Battery charging system

Abstract

The invention discloses a battery charging system. The battery charging system comprises a battery charging circuit and a battery protection circuit, and the battery protection circuit is used for performing charging protection on a battery when the battery charging circuit charges the battery; the battery charging circuit comprises a charging management module which is connected with a battery and is used for performing charging management on the battery; the battery protection circuit comprises a charging protection module which is connected with a battery and a first transistor and is used for performing charging protection on the battery in a battery charging process; the battery protection circuit further comprises a battery reverse connection sampling module which is connected with the battery and is used for collecting reverse connection voltage when the battery is reversely connected; the battery protection circuit further comprises a level conversion module which is connected with the battery reverse connection sampling module and used for performing reverse connection protection on the battery when it is determined that the battery is in the reverse connection state. The technical problem that a battery charging system in the prior art generally does not have an anti-reverse-connection function and has potential safety hazards is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit protection, and in particular to a battery charging system. Background Art

[0002] In the car Tbox device, the Tbox needs to keep working for 10 minutes after the car is powered off, so as to transmit the vehicle data to the relevant platform. Therefore, a backup power supply is required in the TBOX device. This backup power supply generally samples a high-temperature battery such as 14500, with an operating temperature of -40 to 85 degrees Celsius, but it is cylindrical and does not have a charging protection function. In actual application, it is found that there is a possibility that the battery is easily installed in reverse. Due to the cylindrical structure of the battery, it cannot be reversed in structure. In order to ensure the normal use of the circuit, the battery reverse connection function needs to be implemented in the circuit.

[0003] For example, in the prior art, there is a method of detecting when the battery is installed reversely, detecting the cathode voltage, and introducing a comparator to control the negative pole NMOS. This method has certain limitations. For example, the comparator requires a 12V power supply. When the circuit only has a battery, when the battery is connected forward, the premise for this solution to play an anti-reverse connection role is that the comparator needs an external power supply. If the comparator has no external power supply, the NMOS is disconnected, the circuit itself does not work, let alone the anti-reverse function. Therefore, the solution is limited in many application scenarios.

[0004] For another example, in the prior art, when detecting the reverse connection of the battery, the optocoupler diode is turned on, the transistor inside the optocoupler is turned on, and the collector of the internal transistor is connected to the DO pin of the BMS, that is, a low level is output to DO, so that the MOS tube Q1 is turned off, thereby realizing the function of reverse connection of the battery. The limitation of this solution is that some BMSs have built-in MOS tubes, that is, the MOS tubes that control overcharge and over-discharge of the battery are integrated into the BMS, and this solution is not applicable at this time. In addition, this solution has a defect, that is, when the battery is reversed, it is equivalent to the BMS chip itself being connected in reverse, and the BMS chip may also be burned out at this time. This solution needs to be selected according to the actual situation.

[0005] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0006] The embodiment of the present invention provides a battery charging system to at least solve the technical problem that the battery charging system in the related art generally does not have an anti-reverse connection function and has potential safety hazards.

[0007] According to one aspect of an embodiment of the present invention, a battery charging system is provided, comprising: a battery charging circuit and a battery protection circuit, wherein the battery charging circuit is used to charge a battery, and the battery protection circuit is used to perform charging protection on the battery during the process in which the battery charging circuit charges the battery; the battery charging circuit comprises: a charging management module connected to the battery and used to perform charging management on the battery; the battery protection circuit comprises: a charging protection module connected to the battery and a first transistor and used to perform charging protection on the battery during the process in which the battery is charged; the battery protection circuit further comprises: a battery reverse connection sampling module connected to the battery and used to collect the reverse connection voltage of the battery when it is reversely connected; the battery protection circuit further comprises: a level conversion module connected to the battery reverse connection sampling module and used to perform reverse connection protection on the battery when it is determined that the battery is in a reverse connection state.

[0008] Optionally, the battery charging circuit includes: a power supply connected to the charging management module, and configured to provide power to the battery charging circuit through the charging management module to charge the battery.

