Battery internal resistance detection circuit and electronic device

Abstract

The application provides a battery internal resistance detection circuit and an electronic device, the battery internal resistance detection circuit is applied to a mobile power supply and comprises a battery, a load resistance, a detection control module, a voltage acquisition module and a main control module; the main control module is connected with the voltage acquisition module, the detection control module and the load resistance respectively; the voltage acquisition module is used for acquiring an open circuit voltage of the battery and outputting the open circuit voltage to the main control module; when the detection control module is in an open state controlled by the main control module, the detection control module, the load resistance and the battery form a closed loop, the battery discharges to the load resistance, and the main control module is used for acquiring a current value of the load resistance and determining an internal resistance of the battery according to the open circuit voltage and the current value.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery internal resistance detection circuit and electronic device. Background Technology

[0002] Battery internal resistance is a crucial parameter reflecting battery quality, and changes in it are closely related to the battery's aging process. With use, electrode materials may degrade, and electrolyte may be consumed, both leading to an increase in internal resistance. Abnormal changes in battery internal resistance are often early signs of deteriorating battery health; therefore, testing the internal resistance of batteries in various devices, such as power banks, is essential. Utility Model Content

[0003] To address the existing technical problems, this application provides a battery internal resistance detection circuit and electronic device that can effectively detect internal resistance.

[0004] In a first aspect, embodiments of this application provide a battery internal resistance detection circuit applied to a power bank, comprising: a battery, a load resistor, a detection control module, a voltage acquisition module, and a main control module; the main control module is connected to the voltage acquisition module, the detection control module, and the load resistor respectively; the voltage acquisition module is used to acquire the open-circuit voltage of the battery and output the open-circuit voltage to the main control module; when the main control module controls the detection control module to be in an on state, the detection control module, the load resistor, and the battery form a closed loop, the battery discharges to the load resistor, and the main control module is used to acquire the current value of the load resistor and determine the internal resistance of the battery based on the open-circuit voltage and the current value.

[0005] In a second aspect, an electronic device is provided, including the battery internal resistance detection circuit described in any embodiment of this application.

[0006] In the battery internal resistance detection circuit provided in the above embodiment, the main control module is connected to the voltage acquisition module, the detection control module, and the load resistor respectively. The voltage acquisition module is used to acquire the open-circuit voltage of the battery and output the open-circuit voltage to the main control module. When the main control module controls the detection control module to be in the on state, the detection control module, the load resistor, and the battery form a closed loop. The battery discharges to the load resistor. The main control module is used to acquire the current value of the load resistor and determine the internal resistance of the battery based on the open-circuit voltage and the current value. Thus, by connecting the load resistor and the detection control module at both ends of the battery, and activating the detection control module through the main control module when internal resistance needs to be detected, a conducting loop is formed for the battery to discharge into this loop. The internal resistance of the battery can then be determined based on the current and open-circuit voltage generated during discharge. This facilitates quick and efficient internal resistance detection of batteries in products or various working circuits, and helps to detect battery abnormalities in a timely manner.

[0007] The electronic device provided in the above embodiments belongs to the same concept as the corresponding battery internal resistance detection circuit embodiments, and thus has the same technical effect as the corresponding battery internal resistance detection circuit embodiments, which will not be repeated here. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the battery internal resistance detection circuit in one embodiment of this application;

[0009] Figure 2 This is a schematic diagram of the battery internal resistance detection circuit in another embodiment of this application;

[0010] Figure 3 This is a schematic diagram of the battery internal resistance detection circuit in another embodiment of this application;

[0011] Figure 4 This is a schematic diagram of the battery internal resistance detection circuit in another embodiment of this application;

[0012] Figure 5 This is a functional schematic diagram of the battery internal resistance detection circuit in one embodiment of this application;

[0013] Figure 6 This is a schematic diagram of the battery internal resistance detection circuit in another embodiment of this application;

[0014] Figure 7 This is a partial structural schematic diagram of a battery internal resistance detection circuit in one embodiment of this application;

[0015] Figure 8 This is a schematic diagram of another part of the battery internal resistance detection circuit in one embodiment of this application.

