A segmented pulse equalization charging control method for high-speed electric motorcycle lead-acid battery charger

Abstract

This invention discloses a segmented pulse equalization charging control method for a lead-acid battery charger for high-speed electric motorcycles. The charging process includes six stages: pre-detection protection, pulse fast charging, desulfurization, equalization full charging, temperature-sensing float charging, and shutdown equalization. By real-time acquisition of the battery's total voltage, individual cell voltage, and temperature, the charging current, voltage, and pulse parameters for each stage are dynamically adjusted according to the temperature range. Intermittent negative pulses are used to eliminate polarization and enhance desulfurization. Combined with a three-level mechanism of pre-equalization, synchronous equalization, and deep equalization, this method balances fast charging and battery life. This method reduces the charging time of a 72V, 25Ah battery from 8.5 hours to within 5 hours, increases the cycle life from 350 cycles to over 600 cycles, achieves a low-temperature capacity recovery rate of 82%, features full-temperature adaptive voltage regulation, multiple linkages to prevent thermal runaway, and equalization to increase capacity by more than 10%, ensuring undiminished high-speed power. It is suitable for high-capacity lead-acid battery packs for high-speed electric motorcycles with speeds above 50km / h.

Description

Technical Field

[0001] This invention belongs to the field of lead-acid battery charging control technology, and is particularly applicable to high-power charging of large-capacity series lead-acid power battery packs for high-speed electric motorcycles with speeds above 50 km / h. It belongs to the field of battery management and charger control methods, and specifically relates to a segmented pulse equalization charging control method for a lead-acid battery charger for high-speed electric motorcycles. Background Technology

[0002] High-speed electric motorcycles are generally equipped with high-capacity, high-power lead-acid batteries of 72V or higher, which continuously discharge at high current and high rate during driving and climbing. The conventional three-stage constant current-constant voltage-float chargers used in electric vehicles have many drawbacks when used for high-speed electric motorcycle batteries: 1. Fast charging has a fixed current, and high-power constant current charging can easily cause the internal temperature of the battery to rise too high, resulting in a large amount of electrolyte gas evolution and water loss, battery bulging and deformation, and the cycle life of conventional batteries is only 300 to 400 times. 2. After multiple 12V cells are connected in series, the consistency continues to deteriorate with charge and discharge cycles. During constant voltage charging, the voltage is too high and the cells are continuously overcharged. The low-voltage cells are undercharged. With long-term use, the plates undergo irreversible sulfation, and the vehicle's range decreases rapidly. 3. In low-temperature environments, direct high-current charging below 0°C easily generates dense lead sulfate crystals, resulting in a charging capacity of only 70% of the capacity at room temperature, which significantly reduces the range of high-speed electric motorcycles in winter. 4. Without a temperature-linked current limiting and voltage regulation mechanism, the battery is charged immediately after the residual heat of the vehicle has not dissipated after heavy-load high-speed driving, which poses a safety hazard of thermal expansion, thermal runaway and fire. 5. The equalization circuit passively discharges for equalization only after the charging is complete. The equalization process is time-consuming and energy-intensive, and it cannot correct the individual cell voltage difference in real time during the charging process. 6. There is no logic for repairing sulfidation after high-speed electric motorcycles discharge at high rates. Sulfation caused by long-term high-current discharge cannot be eliminated in time, resulting in a significant decrease in vehicle acceleration and hill-climbing power.

[0003] Existing conventional charging methods only use fixed voltage and fixed current to switch charging stages, which cannot match the characteristics of high-speed electric motorcycles with high rate, large capacity, multiple series connection, and large temperature difference range. It is difficult to balance fast charging speed, battery life and charging safety.

[0004] A search revealed existing technologies related to battery charging and maintenance management. For example, patent application CN121224515A discloses a non-invasive battery maintenance method and system based on direct connection to a DC fast charging port. This method is primarily applicable to lithium-ion batteries for new energy vehicles, collecting battery data through the DC fast charging port and generating maintenance strategies using a cloud-based model. However, this solution relies on cloud data processing and model computation, resulting in a complex system architecture and limited real-time performance. Communication delays exist between data acquisition and strategy distribution, making it difficult to achieve real-time dynamic control of the charging process. Furthermore, this solution does not address the adaptive adjustment mechanism for the pulse parameters of the charger's power stage output, nor does it disclose the specific hardware implementation for real-time synchronous balancing of the voltage of each individual battery cell during charging.