[0009] Optionally, the charging management module includes: a first chip, connected to a power supply, for performing charging management on the battery; a first capacitor and a second capacitor, the first capacitor being connected in parallel with the second capacitor and connected to the first chip and the power supply, for filtering the current coming from the power supply; a first resistor, connected to the first chip, for setting the charging current of the first chip according to the electrical parameters of the battery; a second resistor, connected to the first chip, for managing the charging process of the battery according to the ambient temperature of the charging environment where the battery is located; a third resistor, connected to the first chip and a first diode, for performing current limiting processing on the first diode; a third capacitor and a fourth capacitor, the third capacitor and the fourth capacitor being connected in parallel and connected to the first chip, for filtering the current coming from the first chip.

[0010] Optionally, the charging protection module includes: a second chip, used to protect the battery from overcharging or over-discharging when the charging current of the battery exceeds a charging current threshold or the discharging current of the battery exceeds a discharge current threshold; a fourth resistor, connected to the second chip, used to perform current limiting processing on the second chip; and a fifth capacitor, connected in parallel with the second chip, used to perform filtering processing on the second chip.

[0011] Optionally, the charging protection module also includes: a fifth resistor, connected to the second transistor, for performing current limiting processing on the second transistor; the second transistor, in cooperation with the first transistor, is used to perform charging protection on the charging process of the battery.

[0012] Optionally, the charging protection module also includes: a sixth resistor and a seventh resistor, the sixth resistor is connected in series with the seventh resistor and connected in parallel with the battery, for performing voltage division processing on the battery; a sixth capacitor is connected in parallel with the sixth resistor, for performing filtering processing on the battery.

[0013] Optionally, the level conversion module includes: a third transistor, connected to an eighth resistor and a ninth resistor, and when the battery is connected reversely, outputting a high voltage to trigger the first transistor to be cut off to stop charging the battery; the eighth resistor, used to limit the current of the third transistor; and the ninth resistor, used to provide a steady-state current for the third transistor.

[0014] Optionally, the level conversion module further includes: a fourth transistor connected to the tenth resistor, the eleventh resistor and the twelfth resistor, and when the battery is positively connected, a high voltage is obtained by voltage division from the power supply to maintain the first transistor turned on to charge the battery.

[0015] Optionally, when the battery is connected forwardly, the first transistor and the second transistor are both turned on to charge the battery; when the battery is connected reversely, the first transistor and the second transistor are both turned off to stop charging the battery.

[0016] Optionally, when the battery is forwardly connected, the anode is connected to the cathode of the second diode; when the battery is reversely connected, the cathode is connected to the cathode of the second diode, wherein the anode of the second diode is connected to the sixth resistor.

[0017] In an embodiment of the present invention, a battery charging circuit and a battery protection circuit are provided in a battery charging system, wherein the battery charging circuit is used to charge the battery, and the battery protection circuit is used to charge the battery during the process of the battery charging circuit charging the battery; the battery charging circuit includes: a charging management module connected to the battery for charging management of the battery; the battery protection circuit includes: a charging protection module connected to the battery and a first transistor for charging protection of the battery during the process of the battery charging; the battery protection circuit also includes: a battery reverse connection sampling module connected to the battery for collecting the reverse voltage of the battery when it is reversely connected; the battery protection circuit also includes: a level conversion module connected to the battery reverse connection sampling module for reverse connection protection of the battery when it is determined that the battery is in a reverse connection state. Through the technical solution provided by the present invention, the purpose of automatically cutting off the charging circuit when the battery is reversely connected can be achieved during the battery charging process, so as to prevent the battery from being burned due to reverse connection, reduce the safety hazards during the battery charging process, and improve the safety of the battery charging, thereby solving the technical problem that the battery charging system in the related art generally does not have an anti-reverse connection function and has safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 is a schematic diagram of a battery charging system according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of an optional battery charging system according to an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of another optional battery charging system according to an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of reverse connection of batteries according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] As described in the background art, the battery charging system in the related art generally does not have an anti-reverse connection function, which poses a safety hazard. In view of the above defects, a battery charging system is provided in an embodiment of the present invention.

