Dual-channel lithium battery charging and discharging control circuit with redundancy protection

Abstract

The utility model relates to the technical field of lithium batteries, and discloses a dual-channel lithium battery charge and discharge control circuit with redundancy protection, which comprises a lithium battery protection integrated module; a charging and discharging control module; a PTC protection module; a redundancy protection module; a time delay module; the lithium battery protection integration module is electrically connected with the charging and discharging control module and the time delay module. According to the utility model, a high-precision voltage and current detection circuit is integrated, the charging and discharging states of the lithium battery are monitored in real time, the resistance value is automatically increased when the temperature of the battery is too high, current passing is limited, the lithium battery is prevented from being overheated, the redundancy protection module provides additional safety guarantee, and the protection effect can still be continuously played in time when the main protection circuit breaks down; stable operation of the battery system is ensured; through the dual-channel design, the battery system is allowed to support two independent charging and discharging channels at the same time, and the flexibility and applicability of the battery are improved.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to the field of lithium battery charge and discharge control, specifically a dual-channel lithium battery charge and discharge control circuit with redundancy protection. Background Technology

[0002] Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the positive and negative electrode materials and a non-aqueous electrolyte solution. The charging and discharging process of lithium-ion batteries mainly depends on the movement of lithium ions between the positive and negative electrodes. During charging, lithium ions detach from the positive electrode, cross the electrolyte, and embed themselves in the negative electrode, making the negative electrode lithium-rich; while during discharging, the opposite reaction occurs, with lithium ions detaching from the negative electrode and returning to the positive electrode.

[0003] A search revealed that patent application number CN202020720705.1 discloses a lithium battery charging and discharging control circuit, including a charging module, a discharging module, a circuit breaking module, and a control module; it also includes a storage module, a current sampling module, a current comparison module, a first abnormality alarm module, a data display module, a wireless communication module, a temperature detection module, a temperature comparison module, a second abnormality alarm module, a heat dissipation module, a leakage current monitoring module, and a short circuit monitoring module. This invention uses the current sampling module and the current comparison module to monitor the real-time current value of the constant current discharge of the discharging module, ensuring the accuracy of the lithium battery test results. Furthermore, if a mismatch is detected between the real-time current value and the preset current value, the first abnormality alarm module will issue a current abnormality alarm, promptly alerting maintenance personnel and preventing significant losses.

[0004] Current lithium battery charging and discharging control processes cannot monitor the charging and discharging status of lithium batteries in real time, making it difficult to control charging and discharging quickly and accurately. This reduces the battery's efficiency and safety, and lacks protection mechanisms. When the battery temperature is too high, thermal runaway can easily occur, posing a safety hazard. Furthermore, the protection module for battery charging and discharging control is singular. Once a fault occurs, the battery's charging and discharging will lack protection, which is not conducive to the stable operation of the battery system. Therefore, we need to propose a dual-channel lithium battery charging and discharging control circuit with redundant protection. Summary of the Invention

[0005] The purpose of this invention is to provide a dual-channel lithium battery charge and discharge control circuit with redundant protection. It integrates high-precision voltage and current detection circuits to monitor the charge and discharge status of the lithium battery in real time. When the battery temperature is too high, it automatically increases the resistance to limit current flow and prevent overheating. The redundant protection module provides additional safety assurance; even if the main protection circuit fails, it can still continue to provide protection, ensuring stable operation of the battery system. The dual-channel design allows the battery system to support two independent charge and discharge channels simultaneously, improving the battery's flexibility and applicability, thus solving the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a dual-channel lithium battery charge / discharge control circuit with redundancy protection, comprising:

[0007] A lithium battery protection integrated module responsible for monitoring lithium battery voltage and current and outputting control signals;

[0008] A charge / discharge control module that controls the charging and discharging of lithium batteries based on the control signals output by the lithium battery protection integrated module;

[0009] A PTC protection module that connects to the charging and discharging circuit and provides high-temperature protection for lithium batteries to prevent them from spontaneously combusting at high temperatures.

[0010] A redundant protection module that continues to function even when the main protection circuit fails;

[0011] A time delay module used to distinguish between normal current and surge current;

[0012] The lithium battery protection integrated module is electrically connected to the charge / discharge control module and the delay module, respectively.

