Battery protection circuit and electric device

Abstract

The utility model discloses a battery protection circuit and electrical equipment relates to battery protection technical field, aiming at the problem that traditional battery protection module can not accurately and reliably protect single cell, and the protection effect of multiple cell batteries such as multiple cell parallel connection battery is insufficient, provide a kind of battery protection circuit. Among them, first protection module is arranged in battery main circuit, for realizing the overvoltage, overcurrent protection of battery. Second protection module is multiple, respectively arranged in the single cell loop of each cell in battery, for realizing the overvoltage, overcurrent protection of single cell. Based on this, the circuit can provide protection point, the two layers of progressive overvoltage overcurrent protection mechanism of different protection objects for multiple cell battery. And two overvoltage overcurrent protection redundancies are realized to a certain extent, to further improve safety. When each cell in battery is mutually charged and discharged due to unbalanced charging and discharging, the second protection module can also provide effective protection function for this situation.

Description

Technical Field

[0001] This utility model relates to the field of battery protection technology, and in particular to a battery protection circuit and electrical equipment. Background Technology

[0002] Because the capacity and output capability of a single battery cell are limited, multiple cells are connected in series and parallel to improve battery performance. A common application is the multi-cell parallel battery, which contains multiple cells connected in parallel to provide a larger output current and battery capacity. However, large-capacity batteries also carry greater safety risks, especially multi-cell parallel batteries. When the cell consistency is low, it can lead to uneven charging and discharging of some cells, resulting in safety issues.

[0003] Currently, battery protection modules protect the battery by detecting its total current and voltage, but they cannot provide accurate and reliable protection for individual cells. Therefore, in practical applications of multi-cell parallel batteries, current battery protection solutions cannot solve the safety problems caused by uneven charging and discharging between cells, posing a significant safety hazard that directly threatens the personal and property safety of users.

[0004] Therefore, those skilled in the art urgently need a battery protection circuit to solve the problem that traditional battery protection modules cannot provide accurate and reliable protection for single cells, and have insufficient protection for multi-cell batteries such as those connected in parallel. Utility Model Content

[0005] The purpose of this invention is to provide a battery protection circuit and electrical equipment to solve the problem that traditional battery protection modules cannot effectively protect multi-cell parallel batteries containing multiple cells.

[0006] To solve the above-mentioned technical problems, this utility model provides a battery protection circuit, which is applied to a battery including at least two cells, and the cells are connected in parallel; the circuit includes: a first protection module and a second protection module;

[0007] The first protection module is located in the main circuit of the battery; wherein, the main circuit of the battery is the trunk circuit in the parallel circuit composed of multiple battery cells in the battery;

[0008] The first protection module receives the battery electrical signal output by the battery, and disconnects the main circuit of the battery when the current value of the battery electrical signal is greater than a first current threshold or the voltage value is greater than a first voltage threshold.

[0009] The second protection module comprises multiple modules, each disposed in a single cell circuit of each of the battery cells; wherein, the single cell circuit is the branch corresponding to each battery cell in the parallel circuit composed of multiple battery cells in the battery;

[0010] The second protection module receives the battery cell electrical signal output by each of the battery cells, and cuts off the corresponding single battery cell circuit when the current value of the battery cell electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold.

[0011] Wherein, the second current threshold is greater than the first current threshold, and the second voltage threshold is greater than the first voltage threshold.

[0012] In one optional embodiment, the second protection module includes: a first control module and a first three-terminal fuse;

[0013] Each of the second protection modules shares the same first control module; the output terminal of the first control module is connected to the third terminal of each of the first three-terminal fuses; the first and second terminals of each of the first three-terminal fuses are connected in series in the corresponding single-cell circuit.

[0014] The input terminal of the first control module is connected to the battery electrical signal. When the voltage value of the battery electrical signal exceeds the second voltage threshold, the first control module outputs a signal to blow the first three-terminal fuse.

[0015] In one optional embodiment, the first terminal of each of the first three-terminal fuses is connected to the output terminal of the corresponding battery cell, and the second terminal of each of the first three-terminal fuses is connected to the parallel connection point of each battery cell; wherein, the parallel connection point is the common connection point between the branches corresponding to each battery cell in the parallel circuit composed of multiple battery cells in the battery.

[0016] The first control module includes: a first voltage comparison module and a first switch module;

[0017] The first terminal of the first switch module is connected to the third terminal of the first three-terminal fuse, the second terminal of the first switch module is grounded, and the controlled terminal of the first switch module is connected to the output terminal of the first voltage comparison module.

[0018] The input terminal of the first voltage comparison module is connected to the battery electrical signal, and when the voltage value of the battery electrical signal is greater than the second voltage threshold, it outputs a signal to control the first switch module to turn on.

[0019] In an optional embodiment, it further includes: a second three-terminal fuse;

[0020] The first terminal of the second three-terminal fuse is connected to each of the second protection modules; the second and third terminals of the second three-terminal fuse are connected in series in the main circuit of the battery.