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0027] According to one aspect of an embodiment of the present invention, a battery charging system is provided. Figure 1 is a schematic diagram of a battery charging system according to an embodiment of the present invention. Figure 1 As shown, the battery charging system may include: a battery charging circuit 101 and a battery protection circuit 103; wherein the battery charging circuit 101 is used to charge the battery, and the battery protection circuit 103 is used to protect the battery during the process of the battery charging circuit 101 charging the battery. The battery charging circuit 101 and the battery protection circuit 103 are described in detail below.

[0028] The battery charging circuit 101 includes: a charging management module 1011 connected to the battery and used for managing the charging of the battery.

[0029] Figure 2 is a schematic diagram of an optional battery charging system according to an embodiment of the present invention, such as Figure 2 As shown, the battery charging circuit may include a charging management module 1011 for performing charging management, and the charging process of the battery can be managed through the charging management module.

[0030] Among them, when charging the battery, when the battery voltage is at different stages, three-stage charging can be achieved, for example, trickle charging, constant current charging, and constant voltage charging.

[0031] The battery here can be a cylindrical battery used in Tbox products, and of course it can also be other forms of batteries.

[0032] The battery protection circuit 103 includes: a charging protection module 1031 connected to the battery and the first transistor, and used for performing charging protection on the battery during the battery charging process.

[0033] like Figure 2 As shown, the battery protection circuit 103 may include a charging protection module 1031 for performing charging protection. The first transistor here may be Figure 3 ( Figure 3 FIG. 1 is a schematic diagram of another optional battery charging system according to an embodiment of the present invention, showing transistor Q1.

[0034] Among them, during the charging process, the charging protection module can provide overcharge, over discharge and short circuit protection functions.

[0035] The battery protection circuit 103 further includes: a battery reverse connection sampling module 1033 connected to the battery and used for collecting the reverse connection voltage of the battery when it is reversely connected.

[0036] like Figure 2 As shown, the battery protection circuit 103 here may further include a battery reverse connection sampling circuit (ie, a battery reverse connection sampling module 1033 ) which can collect the reverse connection voltage of the battery when it is reversely connected.

[0037] The battery protection circuit 103 further includes: a level conversion module 1035 connected to the battery reverse connection sampling module, and configured to perform reverse connection protection on the battery when it is determined that the battery is in a reverse connection state.

[0038] like Figure 2 As shown, the charging protection module 103 may further include a level conversion module 1035, which is connected to the battery reverse connection sampling module and can perform reverse connection protection on the battery when the battery is in a reverse connection state.

[0039] As can be seen from the above, in an embodiment of the present invention, a battery charging circuit and a battery protection circuit can be set in a battery charging system, wherein the battery charging circuit includes: a charging management module connected to the battery and used to manage the charging of the battery; the battery protection circuit includes: a charging protection module connected to the battery and the first transistor, and used to protect the battery from charging during the battery charging process; the battery protection circuit also includes: a battery reverse connection sampling module connected to the battery and used to collect the reverse voltage of the battery when it is reversely connected; the battery protection circuit also includes: a level conversion module connected to the battery reverse connection sampling module, and used to perform reverse connection protection on the battery when it is determined that the battery is in a reverse connection state, so that during the battery charging process, the voltage during the charging process can be collected by the battery reverse connection sampling module, and when the battery is determined to be reversely connected according to the sampled voltage, the charging circuit can be automatically cut off to prevent the battery from being burned due to reverse connection, thereby reducing the potential safety hazards during the battery charging process and improving the safety of battery charging.

[0040] Therefore, the technical solution provided by the embodiment of the present invention solves the technical problem in the related art that the battery charging system generally does not have an anti-reverse connection function and has potential safety hazards.

[0041] According to the above embodiment of the present invention, the battery charging circuit includes: a power supply connected to the charging management module, and used to provide power to the battery charging circuit through the charging management module to charge the battery.

[0042] like Figure 2 As shown, the battery charging circuit may include a power supply, that is, a 5V power supply in the figure, which can provide power to the battery charging circuit so that the battery can be charged.

[0043] also, Figure 2 The battery in the device is the battery being charged, and the load is the other circuit S2 that works in the later stage. Figure 3 The MOS tube Q1 in the circuit is used as a switch.

