Lithium battery with MPPT (Maximum Power Point Tracking) charging function

Abstract

The utility model discloses a lithium battery with an MPPT (Maximum Power Point Tracking) charging function. The lithium battery comprises an MPPT charging board, a battery cell group and a battery protection board, the input end of the MPPT charging panel is connected with the output end of an external solar cell panel, and the output end of the MPPT charging panel is connected with the input end of the cell group; the battery protection plate is connected with the battery cell group, and a battery management system is arranged in the battery protection plate. An MPPT controller is arranged in the MPPT charging panel; the MPPT controller comprises a control module, a DC-DC converter and a charging management module. The DC-DC converter is connected in series between the solar cell panel and the cell group, and the control module is connected with the DC-DC converter; and the DC-DC converter adopts a synchronous rectification BUCK circuit. The charging management module comprises a second single-chip microcomputer, a battery detection circuit and a battery protection circuit. The signal receiving end of the second single-chip microcomputer is connected with the battery detection circuit, and the signal output end of the second single-chip microcomputer is connected with the BUCK circuit and the battery protection circuit. The MPPT controller is also provided with a plurality of protection circuits. The lithium battery provides a hardware basis for realizing more efficient and safer charging and discharging.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a lithium battery with MPPT charging function. Background Technology

[0002] Most solar lithium batteries on the market today that do not integrate MPPT charging panels have the following problems: (1) they cannot be charged with optimal charging efficiency when the light conditions change, resulting in low energy utilization efficiency; (2) they rely on additional charging equipment or systems for charging, which increases the complexity and cost of the system.

[0003] To address the aforementioned issues, those skilled in the art have proposed an innovative solution integrating an MPPT charging plate into a lithium battery. The core principle of MPPT technology is to calculate the optimal power point by real-time monitoring of the solar panel's voltage and current, and automatically adjust the system's operating state to ensure the solar panel always operates at its maximum energy conversion rate. Compared to traditional solar lithium batteries, solar lithium batteries integrating an MPPT charging plate possess the following technological advantages: higher charging efficiency and system stability through efficient energy utilization and intelligent charging control. Furthermore, policy support provides strong guarantees for the development of this technology. Therefore, lithium batteries integrating an MPPT charging plate have broad application prospects and significant social importance, representing a future direction for new energy power equipment. At this stage of technological innovation, this application aims to propose a power device with MPPT charging functionality, balancing energy utilization with charging control and protection, and achieving more efficient and safer charging and discharging through a more mature hardware architecture. Utility Model Content

[0004] The main technical problem to be solved by this utility model is to provide a power supply device with MPPT charging function, so as to provide a hardware foundation for achieving more efficient and safer charging and discharging.

[0005] To solve the above-mentioned technical problems, this utility model provides a lithium battery with MPPT charging function, including an MPPT charging board and a cell assembly; the input terminal of the MPPT charging board is connected to the output terminal of an external solar panel, and the output terminal is connected to the input terminal of the cell assembly;

[0006] The MPPT charging board has a built-in MPPT controller; the MPPT controller includes a control module and a DC-DC converter; the DC-DC converter is connected in series between the solar panel and the battery cell assembly, and the control module is connected to the DC-DC converter; the DC-DC converter adopts a synchronous rectification BUCK circuit.

[0007] The MPPT controller also includes a charging management module; the charging management module includes a second microcontroller, a battery detection circuit, and a battery protection circuit; the input terminal of the second microcontroller is connected to the battery detection circuit, and the output terminal is connected to the BUCK circuit and the battery protection circuit.

[0008] The MPPT controller is equipped with several protection circuits.

[0009] In a preferred embodiment, the control module includes a first microcontroller and a voltage / current sampling circuit; the voltage / current sampling circuit is used to collect the output voltage and current of the solar panel for the first microcontroller; the first microcontroller has a built-in MPPT algorithm for controlling the DC-DC converter to adjust the output voltage and current of the solar panel.

[0010] In a preferred embodiment, the voltage / current sampling circuit is provided with a digital-to-analog converter; the digital-to-analog converter is used to convert the detected voltage and current analog signals into digital signals that can be recognized and processed by the first microcontroller.