[0005] Furthermore, patent application CN103812196A discloses a series-to-parallel conversion and intelligent charging system for lead-acid battery packs. This system uses a C8051F020 microcontroller to generate pulse signals with a fixed frequency and duty cycle to charge the lead-acid batteries, and switches the series-connected battery packs to parallel charging via a series-to-parallel conversion circuit. However, this scheme uses only one set of fixed pulse parameters throughout the entire pulse charging phase, failing to differentiate the pulse waveform, period, and amplitude according to changes in the battery's state of charge (SOC). Its balancing method relies on circuit topology switching before charging, making it impossible to monitor the voltage of each individual cell in the string in real time and perform online active balancing during charging. Its temperature compensation is only used as an auxiliary correction for the PWM output, lacking a systematic multi-level temperature-adaptive current and voltage limiting rule, resulting in insufficient charging adaptability and safety over a wide temperature range. Summary of the Invention

[0006] To address the technical shortcomings of existing ordinary three-stage chargers that cannot be adapted to high-speed electric motorcycle power lead-acid batteries, a segmented pulse equalization charging control method for high-speed electric motorcycle lead-acid battery chargers is provided. This method achieves multiple benefits, including fast charging, suppression of plate sulfation, improvement of series battery consistency, and safe charging across the entire temperature range. It also shortens charging time, extends battery cycle life, and eliminates the risk of charging fires and bulging.

[0007] To achieve the objectives of this invention, the technical solution is as follows: This invention provides a segmented pulse equalization charging control method for a high-speed electric motorcycle lead-acid battery charger. The charger includes an MCU main control chip, a high-power switching power supply, a battery total voltage acquisition circuit, multiple single-cell voltage acquisition channels for acquiring individual cell voltages, a battery temperature acquisition probe for acquiring battery temperature, positive and negative pulse charging and discharging circuits, and a single-cell active equalization branch. The segmented pulse equalization charging control method is executed by the MCU program and is divided into six sequentially running charging control stages. Throughout the process, the total battery voltage, the voltage of each individual cell, the battery surface temperature, and the real-time charging current are acquired in real time. The operating parameters of each stage are dynamically switched based on the acquired data. The judgment criteria are set as follows: single-cell voltage difference threshold ΔU = 0.15V; temperature boundary thresholds: low temperature T1 = 5℃, normal temperature range 5℃ ≤ T ≤ 35℃, high temperature T2 > 35℃; and the charging rate C is the ampere-hour of the battery's rated capacity.

[0008] This includes the following steps performed sequentially: Step 1, Pre-detection and protection phase: Start the pre-detection process, collect the total battery voltage, individual cell voltage and battery temperature, perform fault determination based on the collected data, and proceed to step 2 if no fault is found. Step 2 (corresponding to SOC range 0~75%), high-power pulse constant current fast charging stage: set the charging reference current according to the battery temperature, and use a pulse cycle mode of alternating positive charging and intermittent negative pulses to perform constant current charging. When the switching conditions are met, proceed to step 3. Step 3 (corresponding to SOC range 75%~92%), dynamic pressure limiting desulfurization pulse stage: constant pressure and pulse cycle mode charging with enhanced negative pulse. When the differential pressure of a single cell exceeds the differential pressure threshold, the fast charging process is paused. When the charging current drops to the first conversion current, proceed to step 4. Step 4 (corresponding to SOC range 92%~98%), single cell equalization constant voltage full charge stage: constant voltage and cancel negative pulse, charge with a reference current lower than that in step 2, periodically collect single cell voltage and perform differential voltage calibration equalization, and enter step 5 when the charging current drops to the second conversion current. Step 5, Low-temperature adaptive float charging maintenance stage: The float charging voltage is dynamically adjusted according to the battery temperature to set the float charging reference current for constant current float charging. After the float charging timer is completed, proceed to step 6. Step 6, Fully charged and shut down self-discharge equalization stage: Cut off the main power charging output circuit, and only keep the equalization branch working until the voltage difference of each unit reaches below the set value, and control the charger to enter the low power sleep state.