[0016] Explanation of reference numerals in the attached figures

[0017] 1. Battery; 2. Load resistor; 3. Detection and control module; 31. First transistor; 4. Main control module; 41. Pulse control unit; 42. Temperature compensation unit; 5. Voltage acquisition module; 6. Detection resistor; 7. Bidirectional transistor; 71. Second transistor; 72. Third transistor; 8. Temperature detection module; 91. Cut-off module; 92. Latch module; 93. Timing module. Detailed Implementation

[0018] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the following description, the phrase "some embodiments" refers to a subset of all possible embodiments. It should be noted that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0021] In the following description, the terms "first," "second," and "third" are used merely to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that "first," "second," and "third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0022] like Figure 1 As shown, one embodiment of this application provides a battery internal resistance detection circuit for use in a power bank, including: a battery 1, a load resistor 2, a detection control module 3, a main control module 4, and a voltage acquisition module 5;

[0023] The main control module 4 is connected to the voltage acquisition module 5, the detection control module 3 and the load resistor 2 respectively;

[0024] The voltage acquisition module 5 is used to acquire the open-circuit voltage of the battery 1 and output the open-circuit voltage to the main control module 4;

[0025] When the main control module 4 controls the detection control module 3 to be in the open state, the detection control module 3, the load resistor 2 and the battery 1 form a closed loop. The battery 1 discharges to the load resistor 2. The main control module 4 is used to obtain the current value of the load resistor 2 and determine the internal resistance of the battery 1 based on the open circuit voltage and current value.

[0026] Thus, by connecting the load resistor 2 and the detection control module 3 to both ends of the battery 1, the detection control module 3 is turned on by the main control module 4 when it is necessary to detect the internal resistance, thereby forming a conducting circuit for the battery 1 to discharge into the circuit. The internal resistance of the battery 1 can be determined based on the current and open circuit voltage formed by the discharge, which facilitates quick and efficient detection of the internal resistance of the battery 1 in the product or various working circuits, and helps to detect abnormalities of the battery 1 in a timely manner.

[0027] In this embodiment, the battery internal resistance detection circuit can be set in or applied to electronic devices such as power banks. For example, battery 1 can be battery 1 in electronic devices such as power banks. The two poles of battery 1 are also connected to a working circuit. The working circuit includes the output path and input path of battery 1 for charging and discharging battery 1 for charging and discharging operation of power banks.

[0028] In this circuit, when an electronic device such as a power bank charges a load, the load can be connected to the circuit so that battery 1 can charge the load through the output path.

[0029] When it is necessary to charge battery 1, the mains power supply can be connected to the working circuit so that the mains power supply can charge battery 1 through the input path.

[0030] In one embodiment, the load resistor 2 can be a fixed resistor with a fixed resistance value, or it can be a variable resistor, for example, whose resistance value can be adjusted according to the operating state of the battery 1. For example, when the battery 1 operates continuously for a period of time exceeding a preset threshold, the resistance value of the load resistor 2 can be reduced, thereby increasing the current value through the load resistor 2 and improving the sensitivity of internal resistance detection.

[0031] Battery 1 has a first terminal and a second terminal. In one embodiment, the first terminal can be the negative terminal of battery 1, the second terminal can be the positive terminal of battery 1, and the load resistor 2 and the detection and control module 3 can be connected in series between the first and second terminals. The operating circuit of battery 1 can be connected in parallel with the load resistor 2 and the detection and control module 3 between the first and second terminals. For example, the load resistor 2 is connected to the positive terminal of battery 1 and the detection and control module 3, and the detection and control module 3 is connected to the load resistor 2 and the negative terminal of battery 1.

[0032] In one embodiment, the detection control module 3 can be used to control the on and off states of the battery internal resistance detection circuit. When the detection control module 3 is in the on state, the battery internal resistance detection circuit is on; when the detection control module 3 is in the off state, the battery internal resistance detection circuit is off. For example, the detection control module 3 may include one or more transistors connected to the main control module 4.

[0033] In one embodiment, the voltage acquisition module 5 is used to acquire the open-circuit voltage of battery 1. Open-circuit voltage refers to the voltage between the positive and negative terminals of battery 1 when there is no external load (i.e., no electrical appliances are connected and all circuits are disconnected).

[0034] The open-circuit voltage of battery 1 can be measured before the detection and control module 3 is turned on.

[0035] Specifically, the open-circuit voltage of battery 1 can be pre-programmed into the voltage acquisition module 5 and / or the main control module 4. When the battery internal resistance detection circuit starts and detects the internal resistance of battery 1, the voltage acquisition module 5 can acquire the open-circuit voltage of battery 1 pre-programmed into the voltage acquisition module 5 and / or the main control module 4. This improves the efficiency of acquiring the open-circuit voltage and enhances the internal resistance detection efficiency of the battery internal resistance detection circuit.