[0021] The second protection module outputs a signal to blow the second three-terminal fuse when the current value of the battery cell's electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold.

[0022] In one optional embodiment, the voltage value of the battery electrical signal is equal to that of each of the cell electrical signals; the second protection module includes: a second voltage comparison module, a second switching module, and a fuse at both ends;

[0023] The two-terminal fuses are connected in series in the corresponding single-cell circuit;

[0024] Each of the second protection modules shares the same second voltage comparison module; the input terminal of the second voltage comparison module is connected to the battery electrical signal, and the output terminal of the second voltage comparison module is connected to the controlled terminal of each of the second switch modules; the first terminal of the second switch module is connected to the first terminal of the second three-terminal fuse, and the second terminal of the second switch module is grounded;

[0025] When the voltage value of the battery electrical signal is greater than the second threshold, the second voltage comparison module outputs a signal to control the second switch module to turn on.

[0026] In one optional embodiment, the battery cell is a battery cell using silicon-based negative electrode technology, and both the first current threshold and the first voltage threshold include a first sub-value and a second sub-value; and the first sub-value is less than the corresponding second sub-value.

[0027] It also includes: a discharge status detection module;

[0028] The input terminal of the discharge state detection module is connected to the battery electrical signal, and the output terminal of the discharge state detection module is connected to the controlled terminal of the first protection module.

[0029] Specifically, when the discharge state detection module determines that the battery is in a high-current discharge state based on the battery electrical signal, it outputs a first protection signal; when the discharge state detection module determines that the battery is in a trickle discharge state based on the battery electrical signal, it outputs a second protection signal.

[0030] When the first protection module receives the first protection signal at the controlled end, the first sub-value of the first current threshold and the first voltage threshold takes effect; when the first protection module receives the second protection signal at the controlled end, the second sub-value of the first current threshold and the first voltage threshold takes effect.

[0031] In one alternative embodiment, the discharge state detection module is an electrical device powered by the battery.

[0032] In one optional embodiment, the discharge state detection module is a current comparison module;

[0033] The current comparison module outputs the first protection signal when the current value of the battery electrical signal is greater than the third current threshold.

[0034] The current comparison module outputs the second protection signal when the current value of the battery electrical signal is less than the fourth current threshold.

[0035] In one optional embodiment, the first protection module includes: a second control module and a third switch module;

[0036] The first and second ends of the third switch module are connected in series in the main battery circuit, and the controlled end of the third switch module is connected to the output end of the second control module.

[0037] The input terminal of the second control module is connected to the battery electrical signal; and when the current value of the battery electrical signal is greater than the first current threshold or the voltage value is greater than the first voltage threshold, the second control module outputs a signal to control the third switch module to turn off.

[0038] To solve the above-mentioned technical problems, this utility model also provides an electrical device, including the battery protection circuit as described above, and a silicon negative electrode parallel battery.

[0039] This utility model provides a battery protection circuit comprising a first protection module and a second protection module. The first protection module is located in the main battery circuit and provides overvoltage and overcurrent protection. Multiple second protection modules are configured in the individual cell circuits of each battery cell, providing overvoltage and overcurrent protection for each individual cell. Based on this structure, this circuit provides a two-layer progressive overvoltage and overcurrent protection mechanism for multi-cell parallel batteries, offering overvoltage and overcurrent protection for both the battery as a whole and each individual cell connected in parallel. Furthermore, the first and second protection modules achieve redundancy in overvoltage and overcurrent protection, resulting in safer and more reliable battery protection and further reducing safety hazards during battery use. When cells in the battery charge and discharge each other due to uneven charging and discharging, the second protection module also provides effective protection in this situation. In addition, the first and second protection modules in this circuit employ different protection points (voltage threshold and current threshold), providing a hierarchical protection mechanism to further improve battery safety.

[0040] The electrical equipment provided by this utility model corresponds to the above-mentioned battery protection circuit and has the same effect. Attached Figure Description

[0041] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 A structural diagram of a battery protection circuit provided in an embodiment of this utility model;

[0043] Figure 2 A structural diagram of the first second protection module scheme provided in the embodiments of this utility model;

[0044] Figure 3 Circuit diagram of the first second protection module scheme provided for the embodiments of this utility model;

[0045] Figure 4 A structural diagram of the second protection module scheme provided in the embodiments of this utility model;

[0046] Figure 5 A structural diagram of another second protection module scheme provided in this embodiment of the utility model;

[0047] Among them, 10 is the first protection module, 11 is the second control module, 12 is the third switch module, 20 is the second protection module, 21-A is the first control module, 211-A is the first voltage comparison module, 212-A is the first switch module, 22-A is the first three-terminal fuse, 21-B is the second voltage comparison module, 22-B is the second switch module, 23-B is the two-terminal fuse, and 30-B is the second three-terminal fuse. Detailed Implementation

[0048] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0049] The core of this utility model is to provide a battery protection circuit and electrical equipment.