[0013] Preferably, the lithium battery protection integrated module includes electrically connected chips U1 and U2, chip U3, and connector CN1 connected to the lithium battery. A resistor R61 is connected between pins 6 and 7 of chip U1 and pin 2 of chip U2. A resistor R32 is connected between pin 5 of chip U2 and pin 1 of connector CN1. A capacitor C11 is connected between pin 5 of chip U2 and pin 2 of connector CN1.

[0014] Preferably, pin 2 of chip U3 is connected to resistors R41 and R51 connected in series; pin 4 of chip U3 is connected to capacitors C21 and C31 connected in parallel; pin 5 of chip U3 is connected to capacitors C411 and C51 connected in parallel; pin 6 of chip U3 is connected to LED2 and resistor R21 connected in series; and pin 7 of chip U3 is connected to LED1 and resistor R11 connected in series.

[0015] Preferably, the charging and discharging control module includes a USB connector, a chip U4, a chip K1, and a connector RS. Pin 1 of the USB connector is connected to pin 1 of the chip U4. Pin 8 of the chip U4 and pin 3 of the chip K1 are connected to capacitors C1, C2, C3, and C4 connected in parallel. Pin 2 of the chip U4 is connected to LEDs DS1 and DS3 connected in parallel. Pin 3 of the chip U4 is connected to LEDs DS2 and DS4 connected in parallel. An inductor L1 is connected between pin 6 of the chip U4 and pin 1 of the connector RS. Pin 1 of the connector RS is also connected to a resistor R2, a capacitor C6, and a capacitor C8 forming a closed loop.

[0016] Preferably, the PTC protection module includes a chip U8, a MOSFET Q4, and a MOSFET Q5. A resistor R30 and a resistor R31 are connected between pins 1 and 8 of the chip U8. A resistor R29 and a capacitor C24 are connected in parallel between pins 2 and 3 of the chip U8. A resistor R36 and a resistor R37 and a capacitor C26 are connected in parallel between pin 4 of the chip U8. A resistor R33 is connected between pin 7 of the chip U8 and the gate of the MOSFET Q4. A resistor R34 is connected between pin 5 of the chip U8 and the gate of the MOSFET Q5.

[0017] Preferably, a thermistor PTC1, a fuse F1, a fuse F2, and a thermistor PTC2 are connected in sequence between the drain of MOSFET Q4 and the drain of MOSFET Q5. A capacitor C64 and a capacitor C65 are connected in series between the source and the drain of MOSFET Q4, and a capacitor C66 and a capacitor C67 are connected in series between the source and the drain of MOSFET Q5.

[0018] Preferably, the redundancy protection module includes chip U5, MOSFET Q6, and MOSFET Q7. A resistor R72 is connected between pins 1 and 3 of chip U5, a resistor R73 is connected between pins 3 and 4 of chip U5, a resistor R74 is connected between pins 4 and 9 of chip U5, and a resistor R71 and a resistor R75 are connected to pin 11 of chip U5. Resistor R75 is connected to the gate of MOSFET Q6. The sources of MOSFET Q6 and MOSFET Q7 are both connected to pin 12 of chip U5. The drain of MOSFET Q6 is connected to pin 1 of chip U5, and the drain of MOSFET Q7 is connected to pin 8 of chip U5.

[0019] Preferably, the delay module includes a transistor Q1, with a light-emitting diode LED15, a resistor R15 and a diode D15 connected in parallel between the base and collector of the transistor Q1, and a resistor C15 connected between the base and emitter of the transistor Q1.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] 1. This utility model integrates a high-precision voltage and current detection circuit to monitor the charging and discharging status of the lithium battery in real time, and automatically increases the resistance when the battery temperature is too high to limit the current flow and prevent the lithium battery from overheating.

[0022] 2. The redundant protection module of this utility model provides additional safety assurance. Even if the main protection circuit fails, it can still continue to play a protective role and ensure the stable operation of the battery system. Through the dual-channel design, the battery system can support two independent charging and discharging channels at the same time, improving the flexibility and applicability of the battery. Attached Figure Description

[0023] Figure 1 This is a circuit diagram of the lithium battery protection integrated module of this utility model;

[0024] Figure 2 This is a circuit diagram of the charging and discharging control module of this utility model;

[0025] Figure 3 This is the circuit diagram of the PTC protection module of this utility model;

[0026] Figure 4 This is a circuit diagram of the redundancy protection module of this utility model;

[0027] Figure 5 This is the circuit diagram of the delay module of this utility model. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Please see Figure 1-5 This utility model provides a technical solution: a dual-channel lithium battery charging and discharging control circuit with redundancy protection, comprising:

[0030] A lithium battery protection integrated module responsible for monitoring lithium battery voltage and current and outputting control signals;

[0031] The lithium battery protection integrated module includes electrically connected chips U1, U2, and U3, and a connector CN1 connected to the lithium battery. A resistor R61 is connected between pins 6 and 7 of chip U1 and pin 2 of chip U2. A resistor R32 is connected between pin 5 of chip U2 and pin 1 of connector CN1. A capacitor C11 is connected between pin 5 of chip U2 and pin 2 of connector CN1.