[0036] Specifically, the open-circuit voltage of battery 1 can be detected again each time the battery internal resistance detection circuit is activated to detect the internal resistance of battery 1. In other words, the open-circuit voltage of battery 1 is detected every time the internal resistance of battery 1 is detected. This improves the accuracy of the battery internal resistance detection circuit in detecting the internal resistance of battery 1.

[0037] Furthermore, each time the internal resistance of battery 1 is detected, the voltage acquisition module 5 can detect the open-circuit voltage of battery 1. The voltage acquisition module 5 is connected to both ends of battery 1, and measures the open-circuit voltage of battery 1 at the instant before the detection control module 3 controls the internal resistance detection circuit of battery 1 to conduct.

[0038] In one embodiment, the main control module 4 can be a microcontroller (MCU) or similar device. The main control module 4 can activate the detection and control module 3 by sending a short pulse.

[0039] In one embodiment, the detection and control module 3, the voltage acquisition module 5, and the main control module 4 can all be parts of a microcontroller. Specifically, the microcontroller can be a chip of model STM32F103C8T6, STM32G030F6P6, or CS8M321.

[0040] The pulse injection time of the short pulse can range from 50μs to 5000μs. Examples include 50μs, 75μs, 100μs, 150μs, 200μs, 500μs, 700μs, 800μs, 1000μs, 1500μs, 1800μs, 2000μs, 2500μs, 3000μs, 4000μs, and 5000μs, etc., without limitation. This allows the battery internal resistance detection circuit to stably determine the internal resistance of battery 1 while avoiding excessive losses in the battery internal resistance detection circuit.

[0041] When the main control module 4 sends a short pulse to the detection control module 3, the detection control module 3 is activated. When the main control module 4 stops sending short pulses, the detection control module 3 is deactivated.

[0042] It is understandable that, due to the capacitance effect of battery 1, when the pulse injection time of the short pulse is less than 50μs, the voltage fluctuation of battery 1 will not be stable due to the short pulse injection time. As a result, the overall voltage in the battery internal resistance detection circuit will not be stable, which in turn will lead to inaccurate detection of the internal resistance of battery 1 by the battery internal resistance detection circuit.

[0043] It is understandable that when the pulse injection time of the short pulse is greater than 5000μs, it will cause the battery internal resistance detection circuit to generate a large loss in the process of obtaining the internal resistance of battery 1, resulting in energy waste.

[0044] In some embodiments, such as Figure 8 As shown, the main control module 4 includes a pulse control unit 41, and the detection control module 3 includes a first transistor 31. The pulse control unit 41 is connected to the first transistor 31, and the pulse control unit 41 is used to send pulse signals to the first transistor 31 to turn on the first transistor 31 during a first time period. Here, the duration of the first time period ranges from 50μs to 5000μs.

[0045] The duration of the first time period is the same as the pulse injection time of the short pulse. In other words, the pulse injection time of the first transistor 31 is the turn-on time of the first transistor 31, which is also the conduction time of the battery internal resistance detection circuit.

[0046] Thus, the pulse injection time of the short pulse can be controlled by the pulse control unit 41 in the main control module 4, thereby enabling precise control of the first time period.

[0047] In one embodiment, the main control module 4 can control the detection control module 3 to be in the on state according to a predetermined period. For example, it can send short pulses to the detection control module 3 to turn it on according to a predetermined period, and / or the main control module 4 can control the detection control module 3 to be in the on state when the battery 1 starts charging and discharging. In this way, by periodically detecting the internal resistance of the battery 1, the internal resistance of the battery 1 can be continuously monitored.

[0048] For example, the predetermined period can be from 6 hours to 1440 hours. For example, it can be 6 hours, 10 hours, 12 hours, 15 hours, 20 hours, 24 hours, 28 hours, 30 hours, 48 ​​hours, 80 hours, 100 hours, 120 hours, 150 hours, 168 hours, 200 hours, 240 hours, 336 hours, 360 hours, 480 hours, 504 hours, 1000 hours, 1440 hours, etc., and is not limited here.

[0049] For example, such as Figure 7 As shown, the battery internal resistance detection circuit may also include a timing module 93, which is connected to the main control module 4 or located inside the main control module 4, and is used to control the main control module 4 to turn on the detection control module 3 based on a predetermined cycle.

[0050] The timing module 93 can periodically activate the detection control module 3 to start the battery internal resistance detection circuit to detect the internal resistance of battery 1. In this way, by periodically detecting the internal resistance of battery 1, the internal resistance of battery 1 can be continuously monitored.

