Battery cell charging protection failure additional identification protection circuit and battery pack

Abstract

The invention discloses an identification protection circuit for battery cell overcharge protection failure and a battery pack. The circuit comprises a battery cell module, an analog front-end chip, a primary protection module, a secondary protection module, a secondary protection chip, a discharge control module, a main control chip, an overcharge detection module, an activation module, a fusing module and an electric quantity consumption module. The front-end analog chip and the secondary protection chip synchronously detect charging voltage in real time, and when the primary protection module and the secondary protection module fail, the secondary protection chip activates the analog front-end chip through the activation module so as to activate the main control chip, control the power consumption module to consume voltage or start the fusing module to cut off a charging loop. According to the invention, the overcharge detection module, the electric quantity consumption module and the fusing module are additionally designed under the condition that both the primary protection and the secondary protection are invalid, so that the internal voltage of the battery cell is consumed or the charging loop is disconnected, the charging is stopped, the safety accident after overcharge is avoided, and the service life of the battery pack is also prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of battery pack circuits, and in particular to a protection circuit and a battery pack for identifying failure of overcharge protection of a battery cell. Background Art

[0002] The function of the battery pack is to provide power for the entire device and it needs to have a charging function. The battery pack is equipped with three external interfaces (P+, C+, P- / C-). As we all know, overcharging the battery pack will catch fire or even explode, posing a huge safety risk. Therefore, developers usually involve multiple overcharge protections in the charging circuit, that is, between P+ and C+ to ensure charging safety. However, if the P+ and C+ outside the battery pack are short-circuited, or the P+ port is mistakenly used as the C+ port for charging, all overcharge protection circuits will be short-circuited. When the charging protection circuit is short-circuited, or the main control chip program that controls the action of the protection circuit fails, the charging protection function will fail, and the battery pack will catch fire or even explode during the charging process, causing a safety accident. Application Contents

[0003] In view of this, the purpose of the present application is to provide a protection circuit and battery pack for identifying failure of overcharging protection of a battery cell. By additionally designing an overcharging detection module, a power consumption module and a fuse module when both the primary protection and the secondary protection fail, the excess charging power is consumed or the main circuit is disconnected in time, so as to achieve the purpose of preventing the battery pack from being charged further. This avoids safety accidents after overcharging to a certain extent and also increases the service life of the battery pack.

[0004] In order to achieve the above purpose, this application adopts the following technical solutions: It includes a battery cell module, an analog front-end chip, a primary protection module, a secondary protection module, a secondary protection chip, a discharge control module and a main control chip; it is characterized in that it also includes: an overcharge detection module, an activation module, a fuse module and a power consumption module.

[0005] Among them, the battery cell module is respectively connected to the secondary protection chip, the activation module, the analog front-end chip, the discharge control module, the fuse module and the power consumption module, the second end of the analog front-end chip is connected to the first end of the main control chip, the third end of the analog front-end chip is respectively connected to the discharge control module and the second end of the primary protection module, the secondary protection chip is respectively connected to the first end of the secondary protection module, the activation module, the fuse module and the overcharge detection module, the second end of the main control chip is connected to the overcharge detection module, the third end of the secondary protection module is connected to the third end of the primary protection module, and the first end of the primary protection module is connected to the positive terminal C+ of the charging circuit.

[0006] The second end of the main control chip is connected to the fuse module and the power consumption module respectively, the other ends of the fuse module and the power consumption module are connected to the battery module, and the third end of the secondary protection module is connected to the third end of the primary protection module; wherein the fuse module and the power consumption module are also connected to the positive terminal P+ of the charging circuit, and the discharge control module is connected to the negative terminal P- of the charging circuit or the negative terminal C- of the charging circuit; The real-time charging status is synchronously monitored by the analog front-end chip and the secondary protection chip. When both the primary protection module and the secondary protection module fail or malfunction, the main control chip detects the battery cell voltage through the overcharge detection module, and controls the power consumption module to consume the battery cell charging voltage, or starts the fuse module to blow the passive fuse to cut off the battery pack charging circuit.

[0007] In the present application, the overcharge detection module at least includes a field effect transistor Q6 and a resistor R4.

[0008] Among them, the second end of the main control chip is connected to the D pole of the field effect transistor Q6, and one end of the resistor R4 is also connected in the middle. The S pole of the field effect transistor Q6 is connected to the ground terminal, the G pole of the field effect transistor Q6 is connected to the secondary protection chip, and the other end of the resistor R4 is connected to the main control chip.

