Charging and discharging control method for rechargeable battery

Abstract

The embodiment of the application relates to the technical field of battery charging and discharging control, in particular to a charging and discharging control method and system of a rechargeable battery. The charging and discharging control method comprises the following steps: controlling the rechargeable battery to output a step-down voltage based on the working parameter of a charging and discharging control system; in response to the working parameter of the charging and discharging control system falling to a discharging cut-off threshold value, controlling the rechargeable battery to stop discharging, or in response to the working parameter of the charging and discharging control system rising to a discharging upper limit threshold value, controlling the discharging behavior of the rechargeable battery; and in response to the working parameter of the charging and discharging control system reaching a recovery threshold value, controlling the rechargeable battery to resume charging or controlling the step-down voltage to recover to a target voltage. The embodiment of the application utilizes the hysteresis interval to suppress frequent on-off actions caused by small fluctuations in the suppression parameter, thereby preventing intermittent start-stop of power equipment and abnormal working.

Description

Technical Field

[0001] This application relates to the field of battery charge and discharge control technology, and in particular to a charge and discharge control method for a rechargeable battery. Background Technology

[0002] Dry cell batteries are widely used in electronic devices such as digital cameras, smart locks, and flashlights. Low battery status is typically determined by detecting the real-time output voltage of the dry cell battery; for example, a voltage below 1.1V indicates low battery, below 1.0V causes the image to flash, and below 0.9V shuts down the output. While widely used, dry cell batteries generally suffer from low energy storage, short discharge time, and low output conversion efficiency. Furthermore, in common applications like flashlights where prolonged high-current discharge can cause significant heat generation. Additionally, dry cell batteries are disposable, resulting in low recyclability.

[0003] Given the common problems of existing dry-cell batteries, such as short discharge time, severe overheating during prolonged use, and inability to be recycled, using rechargeable batteries as a replacement can significantly optimize the daily user experience. However, some rechargeable batteries immediately stop regulated voltage output when the lithium-ion battery discharge temperature exceeds its upper discharge limit. When the output is turned off and the device stops operating, the temperature drops rapidly, regulated voltage output resumes quickly, and the device restarts. This can cause power devices to malfunction, such as flashlights flickering on and off, or shavers spinning intermittently. Summary of the Invention

[0004] One objective of this application is to provide a charging and discharging control method for rechargeable batteries, thereby improving the technical problem in related technologies where power devices cannot function properly due to repeated start-stop cycles.

[0005] This application provides a charging and discharging control method for a rechargeable battery, applied to a charging and discharging control system. The charging and discharging control system is electrically connected to the rechargeable battery, and the rechargeable battery is connected to an external charging power supply. The charging and discharging control method includes: controlling the rechargeable battery to enter a discharging state based on a disconnection signal from the charging power supply; controlling the charging and discharging control system to output a step-down voltage based on operating parameters of the charging and discharging control system; controlling the rechargeable battery to stop discharging in response to the operating parameters of the charging and discharging control system falling to a discharge cutoff threshold, or controlling the discharging behavior of the rechargeable battery in response to the operating parameters of the charging and discharging control system rising to a discharge upper limit threshold, the discharging behavior including stopping discharging or limiting discharging; and controlling the rechargeable battery to resume charging or controlling the step-down voltage to recover to a target voltage in response to the operating parameters of the charging and discharging control system reaching a recovery threshold, wherein a hysteresis interval is formed between the recovery threshold and the discharge upper limit threshold.

[0006] Optionally, in a first implementation of the first aspect of this application, the operating parameters include the output voltage of the rechargeable battery, the output voltage of the charge-discharge control system, and the output current of the charge-discharge control system. Controlling the output voltage of the rechargeable battery based on the operating parameters of the charge-discharge control system includes: allowing the rechargeable battery to perform a discharge operation in response to the output voltage of the rechargeable battery being higher than the discharge cutoff recovery voltage and the discharge temperature of the rechargeable battery being lower than the discharge recovery temperature; detecting the discharge state of the rechargeable battery; and synchronously adjusting the output voltage of the charge-discharge control system to obtain a stepped-down voltage in response to the discharge state being a decrease in the output voltage of the rechargeable battery; and / or, stepping down the output voltage of the charge-discharge control system based on the output current of the charge-discharge control system to obtain a stepped-down voltage.

[0007] Optionally, in a second implementation of the first aspect of this application, detecting the discharge state of the rechargeable battery and synchronously adjusting the output voltage of the charge-discharge control system to obtain a step-down voltage in response to the discharge state being a decrease in the output voltage of the rechargeable battery includes: detecting the discharge state of the rechargeable battery; and reducing the output voltage by a first proportional coefficient in response to the discharge state being a decrease in the output voltage of the rechargeable battery to obtain a step-down voltage.

[0008] Optionally, in a third implementation of the first aspect of this application, the operating parameters include the output voltage of the rechargeable battery, the discharge temperature of the rechargeable battery, the charging temperature of the rechargeable battery, the output current of the charge / discharge control system, and the output voltage of the charge / discharge control system. The recovery threshold includes the load recovery current, a first discharge upper limit recovery temperature, a second discharge upper limit recovery temperature, a voltage threshold, and a voltage recovery threshold. The step of controlling the rechargeable battery to resume charging or controlling the step-down voltage to recover to the target voltage in response to the operating parameters of the charge / discharge control system reaching the recovery threshold includes: responding to the output current of the charge / discharge control system being lower than the target voltage... The load recovery current is used to control the step-down voltage to recover to the target voltage; or, in response to the discharge temperature of the rechargeable battery being lower than the first upper discharge limit recovery temperature, the step-down voltage is controlled to recover to the target voltage; or, in response to the discharge temperature of the rechargeable battery being lower than the second upper discharge limit recovery temperature, the step-down voltage is controlled to recover to the target voltage; or, in response to the step-down voltage being lower than a voltage threshold, the step-down voltage is increased by a second proportional coefficient to obtain a regulated voltage; in response to the regulated voltage being higher than a voltage recovery threshold, the second proportional coefficient is reset to a first proportional coefficient and the regulated voltage is decreased by the first proportional coefficient to obtain and output the target voltage.

[0009] Optionally, in the fourth implementation of the first aspect of this application, the step of reducing the output voltage of the charging and discharging control system based on the output current of the charging and discharging control system to obtain a reduced voltage includes: in response to the output current of the charging and discharging control system being higher than a preset load current, reducing the output voltage of the charging and discharging control system by a third proportional coefficient to obtain a reduced voltage.

[0010] Optionally, in the fifth implementation of the first aspect of this application, the charging and discharging control method further includes: connecting the charging power supply to enable the rechargeable battery to enter a charging state; and controlling the charging behavior of the rechargeable battery based on the charging temperature of the rechargeable battery or the output current of the charging power supply, wherein the charging behavior includes stopping charging or continuous charging.

[0011] Optionally, in the sixth implementation of the first aspect of this application, the charging behavior further includes resuming charging, and controlling the charging behavior of the rechargeable battery based on the charging temperature of the rechargeable battery includes: controlling the rechargeable battery to stop charging when the charging temperature of the rechargeable battery rises to the upper limit charging temperature; and controlling the rechargeable battery to resume charging in response to the charging temperature of the rechargeable battery falling below the upper limit charging recovery temperature.

[0012] Optionally, in the seventh implementation of the first aspect of this application, the rechargeable battery includes an output port, and controlling the rechargeable battery to enter a discharge state based on the disconnection signal of the charging power supply includes: releasing excess electrical energy in the output port based on the disconnection signal of the charging power supply, so that the voltage between the positive and negative terminals of the rechargeable battery is reduced to below or equal to the maximum open circuit voltage and the rechargeable battery is controlled to enter a discharge state.