[0044] According to the above embodiment of the present invention, the charging management module includes: a first chip, connected to a power supply, for performing charging management on a battery; a first capacitor and a second capacitor, the first capacitor being connected in parallel with the second capacitor and being connected to the first chip and the power supply, for filtering the current coming from the power supply; a first resistor being connected to the first chip, for setting the charging current of the first chip according to the electrical parameters of the battery; a second resistor being connected to the first chip, for managing the charging process of the battery according to the ambient temperature of the charging environment in which the battery is located; a third resistor being connected to the first chip and the first diode, for performing current limiting processing on the first diode; a third capacitor and a fourth capacitor, the third capacitor and the fourth capacitor being connected in parallel and being connected to the first chip, for filtering the current coming from the first chip.

[0045] like Figure 3 As shown, the charging management module may include: a first chip U1, which is connected to a power supply (VCC_5V) through a transistor Q1 (when Q1 is turned on), so that the power supply can charge the battery, and R2 and R3 are used to divide the voltage of VCC_5V, which are the G pole and S pole of the MOS tube respectively, and can provide a suitable voltage to control the on and off of the MOS tube Q1.

[0046] Here, a first capacitor (ie, C1) and a second capacitor (ie, C2) are also included. Figure 3 As shown, capacitor C1 and capacitor C2 are connected in parallel and connected to chip U1, so as to filter the current coming from the power supply.

[0047] Figure 3 The middle resistor R4 (i.e., the first resistor) is connected to the chip U1, and the charging current of the chip U1 can be set according to the electrical parameters of the battery. That is, the resistor R4 can be adjusted according to the electrical parameters of the battery to be charged (for example, capacity, voltage, internal resistance, power, etc.), and then the charging current of the chip U1 can be adjusted, so that the current adjusted by the chip U1 can meet the charging requirements of the battery.

[0048] like Figure 3 As shown, resistors R5 (i.e., the second resistor) and R6 (i.e., the third resistor) are also included here, wherein R5 is connected to the chip U1, and the charging process of the battery can be managed according to the ambient temperature of the charging environment where the battery is located. For example, when the charging environment is monitored to be less than 0°C or greater than 40°C, the resistor R5 can be used to stop charging the battery to protect the battery.

[0049] The above R6 is also connected to the chip U1 and also connected to the diode D1, so as to limit the current of D1.

[0050] As above Figure 3 As shown, capacitor C3 (ie, the third capacitor) and capacitor C4 (ie, the fourth capacitor) are also included here. Capacitor C3 and capacitor C4 are connected in parallel and connected to chip U1, so as to filter the current coming from chip U1.

[0051] The chip U1 may be a BQ21040DBVR chip.

[0052] According to the above embodiment of the present invention, the charging protection module includes: a second chip, used to protect the battery from overcharging or over-discharging when the charging current of the battery exceeds the charging current threshold or the discharging current of the battery exceeds the discharge current threshold of the battery; a fourth resistor, connected to the second chip, used to limit the current of the second chip; and a fifth capacitor, connected in parallel with the second chip, used to filter the second chip.

[0053] like Figure 3 As shown, the charging protection module may include a chip U2 (ie, a second chip), which may protect the battery from overcharging or overdischarging when the charging current of the battery exceeds a charging current threshold or the discharging current of the battery exceeds a discharging current threshold.

[0054] like Figure 3 As shown, the charging protection module may further include a resistor R11 (i.e., a fourth resistor), which is connected to the chip U2 and can perform current limiting processing on the chip U2. In addition, it may further include a capacitor C5 (i.e., a fifth capacitor), which is connected to the chip U2 and can perform filtering processing on the chip U2.

[0055] The chip U2 here can be a SC5510ADFER model chip. It provides overcharge, over-discharge and short-circuit protection functions during the charging process. It detects the different currents flowing through the two internally integrated MOS and the different voltage drops generated on the on-resistance, thereby achieving overcharge, over-discharge and short-circuit protection.

[0056] According to the above embodiment of the present invention, the charging protection module also includes: a fifth resistor, connected to the second transistor, and used to perform current limiting processing on the second transistor; the second transistor, cooperating with the first transistor, is used to perform charging protection on the charging process of the battery.