[0009] Furthermore, in step 1, after the charger is connected to the battery pack, the MCU program initiates a pre-detection process lasting 8-10 seconds; simultaneously, it collects the total battery voltage, all individual cell voltages, and battery temperature; and performs multi-level fault determination. The fault determination includes: when any single cell voltage is below 1.75V, it is determined to be severely depleted, and a 0.05C small current repair pulse pre-charge is activated; If any single cell voltage is higher than 2.47V, the cell is determined to be overcharged, and the active balancing branch of the single cell is activated to discharge the high voltage cell. When the battery temperature exceeds 45℃, the fast charging function is locked, the charging current is limited to 0.05C, and only a small current of 0.05C is output for cooling and maintenance. When the maximum voltage difference between cells is greater than 0.15V, pause charging for 3 minutes until the voltage difference between cells drops to within 0.1V.

[0010] Furthermore, in step 2, the charging reference current is adaptively adjusted according to the battery temperature: when 5℃≤T≤35℃, the charging current is 0.5C; when T<5℃, the charging current is 0.3C; when 35℃<T≤45℃, the charging current is 0.2C. The pulse cycle of the pulse cycle mode is 980ms, with a positive charging pulse width of 900ms, an intermittent negative discharge pulse width of 80ms, and a negative pulse discharge current of 0.03C, in order to eliminate charging concentration polarization and reduce sulfate accumulation on the electrode surface.

[0011] Furthermore, the switching conditions in step 2 are any of the following: the total voltage of the battery pack reaches 2.4V per string multiplied by the total number of connected cells, the cumulative fast charging time reaches 90 minutes, and the battery temperature rise rate is greater than 1.2℃ / min.

[0012] Further, in step 3, the constant voltage value is 2.47V per string multiplied by the total number of strings connected in series; the pulse period of the pulse cycle mode is 720ms, where the positive charging pulse width is 600ms, the negative discharging pulse width is 120ms, and the negative pulse discharge current is 0.05C; the voltage difference threshold is 0.15V; and the first conversion current is 0.06C.

[0013] Furthermore, the constant voltage value in step 4 is 2.47V per string multiplied by the number of individual units in series; the reference current lower than that in step 2 is 0.05C; and the second conversion current is 0.02C. The periodic acquisition of individual cell voltage and the execution of differential voltage calibration equalization involves acquiring the voltage of all individual cells every 30 seconds. When the detected differential voltage is greater than 0.15V, a differential voltage calibration equalization is performed, which involves pausing charging for 3 minutes. If the individual cell differential voltage remains higher than 0.1V, the duration of differential voltage calibration equalization is extended until the individual cell differential voltage is stably controlled within 0.05V.

[0014] Further, the float charge voltage in step 5 is: 2.35V for single-string float charge when T < 5℃; 2.3V for single-string float charge when 5℃ ≤ T ≤ 35℃; and 2.24V for single-string float charge when T > 35℃. The float charging reference current is 0.015C; the float charging duration is 90 minutes.

[0015] Furthermore, in step 5, the individual cell voltage is collected every 10 minutes during the float charging process, and equalization correction is performed when the detected voltage difference is greater than 0.15V; the equalization correction is to pause charging for 3 minutes.

[0016] Furthermore, the balancing branch described in step 6 operates continuously for 15 minutes, with the differential voltage set at 0.05V. This balancing branch involves multiple batteries connected in parallel for balancing, using the high-voltage battery to charge the low-voltage battery, thereby achieving a dynamic balance as the high voltage drops and the low voltage rises.

[0017] Beneficial effects of this invention: 1. Significantly improved charging speed: Taking a 72V, 25Ah high-speed electric motorcycle battery as an example, a conventional charger takes 8.5 hours to fully charge, while this method reduces the charging time to less than 5 hours, increasing the fast charging efficiency by 230%. 2. Significantly extends battery cycle life: Segmented differentiated negative pulses continuously decompose plate sulfation, and the entire charging process synchronously and evenly eliminates overcharging and undercharging of individual cells, increasing battery cycle life from 350 times to more than 600 times, reducing battery bulging, water loss and failure problems. 3. Full temperature range adaptation, significantly improved winter range reduction: adaptive voltage regulation and current limiting in the range of -15℃ to 45℃, the low temperature charging capacity recovery rate can reach more than 82% of the normal temperature, solving the problem of significant reduction in the winter range of high-speed electric motorcycles; 4. Multiple safety protections to eliminate the risk of thermal runaway: multi-level linkage protection for total voltage, individual cell voltage, battery temperature, and temperature rise rate; automatic current reduction of the battery due to residual heat during heavy discharge to avoid the risk of fire during high-temperature charging. 5. Balanced charging, good consistency, and higher capacity: Unlike traditional single passive equalization after charging, this invention sets up a three-level equalization mechanism of pre-equalization, charging synchronous equalization, and shutdown deep equalization. Compared with the three-stage equalization, the capacity is higher, and the capacity in the early and middle stages of life is more than 10% higher. 6. Adapted to high-speed electric motorcycle operating conditions: Adopting a sulfation compensation process (negative pulse desulfation), the battery internal resistance increases slowly with long-term use, and there is no significant decrease in vehicle power during high-speed acceleration and hill climbing. Attached Figure Description