[0011] In a preferred embodiment, the second microcontroller is integrated with the first microcontroller.

[0012] In a preferred embodiment, the protection circuit includes a first reverse protection circuit and a second reverse protection circuit; the first reverse protection circuit is disposed at the input terminal of the MPPT controller; the second reverse protection circuit is disposed between the DC-DC converter and the battery pack.

[0013] In a preferred embodiment, the protection circuit further includes a cycle-by-cycle protection circuit; the cycle-by-cycle protection circuit is disposed within the DC-DC converter.

[0014] In a preferred embodiment, the MPPT controller further includes an interaction module; the interaction module includes a display screen and buttons.

[0015] In a preferred embodiment, the MPPT controller further includes a DC-DC auxiliary power supply circuit for supplying power to the control module and the DC-DC converter.

[0016] In a preferred embodiment, the DC-DC converter further includes a driving circuit; the driving circuit is connected in series between the control module and the BUCK circuit; the driving circuit is used to receive a pulse width modulation signal sent by the control module and drive the BUCK circuit to change its duty cycle.

[0017] In a preferred embodiment, the lithium battery further includes a battery protection board; the battery protection board is connected to the cell assembly; and the battery protection board has a built-in battery management system.

[0018] Compared with the prior art, the technical solution of this utility model has the following beneficial effects:

[0019] Improving energy efficiency. The lithium battery provided by this invention can track the maximum power point of the solar panel in real time, ensuring that the solar panel can output maximum power under any lighting conditions, which greatly improves the efficiency of solar energy utilization. According to actual application data and market research, compared with lithium batteries without integrated MPPT charging function, the energy utilization efficiency of the lithium battery may be improved by 20% to 30%. In ideal conditions, MPPT technology can even increase the output power of the solar panel by 50%, although this improvement is still limited by factors such as environmental influences and heat loss.

[0020] Extending lithium battery lifespan. The built-in MPPT controller not only focuses on energy conversion efficiency but also emphasizes the charge and discharge protection of the battery pack. By monitoring the charging stage and charge / discharge temperature in real time, the MPPT controller automatically adjusts the charging voltage and current of the battery pack and provides power-off protection in case of overcharging, over-discharging, and overheating, ensuring the safe and efficient operation of the battery pack. The integration of the MPPT controller typically extends the lifespan of the lithium battery by 10% to 20%, with the specific extension depending on the initial state of the lithium battery and the usage environment.

[0021] Enhanced stability and reliability. The built-in MPPT controller employs advanced electronic regulation technology, automatically adapting to varying light and temperature conditions. This effectively resists the effects of fluctuations in solar panel output voltage and load changes, ensuring the photovoltaic system operates stably at maximum power. Furthermore, the MPPT controller provides multiple protection functions for the charging circuit, such as overvoltage protection, overcurrent protection, and short-circuit protection, further enhancing the stability of lithium battery charging and discharging.

[0022] This provides an efficient and flexible charging solution. The lithium battery, integrated with an MPPT charging board, can achieve a maximum input voltage of 100V, making it compatible with most solar panels and solving the problem of module matching difficulties, thus facilitating cell selection. Furthermore, the MPPT controller has the advantages of being able to be integrated with DC distribution cabinets for low-power applications and multiple units connected in parallel for high-power applications, making system expansion and maintenance easier. These characteristics make the lithium battery provided in this embodiment more flexible and scalable in practical applications, meeting the charging needs of different scenarios. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of the lithium battery described in the embodiments of this utility model;

[0024] Figure 2This is a circuit block diagram of the MPPT controller described in an embodiment of the present invention.