[0050] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] In related technologies, to improve battery capacity and output capability, multiple cells can be connected in series and parallel to form a multi-cell battery. Among these, multi-cell parallel batteries, by connecting multiple cells in parallel, can increase the overall battery capacity and output current. However, increased battery capacity also means greater safety risks, especially since multi-cell parallel batteries contain multiple cells connected in parallel. If inconsistencies exist between these cells, it can lead to uneven charging and discharging, resulting in safety issues.

[0052] Currently, common battery protection solutions primarily provide overvoltage and overcurrent protection for the battery itself, failing to offer accurate and reliable protection for individual cells within the battery. While this approach is sufficient to ensure battery safety for traditional batteries, it is inadequate for batteries involving multiple cells connected in parallel, where the protection provided by traditional solutions is insufficient to meet safety requirements.

[0053] To solve the above problems, this utility model provides a battery protection circuit, such as... Figure 1 As shown, the battery protection circuit includes: a first protection module 10 and a second protection module 20.

[0054] The first protection module 10 is located in the battery main circuit; wherein, the battery main circuit is the main circuit in the parallel circuit of the battery composed of multiple cells (e.g., Figure 1 (The circuit part is highlighted with green lines in the middle); the first protection module 10 receives the battery electrical signal output by the battery, and cuts off the main circuit of the battery when the current value of the battery electrical signal is greater than the first current threshold or the voltage value is greater than the first voltage threshold.

[0055] The second protection module 20 comprises multiple modules, each installed in the single-cell circuit of each cell in the battery; wherein, the single-cell circuit is the branch corresponding to each cell in the parallel circuit composed of multiple cells in the battery (e.g., Figure 1 (The circuit part is highlighted with blue lines in the middle); the second protection module 20 connects to the cell electrical signals output by each cell in the battery, and cuts off the corresponding single cell circuit when the current value of the cell electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold.

[0056] Among them, the second current threshold is greater than the first current threshold, and the second voltage threshold is greater than the first voltage threshold.

[0057] It should be noted that, as described above, the first protection module 10 and the second protection module 20 are used to implement overvoltage protection and overcurrent protection for the set circuit. Currently, there are various mature overvoltage and overcurrent protection modules available. Appropriate implementation schemes can be selected as the first protection module 10 and the second protection module 20 according to actual needs, and this embodiment does not impose any limitations on this. In an optional embodiment, both the first protection module 10 and the second protection module 20 can be implemented using a control module and a switch module; the switch module is set in the protected circuit, and the control module is used to detect the voltage and current of the protected circuit; when the voltage exceeds the protection point, the control module cuts off the circuit, thereby achieving the protection function.

[0058] However, it should be noted that the first protection module 10 and the second protection module 20 are located in different positions, and therefore the objects they protect are also different. The first protection module 10 is located in the battery main circuit. Therefore, the battery electrical signal is also the electrical signal of the entire battery, and the first protection module 10 protects the entire battery (or can be considered as protecting the battery as a whole). Figure 1 The battery cell module shown provides overvoltage and overcurrent protection. Multiple second protection modules 20 are configured, one-to-one, in the single-cell circuit of each cell (i.e., the parallel branch where each cell is connected in parallel). Therefore, the cell electrical signal is the electrical signal of a single cell, and the second protection module 20 provides overvoltage and overcurrent protection for each individual cell. It should be noted that this embodiment only requires the circuit in which the first protection module 10 and the second protection module 20 are located, but their specific placement within the circuit is not limited. One possible placement is as follows: Figure 1 As shown. Furthermore, this embodiment does not limit the specific number of the second protection module 20; it should be consistent with the number of cells connected in parallel in the battery. For example... Figure 1 As shown, the battery cell module includes two cells connected in parallel, so the number of the second protection module 20 is also correspondingly two.

[0059] It should also be noted that because the cells are connected in parallel, the voltage across each cell is equal, which is also equal to the voltage across the battery. Therefore, the overvoltage protection provided by each of the second protection modules 20 for different cells is always synchronized (i.e., under normal operating conditions, if one second protection module 20 triggers overvoltage protection, it means that the other second protection modules 20 will also trigger overvoltage protection). Furthermore, since the voltage across the cell is the same as the voltage across the battery, the second protection module 20 can also detect the voltage across the battery, without needing to specifically detect the voltage across the corresponding cell. In other words, when implementing overvoltage protection for a single cell, each second protection module 20 only needs to detect the battery's charge / discharge voltage.

