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Abstract

This article conducts an in-depth discussion on forklift lead-acid batteries, elaborately analyzes common fault types, systematically expounds the principles and methods of fault early warning, and proposes comprehensive and targeted preventive measures. The aim is to provide scientific and effective references for forklift user enterprises and maintenance personnel, ensure the stable operation of forklift lead-acid batteries, improve forklift operation efficiency and safety, and reduce operating costs.

1. Introduction

In the modern logistics and warehousing industry, forklifts are indispensable and important equipment, undertaking key tasks such as goods handling and stacking. As the core power source of electric forklifts, the performance of lead-acid batteries directly determines the working efficiency, endurance and operating costs of the forklifts. However, in the actual usage process, the lead-acid batteries of forklifts can be affected by various factors, leading to frequent malfunctions. This not only affects the normal operation progress but may also bring potential safety hazards. Therefore, in-depth research on the fault early warning and prevention methods of lead-acid batteries in forklifts has important practical significance.

2. Common Fault Types of Lead-Acid Batteries in Forklifts

(1) Capacity decline

As the usage time increases, the capacity of lead-acid batteries will gradually decrease, which is a common fault phenomenon. The reasons for the decline in capacity are rather complex, among which sulfation of the plates is one of the main factors. When a storage battery is in a state of undercharging, over-discharging or the electrolyte level is too low for a long time, the lead sulfate on the plates cannot be completely converted into active substances. Instead, it adheres to the surface of the plates in the form of coarse and hard lead sulfate crystals, thereby reducing the effective reaction area of the plates and causing a decrease in the battery capacity. In addition, abnormal electrolyte density, excessively high or low temperatures, and other factors can also accelerate the capacity attenuation of the battery.

(2) Severe self-discharge

Under normal circumstances, lead-acid batteries have a certain degree of self-discharge. However, if the self-discharge rate is too fast, it falls within the category of faults. Severe self-discharge may be due to the shedding of active substances from the internal plates of the battery, which deposit at the bottom of the battery, causing a short circuit between the positive and negative electrodes. It could also be that the electrolyte contains impurities, which form local micro-batteries in the electrolyte, causing self-discharge. In addition, if the battery casing or cover is poorly sealed, causing the electrolyte to leak and allowing impurities to mix into the electrolyte, it will also intensify the self-discharge phenomenon.

(3) Plate deformation and damage

Deformation and damage of the plates can seriously affect the performance and service life of the battery. Overcharging or discharging with a large current will cause the plates to heat up, leading to the expansion and softening of the active material on the plates, and subsequently causing the plates to deform. During the operation of a forklift, jolts and vibrations may cause mechanical damage to the plates, resulting in breakage or perforation, etc. In addition, the drying up of the electrolyte and the long-term immersion of the plates in electrolyte with excessively high density will also accelerate the damage of the plates.

(4) Abnormal charging and discharging

Abnormal charging and discharging is manifested as the voltage rising too fast and reaching the terminal voltage prematurely during charging, while the voltage drops rapidly during discharging. This might be due to unstable output voltage and current of the charger, resulting in insufficient charging or overcharging of the battery. It could also be that there is a short circuit or open circuit fault in a single cell inside the battery, which affects the overall charging and discharging performance. In addition, problems such as loose connection lines and poor contact can also cause abnormal charging and discharging.

3. Early Warning Methods for Forklift Lead-Acid Battery Faults

(1) Real-time monitoring based on sensors

Voltage sensor: Install voltage sensors on each individual cell of the battery pack to monitor the voltage changes of each cell in real time. Under normal circumstances, the voltage of a single cell battery fluctuates within a certain range. When the voltage of a certain cell battery abnormally rises or drops, it indicates that the battery may be faulty. By setting a reasonable voltage threshold, when the detected voltage exceeds the threshold range, the system immediately issues a warning signal.

Current sensor: The current sensor is used to monitor the magnitude of the current during the charging and discharging process of the battery. During the charging process, if the current is too large and lasts for a long time, it may be due to a charger malfunction or a short circuit problem in the battery. During the discharge process, if the current suddenly increases, it may indicate that the forklift is under excessive load or there is a short circuit in the circuit. Through real-time analysis of current data, abnormal situations can be detected promptly and early warnings issued.

Temperature sensor: Temperature has a significant impact on the performance and lifespan of lead-acid batteries. Install temperature sensors at key parts inside the battery to monitor the battery's temperature in real time. When the temperature exceeds the normal working range, it may accelerate the occurrence of faults such as sulfation of the plates and shedding of active substances. Once the temperature sensor detects an abnormal high temperature, the system promptly issues a warning to remind the operator to take cooling measures.