[0025] The diagram is labeled as follows: 1-MPPT charging board, 2-battery protection board, 3-cell pack, 4-casing. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped with", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0029] like Figures 1-2 As shown, this embodiment of the present invention provides a lithium battery with MPPT charging function, including an MPPT charging board 1, a battery protection board 2, and a cell assembly 3. The input terminal of the MPPT charging board 1 is connected to the output terminal of an external solar panel, and the output terminal is connected to the input terminal of the cell assembly 3. The battery protection board 2 is connected to the cell assembly 3. The lithium battery also includes a casing 4, in which the MPPT charging board 1, battery protection board 2, and cell assembly 3 are installed. It should be explained that MPPT, or Maximum Power Point Tracking, is a technology used to optimize the energy conversion efficiency of photovoltaic (solar) systems. Its core is to dynamically adjust the voltage and current of the photovoltaic panel so that the photovoltaic panel always outputs maximum power, which is a mature existing technology.

[0030] The MPPT charging board 1 has a built-in MPPT controller, which includes a control module, a DC-DC converter, a charging management module, and an interaction module. The control module includes a first microcontroller and a voltage / current sampling circuit, and the DC-DC converter includes a BUCK circuit and a drive circuit. In this embodiment, the charging management module is integrated into the circuit board of the BUCK circuit. Additionally, the control circuit also includes a protection circuit, a DC-DC auxiliary power supply circuit, etc. The protection circuit includes a first reverse protection circuit, a second reverse protection circuit, and a cycle-by-cycle protection circuit. The following description, in conjunction with... Figure 2 The charging board will be further described below. It should be noted that, to better understand how the various modules of the lithium battery achieve their preset functions through hardware connections and communication, this embodiment involves software control in several places. However, the claims protect the hardware composition and hardware connection relationships in this embodiment, and do not involve the aforementioned software control content.

[0031] The MPPT controller uses a solar panel as its energy source. After the solar panel is connected to the MPPT charging panel 1, its output current first passes through a first reverse protection circuit located at the input of the MPPT controller to prevent damage to the MPPT controller due to excessive photovoltaic panel voltage or reverse connection. Furthermore, the voltage and current output by the solar panel are constantly changing due to environmental factors such as light intensity and temperature. Therefore, an input filter needs to be configured in the MPPT controller to preprocess the output voltage and current of the solar panel, filtering out high-frequency noise and ripple, and providing a stable power supply and signal input for the subsequent control module and DC-DC converter.

[0032] The charging current flowing from the first reverse protection circuit enters the DC-DC converter, and after conversion, passes through the second reverse protection circuit before finally connecting to the cell assembly 3 and the load. When the cell assembly 3 is reverse-connected to the MPPT charging board 1, the second reverse protection circuit will immediately respond with reverse connection protection to prevent damage to circuit components. The core component of the DC-DC converter is a BUCK circuit composed of switching devices, inductors, capacitors, and other components. In this embodiment, the DC-DC converter uses a synchronous rectification BUCK circuit, and the switching device uses a MOSFET. Driven by a pulse width modulation (PWM) signal, the MOSFET changes its switching frequency and duty cycle, thereby converting the unstable high-voltage DC output from the solar panel into a stable low-voltage DC suitable for charging the cell assembly 3. Then, the output filter in the BUCK circuit further filters out high-frequency noise and ripple in the low-voltage DC to ensure a stable and pure charging voltage. It should be understood that when the DC-DC converter performs voltage conversion, it also changes the output voltage and current of the solar panel.

[0033] We know that under specific environmental factors such as light and temperature, the output voltage and current of a solar panel can be adjusted to a certain combination using the aforementioned DC-DC converter, enabling the solar panel to achieve maximum power generation and efficiently charge the lithium battery with maximum energy utilization. However, since the internal resistance of the solar panel constantly changes with factors such as light and temperature, the maximum power generation is constantly changing. Therefore, the control module is needed to adjust the output voltage and current of the solar panel to an ideal combination in real time according to the changing operating environment, so as to maintain it at maximum power generation at all times.