[0060] Furthermore, in this embodiment, the protection points of the first protection module 10 (including voltage protection points and current protection points, i.e., the aforementioned first voltage threshold and first current threshold) are smaller than the protection points of the second protection module 20 (i.e., the second voltage threshold and the second current threshold). That is, in practical applications, the battery protection circuit provided in this embodiment involves the first protection module 10 triggering the protection action first, followed by the second protection module 20. The possible scenarios for the second protection module 20 triggering the protection action are as follows:

[0061] 1. First protection module 10 has failed;

[0062] At this point, even if the first protection module 10 has been triggered, it still cannot effectively protect the battery, so the battery will still experience overvoltage or overcurrent. As the output voltage and current of each cell continue to increase, the second protection module 20 will eventually be triggered.

[0063] 2. The first protection module 10 is normal, but some battery cells have an uneven charging and discharging problem;

[0064] At this point, the first protection module 10 only cuts off the path between the battery and the external device (connector); the path between the cells remains. Due to the imbalance between the cells, there is mutual charging and discharging between them. These cells still have charging and discharging currents and voltage imbalances. When this imbalance reaches a certain level, it will trigger the protection action of the second protection module 20.

[0065] The second protection scenario mentioned above is more common in batteries using "large-capacity cells." That is, in a multi-cell parallel battery, the capacity of each individual cell is sufficiently large, and the imbalance in charging and discharging current and voltage between cells becomes increasingly significant, requiring protection for each individual cell. For example, a silicon-based anode technology exists that can significantly improve the energy density of a battery or cell, increasing its capacity without changing its volume. When silicon-carbon anode technology is applied to multi-cell parallel batteries, each cell in the parallel battery is equivalent to the aforementioned "large-capacity cell." Therefore, the battery protection circuit provided in this application has a more significant advantage in protecting the circuit safety in multi-cell parallel battery scenarios using silicon-carbon anode technology.

[0066] In summary, the second protection module 20 in this circuit not only provides accurate and reliable overvoltage and overcurrent protection for each cell in a multi-cell parallel battery, but also provides redundant protection for the first protection module 10, and protects against inter-cell charging and discharging issues caused by uneven charging and discharging. Therefore, the battery protection circuit provided by this invention offers more reliable and safer circuit protection compared to traditional battery protection schemes, further ensuring the normal use of the battery. Especially for large-capacity batteries such as parallel silicon anode batteries, this circuit can better address safety hazards during the use of large-capacity batteries, making the application of batteries and electrical equipment safer.

[0067] On the other hand, as can be seen from the above description of the embodiments, there are already many mature overvoltage protection schemes and overcurrent protection schemes. The above embodiments do not impose any limitations on the specific structure of the first protection module 10 and the second protection module 20. However, to better illustrate this circuit, this utility model also provides several optional embodiments for the first protection module 10 and the second protection module 20 respectively.

[0068] First, regarding the second protection module 20, which is a key improvement in this circuit, this embodiment provides an optional implementation scheme:

[0069] like Figure 2 As shown, the second protection module 20 includes a first control module 21-A and a first three-terminal fuse 22-A; wherein, each second protection module 20 shares the same first control module 21-A; the output terminal of the first control module 21-A is connected to the first terminal of each first three-terminal fuse 22-A; the second and third terminals of each first three-terminal fuse 22-A are connected in series in the corresponding single-cell circuit; the input terminal of the first control module 21-A is connected to the battery electrical signal, and when the voltage value of the battery electrical signal exceeds the second voltage threshold, the first control module 21-A outputs a signal for blowing the first three-terminal fuse 22-A.

[0070] It should be noted that a three-terminal fuse is a device that will melt when the current flowing through any two of its three terminals exceeds the fusing current. That is, in this embodiment, the second and third terminals of the first three-terminal fuse 22-A provide overcurrent protection for a single-cell circuit. The melting current interruption of the first three-terminal fuse 22-A is the aforementioned second current threshold. In this embodiment, the first and second / third terminals of the first three-terminal fuse 22-A provide overvoltage protection that is permanently activated upon triggering. As can be seen from the above embodiment, the charging and discharging voltages of the parallel cells are equal to the battery's charging and discharging voltage. Therefore, the overvoltage protection function of each cell can be uniformly implemented by a single control device (i.e., the aforementioned first control module 21-A) by detecting the battery's charging and discharging voltage. When overvoltage protection needs to be triggered, the first control module 21-A can inject a current sufficient to melt all the first three-terminal fuses 22-A (because the overvoltage protection of each cell is synchronized).

[0071] As can be seen from the above description of the embodiments, the protection point of the second protection module 20 is higher than that of the first protection module 10. That is, the second protection module 20 is an emergency backup measure when the first protection module 10 fails to perform its protection function. Therefore, when the second protection module 20 is triggered, it can generally be considered that the battery is currently seriously faulty and requires maintenance. That is, there is an application scenario where the second protection module 20 is expected to be permanently effective after being triggered, so as to avoid the situation where a battery with serious safety hazards after the second protection module 20 is effective can still be used after the protection function is reset. Therefore, the specific implementation scheme of the second protection module 20 provided in this embodiment, in addition to achieving the function of the second protection module 20 in the above embodiments, can also achieve the problem of the second protection module 20 being permanently effective after a single trigger (whether it is current protection or voltage protection), further improving the safety of battery applications.

