the three-terminal fuse F1 is connected with the D pole of the field effect transistor Q1. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 8.The battery cell overcharge detection circuit according to claim 7, wherein the activation module comprises at least a field effect transistor Q3 and a triode Q5. The D terminal of the field effect transistor Q3 is connected to the battery cell module. The S terminal of the field effect transistor Q3 is connected to the VCC pin of the analog front end chip. The G terminal of the field effect transistor Q3 is connected to the c terminal of the triode Q5. The b terminal of the triode Q5 is connected to the co pin of the secondary protection chip. The e terminal of the triode Q5 is connected to the ground terminal. 9.The battery cell overcharge detection circuit according to claim 8, wherein the analog front end chip comprises at least a CHG pin and a DSG pin of the analog front end chip. The DSG pin of the analog front end chip is connected to the discharge control module. The CHG pin of the analog front end chip is connected to the primary protection module. The battery pack comprises at least the battery cell overcharge detection circuit according to any one of claims 1 to 9. ​ 10. A battery pack, characterized by, ​

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