[0013] Optionally, in an eighth implementation of the first aspect of this application, the charge-discharge control method further includes: detecting the discharge state of the rechargeable battery in response to the output voltage of the rechargeable battery after charging being higher than the discharge cutoff recovery voltage; reducing the output voltage by a first proportional coefficient in response to the discharge state being a decrease in the output voltage of the rechargeable battery to obtain a step-down voltage; increasing the step-down voltage by a second proportional coefficient in response to the step-down voltage being lower than a voltage threshold to obtain a regulated voltage; and resetting the second proportional coefficient to the first proportional coefficient and reducing the regulated voltage by the first proportional coefficient in response to the regulated voltage being higher than a voltage recovery threshold to obtain and output a target voltage.

[0014] Optionally, in the ninth implementation of the first aspect of this application, the operating parameters include the output voltage of the charge / discharge control system and the discharge temperature of the rechargeable battery, the discharge cutoff threshold includes the discharge cutoff voltage, the discharge upper limit threshold includes a first discharge upper limit temperature and a second discharge upper limit temperature, the discharge behavior includes stopping discharge or limiting discharge, and controlling the rechargeable battery to stop discharging in response to the operating parameters of the charge / discharge control system falling to the discharge cutoff threshold, or controlling the discharge behavior of the rechargeable battery in response to the operating parameters of the charge / discharge control system rising to the discharge upper limit threshold, includes: controlling the rechargeable battery to stop discharging in response to the output voltage of the rechargeable battery falling to the discharge cutoff voltage; or controlling the rechargeable battery to limit discharge in response to the discharge temperature of the rechargeable battery rising to the first discharge upper limit temperature; or controlling the rechargeable battery to stop discharging in response to the discharge temperature of the rechargeable battery rising to the second discharge upper limit temperature.

[0015] The embodiments of this application achieve the following technical effects: By setting an independent recovery threshold, a hysteresis interval is formed with the upper discharge threshold. When operating parameters such as temperature and output current reach the upper discharge threshold, the voltage regulation output stops. Only when the operating parameters drop to a lower recovery threshold is the charge / discharge control system controlled to restore the output voltage. The hysteresis interval suppresses frequent on / off actions caused by small parameter fluctuations, preventing intermittent start / stop and abnormal operation of power equipment. Simultaneously, combined with the discharge cutoff threshold, low-voltage power loss protection is achieved, significantly improving the operational stability of load equipment and the user experience while ensuring the safety of lithium battery discharge. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a charging and discharging control system provided in an embodiment of this application; Figure 2 This is a schematic diagram illustrating the working principle of the first control circuit provided in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the working principle of the second control circuit provided in the embodiments of this application; Figure 4 A flowchart of a charging and discharging control method provided in an embodiment of this application; Figure 5This is a schematic diagram of a charging and discharging control system provided in another embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0019] It should be noted that, unless there is a conflict, the various features in the embodiments of this application can be combined with each other, all of which are within the protection scope of this application. Furthermore, although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than the module division in the device or the order in the flowchart. Moreover, the terms "first," "second," and "third" used in this application do not limit the data or execution order, but only distinguish identical or similar items with essentially the same function and effect.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0021] Please see Figure 1 This application provides a charging and discharging control system 100 for a rechargeable battery 15. The charging and discharging control system 100 is electrically connected to the rechargeable battery 15 and is applied in power devices, including flashlights, shavers, and other devices. The charging and discharging control system 100 includes a first control circuit 11, a second control circuit 12, a third control circuit 13, and a fourth control circuit 14. The first control circuit 11, the second control circuit 12, and the third control circuit 13 are electrically connected to the rechargeable battery 15, and are connected in parallel. The fourth control circuit 14 is electrically connected to the first control circuit 11, the second control circuit 12, and the third control circuit 13. An adapter 16 is electrically connected to the first control circuit 11.

[0022] The first control circuit 11 is used to safely charge the rechargeable battery 15, balancing the charging time and heat generation of the rechargeable battery 15 during charging, ensuring rapid cycle use and long service life of the rechargeable battery 15. The rechargeable battery 15 is the main body for realizing the mutual conversion of electrical energy and chemical energy, and includes structures such as positive electrode, negative electrode, electrolyte, and separator. Lithium-ion rechargeable batteries and lithium polymer rechargeable batteries both fall under the category of rechargeable battery 15, and have the basic functions of storing electrical energy and performing charging and discharging chemical reactions.

[0023] In some embodiments, the first control circuit 11 is a linear charging circuit. The linear charging circuit adopts a linear constant current and voltage regulation charging topology, and relies on the power linear transistor to divide the voltage and limit the current, and performs constant current pre-charging and constant voltage full charging control on the rechargeable battery 15.

[0024] Please see Figure 2 The charging and discharging control system 100 also includes an adapter 16, a first capacitor C1, and a first switching transistor Q1. One end of the first control circuit 11 is electrically connected to the gate of the first switching transistor Q1, the drain of the first switching transistor Q1 is electrically connected to the positive terminal of the rechargeable battery 15, the source of the first switching transistor Q1 is electrically connected to the positive terminal of the adapter 16, the negative terminal of the rechargeable battery 15 is electrically connected to the ground terminal of the adapter 16, and the source of the first switching transistor Q1 and the positive terminal of the adapter 16 are both connected to one end of the first capacitor C1, while the other end of the first capacitor C1 is grounded.

[0025] The first switching transistor Q1 is a P-channel MOSFET. The second control circuit 12 is used to convert the voltage of the rechargeable battery 15 into the output voltage of the dry cell battery based on the voltage and / or discharge current of the rechargeable battery 15, and to simulate the discharge curve of the dry cell battery. The output voltage of the actual charge-discharge control system 100 will change with the output voltage of the rechargeable battery 15 according to the proportional coefficient at both ends to fit the change of the actual dry cell battery output voltage as energy decreases. In the process of adjusting with the output voltage of the rechargeable battery 15, the output voltage of the charge-discharge control system 100 is reduced within a certain range according to the change of the output current of the charge-discharge control system 100, thereby meeting the compatibility with existing dry cell battery devices and high-efficiency energy conversion. The dry cell battery output voltage refers to the standard output voltage level of a conventional disposable dry cell battery, which is the rated input voltage for power devices.

[0026] In some embodiments, the second control circuit 12 is a BUCK step-down circuit, which is a synchronous or asynchronous DC-DC step-down converter circuit. The input of the second control circuit 12 is the wide voltage of the rechargeable battery 15. By adjusting the PWM duty cycle, the output step-down voltage is stabilized. The magnitude of the step-down voltage is equal to the standard voltage of the dry cell battery, which can be 1.5V, 3V, etc., to realize the lithium battery simulating dry cell battery power supply.

[0027] Please see Figure 3 The charging and discharging control system 100 also includes a second capacitor C2, a third capacitor C3, a second switch Q2, a third switch Q3, and a first inductor L1. The second control circuit 12 is electrically connected to the gate of the second switch Q2. The source of the second switch Q2 is electrically connected to the positive terminal of the rechargeable battery 15 and one end of the second capacitor C2. The other end of the second capacitor C2 is connected to the negative terminal of the rechargeable battery 15 and grounded. The drain of the second switch Q2 is electrically connected to one end of the first inductor L1 and the drain of the third switch Q3. The other end of the first inductor L1 is electrically connected to one end of the third capacitor C3. The other end of the third capacitor C3 is grounded.

[0028] In some embodiments, the second switch Q2 is a P-channel MOSFET and the third switch Q3 is an N-channel MOSFET.