[0057] like Figure 3 As shown, the charging protection module may further include a resistor R12 (i.e., a fifth resistor), which is connected to a transistor Q2 (i.e., a second transistor), and may perform current limiting on the transistor Q2; the transistor Q2 is used in conjunction with the transistor Q1 to protect the charging process of the battery.

[0058] According to the above embodiment of the present invention, the charging protection module also includes: a sixth resistor and a seventh resistor, the sixth resistor is connected in series with the seventh resistor and connected in parallel with the battery, and is used to perform voltage division processing on the battery; a sixth capacitor is connected in parallel with the sixth resistor and is used to perform filtering processing on the battery.

[0059] like Figure 3 As shown, the charging protection module may also include a resistor R13 (i.e., a sixth resistor) and a resistor R14 (i.e., a seventh resistor). The resistor R13 and the resistor R14 are connected in series and in parallel with the battery (BAT), and the battery can be voltage-divided; the capacitor C6 (i.e., the sixth capacitor) is connected in parallel with the resistor R13, and can be used for filtering the battery.

[0060] According to the above embodiment of the present invention, the level conversion module includes: a third transistor, which is connected to an eighth resistor and a ninth resistor, and when the battery is connected reversely, outputs a high voltage to trigger the first transistor to be cut off to stop charging the battery; the eighth resistor is used to limit the current of the third transistor; and the ninth resistor is used to provide a steady-state current for the third transistor.

[0061] like Figure 3 As shown, the level conversion module may include a transistor Q2 (i.e., a third transistor), which is connected to a resistor R7 (i.e., an eighth resistor) and a resistor R8 (i.e., a ninth resistor). When the battery is reversely connected, the high voltage output by V_DET triggers the transistor Q1 to be turned off, thereby stopping the charging of the battery to achieve charging protection when the battery is reversely connected; the resistor R7 here can limit the current of the transistor Q2, and the resistor R8 can provide a steady-state current for the transistor Q2.

[0062] According to the above embodiment of the present invention, the level conversion module also includes: a fourth transistor, which is connected to the tenth resistor, the eleventh resistor and the twelfth resistor. When the battery is positively connected, a high voltage is obtained by dividing the voltage from the power supply to maintain the first transistor turned on to charge the battery.

[0063] like Figure 3 As shown, the level conversion module (i.e., the level conversion module) may include a transistor Q3 (i.e., the fourth transistor), which is connected to a resistor R1 (i.e., the tenth resistor), a resistor R9 (i.e., the eleventh resistor), and a resistor R10 (i.e., the twelfth resistor). When the battery is in a positive connection state, a high voltage is obtained by dividing the voltage from the power supply to maintain the conduction of the transistor Q1 to charge the battery.

[0064] As can be seen from the above, the level conversion module is composed of transistor Q2, transistor Q3, resistor R1, resistor R7, resistor R8, resistor R9, and resistor R10. Its function is to convert the voltage of voltage V_DET. Because the high voltage range of V_DET is 0.7-2V, this high voltage is not enough to directly drive transistor Q1. Therefore, a level conversion circuit is required for conversion. The result of the conversion is that the low level of V_DET is converted to a low level electricity, and the high voltage of V_DET is converted to a uniform 5V.

[0065] According to the above embodiment of the present invention, when the battery is connected forwardly, the first transistor and the second transistor are both turned on to charge the battery; when the battery is connected reversely, the first transistor and the second transistor are both turned off to stop charging the battery.

[0066] In this embodiment, the battery reverse connection sampling circuit can detect the voltage V_DET at both ends of the battery when the battery is forwardly connected and reversely connected. The battery protection circuit is composed of: a battery BAT, a resistor R13, a resistor R14, and a diode D2. The resistors R14 and R13 analyze the battery voltage to obtain V_DET, and the capacitor C6 filters the divided voltage V_DET.

[0067] Among them, when the battery is connected forwardly, V_DET is at a low level (less than 0.6V), transistor Q1 is turned on, and transistor Q4 is turned off; when the battery is connected reversely, V_DET is at a high level (greater than 0.6V), transistor Q1 is turned off, and transistor Q4 is turned on.

[0068] According to the above embodiment of the present invention, when the battery is connected forwardly, the anode is connected to the cathode of the second diode; when the battery is connected reversely, the cathode is connected to the cathode of the second diode, wherein the anode of the second diode is connected to the sixth resistor.