[0051] In one embodiment, the main control module 4 can also record data such as the current working state, charging and discharging current, and voltage of the battery 1.

[0052] Specifically, when the battery internal resistance detection circuit detects the internal resistance of battery 1, regardless of whether battery 1 is currently charging or discharging, the main control module 4 can record data such as the current operating state, charging / discharging current, and voltage of battery 1. This improves the accuracy of the internal resistance detection circuit in detecting the internal resistance of battery 1.

[0053] For example, when detecting the internal resistance of battery 1, if battery 1 has just stopped charging and its voltage is still in a high polarization state and has not yet fallen back to a stable open-circuit voltage, the data will be inaccurate if the internal resistance is measured immediately at this time. However, if the main control module 4 records "just finished charging", it can perform a delayed measurement of the internal resistance of battery 1 or mark the data as "non-steady-state data, for reference only", thereby improving the accuracy of the detected internal resistance of battery 1.

[0054] In one embodiment, "obtaining the current value of load resistor 2" may refer to obtaining the current value passing through load resistor 2 during the pulse.

[0055] Specifically, since the battery internal resistance detection circuit forms a series loop, the main control module 4 can obtain the current value of the load resistance 2 by sampling any part of the battery internal resistance detection circuit.

[0056] In one embodiment, the battery internal resistance detection circuit may further include an adjustment module, which can be connected to the main control module 4. This adjustment module is used to detect whether the battery 1 is currently in a high-current charging / discharging state. If so, after the battery 1 reduces its charging / discharging current, the main control module 4 can control the detection control module 3 to be turned on, activating the battery internal resistance detection circuit. After the main control module 4 determines the internal resistance, the charging / discharging state before measurement can be restored. This facilitates rapid pulse injection to measure the internal resistance of the battery 1 under high-current charging / discharging scenarios.

[0057] Here, being in a high-current charging and discharging state can mean that the charging and discharging current value of battery 1 has reached the predetermined current value.

[0058] Thus, by connecting the load resistor 2 and the detection control module 3 to both ends of the battery 1, the detection control module 3 is turned on by the main control module 4 when it is necessary to detect the internal resistance, thereby forming a conducting circuit for the battery 1 to discharge into the circuit. The internal resistance of the battery 1 can be determined based on the current generated by the discharge, which facilitates quick and efficient detection of the internal resistance of the battery 1 in the product or various working circuits, and helps to detect abnormalities of the battery 1 in a timely manner.

[0059] In some embodiments, such as Figure 2 As shown, the battery internal resistance detection circuit also includes a detection resistor 6. The first end of the detection resistor 6 is connected to the negative terminal of the battery 1, the second end of the detection resistor 6 is connected to the detection control module 3, and the first end and the second end of the detection resistor 6 are also connected to the main control module 4.

[0060] In one embodiment, the sensing resistor 6 can be a fixed resistor with a fixed resistance value, or it can be a variable resistor, for example, whose resistance value can be adjusted according to the operating state of the battery 1. For example, when the battery 1 operates continuously for a period of time exceeding a preset threshold, the resistance value of the sensing resistor 6 can be reduced, thereby increasing the current value passing through the sensing resistor 6 and improving the sensitivity of internal resistance detection.

[0061] In one embodiment, the current value of the load resistor 2 can be determined based on the voltage drop across the sensing resistor 6.

[0062] Thus, the detection resistor 6 can be used to detect current, improving the accuracy of detection. Furthermore, since the current needs to return to the negative terminal of the battery, connecting the detection resistor 6 to the negative terminal of the battery 1 can improve the accuracy of detection.

[0063] In one embodiment, the first transistor 31 and the load resistor 2 are connected in series between the detection resistor 6 and the positive terminal of the battery 1; the pulse control unit 41 of the main control module 4 is connected to the gate of the first transistor 31, and the source and drain of the first transistor 31 are connected to the load resistor 2 and the detection resistor 6, respectively.

[0064] Here, the first transistor 31 can be a MOSFET.

[0065] In some embodiments, the detection control module 3 further includes: a bidirectional transistor 7, which includes two transistors connected in parallel with opposite conduction directions; the first end of the bidirectional transistor 7 is connected to the battery 1, the second end of the bidirectional transistor 7 is connected to an electrical component other than the battery internal resistance detection circuit in the power bank, and the main control module 4 is also connected to the bidirectional transistor 7.