[0072] Furthermore, regarding how the first control module 21-A outputs a signal that causes the first three-terminal fuse 22-A to blow, this embodiment also provides an optional implementation scheme, such as... Figure 3 As shown:

[0073] The second terminal of each first three-terminal fuse 22-A (F1, F2) is connected to the output terminal of the corresponding battery cell, and the third terminal of each first three-terminal fuse 22-A is connected to the common point of each single-cell circuit; the first control module 21-A includes: a first voltage comparison module 211-A (U2, R2, C3, C4) and a first switch module 212-A (Q2); the first terminal of the first switch module 212-A is connected to the first terminal of the first three-terminal fuse 22-A, the second terminal of the first switch module 212-A is grounded, and the controlled terminal of the first switch module 212-A is connected to the output terminal of the first voltage comparison module 211-A; the input terminal of the first voltage comparison module 211-A is connected to the battery electrical signal, and when the voltage value of the battery electrical signal is greater than the second voltage threshold, it outputs a signal to control the first switch module 212-A to be turned on.

[0074] Specifically, the first voltage comparison module 211-A can be implemented using an integrated circuit (IC) chip, which has voltage acquisition and voltage comparison functions. For example... Figure 3 As shown, the IC chip can also be used with other electrical components to jointly form the first voltage comparison module 211-A of this embodiment. For example, the current-limiting resistor R2 to prevent burnout of the IC chip U2, and the filter capacitors C3 and C4 to maintain a stable IC power supply voltage, etc., are not limited in this embodiment. For the first switching module 212-A, the following can be used: Figure 3 The switch Q2 shown can be implemented using other electronic switches, and this embodiment is not limited to this.

[0075] Depend on Figure 3 As can be seen, when the first switch module 212-A is disconnected, only the first and second terminals of the first three-terminal fuse 22-A are connected to the circuit. At this time, the first three-terminal fuse 22-A is equivalent to a two-terminal fuse connected in series in a single-cell circuit, realizing the overcurrent protection function for the single-cell circuit. When the first voltage comparison module 211-A detects that the battery charging / discharging voltage is greater than the second voltage threshold, it controls the first switch module 212-A to conduct. At this time, the first and third terminals of the first three-terminal fuse 22-A are equivalent to being connected to both ends of the cell, and the cell will output a current sufficient to fuse the first three-terminal fuse 22-A, thereby achieving overvoltage protection.

[0076] Therefore, it can be seen that the specific structure of the first control module 21-A provided in this embodiment can realize the fuse control of the first three-terminal fuse 22-A, and the circuit structure is simple, reliable and easy to implement.

[0077] On the other hand, besides the optional solution provided in the above embodiment, this embodiment also provides another optional implementation scheme, which can also achieve the purpose of the second protection module 20 becoming permanently effective after a single triggering. Specifically, as follows... Figure 4As shown, this circuit also includes: a second three-terminal fuse 30-B.

[0078] The first terminal of the second three-terminal fuse 30-B is connected to each of the second protection modules 20; the second and third terminals of the second three-terminal fuse 30-B are connected in series in the main circuit of the battery; wherein, when the current value of the cell electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold, the second protection module 20 outputs a signal to blow the second three-terminal fuse 30-B.

[0079] The main difference between this embodiment and the previous embodiment is that the three-terminal fuse is placed in the main battery circuit. Based on this arrangement, only one three-terminal fuse is needed to permanently disconnect the battery from external charging and discharging after the second protection module 20 is triggered, resulting in lower costs. Furthermore, the second protection module 20 only needs to perform overcurrent protection; overvoltage protection can be achieved by controlling the second three-terminal fuse 30-B.

[0080] However, compared to the solution provided in the previous embodiment, this solution has the drawback that it can only permanently disconnect the battery's charging and discharging circuit, and cannot permanently disconnect the charging and discharging between battery cells. Based on this, the present invention also provides a further implementation scheme, such as... Figure 5 As shown:

[0081] The voltage values ​​of the battery electrical signal and the electrical signals of each cell are equal; the second protection module 20 includes: a second voltage comparison module 21-B, a second switch module 22-B and a fuse at both ends 23-B.

[0082] Among them, the two-terminal fuse 23-B is connected in series in the corresponding single-cell circuit; each second protection module 20 shares the same second voltage comparison module 21-B; the input terminal of the second voltage comparison module 21-B is connected to the battery electrical signal, and the output terminal of the second voltage comparison module 21-B is connected to the controlled terminal of each second switch module 22-B; the first terminal of the second switch module 22-B is connected to the first terminal of the second three-terminal fuse 30-B, and the second terminal of the second switch module 22-B is grounded; when the voltage value of the battery electrical signal is greater than the second threshold, the second voltage comparison module 21-B outputs a signal to control the second switch module 22-B to conduct.