[0029] The third control circuit 13 is used to detect the temperature of the rechargeable battery 15 and control the output voltage and output current of the charge / discharge control system 100. It is mainly responsible for balancing the charging / discharging power and temperature of the rechargeable battery 15, and achieving higher energy conversion efficiency while ensuring safety. During charging, the charging current is turned off when the temperature of the rechargeable battery 15 is abnormal to reduce heat generation. During discharging, the output current or output voltage can be reduced when the temperature of the rechargeable battery 15 is abnormal, thereby reducing the output power of the rechargeable battery 15 and thus reducing the load on the rechargeable battery 15. In some embodiments, the third control circuit 13 is an NTC detection circuit or a junction temperature detection circuit. The NTC detection circuit is an external rechargeable battery 15 temperature sampling circuit with an NTC thermistor as its core. The NTC thermistor is in close contact with the outer wall of the rechargeable battery 15, and its resistance value changes with the ambient temperature or the temperature of the rechargeable battery 15. The resistance change is converted into a voltage signal by the voltage divider sampling circuit, and the processor calculates the surface temperature of the rechargeable battery 15. The junction temperature detection circuit collects the internal junction temperature of the power MOSFET, buck converter chip, and power management chip through the internal PN junction temperature measurement unit, reflecting the heating temperature of the power circuit.

[0030] The fourth control circuit 14 is used to control the switching between discharge and charge, detect abnormal charging and discharging, and provide protection. While the first control circuit 11 is operating, the fourth control circuit 14 shuts down the second control circuit 12 and eliminates the effects of the second control circuit 12's operation. Before the second control circuit 12 operates, the first control circuit 11 is shut down, ensuring that only one of the first and second control circuits is active at any given time, or neither is active, and that there is no mutual interference. The third control circuit 13 remains operational and controllable throughout the complete operating cycle of the rechargeable battery 15. Furthermore, the fourth control circuit 14 is responsible for adjusting the first and second control circuits 11 and 12 in a timely manner when abnormalities occur, preventing damage to the rechargeable battery 15 caused by abnormalities. It is also responsible for real-time adjustment of the first and second control circuits 11 and 12 using the third control circuit 13. Abnormalities include output undervoltage, output short circuit, and output overcurrent.

[0031] In this embodiment, the rechargeable battery 15 is charged by the first control circuit 11 for cyclic use, and the output voltage of the rechargeable battery 15 is converted into the output voltage of a common dry cell battery by the second control circuit 12 to meet the needs of dry cell batteries in daily life. At the same time, the output voltage of the second control circuit 12 changes synchronously with the voltage of the rechargeable battery 15, which is more in line with the output voltage changes of dry cell batteries in daily use.

[0032] Please see Figure 4 This application embodiment also provides a charging and discharging control method for a rechargeable battery 15, applied to a charging and discharging control system 100. The rechargeable battery 15 is connected to an external charging power supply. The charging and discharging control method includes the following steps S101 to S104: S101. Based on the disconnection signal of the charging power supply, control the rechargeable battery 15 to enter the discharge state.

[0033] The power supply disconnection signal refers to the voltage level change of the charging detection pin of the rechargeable battery 15 after the power supply is removed from the charging interface of the rechargeable battery 15, generating an electrical signal indicating that the external charging power supply has been disconnected. The discharge state refers to the battery's operating mode after the charging power supply is removed, supplying power to an external load.

[0034] When the charging power supply is connected, the charging detection pin is at a high level; when the charging power supply is disconnected, the charging detection pin is at a low level, thus obtaining a disconnection signal from the charging power supply. Based on the disconnection signal, the charging and discharging control system 100 executes two sets of control actions: shutting down the first control circuit 11 to cut off the charging input circuit and avoid standby leakage; releasing the charging and discharging interlock and enabling the second control circuit 12. The voltage of the rechargeable battery 15 is stepped down by the second control circuit 12 and converted into a 1.5V dry cell voltage output, and the rechargeable battery 15 officially enters the discharging state.

[0035] When adapter 16 is unplugged, the charging and discharging control system 100 automatically switches to external power supply mode, allowing devices such as flashlights and shavers to work immediately, simplifying the usage process and improving the user experience. During charging, the discharge circuit is locked, and the discharge path is only released after the charging power is disconnected. The charging and discharging circuits are not simultaneously activated, preventing backflow of current from the rechargeable battery 15 from burning out the first switch Q1, the second switch Q2, and the third switch Q3, thus extending the circuit's lifespan.

[0036] S102. Based on the operating parameters of the charge-discharge control system 100, control the output of the charge-discharge control system 100 to reduce the voltage.

[0037] The operating parameters of the charge / discharge control system 100 refer to the output voltage of the rechargeable battery 15, the charging temperature of the rechargeable battery 15, the discharging temperature of the rechargeable battery 15, the output current of the charge / discharge control system 100, and the output voltage of the charge / discharge control system 100. The step-down voltage refers to the non-standard voltage used for temporary protection against voltage drops.

[0038] The charge and discharge control system 100 reads the output voltage of the rechargeable battery 15 in real time and dynamically adjusts the PWM duty cycle of the second control circuit 12: the higher the output voltage of the rechargeable battery 15, the smaller the PWM duty cycle; the lower the output voltage of the rechargeable battery 15, the larger the PWM duty cycle. Throughout the process, the output voltage of the charge and discharge control system 100 is clamped to the step-down voltage.

[0039] This embodiment of the application actively and slightly reduces the output voltage of the charging and discharging control system 100 during high-load operation, reducing the power consumption and heat generation of the second control circuit 12, lowering the probability of triggering high-temperature protection, reducing the occurrence of power equipment shutdowns, and increasing the continuous working time of high-power loads. Temperature is incorporated into the operating parameters for output control, distinguishing between high-temperature shutdown thresholds and low-temperature recovery thresholds to form a hysteresis range; small temperature fluctuations will not cause repeated start-stop outputs, completely avoiding problems such as flashlights flickering and shavers intermittently rotating. In this embodiment, taking the voltage range of the rechargeable battery 15 as 3~4.2V as an example, the rechargeable battery 15 dynamically adjusts its voltage throughout the entire process from a full charge of 4.2V to a discharge cutoff of 3.0V, preventing premature voltage drops due to voltage decreases in the rechargeable battery 15, maximizing the release of the rechargeable battery 15's charge, and extending the single-use life.

[0040] S103. In response to the operating parameters of the charge / discharge control system 100 decreasing to the discharge cutoff threshold, the rechargeable battery 15 is controlled to stop discharging; or, in response to the operating parameters of the charge / discharge control system 100 increasing to the discharge upper limit threshold, the discharge behavior of the rechargeable battery 15 is controlled, the discharge behavior including stopping discharge or limiting discharge.

[0041] The discharge cutoff threshold refers to the low-voltage protection threshold. When the voltage of rechargeable battery 15 drops to the discharge cutoff threshold, it is determined that the charge is depleted, and the discharge is stopped to prevent damage to rechargeable battery 15 from over-discharge. The discharge upper limit threshold includes the discharge upper limit temperature and the discharge upper limit power. The discharge upper limit temperature refers to the high-temperature protection shutdown threshold. When the discharge temperature rises to the discharge upper limit temperature, it is determined that rechargeable battery 15 or power devices are overheated, and the output is cut off or limited to avoid thermal runaway. When the discharge power of rechargeable battery 15 reaches the discharge upper limit power, the output is cut off or the discharge power is reduced. The recovery threshold refers to the low-temperature restart threshold. The value of the recovery threshold is lower than the value of the discharge upper limit threshold.

[0042] Simultaneously setting discharge cutoff threshold and discharge upper limit threshold: This not only prevents the rechargeable battery 15 from being over-discharged to the point of capacity decay and bulging, but also avoids safety hazards caused by overheating during high-power discharge, thus providing double protection for the lifespan of the rechargeable battery 15.

[0043] S104. In response to the operating parameters of the charge / discharge control system 100 reaching the recovery threshold, the rechargeable battery 15 is controlled to resume charging or the step-down voltage is controlled to recover to the target voltage, and a hysteresis interval is formed between the recovery threshold and the upper limit of discharge threshold.

[0044] The recovery threshold refers to an independently set safety recovery judgment threshold. The target voltage refers to the rated voltage of the dry cell battery, which is the standard voltage actually required for the normal operation of the equipment. Resumption charging means that after the first control circuit 11 is shut down due to excessive temperature or current during the charging phase, and the operating parameters drop back to the recovery threshold, the charge and discharge control system 100 restarts the second control circuit 12 to continue charging the rechargeable battery 15.