[0009] In the present application, the fuse module at least includes a field effect transistor Q2 and a resistor R1.

[0010] Among them, the G pole of the field effect transistor Q2 is connected to the second end of the main control chip, the S pole of the field effect transistor Q2 is grounded through the resistor R1, and the D pole of the field effect transistor Q2 is respectively connected to the battery cell module and the secondary protection module, and is also connected to the positive terminal P+ of the charging circuit.

[0011] In the present application, the power consumption module at least includes a field effect transistor Q3 and a resistor R2.

[0012] Among them, the S pole of the field effect transistor Q3 is grounded through the resistor R2, the G pole of the field effect transistor Q2 is connected to the second end of the main control chip, and the D pole of the field effect transistor Q3 is respectively connected to the battery cell module and the secondary protection module, and is also connected to the positive terminal P+ of the charging circuit.

[0013] In the present application, the secondary protection chip at least includes a CO pin of the secondary protection chip.

[0014] The second end of the main control chip includes an IO1 pin of the main control chip, an IO2 pin of the main control chip and an IO3 pin of the main control chip.

[0015] The CO pin of the secondary protection chip is connected to the activation module, the secondary protection module and the field effect transistor Q4 respectively.

[0016] The first end of the main control chip includes an SDA1 pin of the main control chip and an SCL1 pin of the main control chip.

[0017] The second end of the analog front-end chip includes an SDA2 pin of the analog front-end chip and an SCL2 pin of the analog front-end chip.

[0018] The SDA1 pin of the main control chip is connected to the SDA2 pin of the analog front-end chip.

[0019] The SCL1 pin of the main control chip is connected to the SCL2 pin of the analog front-end chip.

[0020] In the present application, the primary protection module at least includes a field effect transistor Q1; the secondary protection module at least includes a secondary protection chip, a field effect transistor Q4 and a three-terminal fuse F1.

[0021] Wherein, the G pole of the field effect tube Q1 is connected to the third terminal of the analog front-end chip; The S pole of the field effect transistor Q1 is connected to the positive terminal C+ of the charging circuit; The D pole of the field effect tube Q1 is connected to the first end of the three-terminal fuse F1; The third terminal of the three-terminal fuse F1 is also connected to the positive terminal P+ of the charging circuit; The second end of the three-terminal fuse F1 is connected to the D pole of the field effect tube Q4; The S pole of the field effect tube Q4 is grounded; The G pole of the field effect transistor Q4 is connected to the CO pin of the secondary protection chip, and is also connected to the first end of the analog front-end chip or the b pole of the transistor Q7.

[0022] In this application, the power consumption module is specifically: The CO pin of the secondary protection chip outputs a high-level signal to activate the analog front-end chip through the activation module, and then activates the main control chip. The analog front-end chip activates the main control chip to drive the power consumption module into the on state to consume excess voltage in the charging circuit, and at the same time invites the host to turn off the charging switch through communication.

[0023] In this application, the fuse module is specifically: The analog front-end chip activates the main control chip, and the main control chip outputs a high-level signal to control the field effect tube Q2 to enter the on state, and the passive fuse F2 is blown to cut off the charging circuit.

[0024] In order to achieve the above purpose, this application also adopts the following technical solutions: A battery pack, the battery pack comprising at least one of the battery cell charging protection failure additional identification protection circuits as described above.

[0025] Compared with the prior art, the beneficial effects of this application are: The present application proposes an additional identification protection circuit and battery pack for failure of battery cell charging protection. By further identifying the protection circuit, when the primary and secondary protection modules fail, the system will automatically start the power consumption module or the fuse module to prevent overcharging of the battery cell and reduce the risk of fire or safety accidents. It effectively avoids overcharging of the battery pack, extends the service life of the battery, and improves the stability and reliability of the battery system. The main control chip and the secondary protection chip can synchronously monitor the charging status in real time. When the protection mechanism fails, measures are taken quickly to cut off the charging circuit or consume excess power to ensure the safe operation of the battery. Through the power consumption module and the fuse module, the system safety hazards caused by the failure of overcharging protection are effectively reduced, and the stability and safety of the overall system are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The invention discloses a structural diagram of a circuit for additionally identifying a protection circuit for charging protection failure of a battery cell.

[0027] Figure 2 The invention discloses a circuit schematic diagram of an additional identification protection circuit for a battery cell charging protection failure.