[0083] As can be seen from the above embodiments, after the presence of the second three-terminal fuse 30-B, the overvoltage protection can be permanently activated. At this time, the second protection module 20 only needs to focus on the permanent activation of overcurrent protection, and this embodiment achieves this purpose through a two-terminal fuse. As described above, the fuse can realize the overcurrent protection function, and the fusing current is the overcurrent protection point (i.e., the second current threshold). Moreover, after the fuse blows, unless the fuse is replaced, the circuit is permanently disconnected, thus achieving the purpose of permanent overcurrent protection. Based on this, the implementation scheme of the second protection module 20 provided in this embodiment has the same function as the implementation scheme provided in the above embodiments, the difference being that one uses two three-terminal fuses (assuming the number of battery cells is 2), and the other uses two two-terminal fuses 23-B and one three-terminal fuse. However, the scheme of this embodiment can also achieve further overcurrent protection redundancy by setting an additional fuse in the battery main circuit. Therefore, the two second protection modules 20 provided above each have their advantages, and the appropriate implementation scheme can be selected based on actual needs. This embodiment does not impose any restrictions on this.

[0084] On the other hand, regarding the first protection module 10, as can be seen from the above embodiments, both the first protection module 10 and the second protection module 20 can be implemented using a control module and a switch module. Since the first protection module 10 in this circuit implements basic overvoltage and overcurrent protection for the battery, it does not need to be overly complex and can be implemented using the above-described scheme. Specifically, this embodiment provides an optional implementation scheme for the first protection module 10. For example... Figure 3 As shown, the first protection module 10 mentioned above includes: a second control module 11 (U1, R1, R3, R9, RS1, C1, C2, C9) and a third switch module 12 (Q1, C5, C6).

[0085] The first and second terminals of the third switch module 12 are connected in series in the main battery circuit. The controlled terminal of the third switch module 12 is connected to the output terminal of the second control module 11. The input terminal of the second control module 11 is connected to the battery electrical signal. When the current value of the battery electrical signal is greater than the first current threshold or the voltage value is greater than the first voltage threshold, the second control module 11 outputs a signal to control the third switch module 12 to turn off.

[0086] It should be noted that, Figure 3The second control module 11 shown primarily utilizes the IC chip U1 and the sensing resistor RS1. The IC chip U1 performs voltage comparison, and the sensing resistor RS1 converts the current flowing through the battery's main circuit into a voltage signal for the IC chip U1 to recognize. That is, the IC chip U1, which only has voltage comparison functionality, can detect the battery's charging and discharging current through the sensing resistor RS1. When the IC chip U1 detects that the charging or discharging voltage or current reaches the protection point, it outputs signals through the CO and DO terminals to control the shutdown of the third switch module 12, executing a protection action. Regarding the other electrical components in the second control module 11, resistors R1 and R3 limit current to prevent large currents from burning out the IC pins; capacitors C1 and C2 filter to maintain the stability of the IC power supply voltage; and capacitor C9 prevents interference from differential-mode signals on the precision resistor detection line.

[0087] Similarly, for Figure 3 The third switch module 12 shown has a main switching device, the switch chip Q1, which is controlled by the IC chip U1. C5 and C6 are used for filtering, freewheeling, and preventing damage to the MOSFETs (field-effect transistors) in the switch chip during switching.

[0088] As described above, this embodiment provides a simple and reliable implementation of the first protection module 10. Based on this structure, the first protection module 10 can achieve overvoltage and overcurrent protection for the entire battery, ensuring the safe operation of the battery.

[0089] On the other hand, it should be noted that batteries using silicon-based anode technology can still have a significant capacity even at low voltages. If a conventional protection scheme is used, and the over-discharge voltage protection point is set too high, the battery will quickly reach the protection point during high-current discharge, at which point the capacity of the silicon-carbon anode battery cannot be fully utilized. Conversely, if the over-discharge voltage protection point is set too low, the silicon-carbon anode battery may experience severe over-discharge when trickle-discharged to a low voltage, which could damage the crystal structure of the electrode and create a safety hazard.

[0090] To address the aforementioned problems with batteries employing silicon-based anode technology—specifically, batteries employing silicon-based anode technology where the anode active material layer in the cell comprises silicon-carbon or silicon-oxygen materials—this embodiment also provides a further implementation scheme for the first protection module 10:

[0091] Both the first current threshold and the first voltage threshold include a first sub-value and a second sub-value; and the first sub-value is always less than the corresponding second sub-value.

[0092] like Figure 3As shown, this circuit also includes a discharge state detection module. The input terminal of the discharge state detection module is connected to the battery electrical signal, and the output terminal of the discharge state detection module is connected to the controlled terminal (CTRL) of the first protection module 10. When the discharge state detection module determines that the battery is in a high-current discharge state based on the battery electrical signal, it outputs a first protection signal. When the discharge state detection module determines that the battery is in a trickle discharge state based on the battery electrical signal, it outputs a second protection signal. When the first protection module 10 receives the first protection signal at its controlled terminal, a first sub-value of the first current threshold and the first voltage threshold becomes effective. When the first protection module 10 receives the second protection signal at its controlled terminal, a second sub-value of the first current threshold and the first voltage threshold becomes effective.