[0069] In this embodiment, if Figure 4 ( Figure 4 is a schematic diagram of reverse connection of batteries according to an embodiment of the present invention, wherein the positive connection of the lower battery refers to the connection of the positive electrode of the battery BAT with the cathode of the diode D2; the reverse connection of the lower battery refers to the connection of the negative electrode of the battery BAT with the cathode of the diode D2; that is, the negative electrode of the battery BAT is connected to the cathode of D2, that is, the positive electrode is connected to BAT-, and the negative electrode is connected to BAT+.

[0070] As can be seen from the above, in the embodiment of the present invention, the above circuit functions are combined to achieve protection during the battery charging process when the battery is reversely connected. When the battery is connected forward, the battery is charged normally and the entire circuit loop is normal, that is, the transistor Q1 and the transistor Q4 are turned on.

[0071] Among them, when the battery is reversely connected: 1) transistor Q1 is disconnected, and the power supply to the charging chip U1 is stopped to prevent the charging circuit from continuing to reversely charge the battery after the battery is reversely connected; 2) transistor Q4 is disconnected, the circuit of the protection chip U2 is disconnected, and the battery is reversely connected, and no power is supplied to the subsequent circuit. Here, transistor Q1 is a PMOS, and when VGS (the gate-source voltage of the MOS tube) is less than 1.5V, Q1 is turned on, otherwise it is cut off; transistor Q4 is an NMOS, and when VGS (the gate-source voltage of the MOS tube) is greater than 2V, it is turned on, otherwise it is cut off.

[0072] When the battery is connected positively: When the battery is normal, that is, as shown in the figure above, BAT (BAT stands for battery), the positive pole is connected to BAT+ and the negative pole is connected to BAT-; when the external power supply is normal (the voltage at VCC_5V is 5V), the charging management chip U1 outputs 5V, and the chip U2 is powered normally and starts to work. At this time, the G pole of transistor Q4 is at a high level, VGS is greater than 2V, and transistor Q4 is turned on. The negative pole level of BAT is 0V, and the voltage divided by resistors R13 and R14 is also 0V. The level conversion circuit composed of transistors Q2 and Q3 outputs 0V level, that is, the G pole of transistor Q1 is at a low level, transistor Q1 is turned on, and chip U1 completes charging of the battery. When the external power supply is disconnected (the voltage at VCC_5V is 0V), chip U1 has no power input and does not work. Because the battery is normally connected to the circuit, the chip U2 supplies power normally. As long as the battery is not in an over-discharge or short-circuit state, the built-in MOS of chip U2 is turned on, the G pole of transistor Q4 is at a high level, the corresponding VGS is high, transistor Q4 is turned on, and the battery BAT supplies power to the load normally.

[0073] When the battery is reversely connected: When the battery is normal, that is, as shown in the figure above BAT (BAT stands for battery), the positive pole is connected to BAT-, and the negative pole is connected to BAT+; when there is an external power supply, first assume that transistor Q1 is turned on, the charging management chip U1 outputs a 5V voltage to power chip U2, and the VGS of transistor Q4 is high, and transistor Q4 is turned on, but due to the reverse connection of the battery, resistors R14 and R15 share a high voltage. After passing through the level conversion circuit, transistor Q1 is turned off, and chip U1 does not charge the battery, which protects the battery. At the same time, since chip U1 has no output and the battery is reversely connected, the G pole of transistor Q4 is low, transistor Q4 is not turned on, and chip U2 cannot be powered, completing the protection of U2 by reverse battery connection; when there is no external power supply, chip U1 does not work, its pin 2 has no voltage output, transistor Q1 is turned on or off, and chip U1 does not charge the battery. Since the battery BAT is reversely connected, the G pole of the MOS tube Q4 is at a low level, the transistor Q4 is not turned on, and the chip U2 cannot be powered, thus completing the protection of the chip U2 from the reverse connection of the battery.