[0028] Figure 3 The present invention is a logic diagram of an additional identification protection circuit for a battery cell charging protection failure. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The drawings provide preferred embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein.

[0030] Embodiment 1: like Figure 1 As shown, a monitoring protection circuit for solving the problem of out-of-control charging protection of a battery cell includes a battery cell module, an analog front-end chip, a primary protection module, a secondary protection module, a secondary protection chip, a discharge control module and a main control chip; it is characterized in that it also includes: an overcharge detection module, an activation module, a fuse module and a power consumption module.

[0031] Compared with the battery cell charging protection circuit in the prior art, the embodiment of the present application adds an overcharge detection module, a power consumption module and a fuse module on the basis of the prior art. By additionally designing the overcharge detection module, the power consumption module and the fuse module, when the primary protection and the secondary protection fail, the present application can still effectively prevent overcharging during the battery charging process, avoid safety accidents, and improve the safety of battery use.

[0032] Among them, the battery module is respectively connected to the secondary protection chip, the activation module, the analog front-end chip, the discharge control module, the fuse module and the power consumption module, the second end of the analog front-end chip is connected to the first end of the main control chip, the third end of the analog front-end chip is respectively connected to the discharge control module and the second end of the primary protection module, the secondary protection chip is respectively connected to the first end of the secondary protection module, the activation module, the fuse module and the overcharge detection module, the second end of the main control chip is connected to the overcharge detection module, the third end of the secondary protection module is connected to the third end of the primary protection module, and the first end of the primary protection module is connected to the positive terminal C+ of the charging circuit. The second end of the main control chip is connected to the fuse module and the power consumption module respectively, the other ends of the fuse module and the power consumption module are connected to the battery cell module, and the third end of the secondary protection module is connected to the third end of the primary protection module; wherein, the fuse module and the power consumption module are also connected to the positive terminal P+ of the charging circuit, and the discharge control module is connected to the negative terminal P- of the charging circuit or the negative terminal C- of the charging circuit.

[0033] The real-time charging status is synchronously monitored by the analog front-end chip and the secondary protection chip. When both the primary protection module and the secondary protection module fail or malfunction, the main control chip detects the battery cell voltage through the overcharge detection module, and controls the power consumption module to consume the battery cell charging voltage, or starts the fuse module to blow the passive fuse to cut off the battery pack charging circuit.

[0034] In this embodiment, the connection relationship between the analog front-end chip, the main control chip, the primary protection module and the secondary protection module constitutes the basis of the battery charging protection. When the primary protection and the secondary protection fail, the system adopts two methods to prevent the battery from overcharging, namely the short power consumption module and the fuse module.

[0035] The implementation principle of the embodiment of the present application is: The main control chip and the secondary protection chip synchronously monitor the real-time charging status. When the primary and secondary protection modules fail, the main control chip controls the power consumption module or the fuse module according to the overcharge detection feedback signal.

[0036] The power consumption module forms a conducting state under the control of the main control chip through the field effect transistor Q3 and the resistor R2, continuously consumes the excess power of the battery cell, and prevents safety accidents caused by overcharging.

[0037] The fuse module forms a conducting state under the control of the main control chip through the field effect tube Q2 and the resistor R1, thereby blowing the passive fuse F2, cutting off the main charging circuit and terminating charging.

[0038] In this embodiment, the power consumption module can continuously consume excess power, prevent overcharging of the battery cell, and improve the safety of battery use. The fuse module cuts off the main charging circuit by fusing the passive fuse F2, effectively avoiding overcharging and reducing the risk of safety accidents. The additional design of these two methods improves the stability of the system while maintaining the existing technology, and avoids the potential safety hazards that may occur when the primary and secondary protections fail.

[0039] It should be noted that in the primary protection module, when the charge in the circuit reaches the first-level overvoltage protection threshold V1, the charging circuit will be closed along with the driving action of the analog front-end chip, thereby stopping charging and playing the role of a protection circuit. However, if the primary protection module fails, or the program in the analog front-end chip runs away and cannot issue an action instruction, then the protection of the primary protection module will not take effect.

[0040] The charger continues to charge the battery. In the secondary protection module, when the charge in the circuit reaches the secondary overvoltage protection threshold V2, the charging circuit will be closed with the driving action of the secondary protection chip, thereby melting the three-terminal fuse F1 to stop charging and play a role in protecting the circuit. However, if a fault short circuit occurs at the P+ or C+ terminal at this time, the protection of the secondary protection module will not take effect.