[0093] It should be noted that the first protection module 10 in this embodiment can be an IC chip with built-in configurations of different protection points, selecting different protection point configurations to take effect based on different signals received by the controlled terminal (CTRL). In another optional implementation, the first protection module 10 can also be a comparator connected to different reference signal sources (corresponding to protection points). Different reference signal sources are connected to the input terminal of the comparator for receiving reference signals through a selector. Which channel the selector selects is controlled by the discharge state detection module, thereby realizing protection point adjustment based purely on hardware structure. However, this solution has a higher implementation cost than the solution using IC chips. In practical applications, the choice can be made based on needs, and this embodiment does not impose any restrictions on this.

[0094] In addition, this utility model also provides several optional embodiments for the specific implementation of the discharge state detection module. Among them, this embodiment provides an optional implementation scheme for the discharge state detection module: the discharge state detection module is an electrical device powered by a battery.

[0095] like Figure 3 As shown, the CTRL pin of IC chip U1 is connected to the CTRL pin of the connector, which is used to realize the electrical and communication connection between the battery and the external power device. The external power device, as a device that directly uses the battery as its power source, can monitor and determine the battery output through its built-in power management system and other modules. High current output and trickle discharge are several typical abnormal battery output states, and there are currently many mature detection and judgment schemes for these, which will not be elaborated upon in this embodiment. The advantage of using the power device as the aforementioned discharge state detection module is that it eliminates the need for an additional discharge state detection module, saving costs and being easy to implement.

[0096] However, not all electrical devices have the aforementioned battery status detection function. In this case, this embodiment also provides another optional implementation:

[0097] The discharge state detection module is a current comparison module; the current comparison module outputs a first protection signal when the current value of the battery electrical signal is greater than the third current threshold; the current comparison module outputs a second protection signal when the current value of the battery electrical signal is less than the fourth current threshold.

[0098] It's easy to understand that the most significant difference between high-current output, trickle-current output, and normal output states lies in the magnitude of the battery's output current. Therefore, the current output state of the battery can be quickly determined by comparing it with a pre-set current threshold using a current comparison module.

[0099] This embodiment is an alternative solution when the electrical equipment does not support battery output status detection. It can further improve the applicable scope of this circuit and enable more parallel silicon negative electrode batteries to use this circuit to achieve dynamic adjustment of protection points.

[0100] Finally, this embodiment... Figure 3 Other electrical components not mentioned herein are briefly described:

[0101] Figure 3 The capacitors C7 and C8 in the circuit are used for filtering, aiming to make the battery output voltage more stable. The resistor R4 is used for identification of the Identity Document (ID), which is a typical application of the battery when the device is a mobile terminal such as a mobile phone, and will not be described in detail in this embodiment. The thermistor TH1 is used to detect temperature, which is also a typical application of the device to monitor the battery's operating status. The resistors R5, R6, R7, and R8 are used for current limiting, which protects the circuit. Q3 is used as a switch. When the device is a mobile terminal such as a mobile phone, the device may need to perform more precise detection of the battery output. In this case, the battery output is detected through another circuit (the connection point is closer to the battery cell) in addition to the positive and negative terminals of the battery output. The capacitors C10 and C11 are also used for filtering to prevent the switch Q3 from being damaged during the switching process. J1 is a connector.

[0102] In the above embodiments, a battery protection circuit has been described in detail. This utility model also provides an embodiment corresponding to an electrical device.

[0103] This embodiment provides an electrical device, including the battery protection circuit provided in any of the above embodiments, and a silicon negative electrode parallel battery.

[0104] Since the embodiments of the electrical equipment section and the battery protection circuit section correspond to each other, please refer to the description of the embodiments of the battery protection circuit section for the embodiments of the electrical equipment section, which will not be repeated here. However, since this electrical equipment includes the battery protection circuit provided in any of the above embodiments, the safety hazards caused by the battery during the application of this electrical equipment are greatly reduced, the safety of use is higher, and it can better protect the personal and property safety of users.

[0105] The battery protection circuit and electrical device provided by this utility model have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

[0106] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A battery protection circuit, characterized in that, Applied to a battery comprising at least two cells connected in parallel; the circuit includes: a first protection module and a second protection module; The first protection module is located in the main circuit of the battery; wherein, the main circuit of the battery is the trunk circuit in the parallel circuit composed of multiple battery cells in the battery; The first protection module receives the battery electrical signal output by the battery, and disconnects the main circuit of the battery when the current value of the battery electrical signal is greater than a first current threshold or the voltage value is greater than a first voltage threshold. The second protection module comprises multiple modules, each disposed in a single cell circuit of each of the battery cells; wherein, the single cell circuit is the branch corresponding to each battery cell in the parallel circuit composed of multiple battery cells in the battery; The second protection module receives the battery cell electrical signal output by each of the battery cells, and cuts off the corresponding single battery cell circuit when the current value of the battery cell electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold. Wherein, the second current threshold is greater than the first current threshold, and the second voltage threshold is greater than the first voltage threshold.