[0045] When the rechargeable battery 15 is discharging normally: the discharge temperature is less than the upper limit threshold of discharge, and the second control circuit 12 continuously outputs the target voltage. When the rechargeable battery 15 overheats and shuts down: the discharge load operates at high power, the temperature continues to rise and reaches the upper limit threshold of discharge, the fourth control circuit 14 shuts down the second control circuit 12 and stops the output voltage. When the rechargeable battery 15 cools down and enters the hysteresis range: when the power device stops generating heat after power failure, the temperature drops back to the range between the recovery threshold and the upper discharge threshold; at this time, although the temperature is lower than the upper discharge threshold, it has not reached the recovery threshold, so the discharge is stopped and the output is not restarted. When the rechargeable battery 15 meets the recovery conditions—the temperature continues to drop until it reaches or falls below the recovery threshold—the fourth control circuit 14 reopens the second control circuit 12, restoring the output voltage and allowing the load to operate normally. Alternatively, it can restore the normal charging current from a smaller charging current.

[0046] When the rechargeable battery 15 is charging, charging stops due to excessively high charging temperature or excessive charging current. Once the charging temperature or charging current drops to a recovery threshold, the fourth control circuit 14 restarts the first control circuit 11 to resume charging. Charging of the rechargeable battery 15 stops when its temperature rises to the upper limit charging temperature, and resumes when its temperature drops below the upper limit charging recovery threshold. The upper limit charging recovery threshold is equal to the difference between the upper limit charging temperature and a preset hysteresis temperature.

[0047] The hysteresis interval distinguishes between the shutdown threshold and the restart threshold, creating a difference between the two thresholds. This prevents the output voltage from repeatedly starting and stopping when the temperature fluctuates slightly around the upper discharge threshold, thus solving the defects of flashlight flickering and shaver intermittent operation in the background technology.

[0048] In this embodiment, after overheating shutdown, the output can only be restarted when the temperature drops significantly to a lower recovery threshold; when the temperature drops only slightly and is in the hysteresis range, the power is kept off, and there will be no repeated on and off of the output, ensuring the continuous and stable operation of high-power devices such as flashlights and shavers.

[0049] This embodiment sets an independent recovery threshold, forming a hysteresis range with the upper discharge threshold. When operating parameters such as temperature and output current reach the upper discharge threshold, the voltage regulation output stops. Only when the operating parameters drop to a lower recovery threshold is the rechargeable battery 15 controlled to restore the output voltage. The hysteresis range suppresses frequent on / off actions caused by small parameter fluctuations, effectively solving the problems of intermittent start / stop and abnormal operation of high-power equipment. Simultaneously, combined with the discharge cutoff threshold, low-voltage power loss protection is achieved, significantly improving the operational stability of the load equipment and the user experience while ensuring the safety of lithium battery discharge.

[0050] In some embodiments, controlling the output voltage of the charge-discharge control system 100 based on the operating parameters of the charge-discharge control system 100 includes: allowing the rechargeable battery 15 to perform a discharge operation in response to the output voltage of the rechargeable battery 15 being higher than the discharge cutoff recovery voltage and the discharge temperature of the rechargeable battery 15 being lower than the discharge recovery temperature; detecting the discharge state of the rechargeable battery 15, and synchronously adjusting the output voltage of the charge-discharge control system 100 in response to the discharge state being a decrease in the output voltage of the rechargeable battery 15 to obtain a stepped-down voltage; and / or, stepping down the output voltage of the charge-discharge control system 100 based on the output current of the charge-discharge control system 100 to obtain a stepped-down voltage.

[0051] The discharge cutoff recovery voltage refers to the minimum recoverable discharge voltage threshold of the rechargeable battery 15. Only when the voltage of the rechargeable battery 15 is higher than the discharge cutoff recovery voltage can it have the capacity to restart discharge, preventing rapid over-discharge after low-temperature recovery. When the discharge recovery temperature is lower than the first discharge upper limit temperature, the overheat protection is released, allowing discharge to resume. The rechargeable battery 15 is only allowed to perform a discharge operation if both the output voltage of the rechargeable battery 15 are higher than the discharge cutoff recovery voltage and the discharge temperature of the rechargeable battery 15 are lower than the discharge recovery temperature.

[0052] In some embodiments, detecting the discharge state of the rechargeable battery 15 and synchronously adjusting the output voltage of the charge-discharge control system 100 in response to a decrease in the output voltage of the rechargeable battery 15 in the discharge state to obtain a step-down voltage includes: detecting the discharge state of the rechargeable battery 15; and reducing the output voltage of the charge-discharge control system 100 by a first proportional coefficient in response to a decrease in the output voltage of the rechargeable battery 15 in the discharge state to obtain a step-down voltage.

[0053] The first proportional coefficient is a voltage regulation coefficient used to compensate for voltage drops in the output voltage of the charge / discharge control system 100.

[0054] This application embodiment detects the discharge condition in real time and continuously collects the output voltage of the rechargeable battery 15. If it is determined that the output voltage of the rechargeable battery 15 continues to decrease with discharge, the synchronous voltage regulation logic is triggered. The charge and discharge control system 100 retrieves the first proportional coefficient and synchronously corrects the PWM duty cycle of the second control circuit 12 according to the drop amplitude of the rechargeable battery 15 to compensate for voltage loss. After adjustment by the first proportional coefficient, a stable step-down voltage is obtained and output as the current power supply voltage. The rechargeable battery 15 dynamically compensates from a full charge of 4.2V to a depleted charge of 3.0V throughout the entire process, relying on the first proportional coefficient to synchronously correct the output, so that the brightness will not dim or the power will weaken as the rechargeable battery 15's power decreases.

[0055] In some embodiments, the operating parameters include the output voltage of the rechargeable battery 15, the discharge temperature of the rechargeable battery 15, the charging temperature of the rechargeable battery 15, the output current of the charge / discharge control system 100, and the output voltage of the charge / discharge control system 100. The recovery threshold includes the load recovery current, the first upper discharge limit recovery temperature, the second upper discharge limit recovery temperature, the voltage threshold, and the voltage recovery threshold. In response to the operating parameters of the charge / discharge control system 100 reaching the recovery threshold, controlling the rechargeable battery 15 to resume charging or controlling the step-down voltage to recover to the target voltage includes: in response to the output current of the charge / discharge control system 100 being lower than the load recovery current, controlling the step-down voltage to recover to the target voltage; or... In response to the discharge temperature of the rechargeable battery 15 being lower than the first discharge upper limit recovery temperature, the voltage reduction is controlled to recover to the target voltage or the reduced output current is controlled to recover to the original output current; or... In response to the discharge temperature of the rechargeable battery 15 being lower than the second upper limit discharge recovery temperature, the step-down voltage is controlled to recover to the target voltage; or, In response to the step-down voltage being lower than the voltage threshold, the step-down voltage is increased by a second proportional coefficient to obtain the regulated voltage; In response to the regulated voltage being higher than the voltage recovery threshold, the second proportional coefficient is reset to the first proportional coefficient, and the regulated voltage is reduced by the first proportional coefficient to obtain and output the target voltage.