[0041] If the primary or secondary protection module is short-circuited, or the analog front-end chip and the secondary protection chip program are abnormal, the corresponding protection function may fail. At this time, the power consumption module and the fuse module are particularly critical. This embodiment provides a safer and more reliable battery charging protection system through meticulous circuit design and multiple protection mechanisms, effectively reducing the safety risk of overcharging.

[0042] As attached Figure 2 As shown, in the embodiment of the present application, the overcharge detection module at least includes a field effect transistor Q6 and a resistor R4.

[0043] Among them, the D pole of the field effect transistor Q6 is connected to the second end of the main control chip, and one end of the resistor R4 is also connected in the middle. The S pole of the field effect transistor Q6 is connected to the ground end, the G pole of the field effect transistor Q6 is connected to the secondary protection chip, and the other end of the resistor R4 is connected to the main control chip.

[0044] The power consumption module at least includes a field effect transistor Q3 and a resistor R2.

[0045] Among them, the second end of the main control chip is connected to the G pole of the field effect transistor Q3, the S pole of the field effect transistor Q3 is grounded through the resistor R2, and the D pole of the field effect transistor Q3 is respectively connected to the battery cell module and the secondary protection module, and is also connected to the positive terminal P+ of the charging circuit.

[0046] It should be noted that when the charging circuit is in a normal working state, the field effect tube Q6 is in a closed state and does not affect the charging process. At this time, the charging current passes through the charging circuit and charges the battery normally.

[0047] If both the primary protection and the secondary protection fail, the charging circuit cannot be closed normally, and there is a risk of overcharging. The CO pin of the secondary protection chip outputs a high level, the field effect transistor Q6 will be turned on, and the analog front-end chip will be activated through the activation module, and then the main control chip will be activated. The IO3 pin of the main control chip is connected to the field effect transistor Q3 to activate the field effect transistor Q3 and the resistor R2. The conduction state of the field effect transistor Q3 and the resistor R2 starts the power consumption module, and at the same time invites the host to turn off the charging switch through communication and record the fault information, and terminate charging.

[0048] Or if P+ and C+ are short-circuited due to a fault, there is a risk of continuing to charge through P+. After the main control chip detects the fault according to the state of the field effect tube Q6, it connects the IO2 pin of the main control chip to the G pole of the field effect tube Q2, activating the field effect tube Q2 and the resistor R1. The conduction state of the field effect tube Q2 activates the fuse module to fuse the passive fuse F2, cutting off the path for continuing to charge through P+ to prevent safety accidents.

[0049] Through this design, the field effect transistor Q3 and resistor R2 in the power consumption module can respond quickly when the protection fails, short-circuit the charging circuit, and ensure the safety of the battery during charging. This mechanism provides a reliable backup protection method and enhances the safety of the entire system.

[0050] As attached Figure 2 As shown, in the embodiment of the present application, the fuse module at least includes a field effect transistor Q2 and a resistor R1.

[0051] Among them, the G pole of the field effect transistor Q2 is connected to the IO2 pin of the main control chip, the S pole of the field effect transistor Q2 is grounded through the resistor R1, and the D pole of the field effect transistor Q2 is respectively connected to the battery cell module and the secondary protection module, and is also connected to the positive terminal P+ of the charging circuit.

[0052] It should be noted that the field effect transistor Q2 acts as a key switching element in the fuse module, and is used to realize the fuse function, that is, to disconnect the circuit when necessary.

[0053] When the battery charge reaches a certain condition, the main control chip disconnects the field effect transistor Q2 by connecting to it, thereby cutting off the charging circuit and preventing overcharging.

[0054] The G pole of the field effect transistor Q2 is connected to the IO2 pin of the main control chip, and the control signal of the main control chip is transmitted to the field effect transistor Q2.

[0055] The S pole of the field effect tube Q2 is grounded to ensure stable grounding of the circuit. The D pole of the field effect tube Q2 is connected to the battery module and the secondary protection module respectively, and is also connected to the positive terminal P+ of the charging circuit.

[0056] Through the control signal of the main control chip, the field effect tube Q2 can be quickly switched on and off when necessary to achieve the fuse function. This is to disconnect the main circuit and prevent overcharging when both the primary protection and the secondary protection fail, thus enhancing safety.

[0057] The D pole of the field effect transistor Q2 is connected to the positive terminal P+ of the charging circuit at the same time, which ensures that the field effect transistor Q2 can directly affect the charging circuit, realize timely power-off, and avoid safety problems caused by continued charging.