[0018] Figure 1 Cyclic comparison curves of 6-DMF-25 batteries under different charging modes; where segmented pulse equalization charging 6-DMF-25 represents Example 1, and conventional three-segment charging 6-DMF-25 represents Comparative Example 1.

[0019] Figure 2Comparison curves of temperature rise during charging of 6-DMF-25 batteries under different charging modes; where the segmented pulse equalization charging 6-DMF-25 represents Example 2, and the conventional three-segment charging 6-DMF-25 represents Comparative Example 1.

[0020] Figure 3 The discharge curves of 6-DMF-25 batteries at -15℃ are compared for different charging modes; among them, the segmented pulse equalization charging 6-DMF-25 represents Example 3, and the conventional three-segment charging 6-DMF-25 represents Comparative Example 1. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to specific embodiments.

[0022] This invention discloses a segmented pulse equalization charging control method for a high-speed electric motorcycle lead-acid battery charger. The charger hardware includes an MCU main control chip, a high-power switching power supply, a battery total voltage acquisition circuit, multiple individual cell voltage acquisition channels, a battery temperature acquisition probe, positive and negative pulse charging and discharging circuits, and an individual cell active equalization branch. The charging process is automatically executed by the MCU program and is divided into six continuous control stages: a pre-detection protection stage, a high-power pulse constant current fast charging stage, a dynamic voltage limiting desulfurization pulse stage, an individual cell equalization constant voltage full charging stage, a low-temperature adaptive float charging maintenance stage, and a full-charge shutdown self-discharge equalization stage. All the following embodiments use a unified judgment criterion: individual cell voltage difference threshold ΔU = 0.15V, low temperature threshold T1 = 5℃, high temperature threshold T2 = 35℃, and the charging rate C is taken as the battery's rated capacity in ampere-hours.

[0023] Example 1: 72V, 25Ah high-speed electric motorcycle lead-acid battery pack (6 series 12V cells, normal temperature operation) This embodiment uses a mainstream standard high-speed electric motorcycle configuration: a 72V, 25Ah lead-acid battery pack with a rated capacity of C=25Ah and an ambient temperature of 25℃, which is considered normal temperature charging condition. After the charger is connected to the battery pack, it first enters the pre-detection protection stage, detecting the total battery voltage, the voltage of each individual cell, and the battery temperature. The maximum voltage difference between individual cells is detected to be 0.06V, with no individual cell undervoltage, overvoltage, or overtemperature faults, meeting the conditions for fast charging.

[0024] Entering the high-power pulse constant current fast charging stage, the charging reference current is set to 0.5C (12.5A) in normal temperature mode, with a pulse period of 980ms. The positive charging pulse width is 900ms, the negative pulse discharge pulse width is 80ms, and the negative pulse discharge current is 0.03C (0.75A). The single-string cutoff voltage is 2.4V, and the total voltage limit for the entire group is 86.4V. After 85 minutes of continuous pulse charging, the total battery voltage reaches the preset voltage limit threshold, automatically switching to the dynamic voltage-limited desulfurization pulse stage.

[0025] During the dynamic voltage-limited desulfurization pulse phase, the entire group maintains a constant voltage of 88.92V, with the pulse period adjusted to 720ms, the positive charging pulse width at 600ms, the negative pulse discharge pulse width at 120ms, and the negative pulse discharge current increased to 0.05C (1.25A). The individual cell voltage difference is monitored in real time during charging. When the detected voltage difference exceeds 0.15V, charging is paused for 3 minutes to reduce the individual cell voltage difference and continuously correct for cell consistency. When the charging current drops to 0.06C (1.5A), the group enters the cell equalization constant voltage full-charge phase.