[0056] The load recovery current refers to the heavy-load voltage reduction exit threshold; if the output current is lower than the load recovery current, the voltage reduction is canceled. The first discharge upper limit recovery temperature refers to the trigger temperature of the first-level high-temperature protection. The second discharge upper limit recovery temperature refers to the trigger temperature of the second-level high-temperature protection, and the second discharge upper limit recovery temperature is greater than the first discharge upper limit recovery temperature. The voltage threshold refers to the falling edge judgment threshold for triggering voltage regulation switching. The voltage recovery threshold refers to the rising edge judgment threshold for triggering proportional coefficient reset; the voltage recovery threshold is higher than the voltage threshold. The first proportional coefficient refers to the output voltage drop stabilization compensation reference coefficient of the charge-discharge control system 100, which outputs the reduced voltage. The second proportional coefficient is a special coefficient for voltage boosting in the low-voltage range, and its value is greater than the first proportional coefficient. It is used to compensate for the output drop when the low-voltage power is insufficient. In this embodiment, the reduced voltage is the temporary output voltage after being reduced by heavy load and high-temperature voltage limits. The stabilized voltage refers to the intermediate voltage after being boosted by the second proportional coefficient under low voltage conditions.

[0057] If the voltage of the rechargeable battery 15 is too low, this embodiment will still switch to the second proportional coefficient for low-voltage compensation; under heavy load and high temperature conditions, a step-down adjustment will be superimposed; charging will automatically resume when the temperature exceeds the charging temperature; under heavy discharge, first-stage high temperature, and second-stage high temperature conditions, the standard output can be automatically restored. After the fault is cleared, there is no need to manually plug or unplug the battery or charger, making it convenient to use. The low voltage is raised by the second proportional coefficient to increase the output voltage of the charge and discharge control system 100. After the output voltage of the charge and discharge control system 100 recovers, it switches back to the first proportional coefficient for voltage regulation. The two linear changes fit the faster voltage drop characteristics of the low voltage of the disposable dry battery, and it is compatible without modifying the load equipment. At the same time, it makes full use of the power of the rechargeable battery 15 to improve the battery life.

[0058] In some embodiments, the output voltage of the charge-discharge control system 100 is reduced based on the output current of the charge-discharge control system 100 to obtain a reduced voltage, including: in response to the output current of the charge-discharge control system 100 being higher than a preset load current, the output voltage of the charge-discharge control system 100 is reduced by a third proportional coefficient to obtain a reduced voltage.

[0059] A preset load current is used as the trigger threshold for heavy-load voltage reduction. A third proportional coefficient is used to linearly reduce the voltage according to the output current. In this embodiment, the voltage reduction is a temporary output voltage generated by reducing the output voltage of the charge-discharge control system 100 using the third proportional coefficient, which is directly supplied to the load for heavy-load power reduction and heat dissipation.

[0060] During the discharge state, the second control circuit 12 continuously collects the output current of the charge-discharge control system 100; the charge-discharge control system 100 compares the real-time output current with the preset load current; if the output current of the charge-discharge control system 100 is higher than the preset load current, the load reduction logic is triggered, the charge-discharge control system 100 reads the third proportional coefficient, and performs a linear voltage reduction operation on the output voltage of the charge-discharge control system 100 in combination with the current output current to obtain the reduced voltage. The charging and discharging control system 100 controls the switching sequence of the second switch Q2 and the third switch Q3 of the second control circuit 12 to output a stepped-down voltage.

[0061] The larger the load current of this embodiment, the lower the output voltage. Existing dry battery devices such as flashlights and shavers can use the rechargeable battery provided in this embodiment without modifying the circuit.

[0062] In this embodiment, the linear charging circuit of the first control circuit 11 adjusts the charging current of the input adapter 16 to the rechargeable battery 15 by controlling the conduction of the first switch Q1, thereby achieving efficient charging of the rechargeable battery 15. Upon detecting the connection of the charging voltage, the first control circuit 11 begins to detect the connectivity of the rechargeable battery 15. After confirming that the connectivity is good, the fourth control circuit 14 shuts down the current second control circuit 12, and the first control circuit 11 turns on the first switch Q1. The first control circuit 11 adjusts the conduction degree of the first switch Q1 according to the current voltage and charging current of the rechargeable battery 15 to ensure that the rechargeable battery 15 is fully charged. The second control circuit 12 controls the alternating conduction of the second switch Q2 and the third switch Q3 and their conduction frequency, thereby causing the output voltage to change linearly with the output voltage of the rechargeable battery 15 according to a preset first proportional coefficient. Furthermore, when the output voltage of the rechargeable battery 15 is lower than a voltage threshold, the control loop in the second control circuit 12 changes the conduction time of the second switch Q2 and the third switch Q3 with the same switching cycle, thereby changing the second control circuit. The output voltage of the control circuit 12 changes with the voltage of the rechargeable battery 15 by a preset second proportional coefficient, realizing two-stage linear changes in the regulated output voltage following the voltage of the rechargeable battery 15. Optionally, when the output current of the regulated output is large, the second control circuit 12 will reduce the output voltage according to the output current of the regulated output by a third proportional coefficient to avoid excessive output power causing severe overheating of the rechargeable battery 15. This conforms to the characteristics of dry cell batteries: the lower the energy, the greater the internal resistance, and the greater the output current, the smaller the battery voltage. By fitting the discharge characteristics of a typical rechargeable battery 15, i.e., the battery voltage drops slowly when the charge is sufficient and drops rapidly when the charge is low, product compatibility in practical applications is achieved, and energy utilization efficiency is improved. The third control circuit 13 monitors the temperature of the rechargeable battery 15 or the chip in real time throughout the process. When the first control circuit 11 is working, if the third control circuit 13 detects that the temperature is too high or too low, it will shut down the first control circuit 11 to avoid damage to the rechargeable battery 15. When the second control circuit 12 is working, if the third control circuit 13 detects that the temperature is too low, it will shut down the second control circuit 12.

[0063] In this embodiment, the output voltage of the charge-discharge control system 100 is the same as that of the dry cell battery. The output voltage decreases linearly in stages with the discharge time. Optionally, when the load current is large, the slope of change is increased to accelerate the decrease of the output voltage of the rechargeable battery 15. That is, as the energy stored inside the rechargeable battery 15 decreases, the output voltage of the charge-discharge control system 100 decreases linearly in sync with the voltage of the rechargeable battery 15. This application embodiment uses a first control circuit 11 for charging the rechargeable battery 15 and a second control circuit 12 for converting the voltage of the rechargeable battery 15 into the voltage of a dry cell battery and outputting it linearly in stages as the capacity of the rechargeable battery 15 decreases. This enables long-term cyclic use and compatibility with existing dry cell battery products. At the same time, considering the heat generated by the rechargeable battery 15 itself and the heat generated by the inductors on the PCBA, as well as the risks in actual use, a third control circuit 13 for detecting temperature and a fourth control circuit 14 for regulating the charging and discharging of the system and detecting abnormalities are added to ensure the safe use of the product.

[0064] In some embodiments, the charge / discharge control method further includes: connecting a charging power source to enable the rechargeable battery 15 to enter a charging state; and controlling the charging behavior of the rechargeable battery 15 based on the charging temperature of the rechargeable battery or the output current of the charging power source, wherein the charging behavior includes stopping charging or continuous charging.

[0065] The preset charging power supply is a dedicated charging input source. It is paired with adapter 16 and outputs a fixed charging voltage and rated charging current to replenish the rechargeable battery 15.

[0066] Charging state is one of the operating modes of the rechargeable battery 15. When a charging power source is connected, the charge / discharge control system 100 detects the connected charging voltage and enters the charging state. In the charging state, the charge / discharge control system 100 turns off the regulated discharge output and starts charging the rechargeable battery 15. The charging state is only entered when a compliant preset charging power source is connected. Without external power supply, the first control circuit 11 will not be accidentally activated, thus avoiding abnormal charging of the rechargeable battery 15 and improving the control stability of the rechargeable battery 15.

[0067] Charging temperature refers to the surface temperature of the rechargeable battery 15 or the junction temperature of the power devices in the first control circuit 11, which is acquired in real time by the third control circuit 13. It is a core safety judgment parameter during the charging stage. The output current of the charging power supply refers to the real-time charging current input to the linear charging circuit, which is acquired through the current sampling loop and used to determine overcurrent abnormalities. Stopping charging means turning off the first control circuit 11, cutting off the charging circuit of the rechargeable battery 15, and suspending the input of electrical energy to the rechargeable battery 15. Continuous charging means that when both the temperature and the charging current are within the preset safe range, the charging and discharging control system 100 maintains the first control circuit 11 on, keeping the rechargeable battery 15 charging normally.