[0058] In the present application, the secondary protection chip at least includes a CO pin of the secondary protection chip; The second end of the main control chip at least includes the IO1 pin of the main control chip, the IO2 pin of the main control chip and the IO3 pin of the main control chip; the first end of the main control chip at least includes the SDA1 pin and the SCL1 pin; The second end of the analog front-end chip includes at least an SDA2 pin and an SCL2 pin; Wherein, the CO pin of the secondary protection chip is respectively connected to the activation module, the secondary protection module and the field effect transistor Q4; The first end of the main control chip includes the SDA1 pin of the main control chip and the SCL1 pin of the main control chip; The second end of the analog front-end chip includes an SDA2 pin of the analog front-end chip and an SCL2 pin of the analog front-end chip; The SDA1 pin of the main control chip is connected to the SDA2 pin of the analog front-end chip; The SCL1 pin of the main control chip is connected to the SCL2 pin of the analog front-end chip.

[0059] It should be noted that SDA (Serial Data Line) and SCL (Serial Clock Line) are two signal lines in the I2C bus communication protocol, through which data transmission and communication between the microcontroller U1 and the analog front-end chip are realized.

[0060] 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 to ensure that the circuit can be cut off in time when the battery status is abnormal to achieve the protection effect.

[0061] At the same time, through the connection with the fuse module and the power consumption module, the main control chip can also control the fuse module or the power consumption module to start, ensuring that the excess power of the battery cell can be quickly consumed or the main circuit can be disconnected when needed. The introduction of the main control chip improves the stability and controllability of the entire system, and through programming, the various components can be flexibly coordinated to ensure the reliable operation of the battery cell charging protection system.

[0062] In summary, the main control chip serves as the core, and through pin connection configuration and communication protocol, it realizes effective control and coordinated work of various components of the system, improving the intelligence and stability of the battery cell charging protection system.

[0063] In the present application, the primary protection module at least includes a field effect transistor Q1.

[0064] Wherein, the G pole of the field effect tube Q1 is connected to the third terminal of the analog front-end chip; The S pole of the field effect transistor Q1 is connected to the positive terminal C+ of the charging circuit; The D pole of the field effect tube Q1 is connected to the first end of the three-terminal fuse F1; It should be noted that the G pole of the field effect tube Q1 is connected to the third terminal of the analog front-end chip, and the field effect tube Q1 can be activated or turned off by the control of the analog front-end chip. The S pole of the field effect tube Q1 is connected to the positive terminal C+ of the battery pack, and the D pole is connected to the first terminal of the three-terminal fuse F1. The third terminal of the three-terminal fuse F1 is connected to P+.

[0065] When the charge in the circuit reaches the first-level overvoltage protection threshold V1, the analog front-end chip controls the field effect transistor Q1 to disconnect the field effect transistor Q1, cutting off the charging circuit and playing a primary protection role.

[0066] The secondary protection module at least includes a secondary protection chip, a field effect transistor Q4 and a three-terminal fuse F1.

[0067] The second end of the three-terminal fuse F1 is connected to the D pole of the field effect tube Q4; The third terminal of the three-terminal fuse F1 is also connected to the positive terminal P+ of the charging circuit; The S pole of the field effect tube Q4 is grounded; The G pole of the field effect transistor Q4 is connected to the CO pin of the secondary protection chip.

[0068] It should be noted that the second end of the three-terminal fuse F1 is connected to the D pole of the field effect tube Q4, the third end of the three-terminal fuse F1 is also connected to the positive terminal P+ of the charging circuit, the S pole of the field effect tube Q4 is grounded, and the G pole of the field effect tube Q4 is connected to the CO pin of the secondary protection chip.

[0069] When the charge in the circuit reaches the secondary overvoltage protection threshold V2, the secondary protection chip controls the field effect tube Q4 to turn on, causing the three-terminal fuse F1 to melt, cutting off the charging circuit and playing a role of secondary protection.

[0070] Through the design of the primary protection module and the secondary protection module, the voltage can be monitored during the charging process, and the charging circuit can be cut off when the first-level overvoltage protection threshold V1 and the second-level overvoltage protection threshold V2 are reached to avoid overcharging and improve battery safety.

[0071] When the primary protection module and the secondary protection module mentioned above are not effective, the circuit will easily cause a safety accident in the case of overcharging. The additional power consumption mechanism provides an additional, independent safety protection method when the primary protection and the secondary protection fail, ensuring that the battery voltage can be controlled in time in various abnormal situations, preventing the battery from overcharging and reducing safety risks. This mechanism plays a key role in ensuring battery safety.