[0026] During the single-cell equalization and constant-voltage full-charge phase, the total battery voltage is maintained at 88.92V, with a reference charging current of 0.05C (1.25A). High-intensity negative pulses are eliminated, and the voltage of all individual cells is collected every 30 seconds. When the detected voltage difference exceeds 0.15V, a voltage difference calibration equalization is performed, i.e., charging is paused for 3 minutes to gradually reduce the single-cell voltage difference. When the charging current drops to 0.02C (0.5A), the low-temperature adaptive float charging maintenance phase begins.

[0027] Under normal temperature conditions, the single-string float charging voltage is set to 2.3V, the total float charging voltage is 82.8V, and the float charging reference current is 0.015C (0.375A). Continuous float charging is timed for 90 minutes. During the float charging process, the voltage of all individual cells is collected every 10 minutes. When the detected voltage difference exceeds 0.15V, a small-scale individual cell equalization correction is performed, i.e., charging is paused for 3 minutes. After the float charging timer ends, the system enters the fully charged, self-discharge equalization phase.

[0028] During the shutdown balancing phase, the main power charging circuit is shut down, and only the multi-cell balancing branch is kept running for 15 minutes. Through high-voltage cell discharge and internal circulating current of the battery pack to compensate for low-voltage cells, the voltage difference of all cells is eventually stabilized within 0.05V. The charger then enters a low-power sleep state, and the charging process ends.

[0029] Actual measurements show that the overall charging time in this embodiment is approximately 4 hours and 45 minutes, which is more than 3.5 hours shorter than the traditional three-stage charging (Comparative Example 1). The battery cycle life is increased from the conventional 360 cycles to 610 cycles. Figure 1 During the charging process, there was no high temperature, no bulging, and no obvious water loss.

[0030] Example 2: 72V, 25Ah high-speed electric motorcycle lead-acid battery pack (6 series 12V cells, low temperature operating conditions) This embodiment uses a 72V, 25Ah high-rate high-speed electric motorcycle battery pack with a rated capacity of C=25Ah. The ambient charging temperature is 2℃, which is considered a low-temperature charging condition. After the charger is powered on, a 10-second pre-test is performed. The single-cell voltage difference is 0.07V, indicating that the battery is in normal condition and has no faults, thus entering the pulse fast charging stage.

[0031] In low-temperature environments (T < 5℃), the fast-charging phase automatically limits the current to 0.3C (7.5A). The pulse period and pulse width parameters remain consistent with Example 1, with a single string voltage limit of 2.4V and a total voltage limit of 86.4V for the entire group. Once the voltage reaches the threshold, the dynamic desulfurization pulse phase begins, maintaining a constant voltage of 88.92V for the entire group and a negative pulse current of 0.05C (1.25A). After the charging current drops to 0.06C (1.5A), the system switches to the balanced full-charge phase.

[0032] During the constant voltage equalization phase, the reference current is 0.05C (1.25A). Continuous low-current fine-tuning is applied, and the individual cell voltage difference is calibrated periodically. Once the current drops to 0.02C (0.5A), the float charge phase begins. Under low-temperature conditions, the single-string float charge voltage increases to 2.35V, the total float charge voltage is 84.6V, and the float charge current is 0.015C (0.375A), maintained for 90 minutes.

[0033] Finally, a 15-minute deep balancing process is performed, and the entire unit enters sleep mode once the individual unit voltage difference stabilizes below 0.05V.

[0034] The results are as follows Figure 2 As shown, in this embodiment, the effective charging capacity recovery rate of the battery can reach 83% in low-temperature environments. Compared with the low-temperature charging capacity of traditional chargers of about 70%, this significantly improves the problem of severe range reduction of high-speed electric motorcycles in winter.

[0035] Example 3: 72V, 38Ah heavy-duty high-speed electric motorcycle battery pack (6 series 12V cells, high-temperature operating conditions) This embodiment uses a 72V, 38Ah high-capacity heavy-duty high-speed electric motorcycle battery pack with a rated capacity of C=38Ah and a charging ambient temperature of 38℃, which falls within the high-temperature charging range. During the pre-detection phase, the initial single-cell voltage difference was detected to reach 0.18V, which is greater than the 0.15V threshold. The fast charging process was paused for 3 minutes until the single-cell voltage difference dropped back to 0.07V before resuming the high-power pulse fast charging phase (Table 1).