[0068] During the charging state, the charge and discharge control system 100 detects the output voltage of the rechargeable battery 15 and selects trickle charging, constant current charging or constant voltage charging method to charge the rechargeable battery 15 according to the output voltage state of the rechargeable battery 15. When adapter 16 malfunctions, causing overcurrent during charging or rechargeable battery 15 overheats, charging can be immediately cut off if either parameter exceeds the limit, preventing battery 15 from bulging or thermal runaway, significantly improving charging safety. Once the temperature drops and the overcurrent fault is eliminated, the circuit automatically resumes continuous charging, allowing the user to fully charge battery 15 without unplugging the charger, improving product usability. The charging phase uses charging temperature and charging input current as the determining factors; the discharging phase uses discharging temperature, discharging output current, and hysteresis buffer range to control the output.

[0069] In some embodiments, controlling the rechargeable battery 15 to stop charging or continue charging based on the charging temperature of the rechargeable battery 15 or the output current of the charging power supply includes: controlling the rechargeable battery 15 to stop charging in response to the charging temperature of the rechargeable battery 15 rising to the upper limit charging temperature, or limiting the charging current of the rechargeable battery 15 in response to the charging temperature of the rechargeable battery 15 rising to a preset charging limit temperature, or controlling the rechargeable battery 15 to stop charging when the output current of the charging power supply is less than or equal to a preset full charge current; controlling the rechargeable battery 15 to continue charging in response to the charging temperature of the rechargeable battery 15 falling below the upper limit charging recovery temperature, or continuously charging the rechargeable battery 15 with the maximum allowable output current of the charging power supply when the maximum allowable output current of the charging power supply is less than a preset charging current threshold.

[0070] The charging upper limit temperature refers to the over-temperature shutdown threshold. When the charging temperature reaches the charging upper limit temperature, the first control circuit 11 is directly shut down to stop charging and prevent thermal runaway of the rechargeable battery 15. If the charging limit temperature is lower than the charging upper limit temperature, the charging current of the rechargeable battery 15 is reduced when the charging temperature reaches the charging limit temperature. The charging upper limit recovery temperature is the charging restart threshold, and its value is lower than the charging upper limit temperature. After the over-temperature shutdown, charging will only resume when the temperature drops to the charging upper limit recovery temperature. These two temperatures form a charging temperature hysteresis range, avoiding repeated start-stop charging due to small temperature fluctuations. The maximum allowable output current of the charging power supply is the rated maximum output current of the adapter 16 hardware.

[0071] During charging, when the charging temperature rises to the upper limit of the charging temperature, the charging and discharging system turns off the first switch Q1, disconnects the charging circuit, and stops charging to avoid damage to the rechargeable battery 15 due to high temperature. When the rechargeable battery 15 is close to full voltage, the charging current continues to decrease. When the output current of the charging power supply is lower than or equal to the preset full charge current, it is determined that the rechargeable battery 15 is fully charged, and charging stops.

[0072] After charging stops, the rechargeable battery 15 and power devices dissipate heat, and the charging temperature drops to the preset charging recovery temperature. The charging and discharging system then re-energizes the first switch Q1, controlling the first control circuit 11 to continue charging. If the maximum output capacity of the external charging power supply is lower than the standard charging current threshold of the battery, the processor automatically adapts, charging at a constant maximum allowable output current, without forcibly drawing current exceeding the capacity of the adapter 16 to avoid overload damage to the adapter 16. If the upper limit charging temperature is higher than the charging recovery temperature, and the temperature falls within the range between the two, charging remains stopped, preventing restarting charging with slight temperature drops to avoid frequent on / off cycles in the charging circuit.

[0073] This embodiment of the application simultaneously incorporates over-temperature protection and full-charge cut-off protection. High temperatures immediately cut off power to prevent the rechargeable battery 15 from bulging or thermal runaway; current decay to a threshold automatically stops charging, preventing overcharging and aging of the rechargeable battery 15 and extending its lifespan. After over-temperature shutdown, charging can only restart after the temperature has significantly decreased to the charging recovery temperature, preventing small temperature fluctuations near the upper charging limit from causing repeated switching of the first control circuit 11 and reducing losses in the first switching transistor Q1. This embodiment of the application can automatically identify the maximum output current of the adapter 16; when the adapter 16's power is insufficient, it automatically reduces the charging current, preventing the adapter 16 from overloading, overheating, or reporting errors. Most commercially available USB adapters 16 are compatible with this rechargeable battery.

[0074] In this embodiment of the application, during the charging process, the charge-discharge control system 100 detects the maximum allowable output current of the charging power supply. When the maximum allowable output current of the charging power supply is less than the set charging current value, the rechargeable battery 15 is charged with the maximum allowable output current of the charging power supply. When the charging current in the constant voltage charging state drops to the set full charge determination current, the charging of the rechargeable battery 15 is stopped. Alternatively, during the charging process of the general-purpose rechargeable battery 15, the charge-discharge control system 100 detects the temperature of the rechargeable battery 15. When the temperature of the rechargeable battery 15 rises to the upper limit charging temperature, the charging of the rechargeable battery 15 is stopped, and the charging is resumed when the temperature of the rechargeable battery 15 drops below the upper limit charging recovery temperature.

[0075] In some embodiments, the rechargeable battery includes an output port. Controlling the rechargeable battery 15 to enter a discharge state based on a disconnection signal of the charging power supply includes: releasing electrical energy in the output port based on the disconnection signal of the charging power supply, so that the voltage between the positive and negative terminals of the rechargeable battery 15 is reduced to below or equal to the maximum open circuit voltage and controlling the rechargeable battery 15 to enter a discharge state.

[0076] The electrical energy refers to the residual charge stored in the capacitors at the output port of the first control circuit 11 immediately after charging ends, which will cause the open-circuit voltage of the rechargeable battery 15 to be temporarily higher. The maximum open-circuit voltage refers to the highest safe resting voltage of the rechargeable battery 15 allowed before discharge starts; directly starting the second control circuit 12 to discharge above the maximum open-circuit voltage will cause instantaneous overshoot and damage to the load.

[0077] When the charging and discharging control system 100 detects a power supply disconnection signal, the charging process ends. After the charger is unplugged, residual charge remains in the filter capacitor and line parasitic capacitance, causing the open-circuit voltage of the rechargeable battery 15 to momentarily exceed the maximum open-circuit voltage. Instead of directly activating the discharge circuit of the second control circuit 12, the charging and discharging control system 100 controls the discharge path to open, releasing excess electrical energy in the circuit and continuously lowering the open-circuit voltage between the positive and negative terminals of the rechargeable battery 15. The voltage across the rechargeable battery 15 is collected in real time. When the voltage of the rechargeable battery 15 is detected to drop below or equal to the maximum open-circuit voltage, it is determined that the residual charge has been discharged.

[0078] This embodiment eliminates residual high-voltage surges after charging, protecting the second control circuit 12 and the load device. When charging is disconnected, residual charge in the capacitor causes the open-circuit voltage of the rechargeable battery 15 to be too high. Directly activating the second control circuit 12 would generate a momentary high-voltage surge, burning out low-voltage dry-cell battery loads such as shavers and flashlights. By first discharging excess energy, the voltage is clamped to within the maximum open-circuit voltage, preventing damage to devices from the momentary high voltage. Pre-discharging buffers the voltage drop, preventing voltage jumps at the start of discharge and avoiding issues such as flashlights becoming instantly too bright or motors overheating due to overload, thus matching the smooth discharge characteristics of dry-cell batteries.