[0072] In the embodiment of the present application, the power consumption mechanism is specifically as follows: The analog front-end chip is activated through the activation module by outputting a high-level signal through the CO pin in the secondary protection chip, thereby activating the main control chip; after the analog front-end chip drives the IO3 pin of the main control chip to generate a high-level signal 2, the field effect transistor Q3 receives the high-level signal 2 and enters a conducting state to consume excess voltage of the battery cell.

[0073] It should be noted that when the primary protection and secondary protection modules fail, the CO pin in the secondary protection chip outputs a high-level signal 1. The high-level signal 1 is transmitted to the analog front-end chip to wake it up. The analog front-end chip drives the IO3 pin of the main control chip to generate a high-level signal 2. The high-level signal 2 is transmitted to the field effect tube Q3 to drive it into the on state.

[0074] The wake-up process of the CO pin of the secondary protection chip outputting a high-level signal ensures that the power consumption mechanism can be quickly activated when the primary and secondary protection modules fail. The field effect transistor Q3 enters the on state and, combined with the resistor R2, continuously consumes the excess voltage of the battery cell. The power consumption effect prevents the battery pack from charging too high, improves the practical performance of the battery pack, and ensures the safety of the battery charging process.

[0075] In the embodiment of the present application, the fuse module is specifically: After being awakened, the analog front-end chip drives the IO2 pin of the main control chip to generate a high-level signal three; after receiving the high-level signal three, the field effect tube Q2 is turned on and blows the passive fuse F2 to disconnect the main circuit.

[0076] It should be noted that when the analog front-end chip is awakened, the IO2 of the main control chip is driven to generate a high-level signal 3. The high-level signal 3 is transmitted to the field effect transistor Q2, causing the field effect transistor Q2 to enter the on state. After the field effect transistor Q2 is turned on, the passive fuse F2 is disconnected, cutting off the main circuit.

[0077] After the analog front-end chip wakes up, the high-level signal 3 generated ensures that the fuse module can be quickly activated when the primary and secondary protection modules fail. The conduction state of the field effect tube Q2 causes the passive fuse F2 to disconnect, realizing the cutting off of the main circuit. The cutting off of the main circuit prevents the battery pack from continuing to charge, avoids overcharging, and improves the safety of battery use.

[0078] By blowing the passive fuse F2, the main circuit can be quickly cut off when the protection circuit fails, protecting the battery from overcharging and ensuring the safety of the battery during charging.

[0079] In summary, the power consumption module and the fuse module can effectively prevent overcharging of the battery cells, reduce the risk of fire or safety accidents, and improve the safety of battery use. By quickly cutting off the charging circuit, the overcharging of the battery pack is effectively avoided, the battery life is extended, and the stability and reliability of the battery system are improved. The main control chip can monitor the charging status in real time. When the protection mechanism fails, it quickly takes measures to cut off the charging circuit to ensure the safe operation of the battery. By short-circuiting the charging circuit and fusing the passive FUSE mechanism, the system safety hazards caused by the failure of the protection circuit are effectively reduced, and the stability and safety of the overall system are improved.

[0080] Embodiment 2: As attached Figure 3 As shown, a battery pack integrates a battery cell charging protection failure additional identification protection circuit mentioned in a preferred embodiment, including a battery cell module, an analog front-end chip, a primary protection module, a secondary protection module, a secondary protection chip, a discharge control module and a main control chip; it is characterized in that it also includes: an overcharge detection module, an activation module, a fuse module and a power consumption module.

[0081] When the battery pack is connected to the charger, the charger starts to supply power to the battery pack, and the identification and protection circuit starts to work and monitors the charging status in real time. The identification and protection circuit is divided into three working stages.

[0082] Phase 1: When the cell voltage is lower than the first-level overvoltage protection threshold V1, the charger is inserted and the host turns on the charging switch. At this time, the CO pin of the secondary protection chip outputs a low level, the field effect transistor Q4, the transistor Q7, and the field effect transistor Q6 are all in the cut-off state, the CHG pin of the analog front-end chip outputs a low level, the field effect transistor Q1 is in the on state, the charger charges the battery pack, and the cell voltage continues to rise.

[0083] The second stage: the battery cell voltage reaches the first-level overvoltage protection threshold V1. At this time, the CHG pin of the analog front-end chip outputs a high level, the field effect transistor Q1 is in the cut-off state, the charging circuit is disconnected, and charging stops.