[0034] The control module, as the core of the lithium battery in this embodiment, comprises a first microcontroller and a voltage / current sampling circuit. The voltage / current sampling circuit uses an analog-to-digital converter (ADC) for sampling. In this embodiment, the ADC is built into the BUCK circuit. Under the software control of the first microcontroller, it detects the output voltage and current of the solar panel, as well as the battery voltage and charging current in real time, and converts these analog signals into digital signals that the first microcontroller can process. This sampled data is the basis for subsequent calculation of the solar panel output power and tracking the maximum power point. To achieve accurate detection, the software control logic needs to configure parameters such as the ADC sampling rate and resolution, and filter the sampling results to reduce noise interference. The first microcontroller, as the control brain of the control module, receives the digital signals transmitted by the ADC and executes advanced MPPT algorithms, such as the perturbation-observation method or the incremental conductance method, to calculate the maximum power point of the solar panel under the current light and temperature conditions, i.e., the optimal operating voltage and current of the solar panel. Subsequently, the first microcontroller generates a corresponding duty cycle signal based on the calculation results and transmits it to the DC-DC converter through a PWM signal generation circuit. Specifically, the DC-DC converter also includes a drive circuit to receive and amplify the PWM signal transmitted by the first microcontroller, thereby driving the BUCK circuit to change the duty cycle of the MOSFET. A cycle-by-cycle protection circuit is also provided between the drive circuit and the BUCK circuit to provide overcurrent protection for the DC-DC converter. Downstream of the first direction protection circuit, a DC-DC auxiliary power supply circuit is provided to provide operating power to the first microcontroller and the drive circuit. When the control module starts working, system initialization should be performed first, including setting the I / O ports, timers, interrupts, etc., of the first microcontroller; parameters related to the MPPT algorithm, such as the disturbance step size and judgment threshold, should also be configured.

[0035] The maximum power point tracking (MPPT) algorithm is the core of the control module. Essentially, it's based on the maximum power transfer theorem, continuously adjusting the equivalent impedance of the DC-DC converter (equivalent to the load resistance) to track and approximate the internal resistance of the solar panel (equivalent to the power supply resistance), thus enabling cell group 3 to achieve maximum charging power. Commonly used MPPT algorithms include the perturbation-observation method and the incremental conductance method. Taking the perturbation-observation method as an example, its software control logic is: perturbation application → power calculation and comparison → tracking direction adjustment → convergence judgment. Specifically, it can be explained as follows: within any control cycle, the duty cycle of the BUCK circuit is changed by altering the PWM signal, affecting the voltage / current of the charging circuit, thereby perturbing the output power of the solar panel. Then, the photovoltaic panel power within this control cycle is acquired and compared with the photovoltaic panel power in the previous control cycle. Based on the relationship between the photovoltaic panel power in the two control cycles, the perturbation direction and magnitude of the next step in the duty cycle are determined, and then the duty cycle is further adjusted in the next control cycle. By continuously looping this logic, the change in photovoltaic panel power between two adjacent control cycles gradually approaches 0, thereby dynamically maintaining the solar panel at its maximum power point.

[0036] The charging management module includes a second microcontroller, a battery detection circuit, and a battery protection circuit. The signal receiving end of the second microcontroller is connected to the battery detection circuit, and the signal output end is connected to the BUCK circuit and the battery protection circuit. The battery detection circuit is used to detect the voltage, charging current, and temperature of the battery cell group 3 in real time. Based on the results of the above detection items, the second microcontroller automatically sends a PWM signal to the BUCK circuit to control the latter to switch the charging mode and adjust the charging and discharging current. When the battery cell group 3 is overcharged, over-discharged, or overheated, the second microcontroller also controls the battery protection circuit to disconnect to ensure that the battery cell group 3 can always operate safely. The charging modes typically include constant current mode, constant voltage mode, and float charging mode. Specifically, during the charging process, when the battery cell group 3 has a low charge level, the second microcontroller controls the charging mode to constant current charging mode, at which time the charging current remains unchanged, while the voltage gradually increases as charging progresses. As the charge of battery cell 3 increases, its voltage rises to a certain value. At this point, the second microcontroller automatically switches the charging mode to constant voltage mode to maintain a stable voltage in battery cell 3, while the charging current continuously decreases during the charging process. When battery cell 3 is fully charged and enters the float charging stage, the second microcontroller automatically switches the charging mode to float charging mode to prevent overcharging and damage to the battery. Furthermore, if the charging temperature of battery cell 3 is detected to be too high, the second microcontroller reduces the charging current to decrease battery heat generation. If the temperature of battery cell 3 continues to rise, the charging current continues to decrease. If the temperature of battery cell 3 reaches a dangerous level, the second microcontroller controls the battery protection circuit to cut off the charging circuit and stop charging. During the discharge process, when the charge of battery cell 3 is about to be depleted or the temperature reaches a dangerous level, the second microcontroller controls the battery protection circuit to cut off the load output and stop discharging. Similarly, the charging management module also needs to be initialized when it starts working, such as reading or setting parameters like battery type and voltage level, for subsequent precise battery management. In this embodiment, the charging management module and the control module share a single microcontroller; that is, the second microcontroller and the first microcontroller are integrated into one unit. Figure 2 China embodies this with the title of "the first single-chip microcomputer".