(2) Data Analysis and Fault Diagnosis Algorithms

By leveraging big data and artificial intelligence technologies, in-depth analysis is conducted on the voltage, current, temperature and other data collected by sensors. By establishing a battery performance model, analyzing the changing trends and patterns of the data, and predicting the possible faults of the battery. For example, machine learning algorithms are adopted to train historical fault data and normal operation data to construct a fault diagnosis model. When new data is input, the model can determine whether there is a fault in the battery and the type of fault based on the training results, and provide corresponding early warning information.

(3) Early warning for appearance and condition inspection

Regularly conduct visual inspections on the lead-acid batteries of forklifts to observe whether the battery casing is damaged or leaking, whether the plates are deformed, and whether the active substances have fallen off, etc. At the same time, check the height and density of the electrolyte level. If the electrolyte level is found to be too low or the density abnormal, it should be replenished and adjusted in a timely manner. In addition, by observing the performance of the battery during the charging and discharging process, such as whether there is abnormal heating or gas leakage, potential faults can also be detected in a timely manner and early warnings can be issued.

4. Preventive Measures for Forklift Lead-Acid Battery Faults

(1) Standardize usage and operation

Reasonable control of charging and discharging: Strictly follow the battery's user manual for charging and discharging operations to avoid overcharging and overdischarging. When the battery power remains at 20% - 30%, it should be charged in time. During the charging process, charging should be stopped when the terminal voltage is reached to prevent overcharging from causing damage to the plates and evaporation of the electrolyte. At the same time, frequent high-current discharges should be avoided. When the forklift starts, accelerates and climbs slopes, it should be operated smoothly to reduce the instantaneous current impact.

Control the operating environment temperature: Try to keep the operating environment temperature of the forklift lead-acid battery within an appropriate range. In high-temperature environments, measures such as ventilation and shading can be taken to lower the battery temperature. In low-temperature environments, insulation covers or heating devices can be used to increase the battery temperature and ensure its normal operation. In addition, avoid storing the battery for a long time in extreme temperature environments.

(2) Regular maintenance and upkeep

Electrolyte inspection and replenishment: Regularly check the height of the electrolyte level to ensure it is 10-15mm higher than the plates. When the electrolyte is insufficient, distilled water or special lead-acid battery replenishment liquid should be added. Do not add tap water to prevent impurities in tap water from affecting the performance of the battery. Meanwhile, regularly test the density of the electrolyte and adjust it appropriately according to the usage environment and seasonal changes.

Plate inspection and cleaning: Regularly open the battery cover to check the condition of the plates, and promptly remove sulfides and fallen active substances on the surface of the plates. For slightly vulcanized plates, the method of long-term charging with a small current can be adopted for repair. For severely vulcanized or damaged plates, they should be replaced in a timely manner.

Maintenance of connection lines: Check whether the battery connection lines are loose or oxidized to ensure a firm connection and good contact. Regularly clean and apply conductive paste to the connection terminals to prevent oxidation and corrosion, reduce contact resistance, and ensure the normal transmission of charging and discharging currents.

(3) Construction of a scientific management and maintenance system

Establish battery files: Establish detailed files for each group of forklift lead-acid batteries, recording information such as the battery brand, model, production date, usage time, charge and discharge frequency, maintenance and care conditions, as well as fault records. By analyzing the archival data, we can grasp the performance change trend of the battery, promptly identify potential problems, and formulate reasonable maintenance and replacement plans.

Training operators and maintenance personnel: Provide professional training for forklift operators and battery maintenance personnel to familiarize them with the working principle, performance characteristics, correct usage methods and maintenance knowledge of lead-acid batteries. Enhance the awareness of standardized operation among operators, strengthen the fault diagnosis and handling capabilities of maintenance personnel, and reduce the occurrence of faults from the perspective of human factors.

5. Conclusion

The fault early warning and prevention of lead-acid batteries in forklifts is a systematic and comprehensive task, which requires efforts from multiple aspects such as fault type analysis, research on early warning methods, and formulation of preventive measures. By adopting advanced sensor technology, data analysis algorithms and a scientific management and maintenance system, potential faults of the battery can be detected in a timely manner and early warnings can be issued. At the same time, effective preventive measures can be taken to extend the service life of the battery, improve the working efficiency and reliability of forklifts, and reduce the operating costs of enterprises. With the continuous development of technology, the fault early warning and prevention technology of forklift lead-acid batteries will also be constantly innovated and improved, providing more powerful support for the development of modern logistics and warehousing industries.