[0036] Table 1 During the high-temperature range of 35℃ to 45℃, the charging current automatically adjusts to 0.2C (7.6A), with a single-string voltage limit of 2.4V and a total voltage limit of 86.4V for the entire group. Once the voltage threshold is reached, the system enters a dynamic desulfurization pulse stage, maintaining a constant voltage of 88.92V for the entire group. The system switches to a new stage when the charging current drops to 0.06C (2.28A).

[0037] During the balanced constant voltage full charge stage, the current is set to 0.05C (1.9A). Continuous low-current voltage regulation and replenishment continuously corrects battery consistency. Once the current drops to 0.02C (0.76A), the high-temperature float charge stage begins. When the ambient temperature exceeds 35℃, the float charge voltage of a single string drops to 2.24V, the total float charge voltage is 80.64V, and the float charge current is 0.015C (0.57A). This constant-temperature maintenance lasts for 90 minutes to suppress water loss due to high-temperature overcharging.

[0038] After a 15-minute shutdown and equalization period, the individual unit pressure differential stabilizes and meets the requirements, and the entire unit enters hibernation mode.

[0039] The results are as follows Figure 3 As shown, under 35℃ conditions, the maximum temperature rise during the segmented pulse equalization charging process is 8.9℃; the maximum temperature rise during the conventional three-stage charging process is 11.9℃. This indicates that the temperature rise in this embodiment is gradual throughout the entire process, with the maximum temperature rise not exceeding 11℃, effectively avoiding the risks of thermal runaway, bulging, and water loss caused by high-speed heavy-load battery residual heat charging. At the same time, the three-stage equalization mechanism significantly reduces the accumulation rate of voltage difference between series batteries, resulting in minimal battery capacity decay and stable power output over long-term use.

[0040] Example 4: Supplementary Example for Battery Severe Discharge Repair Conditions For 72V, 25Ah battery packs that have been idle for a long time and are severely depleted, the lowest voltage of a single string is as low as 1.68V, below the 1.75V depletion threshold. During the pre-detection phase, the battery is determined to be severely depleted, prohibiting high-power fast charging and initiating a 0.05C low-current repair pulse pre-charge mode. A weak pulse current of 1.25A is continuously used for 22 minutes of repair pre-charge, gradually activating the slight irreversible sulfation on the plate surface, causing the single-cell voltage to rise above 1.82V, and the single-cell voltage difference to return to the normal range. After repair, the system automatically transitions to the following stages in sequence: high-power pulse constant current fast charging, dynamic voltage-limited desulfation pulse charging, single-cell equalization constant voltage full charging, low-temperature adaptive float charging maintenance, and full-charge shutdown self-discharge equalization. The steps are the same as in Example 1, avoiding the plate breakdown and battery failure problems caused by direct high-current charging in traditional charging methods. This effectively repairs old, depleted batteries, improving battery reuse rate and charging safety.

[0041] Comparative Example 1: A 72V, 25Ah lead-acid battery pack using the conventional three-stage charging method. Step 1: Constant current charging at 3.8A for 5 hours and 10 minutes until the voltage reaches 88.8V. Then proceed to Step 2: Constant voltage charging at 88.8V with a current limit of 3.0A for 1 hour and 40 minutes until the current drops to 0.65A. Then proceed to Step 3: Float charging at 82.8V for 1.5 hours. The total charging time is 8 hours and 20 minutes, and the battery is fully charged, completing the process.

Claims

1. A segmented pulse equalization charging control method for a high-speed electric motorcycle lead-acid battery charger, the charger comprising an MCU main control chip, a high-power switching power supply, a battery total voltage acquisition circuit, a multi-channel single-cell voltage acquisition channel for acquiring the voltage of each individual cell, a battery temperature acquisition probe for acquiring the battery temperature, a positive and negative pulse charging and discharging circuit, and a single-cell active equalization branch, characterized in that, This includes the following steps performed sequentially: Step 1, Pre-detection and protection phase: Start the pre-detection process, collect the total battery voltage, individual cell voltage and battery temperature, perform fault determination based on the collected data, and proceed to step 2 if no fault is found. Step 2, High-power pulse constant current fast charging stage: Set the charging reference current according to the battery temperature, and use a pulse cycle mode that alternates between positive charging and intermittent negative pulses to perform constant current charging. When the switching conditions are met, proceed to step 3. Step 3, Dynamic pressure limiting desulfurization pulse stage: Constant pressure and pulse cycle mode charging with enhanced negative pulse. When the differential pressure of a single cell exceeds the differential pressure threshold, the fast charging process is paused. When the charging current drops to the first conversion current, proceed to step 4. Step 4, Single cell equalization constant voltage full charge stage: Maintain constant voltage and cancel negative pulses, charge with a reference current lower than that in step 2, periodically collect single cell voltage and perform differential voltage calibration equalization, and proceed to step 5 when the charging current drops to the second conversion current. Step 5, Low-temperature adaptive float charging maintenance stage: The float charging voltage is dynamically adjusted according to the battery temperature to set the float charging reference current for constant current float charging. After the float charging timer is completed, proceed to step 6. Step 6, Fully charged and shut down self-discharge equalization stage: Cut off the main power charging output circuit, and only keep the equalization branch working until the voltage difference of each unit reaches below the set value, and control the charger to enter the low power sleep state.