[0074] The technical solution provided by the embodiment of the present invention effectively solves the problem of battery reverse connection and battery or charging protection chip burning. When no charging current is loaded, after the battery is reversed, the power supply circuit of the charging protection chip is automatically cut off to protect the charging chip; when the battery is reversed during charging, the charging circuit is automatically cut off to protect the battery from being damaged and the charging protection chip from being burned.

[0075] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0076] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0078] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0079] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0080] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A battery charging system, characterized in that: include: A battery charging circuit and a battery protection circuit, wherein the battery charging circuit is used to charge a battery, and the battery protection circuit is used to perform charging protection on the battery during the process of the battery charging circuit charging the battery; The battery charging circuit comprises: a charging management module connected to the battery and used for performing charging management on the battery; The battery protection circuit comprises: a charging protection module connected to the battery and the first transistor, and used for performing charging protection on the battery during the charging process of the battery; The battery protection circuit further includes: a battery reverse connection sampling module, connected to the battery, for collecting the reverse connection voltage of the battery when reversely connected; The battery protection circuit further includes: a level conversion module connected to the battery reverse connection sampling module, and configured to perform reverse connection protection on the battery when it is determined that the battery is in a reverse connection state.

2. The battery charging system according to claim 1, characterized in that: The battery charging circuit includes: a power supply connected to the charging management module, and configured to provide power to the battery charging circuit through the charging management module so as to charge the battery.

3. The battery charging system according to claim 1, characterized in that: The charging management module comprises: A first chip, connected to a power source, for managing charging of the battery; a first capacitor and a second capacitor, wherein the first capacitor is connected in parallel with the second capacitor and is connected to the first chip and the power supply, and is used to filter the current from the power supply; a first resistor, connected to the first chip, and used to set a charging current of the first chip according to electrical parameters of the battery; a second resistor, connected to the first chip, and used to manage the charging process of the battery according to the ambient temperature of the charging environment where the battery is located; a third resistor, connected to the first chip and the first diode, and used for current limiting processing of the first diode; A third capacitor and a fourth capacitor are connected in parallel and connected to the first chip, and are used for filtering the current coming from the first chip.

4. The battery charging system according to claim 1, characterized in that: The charging protection module comprises: A second chip is used to protect the battery from overcharge or overdischarge when the charging current of the battery exceeds a charging current threshold or the discharging current of the battery exceeds a discharging current threshold; a fourth resistor, connected to the second chip, and used for performing current limiting processing on the second chip; A fifth capacitor is connected in parallel with the second chip and is used for filtering the second chip.

5. The battery charging system according to claim 1, characterized in that: The charging protection module also includes: a fifth resistor, connected to the second transistor, and configured to perform current limiting processing on the second transistor; The second transistor cooperates with the first transistor to provide charging protection for the charging process of the battery.

6. The battery charging system according to claim 1, characterized in that: The charging protection module also includes: a sixth resistor and a seventh resistor, wherein the sixth resistor is connected in series with the seventh resistor and is connected in parallel with the battery, and is used to perform voltage division processing on the battery; A sixth capacitor is connected in parallel with the sixth resistor and is used for filtering the battery.

7. The battery charging system according to claim 1, characterized in that: The level conversion module comprises: a third transistor connected to the eighth resistor and the ninth resistor, and outputting a high voltage to trigger the first transistor to be turned off to stop charging the battery when the battery is connected reversely; The eighth resistor is used to perform current limiting processing on the third transistor; The ninth resistor is used to provide a steady-state current for the third transistor.

8. The battery charging system according to claim 7, characterized in that: The level conversion module also includes: The fourth transistor is connected to the tenth resistor, the eleventh resistor and the twelfth resistor, and when the battery is positively connected, divides the voltage from the power supply to obtain a high voltage, and maintains the first transistor turned on to charge the battery.

9. The battery charging system according to claim 5, characterized in that: When the battery is connected forwardly, the first transistor and the second transistor are both turned on to charge the battery; when the battery is connected reversely, the first transistor and the second transistor are both turned off to stop charging the battery.

10. The battery charging system according to claim 6, characterized in that: When the battery is forwardly connected, the positive electrode is connected to the cathode of the second diode; when the battery is reversely connected, the negative electrode is connected to the cathode of the second diode, wherein the positive electrode of the second diode is connected to the sixth resistor.

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