2. The battery protection circuit according to claim 1, characterized in that, The second protection module includes: a first control module and a first three-terminal fuse; Each of the second protection modules shares the same first control module; the output terminal of the first control module is connected to the third terminal of each of the first three-terminal fuses; the first and second terminals of each of the first three-terminal fuses are connected in series in the corresponding single-cell circuit. The input terminal of the first control module is connected to the battery electrical signal. When the voltage value of the battery electrical signal exceeds the second voltage threshold, the first control module outputs a signal to blow the first three-terminal fuse.

3. The battery protection circuit according to claim 2, characterized in that, The first terminal of each of the first three-terminal fuses is connected to the output terminal of the corresponding battery cell, and the second terminal of each of the first three-terminal fuses is connected to the parallel connection point of each battery cell; wherein, the parallel connection point is the common connection point between the branches corresponding to each battery cell in the parallel circuit composed of multiple battery cells in the battery. The first control module includes: a first voltage comparison module and a first switch module; The first terminal of the first switch module is connected to the third terminal of the first three-terminal fuse, the second terminal of the first switch module is grounded, and the controlled terminal of the first switch module is connected to the output terminal of the first voltage comparison module. The input terminal of the first voltage comparison module is connected to the battery electrical signal, and when the voltage value of the battery electrical signal is greater than the second voltage threshold, it outputs a signal to control the first switch module to turn on.

4. The battery protection circuit according to claim 1, characterized in that, Also includes: Second and third terminal fuses; The first terminal of the second three-terminal fuse is connected to each of the second protection modules; the second and third terminals of the second three-terminal fuse are connected in series in the main circuit of the battery. The second protection module outputs a signal to blow the second three-terminal fuse when the current value of the battery cell's electrical signal is greater than the second current threshold or the voltage value is greater than the second voltage threshold.

5. The battery protection circuit according to claim 4, characterized in that, The voltage value of the battery electrical signal is equal to the voltage value of each of the battery cell electrical signals; the second protection module includes: a second voltage comparison module, a second switch module, and a fuse at both ends; The two-terminal fuses are connected in series in the corresponding single-cell circuit; Each of the second protection modules shares the same second voltage comparison module; the input terminal of the second voltage comparison module is connected to the battery electrical signal, and the output terminal of the second voltage comparison module is connected to the controlled terminal of each of the second switch modules; the first terminal of the second switch module is connected to the first terminal of the second three-terminal fuse, and the second terminal of the second switch module is grounded; When the voltage value of the battery electrical signal is greater than the second threshold, the second voltage comparison module outputs a signal to control the second switch module to turn on.

6. The battery protection circuit according to claim 1, characterized in that, The battery cell is a battery cell using silicon-based negative electrode technology. Both the first current threshold and the first voltage threshold include a first sub-value and a second sub-value; and the first sub-value is less than the corresponding second sub-value. It also includes: a discharge status detection module; The input terminal of the discharge state detection module is connected to the battery electrical signal, and the output terminal of the discharge state detection module is connected to the controlled terminal of the first protection module. Specifically, when the discharge state detection module determines that the battery is in a high-current discharge state based on the battery electrical signal, it outputs a first protection signal; when the discharge state detection module determines that the battery is in a trickle discharge state based on the battery electrical signal, it outputs a second protection signal. When the first protection module receives the first protection signal at the controlled end, the first sub-value of the first current threshold and the first voltage threshold takes effect; when the first protection module receives the second protection signal at the controlled end, the second sub-value of the first current threshold and the first voltage threshold takes effect.

7. The battery protection circuit according to claim 6, characterized in that, The discharge state detection module is an electrical device powered by the battery.

8. The battery protection circuit according to claim 6, characterized in that, The discharge state detection module is a current comparison module; The current comparison module outputs the first protection signal when the current value of the battery electrical signal is greater than the third current threshold. The current comparison module outputs the second protection signal when the current value of the battery electrical signal is less than the fourth current threshold.

9. The battery protection circuit according to any one of claims 1 to 8, characterized in that, The first protection module includes: a second control module and a third switch module; The first and second ends of the third switch module are connected in series in the main battery circuit, and the controlled end of the third switch module is connected to the output end of the second control module. The input terminal of the second control module is connected to the battery electrical signal; and when the current value of the battery electrical signal is greater than the first current threshold or the voltage value is greater than the first voltage threshold, the second control module outputs a signal to control the third switch module to turn off.

10. An electrical appliance, characterized in that, Includes the battery protection circuit as described in any one of claims 1 to 9, and a silicon negative electrode parallel battery.

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