[0079] In some embodiments, the charge-discharge control method further includes: in response to the output voltage of the rechargeable battery 15 after charging being higher than the discharge cutoff recovery voltage, detecting the discharge state of the rechargeable battery 15; in response to the output voltage of the rechargeable battery 15 decreasing when the discharge state is that the output voltage decreases, reducing the output voltage by a first proportional coefficient to obtain a step-down voltage; in response to the step-down voltage being lower than a voltage threshold, increasing the step-down voltage by a second proportional coefficient to obtain a regulated voltage; and in response to the regulated voltage being higher than a voltage recovery threshold, resetting the second proportional coefficient to the first proportional coefficient and reducing the regulated voltage by the first proportional coefficient to obtain and output a target voltage.

[0080] In the high-charge range, a first proportional coefficient is used for smooth voltage stabilization, while in the low-charge range, a second proportional coefficient is used for voltage boosting compensation. This aligns with the electrical characteristics of dry cell batteries: slow voltage drop when fully charged and rapid voltage drop when low-charged. This ensures perfect compatibility with various small dry cell battery-powered appliances without requiring modifications to the load circuit. When the rechargeable battery 15 is depleted, there will be no sudden drop in output voltage that would render the device unusable, fully utilizing the battery's capacity and improving energy efficiency. Setting discharge cutoff voltage and discharge cutoff recovery voltage creates a voltage hysteresis range, preventing the battery voltage from repeatedly switching between the two proportional coefficients at the critical point. This results in stable output voltage and no noticeable fluctuations in flashlight brightness or motor power.

[0081] In some embodiments, the discharge cutoff threshold includes a discharge cutoff voltage, the discharge upper limit threshold includes a first discharge upper limit temperature and a second discharge upper limit temperature, and the discharge behavior includes stopping discharge or limiting discharge. In response to the operating parameters of the charge / discharge control system 100 decreasing to the discharge cutoff threshold, the rechargeable battery 15 is controlled to stop discharging; or, in response to the operating parameters of the charge / discharge control system 100 increasing to the discharge upper limit threshold, the discharge behavior of the rechargeable battery 15 is controlled, including: in response to the output voltage of the rechargeable battery 15 decreasing to the discharge cutoff voltage, the rechargeable battery 15 is controlled to stop discharging; or... In response to the discharge temperature of the rechargeable battery 15 rising to a first upper discharge limit temperature, the discharge of the rechargeable battery 15 is controlled to be limited; or, In response to the discharge temperature of the rechargeable battery 15 rising to the second upper discharge limit temperature, the rechargeable battery 15 is controlled to stop discharging.

[0082] The discharge cutoff voltage refers to the low-voltage protection threshold of the rechargeable battery 15. When the output voltage of the rechargeable battery 15 drops to the discharge cutoff voltage, it indicates that the battery is depleted. The first discharge upper limit temperature refers to the overheat shutdown or power reduction threshold. When the discharge temperature reaches the first discharge upper limit temperature, the output voltage of the charge / discharge control system 100 is actively reduced to dissipate heat. The output voltage of the rechargeable battery 15 refers to the voltage across its terminals, which gradually decreases as it discharges. The second control circuit 12 adjusts the duty cycle in real time based on the voltage of the rechargeable battery 15 to stabilize the output voltage. The second discharge upper limit temperature is the secondary high-temperature shutdown threshold. When the temperature reaches the second discharge upper limit temperature, the output is directly cut off to prevent irreversible thermal damage to the rechargeable battery 15 and the chip.

[0083] When the discharge temperature rises to the first discharge limit temperature, the output is not cut off directly. Instead, the output voltage or output current is reduced to lower the load power and reduce heat generation.

[0084] The system remains stationary within the hysteresis range between the recovery temperature and the upper limit temperature, preventing restarts due to slight temperature drops. This avoids flickering flashlights and intermittent operation of shavers, enhancing the continuous operation capability of high-power loads. Real-time PWM adjustment is implemented for the wide discharge voltage range of 3.0~4.2V for lithium batteries. Regardless of whether the battery is fully charged or low-charged, it maintains a stable output of the rated step-down voltage under no-load and light-load conditions, ensuring smooth and undiminished load power. The lithium battery voltage range listed in this embodiment is only one example and is not limited to the aforementioned voltage range. Active voltage reduction and load shedding under high-current loads reduce the losses and heat generation of the second and third switching transistors Q2 and Q3, delaying the temperature triggering of the first discharge upper limit temperature, extending the continuous operating time of the equipment, and reducing the probability of mid-operational shutdowns.

[0085] The two mutually exclusive shutdown triggering conditions in this application embodiment will execute a discharge stop if either one is met: Condition 1: The output voltage of the rechargeable battery 15 reaches the discharge cutoff voltage: The output voltage of the rechargeable battery 15 is continuously collected during the discharge process; when the output voltage of the rechargeable battery 15 drops to the discharge cutoff voltage, it is determined that the rechargeable battery 15 is depleted, and the charging and discharging control system 100 shuts off the second control circuit 12 to stop the discharge.

[0086] Condition 2: Discharge temperature rises to the second upper discharge limit temperature: If the high-power load continues to operate and the temperature rises to the second upper discharge limit temperature, the charge / discharge control system 100 directly shuts down the second control circuit 12, completely cutting off the output. After shutdown, relying on hysteresis logic: the second control circuit 12 will only automatically restart and restore the target voltage when the discharge temperature drops to the second upper discharge limit recovery temperature; when the temperature is between the second upper discharge limit recovery temperature and the second upper discharge temperature, the shutdown is maintained to avoid frequent load starts and stops caused by small temperature fluctuations. The second upper discharge limit temperature is higher than the second upper discharge limit recovery temperature, and the temperature between the second upper discharge limit temperature and the second upper discharge limit recovery temperature is the hysteresis temperature corresponding to the hysteresis voltage of the second upper discharge limit temperature.

[0087] In this embodiment, if an excessively high temperature is detected, the current temperature range is determined. If the first discharge upper limit temperature < the current temperature < the second discharge upper limit temperature, the output current of the regulated output is reduced or the output voltage of the regulated output is decreased. This limits the output power without damaging the rechargeable battery 15, thereby reducing the heat generation of the rechargeable battery 15 and the chip, while ensuring compatibility with actual product use. If the current temperature exceeds the second discharge upper limit temperature, the regulated output is shut off to avoid irreversible damage to the rechargeable battery 15 and the chip. This embodiment's low-voltage discharge cutoff prevents deep over-discharge of the rechargeable battery 15, avoiding capacity decay and bulging. The second discharge upper limit temperature shutdown, combined with a temperature hysteresis range, solves the problem of frequent load starts and stops. After shutdown, there is only a slight temperature drop without immediate restarting the output, completely preventing flashlight flickering and shaver intermittent operation.

[0088] It should be noted that in the above embodiments, there is no necessarily a certain order between the steps. Those skilled in the art can understand from the description of the embodiments of this application that the above steps may have different execution orders in different embodiments, that is, they may be executed in parallel or in turn, etc.

[0089] Please see Figure 5 The charge / discharge control system 100 includes one or more processors 17 and a memory 18. The memory 18 is connected to one or more processors 17, for example, via a bus.

[0090] Processor 17 is configured to support the charge / discharge control system 100 in performing the corresponding functions in the methods described in the above-described method embodiments. Processor 17 may be a central processing unit (CPU), a network processor (NP), a hardware chip, or any combination thereof. The aforementioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The aforementioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof.

[0091] Memory 18 is used to store program code, etc. Memory 18 may include volatile memory (VM), such as random access memory (RAM); memory 18 may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory, hard disk drive (HDD) or solid-state drive (SSD), registers; memory 18 may also include combinations of the above types of memory 18.

[0092] The memory 18 can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the charge-discharge control method in the embodiments of this application. The processor 17 executes the charge-discharge control method by running the non-volatile software programs, instructions, and modules stored in the memory 18, thereby implementing the charge-discharge control method provided in the above-described method embodiments.