[0066] Here, the bidirectional transistor 7 is connected between the sensing resistor 6 and the first transistor 31; the main control module 4 can also be connected to the bidirectional transistor 7 to obtain the current value of the load resistor 2 through the bidirectional transistor 7.

[0067] In one embodiment, one end of the bidirectional transistor 7 is connected to the sensing resistor 6, and the other end is connected to the first transistor 31 and ground. The bidirectional transistor includes two transistors connected in parallel with opposite conduction directions, meaning that the same terminals of the two transistors are connected together.

[0068] For example, the sources of two transistors are connected together, and one end of the bidirectional transistor 7 can be the drain of one of the transistors, while the other end can be the drain of the other transistor.

[0069] Alternatively, the drains of the two transistors can be connected together, and one end of the bidirectional transistor 7 can be the source of one of the transistors, while the other end can be the source of the other transistor.

[0070] In one embodiment, the two transistors in the bidirectional transistor 7 can be metal-oxide-semiconductor field-effect transistors (MOSFETs), and the two transistors can be the same type of transistor, such as both being P-type MOSFETs or both being N-type MOSFETs.

[0071] In one embodiment, such as Figure 3 As shown, the bidirectional transistor 7 includes: a second transistor 71 and a third transistor 72;

[0072] The source S of the second transistor 71 is connected to the source S of the third transistor 72, and the gate G of the second transistor 71 is connected to the gate G of the third transistor 72; the drain D of the second transistor 71 is connected to the detection resistor 6, and the drain D of the third transistor 72 is connected to the first transistor 31.

[0073] Here, the first terminal of the bidirectional transistor, i.e., the drain of the second transistor 71, is connected to the negative terminal of the battery 1 through the detection resistor 6. The second terminal of the bidirectional transistor, i.e., the drain of the third transistor 72, is connected to the first transistor 31 and to electrical components other than the battery internal resistance detection circuit in the power bank. The connection to electrical components other than the battery internal resistance detection circuit in the power bank can refer to the connection to the working circuit of the battery 1.

[0074] In one embodiment, the second transistor 71 and the third transistor 72 are transistors of the same type, such as both being PMOS or both being NMOS, and the gates of the second transistor 71 and the third transistor 72 can be connected to the main control module 4, and the main control module 4 controls the switching of the second transistor 71 and the third transistor 72.

[0075] In one embodiment, when the main control module 4 detects that the internal resistance exceeds a predetermined range, it can control the second transistor 71 and the third transistor 72 to turn off, thereby disconnecting the charging and discharging path of the battery 1.

[0076] In one embodiment, the bidirectional transistor 7 is also connected to ground. For example, the drain of the third transistor 72 is also connected to ground.

[0077] Thus, by setting up the bidirectional transistor 7, both the charging current and the discharging current can pass through the detection resistor 6, thereby enabling internal resistance detection in various operating states of the battery 1, such as charging or discharging. Simultaneously, when the battery 1 is in a static state (i.e., not in operation), the main control module 4 can send a short pulse to control the first transistor 31 to turn on for internal resistance detection, thus achieving internal resistance detection unaffected by the operating state of the battery 1.

[0078] Furthermore, it can prevent current from flowing back into the battery internal resistance detection circuit from the working circuit. It can also prevent current from flowing into the working circuit from the battery internal resistance detection circuit, thereby avoiding energy loss caused by current flowing from the battery internal resistance detection circuit into the working circuit.

[0079] Therefore, by introducing the bidirectional transistor 7, the battery internal resistance detection circuit can be activated regardless of whether the battery 1 is in a charging state, a discharging state, or a resting state. In one embodiment, the drain D of the first transistor 31 is connected to the load resistor 2, and the source S of the first transistor 31 is connected to the detection resistor 6. The connection to the detection resistor 6 can refer to the connection of the detection resistor 6 via the bidirectional transistor 7.

[0080] For example, the source of the first transistor 31 can be connected to the drain of the third transistor 72, and the source of the first transistor 31 and the drain of the third transistor 72 can be grounded together.

[0081] In one embodiment, the main control module 4 is connected to the gate G of the first transistor 31. For example, the pulse control unit is connected to the gate G of the first transistor 31, and controls the first transistor 31 to turn on by sending a short pulse to the gate of the first transistor 31. When the main control module 4 sends a short pulse to the gate of the first transistor 31, the first transistor 31 is in the on state. Here, sending a short pulse is equivalent to injecting a short pulse, and when the injection of short pulses stops, the first transistor 31 enters the off state.