2. The segmented pulse equalization charging control method according to claim 1, characterized in that, The pre-detection process in step 1 takes 8-10 seconds to start; The fault determination includes: when the individual cell voltage is below 1.75V, it is determined to be severely depleted, and a 0.05C current pulse charging is initiated; When the voltage of a single cell is higher than 2.47V, it is determined that the single cell is overcharged, and the active balancing branch of the single cell is activated to discharge the high voltage of the single cell. When the battery temperature is above 45°C, the charging current will be limited to 0.05C. When the maximum voltage difference between cells is greater than 0.15V, pause charging for 3 minutes until the voltage difference between cells drops to within 0.1V.

3. The segmented pulse equalization charging control method according to claim 1, characterized in that, In step 2, the charging reference current is adaptively adjusted according to the battery temperature: when 5℃≤T≤35℃, the charging current is 0.5C; when T<5℃, the charging current is 0.3C; when 35℃<T≤45℃, the charging current is 0.2C. The pulse period of the pulse cycle mode is 980ms, of which the positive charging pulse width is 900ms, the intermittent negative discharge pulse width is 80ms, and the negative pulse discharge current is 0.03C.

4. The segmented pulse equalization charging control method according to claim 3, characterized in that, The switching conditions mentioned in step 2 are any of the following: the total voltage of the battery pack reaches 2.4V per string multiplied by the total number of connected cells, the cumulative fast charging time reaches 90 minutes, and the battery temperature rise rate is greater than 1.2℃ / min.

5. The segmented pulse equalization charging control method according to claim 1, characterized in that, The constant voltage value mentioned in step 3 is 2.47V for a single string multiplied by the total number of strings connected in series; The pulse period of the pulse cycle mode is 720ms, of which the positive charging pulse width is 600ms, the negative discharging pulse width is 120ms, and the negative pulse discharge current is 0.05C. The differential pressure threshold is 0.15V; The first conversion current is 0.06C.

6. The segmented pulse equalization charging control method according to claim 1, characterized in that, The constant voltage value in step 4 is 2.47V per string multiplied by the number of individual units in series; the reference current lower than that in step 2 is 0.05C; the second conversion current is 0.02C; The periodic acquisition of individual cell voltage and the execution of differential voltage calibration equalization involves acquiring the voltage of all individual cells every 30 seconds. When the detected differential voltage is greater than 0.15V, a differential voltage calibration equalization is performed, which involves pausing charging for 3 minutes. If the individual cell differential voltage remains higher than 0.1V, the duration of differential voltage calibration equalization is extended until the individual cell differential voltage is stably controlled within 0.05V.

7. The segmented pulse equalization charging control method according to claim 1, characterized in that, In step 5, the conditions for dynamically adjusting the float charge voltage based on battery temperature are: T < 5℃, single-cell float charge 2.35V; 5℃ ≤ T ≤ 35℃, single-cell float charge 2.3V; T > 35℃, single-cell float charge 2.24V. The float charging reference current is 0.015C; the float charging duration is 90 minutes.

8. The segmented pulse equalization charging control method according to claim 7, characterized in that, In step 5, the individual cell voltage is collected every 10 minutes during the float charging process. When the detected voltage difference is greater than 0.15V, an equalization correction is performed. The equalization correction involves pausing charging for 3 minutes.

9. The segmented pulse equalization charging control method according to claim 1, characterized in that, The equalization branch described in step 6 operates continuously for 15 minutes, and the differential pressure setting value is 0.05V.

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