[0084] However, if the external P+ and C+ are short-circuited, or 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 cell voltage will continue to rise.

[0085] Stage 3: The cell voltage reaches the secondary overvoltage protection threshold V2, and the CO pin of the secondary protection chip outputs a high level. At this time, the battery pack performs the following three actions simultaneously: Action 1: Transistor Q7 is turned on, then field effect transistor Q5 is turned on, B+ starts to supply power to the analog front-end chip, the analog front-end chip starts to supply power to the main control chip, and the main control chip is activated.

[0086] Action 2: Field effect tube Q4 is turned on, three-terminal fuse F1 is blown, charging circuit is disconnected, and charging stops. If the external P+ and C+ are short-circuited, or P+ is mistakenly used as a charging port, or the secondary protection module fails, the charger will continue to charge the battery pack.

[0087] Action 3: Field effect transistor Q6 is turned on, and the IO1 pin of the main control chip becomes a low level.

[0088] After the main control chip is activated, the following three actions are performed simultaneously: Action 1: Detect the output level of the IO1 pin of the main control chip and read the charging current through the analog front-end chip. When the IO1 pin of the main control chip outputs a low level, the CO pin of the secondary protection chip outputs a high level. The battery pack is in a secondary overcharge state. At the same time, the charging current read exceeds the set threshold, and it is determined that the overcharge protection function has failed. Then, the host is requested to turn off the charging switch to terminate charging through communication. When the charging current still exceeds the set threshold after sending the invitation, it is determined that the host has no response, and the count is +1.

[0089] Action 2: Set the IO3 pin level output of the main control chip to high, start the power consumption module to consume excess power, and when the cell voltage is lower than the secondary overvoltage protection threshold V2, set the IO3 pin level output of the main control chip to low, and turn off the power consumption module.

[0090] Action 3: Set the host no response count setting value N. If the host no response is equal to the setting value, the IO2 pin level output of the main control chip will be set high, the fuse module will be started to blow the passive fuse F2, and the battery cell will be disconnected from the outside.

[0091] When the host no response count is less than the set value N, the external P+ and C+ are short-circuited or P+ is mistakenly used as the charging port and the communication is unresponsive or both the primary protection module and the secondary protection module fail, and the fault is not resolved, the battery pack will repeatedly switch back and forth between the second stage and the third stage until the host no response count is equal to the set value N. The fuse module is activated to fuse the charging circuit to terminate charging, and the count returns to zero.

[0092] In summary, this battery pack design can effectively prevent overcharging of the battery cells during the charging process and ensure the safe operation of the battery by embedding the identification and protection circuit.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0094] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0095] Although the description of the present application is carried out in conjunction with the above specific embodiments, it is obvious that those skilled in the art can make many substitutions, modifications and changes based on the above content. Therefore, all such substitutions, improvements and changes are included in the spirit and scope of the appended claims.

Claims

1. A protection circuit for identifying failure of overcharge protection of a battery cell, comprising a battery cell module, an analog front-end chip, a primary protection module, a secondary protection module, a secondary protection chip, a discharge control module and a main control chip; characterized in that: Also includes: Overcharge detection module, activation module, fuse module and power consumption module; The battery cell module is respectively connected to the secondary protection chip, the activation module, the analog front-end chip, the discharge control module, the fuse module and the power consumption module; the second end of the analog front-end chip is connected to the first end of the main control chip; the third end of the analog front-end chip is respectively connected to the discharge control module and the second end of the primary protection module; the secondary protection chip is respectively connected to the first end of the secondary protection module, the activation module, the fuse module and the overcharge detection module; the second end of the main control chip is connected to the overcharge detection module; the third end of the secondary protection module is connected to the third end of the primary protection module; and the first end of the primary protection module is connected to the positive terminal C+ of the charging circuit; The second end of the main control chip is connected to the fuse module and the power consumption module respectively, the other ends of the fuse module and the power consumption module are connected to the battery module, and the third end of the secondary protection module is connected to the third end of the primary protection module; wherein the fuse module and the power consumption module are also connected to the positive terminal P+ of the charging circuit, and the discharge control module is connected to the negative terminal P- of the charging circuit or the negative terminal C- of the charging circuit; The real-time charging status is synchronously monitored by the analog front-end chip and the secondary protection chip. When both the primary protection module and the secondary protection module fail or malfunction, the main control chip detects the battery cell voltage through the overcharge detection module, and controls the power consumption module to consume excess power of the battery cell, or starts the fuse module to blow the passive fuse to cut off the battery pack charging circuit.