[0082] In one embodiment, the main control module 4 includes an input / output interface, such as a general-purpose input / output (GPIO) interface. The pulse control unit can be connected to the gate of the first transistor 31 through the input / output interface to control the first transistor 31 to turn on or off.

[0083] Thus, the main control module 4 can briefly turn on the first transistor 31, thereby allowing the battery 1 to discharge to the load resistor 2, generating a pulse current that can be used to detect changes in the voltage of the battery 1 and thus determine the internal resistance of the battery 1.

[0084] In some embodiments, the voltage acquisition module 5 is connected to both ends of the battery 1 to detect the open circuit voltage and the closed circuit voltage of the battery.

[0085] Here, the voltage acquisition module 5 is also connected to the main control module 4, which controls the detection of the open-circuit voltage and the voltage during the internal resistance detection of the battery. The circuit voltage of the battery 1 is the voltage during the internal resistance detection of the battery 1, that is, the voltage of the battery 1 after the pulse stabilizes, which can be measured during the pulse.

[0086] In some embodiments, the battery internal resistance detection circuit further includes: a temperature detection module 8; the temperature detection module 8 is connected to the battery 1 and the main control module 4, and is used to detect the temperature of the battery 1 and output a feedback signal characterizing the temperature; the main control module 4 is used to perform compensation calculations on the internal resistance of the battery 1 based on the temperature indicated by the feedback signal.

[0087] Here, the temperature detection module 8 may include a thermistor, such as a negative temperature coefficient (NTC) thermistor. The thermistor of the temperature detection module 8 can be connected to the battery 1, and the temperature of the battery 1 can be determined based on the current or voltage value of the thermistor.

[0088] In one embodiment, the temperature detection module 8 can detect the temperature of the battery 1 and also the ambient temperature. The feedback signal can characterize the temperature based on parameters such as voltage or current values, or it can directly carry a field representing the temperature value.

[0089] In one embodiment, such as Figure 8 As shown, the main control module 4 can determine the internal resistance of the battery 1 based on the current value of the detection resistor 6, and then perform compensation calculation on the internal resistance based on the temperature value represented by the feedback signal. For example, the main control module 4 can include a temperature compensation unit 42 to perform the above compensation calculation.

[0090] For example, when the temperature is higher than a preset temperature, the internal resistance is calculated based on the temperature value represented by the feedback signal to a value corresponding to a battery 1 temperature below the preset temperature. The preset temperature could be 25°C, etc.

[0091] In one embodiment, the main control module 4 further includes a temperature compensation unit 42, which is connected to the temperature detection module 8. The temperature compensation unit 42 is used to receive feedback signals and determine the internal resistance compensation value of the battery 1 based on the temperature indicated by the feedback signals, and to compensate the internal resistance of the battery 1 according to the internal resistance compensation value.

[0092] In one embodiment, the internal resistance detection circuit of battery 1 further includes a temperature compensation module connected between the temperature detection module 8 and the main control module 4.

[0093] The temperature compensation module is used to receive feedback signals and determine the internal resistance compensation value of battery 1 based on the temperature indicated by the feedback signals, and then send the internal resistance compensation value to the main control module 4.

[0094] Here, the temperature compensation unit 42 can function similarly to the temperature compensation module. The temperature compensation module can determine the internal resistance compensation value of battery 1 based on the battery 1 temperature represented by the feedback signal and the preset temperature. After sending the internal resistance compensation value to the main control module 4, the main control module 4 can determine the internal resistance of battery 1 based on the current value of the detection resistor 6 and then perform internal resistance compensation calculation based on the internal resistance compensation value. For example, the compensation calculation refers to converting the internal resistance to a value corresponding to a battery 1 temperature below the preset temperature.

[0095] Thus, when the temperature of battery 1 rises and causes inaccurate internal resistance detection, the temperature can be detected and internal resistance compensation calculated based on the temperature detection module 8, thereby improving the accuracy of internal resistance detection in high-temperature scenarios.

[0096] In some embodiments, the battery 1 internal resistance detection circuit further includes: a cut-off module 91;

[0097] The cut-off module 91 is connected to the battery 1 and is used to cut off the input path and / or output path of the battery 1 when the main control module 4 detects that the internal resistance exceeds a predetermined range.

[0098] Here, the cut-off module 91 can be located inside the main control module 4, or it can be connected to the main control module 4. After the main control module 4 calculates the internal resistance based on the current value of the detection resistor 6, or after the main control module 4 calculates the internal resistance based on compensation, and determines that the internal resistance exceeds the predetermined range, the input path and / or output path of the battery 1 can be cut off by the cut-off module 91.