[0032] Pin 2 of chip U3 is connected to resistors R41 and R51 connected in series. Pin 4 of chip U3 is connected to capacitors C21 and C31 connected in parallel. Pin 5 of chip U3 is connected to capacitors C411 and C51 connected in parallel. Pin 6 of chip U3 is connected to LED2 and resistor R21 connected in series. Pin 7 of chip U3 is connected to LED1 and resistor R11 connected in series.

[0033] Chip U3 is a constant current / constant voltage linear charging chip for lithium batteries, which realizes the charging management of lithium batteries. Pin 1 of chip U3 is used to monitor battery temperature, pin 2 of chip U3 is connected to an external resistor to set the charging current, and pins 6 and 7 of chip U3 are used to indicate the charging status.

[0034] Chip U2 is a lithium battery protection chip used to prevent overcharging, overcurrent and over-discharging of the battery. When the battery is abnormal, chip U2 will control chip U1 to cut off the circuit. Chip U1 is a dual N-channel MOSFET, which acts as a switch to realize the on and off control of the battery charging and discharging circuit.

[0035] A charge / discharge control module that controls the charging and discharging of lithium batteries based on the control signals output by the lithium battery protection integrated module;

[0036] The charging and discharging control module includes a USB connector, a chip U4, a chip K1, and a connector RS. Pin 1 of the USB connector is connected to pin 1 of the chip U4. Pin 8 of the chip U4 and pin 3 of the chip K1 are connected to capacitors C1, C2, C3, and C4 in parallel. Pin 2 of the chip U4 is connected to LEDs DS1 and DS3 in parallel, and pin 3 of the chip U4 is connected to LEDs DS2 and DS4 in parallel. An inductor L1 is connected between pin 6 of the chip U4 and pin 1 of the connector RS. Pin 1 of the connector RS is also connected to a resistor R2, a capacitor C6, and a capacitor C8 to form a closed loop.

[0037] Chip U4 is a multi-functional power management chip that integrates a boost converter, lithium battery charging management, and battery power indicator. It receives power through a USB connector. Resistor R1, capacitor C5, and capacitor C7 form a filter circuit to stabilize the input voltage.

[0038] Pins 2, 3, and 4 of chip U4 are connected to multiple LEDs to indicate the charging status and power of the lithium battery. Pin 8 of chip U4 is used to output a stable voltage, which is then filtered by capacitors C1, C2, C3, and C4 before being supplied to the load.

[0039] Inductor L1 and chip U4 form a boost circuit to raise the low voltage of the lithium battery to the required output voltage. Resistor R2 is used for current detection, and resistor R3, in conjunction with button KEY1, acts as a voltage divider. Capacitors C6 and C8 serve to filter, stabilize the voltage, and couple the circuit.

[0040] A PTC protection module that connects to the charging and discharging circuit and provides high-temperature protection for lithium batteries to prevent them from spontaneously combusting at high temperatures.

[0041] The PTC protection module includes chip U8, MOSFET Q4, and MOSFET Q5. Resistors R30 and R31 are connected between pins 1 and 8 of chip U8. Resistors R29 and C24 are connected in parallel between pins 2 and 3 of chip U8. Resistors R36 and R37, along with capacitor C26, are connected in parallel between pin 4 of chip U8. Resistor R33 is connected between pin 7 of chip U8 and the gate of MOSFET Q4. Resistor R34 is connected between pin 5 of chip U8 and the gate of MOSFET Q5.

[0042] A thermistor PTC1, a fuse F1, a fuse F2, and a thermistor PTC2 are connected in sequence between the drain of MOSFET Q4 and the drain of MOSFET Q5. A capacitor C64 and a capacitor C65 are connected in series between the source and the drain of MOSFET Q4, and a capacitor C66 and a capacitor C67 are connected in series between the source and the drain of MOSFET Q5.