[0037] The interactive module includes buttons and a display screen. The display screen provides feedback on the operating status information of the lithium battery, such as the voltage and current of the solar panel, the voltage and charging current of cell group 3, and any operational abnormalities. Users can switch display pages using the buttons to intuitively obtain the above information, and can also control external load switches using the buttons.

[0038] The MPPT controller also includes a fault detection and handling module. This module detects parameters such as the output voltage and current of the solar panel and the battery voltage to determine if there are any faults in the system, such as short circuits or open circuits in the solar panel, or overcharging or over-discharging of the battery. Once a fault is detected, the fault detection and handling module will take corresponding measures, such as cutting off the power supply or triggering an alarm, to protect the safety of the charger and battery.

[0039] Based on the above description, the workflow of the MPPT controller is briefly described. The workflow includes the following steps: (1) Initialization: including setting the initial operating voltage of the solar panel and initializing the control module and charging management module; (2) Data acquisition: detecting the output voltage and current of the solar panel; (3) MPPT algorithm operation: tracking the maximum efficiency point of the solar panel according to the MPPT algorithm; (4) Control output: the control module sends a pulse width modulation signal to the DC-DC converter to adjust the duty cycle of the MOSFET; (5) Battery charging management: controlling the charging process according to the battery status such as voltage, current, and temperature; (6) Protection and monitoring: monitoring the system status in real time, and triggering the protection mechanism in case of overvoltage or overcurrent.

[0040] The battery protection board 2 has a built-in battery management system (BMS) that provides functions such as status monitoring, safety protection, battery balancing, and fault warning for the cell pack 3. The BMS monitors parameters such as voltage, current, temperature, and charge level of the cell pack 3 to assess the battery's charging status and control charging accordingly. When a fault occurs, the BMS triggers a warning and implements safety protection measures such as overcharge protection, overcurrent protection, and temperature protection to ensure safe battery operation. The BMS also includes a balancing circuit to extend battery life. As this is a mature existing technology, the battery management system will not be further described in this document.

[0041] In summary, the lithium battery with MPPT charging function provided in this embodiment of the present invention has multiple advantages in terms of function and hardware architecture:

[0042] (1) Improved energy efficiency. The lithium battery can track the maximum power point of the solar panel in real time, ensuring that the solar panel can output maximum power under any lighting conditions, which greatly improves the efficiency of solar energy utilization. According to actual application data and market research, the energy efficiency of the lithium battery may be improved by 20% to 30% compared to lithium batteries without integrated MPPT charging function. In ideal conditions, MPPT technology can even increase the output power of the solar panel by 50%, although this improvement is still limited by factors such as environmental influences and heat loss.

[0043] (2) Extending the lifespan of lithium batteries. The MPPT controller not only focuses on energy conversion efficiency but also emphasizes the charge and discharge protection of the cell pack 3. By monitoring the charging stage and charge / discharge temperature in real time, the MPPT controller automatically adjusts the charging voltage and current of the cell pack 3 and performs power-off protection in case of overcharging, over-discharging, and overheating, ensuring the safe and efficient operation of the cell pack 3. This typically extends the lifespan of the lithium battery by 10% to 20%, with the specific extension depending on the initial state of the lithium battery and the usage environment.