[0099] In one embodiment, the input path and / or output path of battery 1 may refer to the input path and / or output path of battery 1 in the operating circuit. The second terminal of the bidirectional transistor can be connected to an electrical component other than the battery internal resistance detection circuit in the power bank through this input path and / or output path.

[0100] In this way, the working circuit of battery 1 can be quickly cut off when the internal resistance is abnormal, thus improving safety.

[0101] In some embodiments, the internal resistance detection circuit of battery 1 further includes: a latch module 92;

[0102] The latch module 92 is connected to the input / output interface of the main control module 4 and is used to lock the input / output interface to a low level when the main control module 4 detects that the internal resistance exceeds a predetermined range.

[0103] Here, the latch module 92 can be connected to the input / output interface of the main control module 4, or the latch module 92 can be located inside the main control module 4 and connected to the input / output interface. The latch module 92 can be used to lock the GPIO of the main control module 4 to a low level when the main control module 4 detects that the internal resistance exceeds a predetermined range, so that the second transistor 71 and the third transistor 72 controlling the charging and discharging circuit remain in the off state.

[0104] In one embodiment, bidirectional transistors 7, namely the second transistor 71 and the third transistor 72, can be connected between battery 1 and the working circuit of battery 1.

[0105] In one embodiment, locking the input / output interface to a low level may include writing a protection flag bit into a Flash memory, which ensures that the protection flag bit will not be cleared even if the electronic device containing battery 1 is restarted, thus maintaining the protection of the device.

[0106] In this way, when the internal resistance is abnormal, the interface that outputs the signal to the charging / discharging MOSFET can be quickly locked, thereby preventing battery 1 from outputting and improving safety.

[0107] As an example, the structure of the battery internal resistance detection circuit can be as follows: Figure 4As shown.

[0108] This application also provides an electronic device, including the battery internal resistance detection circuit of any of the foregoing embodiments.

[0109] Here, electronic devices can be devices with battery charging and discharging functions, such as power banks, charging devices, and other types of electronic devices.

[0110] As one possible implementation method, such as Figure 5 As shown, the active pulse injection method supports the detection of the internal resistance of battery 1 during charging and discharging. When the detected internal resistance exceeds a threshold (e.g., increases by 40% compared to the initial value), charging and discharging are stopped. The charging IC refers to the chip (IC) that controls the charging operation.

[0111] like Figure 6 As shown, the internal resistance detection circuit can be composed of a first transistor 31, a load resistor 2, a detection resistor 6, a voltage detection circuit (i.e., a detection control module 3), and a voltage acquisition module 5, where r represents the internal resistance of the battery (E), and pulse control and current detection control represent the functions connected to the main control module 4. Temperature detection is achieved by detecting the temperature using an NTC thermistor. Charging and discharging are stopped by controlling the charging and discharging MOSFETs, i.e., the second transistor 71 (Q1) and the third transistor 72 (Q2).

[0112] The internal resistance detection circuit in this application supports full-condition detection, constant voltage stage detection during charging, no-load detection during discharging, and periodic detection during rest.

[0113] The negative terminal of battery 1 (E) is connected to a sensing resistor 6, Rs, and then connected to the system ground through a bidirectional MOSFET switch, i.e., a bidirectional transistor 7. In this way, both the charging current and the discharging current will pass through Rs, and the current of battery 1 is obtained by measuring the voltage drop across Rs.

[0114] The internal resistance detection pulse circuit, also known as the detection control module 3, consists of a pulse load circuit connected in parallel across the battery 1. This circuit comprises a high-power MOSFET, i.e., the first transistor 31 (Q3), and a load resistor 2 (R_Load) connected in series. When internal resistance needs to be measured, regardless of whether the battery is currently charging or discharging, the main control module 4 controls this circuit to briefly turn on the MOSFET, allowing the battery 1 to discharge through the load resistor 2, thereby generating a pulse current, and then measuring the change in battery 1 voltage.

[0115] I. Internal Resistance Testing Procedure

[0116] 1. When detecting internal resistance (regardless of whether it is currently charging or discharging, the main control module 4 will record the current operating status, charging / discharging current, voltage, etc.).

[0117] 2. A short pulse is emitted to turn on the first transistor 31 (Q3) of the pulse load circuit. At the same time, the open-circuit voltage V_open of battery 1 before the pulse is turned on (measured instantaneously before the pulse is turned on), the voltage V_load of battery 1 after the pulse stabilizes (measured during the pulse), and the current I during the pulse (calculated from the voltage drop of Rs) are measured. The open-circuit voltage of battery 1 can be pre-stored in the main control module 4, for example, measured and stored in the main control module 4 at the factory.