[0043] The input signal PWM1 passes through resistors R28 and R29 and capacitor C24, and the input signal PWM2 passes through resistors R36 and R37 and capacitor C26. After filtering, they are input to the INA and INB pins of chip U8 respectively to control the output of chip U8.

[0044] MOSFETs Q4 and Q5 receive the output signal from chip U8. After being current-limited by resistors R33 and R34, they control the conduction and cutoff of the transistors, thereby controlling the on / off state of high voltage HV+ or the magnitude of the current.

[0045] Thermistors PTC1 and PTC2 provide overcurrent and overheat protection. When the current in the circuit is too large or the temperature is too high, their resistance will increase rapidly, limiting the current.

[0046] Diodes D11 and D12 are used to protect the transistor from damage caused by the reverse electromotive force generated by the inductive load.

[0047] A redundant protection module that continues to function even when the main protection circuit fails;

[0048] The redundancy protection module includes chip U5, MOSFET Q6, and MOSFET Q7. A resistor R72 is connected between pins 1 and 3 of chip U5, a resistor R73 is connected between pins 3 and 4 of chip U5, a resistor R74 is connected between pins 4 and 9 of chip U5, and a resistor R71 and a resistor R75 are connected to pin 11 of chip U5. Resistor R75 is connected to the gate of MOSFET Q6. The sources of MOSFET Q6 and MOSFET Q7 are both connected to pin 12 of chip U5. The drain of MOSFET Q6 is connected to pin 1 of chip U5, and the drain of MOSFET Q7 is connected to pin 8 of chip U5.

[0049] Chip U5 is a diode controller chip used to prevent reverse power flow and reduce forward voltage drop. Pin 3 of chip U5 is used to monitor the input voltage through a voltage divider circuit composed of resistors R72, R73, and R74. When the input voltage is lower than the set undervoltage threshold, chip U5 takes corresponding protection measures.

[0050] MOSFETs Q6 and Q7, controlled by chip U5, achieve unidirectional power supply conduction, reducing the conduction losses of traditional diodes. Capacitor C72 filters the input power supply, and capacitor C71 filters the output power supply.

[0051] A time delay module used to distinguish between normal current and surge current;

[0052] The delay module includes a transistor Q1, with a light-emitting diode LED15, a resistor R15 and a diode D15 connected in parallel between the base and collector of the transistor Q1, and a resistor C15 connected between the base and emitter of the transistor Q1.

[0053] Transistor Q1 is a switching element. When a suitable current flows into the base of transistor Q1, transistor Q1 conducts and diode D15 lights up. When there is no current or insufficient current at the base of transistor Q1, transistor Q1 is cut off and diode D15 turns off.

[0054] Capacitor C15 acts as a time delay. At the instant the power supply VCC is turned on, the voltage across capacitor C15 cannot change abruptly; at this moment, capacitor C15 is essentially short-circuited, and current flows through resistor R15 to charge capacitor C15. As the charging process progresses, the voltage across capacitor C15 gradually increases. After a period of time, capacitor C15 is fully charged, allowing sufficient bias current to reach the base of transistor Q1, turning on transistor Q1 and illuminating diode LED15.

[0055] Resistor R15 is used to limit the charging current of capacitor C15, determine the charging time constant of capacitor C15 (time constant = R15 * C15), and thus control the delay lighting time of diode LED15.

[0056] Diode D15 serves a protective function. When the circuit is powered off, the charge stored in capacitor C15 can be quickly released through the circuit formed by diode D15 and resistor R15, preventing the voltage of capacitor C15 from damaging other components.

[0057] The lithium battery protection integrated module is electrically connected to the charge / discharge control module and the delay module, respectively.

[0058] During normal charging and discharging, the lithium battery protection integrated module monitors parameters such as battery voltage, current, and temperature in real time. The charge and discharge control module controls the battery's charging and discharging circuit according to the instructions from the lithium battery protection integrated module.

[0059] When the battery experiences abnormal conditions such as overcharging, over-discharging, overcurrent, short circuit, or overheating, the lithium battery protection integrated module first detects these abnormalities and then confirms through a delay module whether the protection mechanism truly needs to be activated. If protection is confirmed, a signal is sent to the charge / discharge control module to cut off the corresponding charge / discharge circuit. Simultaneously, the PTC protection module also provides additional protection when the battery overheats.