[0044] (3) Enhanced stability and reliability. The MPPT controller employs advanced electronic regulation technology, enabling it to automatically adapt to varying light and temperature conditions, effectively resisting the effects of fluctuations in solar panel output voltage and load changes, thereby ensuring the photovoltaic system operates stably at maximum power. Furthermore, the MPPT controller provides multiple protection functions for the charging circuit, such as overvoltage protection, overcurrent protection, and short-circuit protection, further enhancing the system's stability and reliability. By applying MPPT technology, the failure rate of the lithium battery is significantly reduced, thereby improving overall stability and reliability.

[0045] (4) Provides an efficient and flexible charging solution. The lithium battery integrating the MPPT charging board 1 has a maximum input voltage of 100V, which can be flexibly adapted to most solar panels, solving the problem of difficult component matching and making the selection of cell pack 3 more convenient. In addition, the MPPT controller also has the advantages of being able to be screened with DC distribution cabinets for low power and to be able to be connected in parallel with multiple cabinets for high power, making the expansion and maintenance of the system easier. These characteristics make the lithium battery provided in this embodiment more flexible and scalable in practical applications, and can meet the charging needs in different scenarios.

[0046] The above description is merely a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All technically equivalent modifications made based on the content of the present utility model specification shall fall within the protection scope of the present utility model.

Claims

1. A lithium battery with MPPT charging function, characterized in that: It includes an MPPT charging board and a battery cell assembly; the input terminal of the MPPT charging board is connected to the output terminal of an external solar panel, and the output terminal is connected to the input terminal of the battery cell assembly. The MPPT charging board has a built-in MPPT controller; the MPPT controller includes a control module and a DC-DC converter; the DC-DC converter is connected in series between the solar panel and the battery cell assembly, and the control module is connected to the DC-DC converter; the DC-DC converter adopts a synchronous rectification BUCK circuit. The MPPT controller further includes a charging management module; the charging management module includes a second microcontroller, a battery detection circuit, and a battery protection circuit; the signal receiving end of the second microcontroller is connected to the battery detection circuit, and the signal output end is connected to the BUCK circuit and the battery protection circuit; The MPPT controller is equipped with several protection circuits.

2. A lithium battery with MPPT charging function according to claim 1, characterized in that: The control module includes a first microcontroller and a voltage / current sampling circuit; the voltage / current sampling circuit is used to collect the output voltage and current of the solar panel for the first microcontroller; the first microcontroller has a built-in MPPT algorithm to control the DC-DC converter to adjust the output voltage and current of the solar panel.

3. A lithium battery with MPPT charging function according to claim 2, characterized in that: The voltage / current sampling circuit is equipped with a digital-to-analog converter; the digital-to-analog converter is used to convert the detected voltage and current analog signals into digital signals that can be recognized and processed by the first microcontroller.

4. A lithium battery with MPPT charging function according to claim 2, characterized in that: The second microcontroller is integrated with the first microcontroller.

5. A lithium battery with MPPT charging function according to claim 1, characterized in that: The protection circuit includes a first reverse protection circuit and a second reverse protection circuit; the first reverse protection circuit is located at the input terminal of the MPPT controller; the second reverse protection circuit is located between the DC-DC converter and the battery pack.

6. A lithium battery with MPPT charging function according to claim 1, characterized in that: The protection circuit also includes a cycle-by-cycle protection circuit; the cycle-by-cycle protection circuit is disposed within the DC-DC converter.

7. A lithium battery with MPPT charging function according to claim 1, characterized in that: The MPPT controller also includes an interaction module; the interaction module includes a display screen and buttons.

8. A lithium battery with MPPT charging function according to claim 1, characterized in that: The MPPT controller also includes a DC-DC auxiliary power supply circuit for supplying power to the control module and the DC-DC converter.

9. A lithium battery with MPPT charging function according to claim 1, characterized in that: The DC-DC converter further includes a drive circuit; the drive circuit is connected in series between the control module and the BUCK circuit; the drive circuit is used to receive and amplify the pulse width modulation signal sent by the control module, and drive the BUCK circuit to change the duty cycle.

10. A lithium battery with MPPT charging function according to claim 1, characterized in that: It also includes a battery protection board; the battery protection board is connected to the battery cell assembly; the battery protection board has a built-in battery management system.

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