[0118] 3. Calculate the internal resistance r: r = (V_open - V_load) / I. Because open-circuit voltage = I × load resistance + I × internal resistance value;

[0119] 4. Perform temperature compensation (calculate the internal resistance to the value at 25℃ based on the temperature measured by the NTC).

[0120] When an abnormal internal resistance is detected, the charging / discharging MOSFET is turned off, and charging / discharging is stopped.

[0121] II. Software Flow

[0122] Check the internal resistance periodically, once at the start of each charge / discharge cycle. If an abnormal internal resistance is detected during charge / discharge, stop the charge / discharge process immediately.

[0123] The main control module 4 saves the current state (state of the charging / discharging MOSFET, current, etc.). If a high-current charging / discharging is currently in progress, the charging / discharging current is reduced first to inject a pulse. Internal resistance measurement is performed (as described above), and the previous charging / discharging state is restored. Since the pulse injection time is extremely short (100μs), it has minimal impact on the charging / discharging process, so there is no need to pause the charging / discharging process.

[0124] III. Protective Latch

[0125] Once an abnormal internal resistance is detected, the protection flag is written to the Flash memory and will not be cleared even after a restart. For safety reasons, output will be completely disabled at this time.

[0126] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, 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. Unless otherwise specified, 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 that element.

[0127] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery internal resistance detection circuit, applied to a power bank, characterized in that, include: Battery, load resistor, detection and control module, voltage acquisition module, and main control module; The main control module is connected to the voltage acquisition module, the detection control module, and the load resistor, respectively. The voltage acquisition module is used to acquire the open-circuit voltage of the battery and output the open-circuit voltage to the main control module; When the main control module controls the detection control module to be in the on state, the detection control module, the load resistor, and the battery form a closed loop, the battery discharges to the load resistor, and the main control module is used to obtain the current value of the load resistor and determine the internal resistance of the battery based on the open circuit voltage and the current value.

2. The battery internal resistance detection circuit according to claim 1, characterized in that, It also includes a detection resistor, the first end of which is connected to the negative terminal of the battery, the second end of which is connected to the detection control module, and the first and second ends of the detection resistor are also connected to the main control module.

3. The battery internal resistance detection circuit according to claim 1, characterized in that, The main control module includes a pulse control unit, and the detection control module includes a first transistor. The pulse control unit is connected to the first transistor, and the pulse control unit is used to send a pulse signal to the first transistor to turn on the first transistor within a first time period.

4. The battery internal resistance detection circuit according to claim 1, characterized in that, The circuit also includes a bidirectional transistor, which comprises two transistors connected in parallel with opposite conduction directions. The first end of the bidirectional transistor is connected to the battery, and the second end of the bidirectional transistor is connected to an electrical component other than the battery internal resistance detection circuit in the power bank. The main control module is also connected to the bidirectional transistor.

5. The battery internal resistance detection circuit according to claim 1, characterized in that, The voltage acquisition module is connected to both ends of the battery and is used to detect the open circuit voltage and the closed circuit voltage of the battery.

6. The battery internal resistance detection circuit according to claim 1, characterized in that, The battery internal resistance detection circuit also includes: a temperature detection module; The temperature detection module is connected to the battery and the main control module, and is used to detect the temperature of the battery and output a feedback signal characterizing the temperature.

7. The battery internal resistance detection circuit according to claim 6, characterized in that, The main control module further includes a temperature compensation unit, which is connected to the temperature detection module. The temperature compensation unit is used to receive the feedback signal and determine the internal resistance compensation value of the battery based on the temperature indicated by the feedback signal, and to compensate the internal resistance of the battery according to the internal resistance compensation value.

8. The battery internal resistance detection circuit according to any one of claims 1 to 7, characterized in that, The battery internal resistance detection circuit further includes: a cut-off module; The cut-off module is connected to the battery and is used to cut off the input path and / or output path of the battery when the main control module detects that the internal resistance exceeds a predetermined range.

9. The battery internal resistance detection circuit according to any one of claims 1 to 7, characterized in that, The battery internal resistance detection circuit also includes: a timing module; The timing module is connected to the main control module and is used to control the main control module to turn on the detection control module based on a predetermined period.

10. An electronic device, characterized in that, Includes the battery internal resistance detection circuit as described in any one of claims 1 to 9.

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