[0060] When the main circuit protection mechanism fails or malfunctions, the redundant protection module can quickly switch to standby mode to take over the work of the faulty part and ensure the continuous operation of the battery system.

[0061] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dual-channel lithium battery charge / discharge control circuit with redundancy protection, characterized in that, include: A lithium battery protection integrated module responsible for monitoring lithium battery voltage and current and outputting control signals; A charge / discharge control module that controls the charging and discharging of lithium batteries based on the control signals output by the lithium battery protection integrated module; A PTC protection module that connects to the charging and discharging circuit and provides high-temperature protection for lithium batteries to prevent them from spontaneously combusting at high temperatures. A redundant protection module that continues to function even when the main protection circuit fails; A time delay module used to distinguish between normal current and surge current; The lithium battery protection integrated module is electrically connected to the charge / discharge control module and the delay module, respectively. The lithium battery protection integrated module includes electrically connected chips U1, U2, and U3, and a connector CN1 connected to the lithium battery. A resistor R61 is connected between pins 6 and 7 of chip U1 and pin 2 of chip U2. A resistor R32 is connected between pin 5 of chip U2 and pin 1 of connector CN1. A capacitor C11 is connected between pin 5 of chip U2 and pin 2 of connector CN1. Pin 2 of chip U3 is connected to resistors R41 and R51 connected in series. Pin 4 of chip U3 is connected to capacitors C21 and C31 connected in parallel. Pin 5 of chip U3 is connected to capacitors C411 and C51 connected in parallel. Pin 6 of chip U3 is connected to a series-connected LED LED2 and resistor R21. Pin 7 of chip U3 is connected to a series-connected LED LED1 and resistor R11. The PTC protection module includes chip U8, MOSFET Q4, and MOSFET Q5. Resistors R30 and R31 are connected between pins 1 and 8 of chip U8. Resistors R29 and capacitor C24 are connected in parallel between pins 2 and 3 of chip U8. Resistors R36 and R37, along with capacitor C26, are connected in parallel between pin 4 of chip U8. Resistor R33 is connected between pin 7 of chip U8 and the gate of MOSFET Q4. Resistor R34 is connected between pin 5 of chip U8 and the gate of MOSFET Q5. A thermistor PTC1, a fuse F1, a fuse F2, and a thermistor PTC2 are connected sequentially between the drain of MOSFET Q4 and the drain of MOSFET Q5. A capacitor C64 and a capacitor C65 are connected in series between the source and the drain of MOSFET Q4. A capacitor C66 and a capacitor C67 are connected in series between the source and the drain of MOSFET Q5. The redundancy protection module includes chip U5, MOSFET Q6, and MOSFET Q7. A resistor R72 is connected between pins 1 and 3 of chip U5, a resistor R73 is connected between pins 3 and 4 of chip U5, a resistor R74 is connected between pins 4 and 9 of chip U5, and a resistor R71 and a resistor R75 are connected to pin 11 of chip U5. Resistor R75 is connected to the gate of MOSFET Q6. The sources of MOSFET Q6 and MOSFET Q7 are both connected to pin 12 of chip U5. The drain of MOSFET Q6 is connected to pin 1 of chip U5, and the drain of MOSFET Q7 is connected to pin 8 of chip U5.

2. The dual-channel lithium battery charging and discharging control circuit with redundancy protection according to claim 1, characterized in that: The charging and discharging control module includes a USB connector, a chip U4, a chip K1, and a connector RS. Pin 1 of the USB connector is connected to pin 1 of the chip U4. Pin 8 of the chip U4 and pin 3 of the chip K1 are connected to capacitors C1, C2, C3, and C4 in parallel. Pin 2 of the chip U4 is connected to LEDs DS1 and DS3 in parallel, and pin 3 of the chip U4 is connected to LEDs DS2 and DS4 in parallel. An inductor L1 is connected between pin 6 of the chip U4 and pin 1 of the connector RS. Pin 1 of the connector RS is also connected to a resistor R2, a capacitor C6, and a capacitor C8 to form a closed loop.

3. The dual-channel lithium battery charge / discharge control circuit with redundancy protection according to claim 1, characterized in that: The delay module includes a transistor Q1, with a light-emitting diode LED15, a resistor R15 and a diode D15 connected in parallel between the base and collector of the transistor Q1, and a resistor C15 connected between the base and emitter of the transistor Q1.

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