[0093] The memory 18 may include a program storage area and a data storage area, wherein the program storage area may store the operating system and application programs required for at least one function. In some embodiments, the memory 18 may optionally include a memory 18 remotely located relative to the processor 17. Examples of the networks described above include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0094] One or more modules are stored in memory 18. When executed by one or more processors 17, they perform the charge and discharge control method in any of the above method embodiments. For example, they perform the method steps described in the above method embodiments to realize the function of the modules described in the above device embodiments.

[0095] This application also provides a computer-readable storage medium storing a computer program, which includes program instructions. When executed by the charge-discharge control system 100, the program instructions cause the charge-discharge control system 100 to perform the method as described in the foregoing embodiments.

[0096] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0097] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with the claims of this application shall still fall within the scope of this application.

Claims

1. A method for controlling the charging and discharging of a rechargeable battery, characterized in that, An application is made in a charge-discharge control system, wherein the charge-discharge control system is electrically connected to a rechargeable battery, the rechargeable battery is connected to an external charging power supply, and the charge-discharge control method includes: Based on the disconnection signal of the charging power supply, the rechargeable battery is controlled to enter the discharge state; Based on the operating parameters of the charging and discharging control system, the charging and discharging control system outputs a step-down voltage. In response to the operating parameters of the charge-discharge control system falling to the discharge cutoff threshold, the rechargeable battery is controlled to stop discharging; or, in response to the operating parameters of the charge-discharge control system rising to the discharge upper limit threshold, the discharge behavior of the rechargeable battery is controlled, the discharge behavior including stopping discharge or limiting discharge. In response to the operating parameters of the charge-discharge control system reaching a recovery threshold, the rechargeable battery is controlled to resume charging or the step-down voltage is controlled to recover to the target voltage. A hysteresis interval is formed between the recovery threshold and the upper limit of discharge.

2. The charging and discharging control method according to claim 1, characterized in that, The operating parameters include the output voltage of the rechargeable battery, the output voltage of the charge / discharge control system, and the output current of the charge / discharge control system. The step of controlling the output step-down voltage of the charge / discharge control system based on the operating parameters of the charge / discharge control system includes: In response to the rechargeable battery's output voltage being higher than the discharge cutoff recovery voltage and the rechargeable battery's discharge temperature being lower than the discharge recovery temperature, the rechargeable battery is allowed to perform a discharge operation; The discharge state of the rechargeable battery is detected, and in response to a decrease in the output voltage of the rechargeable battery due to the discharge state, the output voltage of the charge / discharge control system is synchronously adjusted to obtain a step-down voltage; and / or, Based on the output current of the charging and discharging control system, the output voltage of the charging and discharging control system is stepped down to obtain a stepped-down voltage.

3. The charging and discharging control method according to claim 2, characterized in that, The step of detecting the discharge state of the rechargeable battery, and in response to a decrease in the output voltage of the rechargeable battery, synchronously adjusting the output voltage of the charge-discharge control system to obtain a step-down voltage includes: Detect the discharge state of the rechargeable battery; In response to the discharge state where the output voltage of the rechargeable battery decreases, the output voltage of the charge-discharge control system is reduced by a first proportional coefficient to obtain a step-down voltage.

4. The charging and discharging control method according to any one of claims 1 to 3, characterized in that, The operating parameters include the output voltage of the rechargeable battery, the discharge temperature of the rechargeable battery, the charging temperature of the rechargeable battery, the output current of the charge / discharge control system, and the output voltage of the charge / discharge control system. The recovery threshold includes the load recovery current, the first upper discharge limit recovery temperature, the second upper discharge limit recovery temperature, the voltage threshold, and the voltage recovery threshold. The step of controlling the rechargeable battery to resume charging or controlling the step-down voltage to recover to the target voltage in response to the operating parameters of the charge / discharge control system reaching the recovery threshold includes: In response to the output current of the charge / discharge control system being lower than the load recovery current, the step-down voltage is controlled to recover to the target voltage; or, In response to the rechargeable battery's discharge temperature falling below the first discharge upper limit recovery temperature, the step-down voltage is controlled to recover to the target voltage; or, In response to the rechargeable battery's discharge temperature being lower than the second upper discharge recovery temperature, the step-down voltage is controlled to recover to the target voltage; or, In response to the step-down voltage being lower than a voltage threshold, the step-down voltage is increased by a second proportional coefficient to obtain a regulated voltage; In response to the regulated voltage being higher than the voltage recovery threshold, the second proportional coefficient is reset to the first proportional coefficient, and the regulated voltage is reduced by the first proportional coefficient to obtain and output the target voltage.

5. The charging and discharging control method according to claim 2, characterized in that, The step-down of the output voltage of the charging and discharging control system based on the output current of the charging and discharging control system to obtain the stepped-down voltage includes: In response to the output current of the charge-discharge control system being higher than the preset load current, the output voltage of the charge-discharge control system is reduced by a third proportional coefficient to obtain a step-down voltage.

6. The charging and discharging control method according to claim 1, characterized in that, The charging and discharging control method further includes: Connect the charging power source to put the rechargeable battery into a charging state; The charging behavior of the rechargeable battery is controlled based on the charging temperature of the rechargeable battery or the output current of the charging power supply, wherein the charging behavior includes stopping charging or continuous charging.

7. The charging and discharging control method according to claim 6, characterized in that, The charging behavior also includes recharging, and controlling the charging behavior of the rechargeable battery based on its charging temperature includes: When the charging temperature of the rechargeable battery rises to the upper limit of the charging temperature, the charging of the rechargeable battery is controlled to stop. In response to the charging temperature of the rechargeable battery falling below the upper limit recovery temperature, the rechargeable battery is controlled to resume charging.

8. The charging and discharging control method according to claim 1, characterized in that, The rechargeable battery includes an output port, and the step of controlling the rechargeable battery to enter a discharge state based on the disconnection signal of the charging power supply includes: Based on the disconnection signal of the charging power supply, the electrical energy in the output port is released so that the voltage between the positive and negative terminals of the rechargeable battery is reduced to below or equal to the maximum open circuit voltage and the rechargeable battery is controlled to enter the discharge state.

9. The charging and discharging control method according to claim 1, characterized in that, The charging and discharging control method further includes: In response to the output voltage of the rechargeable battery after charging being higher than the discharge cutoff recovery voltage, the discharge state of the rechargeable battery is detected; In response to the discharge state where the output voltage of the rechargeable battery decreases, the output voltage is reduced by a first proportional coefficient to obtain a step-down voltage; In response to the step-down voltage being lower than a voltage threshold, the step-down voltage is increased by a second proportional coefficient to obtain a regulated voltage; In response to the regulated voltage being higher than the voltage recovery threshold, the second proportional coefficient is reset to the first proportional coefficient, and the regulated voltage is reduced by the first proportional coefficient to obtain and output the target voltage.

10. The charging and discharging control method according to claim 1, characterized in that, The operating parameters include the output voltage of the charge / discharge control system and the discharge temperature of the rechargeable battery. The discharge cutoff threshold includes a discharge cutoff voltage, and the discharge upper limit threshold includes a first discharge upper limit temperature and a second discharge upper limit temperature. The discharge behavior includes stopping discharge or limiting discharge. The control of the rechargeable battery to stop discharging in response to the operating parameters of the charge / discharge control system falling to the discharge cutoff threshold, or the control of the discharge behavior of the rechargeable battery to rise to the discharge upper limit threshold, includes: In response to the output voltage of the rechargeable battery dropping to the discharge cutoff voltage, the rechargeable battery is controlled to stop discharging; or... In response to the discharge temperature of the rechargeable battery rising to a first upper discharge limit temperature, the discharge of the rechargeable battery is controlled to be limited; or, In response to the discharge temperature of the rechargeable battery rising to the second upper discharge limit temperature, the rechargeable battery is controlled to stop discharging.

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