2. A cell overcharge protection failure identification protection circuit according to claim 1, characterized in that: The overcharge detection module at least includes a field effect transistor Q6 and a resistor R4; The second end of the main control chip is connected to the D pole of the field effect transistor Q6, and one end of the resistor R4 is also connected in the middle; The S pole of the field effect transistor Q6 is connected to the ground terminal; The G pole of the field effect transistor Q6 is connected to the secondary protection chip; The other end of the resistor R4 is connected to the main control chip.

3. A cell overcharge protection failure identification protection circuit according to claim 2, characterized in that: The fuse module at least includes a field effect transistor Q2 and a resistor R1; The second end of the main control chip is connected to the G pole of the field effect transistor Q2; The S pole of the field effect tube Q2 is grounded through a resistor R1; The D pole of the field effect tube Q2 is connected to the battery cell module and the secondary protection module respectively, and is also connected to the positive terminal P+ of the charging circuit.

4. The battery cell charging protection failure additional identification protection circuit according to claim 3, characterized in that: The power consumption module at least includes a field effect transistor Q3 and a resistor R2; The second end of the main control chip is connected to the G pole of the field effect transistor Q3; The S pole of the field effect tube Q3 is grounded through the resistor R2; The D pole of the field effect tube Q3 is connected to the battery cell module and the secondary protection module respectively, and is also connected to the positive terminal P+ of the charging circuit.

5. The battery cell charging protection failure additional identification protection circuit according to claim 3, characterized in that: The secondary protection chip at least includes a CO pin of the secondary protection chip; The second end of the main control chip at least includes an IO1 pin of the main control chip, an IO2 pin of the main control chip and an IO3 pin of the main control chip; The first end of the main control chip includes at least an SDA1 pin and an SCL1 pin; The second end of the analog front-end chip includes at least an SDA2 pin and an SCL2 pin; The CO pin of the secondary protection chip is respectively connected to the activation module, the secondary protection module and the field effect transistor Q4; The first end of the main control chip includes the SDA1 pin of the main control chip and the SCL1 pin of the main control chip; The second end of the analog front-end chip includes an SDA2 pin of the analog front-end chip and an SCL2 pin of the analog front-end chip; The SDA1 pin of the main control chip is connected to the SDA2 pin of the analog front-end chip; The SCL1 pin of the main control chip is connected to the SCL2 pin of the analog front-end chip.

6. A battery cell charging protection failure additional identification protection circuit according to claim 5, characterized in that: The primary protection module at least includes a field effect transistor Q1; The secondary protection module at least includes a secondary protection chip, a field effect transistor Q4 and a three-terminal fuse F1.

7. A battery cell charging protection failure additional identification protection circuit according to claim 6, characterized in that: The G pole of the field effect transistor Q1 is connected to the third terminal of the analog front-end chip; The S pole of the field effect transistor Q1 is connected to the positive terminal C+ of the charging circuit; The D pole of the field effect tube Q1 is connected to the first end of the three-terminal fuse F1; The third terminal of the three-terminal fuse F1 is also connected to the positive terminal P+ of the charging circuit; The second end of the three-terminal fuse F1 is connected to the D pole of the field effect tube Q4; The S pole of the field effect tube Q4 is grounded; The G pole of the field effect transistor Q4 is connected to the CO pin of the secondary protection chip, and is also connected to the first end of the analog front-end chip or the b pole of the transistor Q7.

8. The battery cell charging protection failure additional identification protection circuit according to claim 7, characterized in that: The power consumption module is specifically: The CO pin of the secondary protection chip outputs a high-level signal to activate the analog front-end chip through the activation module, thereby activating the main control chip; The analog front-end chip activates the main control chip to drive the power consumption module into a conducting state to consume excess voltage of the battery cell, and at the same time invites the host to turn off the charging switch through communication.

9. A battery cell charging protection failure additional identification protection circuit according to claim 8, characterized in that: The fuse module is specifically: The analog front-end chip activates the main control chip; The main control chip outputs a high level signal to control the field effect transistor Q2 to enter a conducting state, and the passive fuse F2 is blown to cut off the charging circuit.

10. A battery pack, characterized in that: The battery pack comprises at least one of claims 1 to 9 of the additional identification protection circuit for battery cell charging protection failure.

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