The internal formation charging process for lead-acid batteries plays a crucial role in battery manufacturing. While it offers advantages over external formation processes, it also faces challenges. Internal formation processes lack dedicated cooling systems, making controlling the charging temperature a major challenge. The close and complex relationship between temperature and internal formation charging processes is crucial for improving the performance and quality of lead-acid batteries.

During the internal charging process of lead-acid batteries, temperature changes directly affect the battery's internal electrochemical corrosion. During charging, a complex series of electrochemical corrosion reactions occur within the battery's structure, all accompanied by heat. Failure to effectively control temperature can lead to excessively high internal battery temperatures, impacting the battery's charging efficiency and lifespan. For example, excessively high temperatures can accelerate the aging and dissolution of active components within the battery's structure, reducing battery capacity and performance.

The impact of temperature on polarization during charging: Polarization occurs during the internal charging phase of lead-acid batteries and is a major factor affecting charging efficiency. During charging, electrochemical corrosion occurs within the battery's internal structure, leading to polarization. Polarization primarily occurs in three types: Ω polarization, concentration polarization, and photoelectrocatalytic polarization. Ω polarization is primarily due to the presence of internal resistance in the battery, generating a current during the flow of current; concentration polarization is primarily caused by differences in ion concentrations within the aqueous solution on the electrode surface; and photoelectrocatalytic polarization is caused by the slowness of the electrode reaction.

Temperature has a significant impact on polarization. Generally speaking, rising temperatures accelerate the diffusion of ions, thereby reducing concentration polarization. However, excessively high temperatures can exacerbate both Ω polarization and photoelectrocatalytic polarization. When the temperature is too high, the internal resistance of the battery increases significantly, exacerbating Ω polarization. At the same time, excessively high temperatures can also affect the mechanical processes of the electrode reactions, making photoelectrocatalytic polarization more pronounced. For example, at high temperatures, the chemical reactions within the battery accelerate, but the active components on the electrode surface may undergo structural changes due to overheating, causing the electrode reactions to slow down and thus exacerbating photoelectrocatalytic polarization.

If polarization during charging is not properly controlled, the battery's internal structure will heat up. Polarization increases energy loss within the battery, which is ultimately released as heat, causing the battery temperature to rise. As the battery temperature rises, the acceptable charging current decreases. This is primarily because sustained high temperatures complicate the battery's internal chemical reactions, increasing its internal resistance and hindering the flow of charging current. This vicious cycle further impacts charging efficiency, making it difficult to fully charge the battery and prolonging charging times.

The impact of temperature on battery size and charging time. Temperature has a significant impact on the capacity of lead-acid batteries. Generally speaking, within a certain temperature range, battery capacity increases with increasing temperature. This is primarily because rising temperature accelerates chemical reactions within the battery and increases the diffusion of ions, allowing the battery's active components to participate more fully. However, when the temperature exceeds a certain range, battery capacity decreases as the temperature rises. This is primarily because excessively high temperatures accelerate the aging and dissolution of active components within the battery's internal structure, reducing the battery's high-efficiency active components and potentially reducing its capacity. For example, in a high-temperature environment, hydrochloric acid within the battery will accelerate corrosion of the electrode plates, damaging their structure and thus affecting battery capacity.

Temperature also affects the charging time of lead-acid batteries. At low temperatures, the rate of chemical changes within the battery slows down, and the diffusion rate of positive ions also slows down. This reduces the battery's acceptable charging current, resulting in longer charging times. At high temperatures, although the battery's acceptable charging current increases, the increased polarization and changes in the battery's internal structure also increase charging times. For example, at high temperatures, hydrogen and oxygen evolution reactions within the battery intensify. These reactions consume a large amount of electromagnetic energy, reducing charging efficiency and increasing charging times.

Improvements to the internal formation charging process in different temperature ranges and process optimization in low-temperature environments are necessary to maintain the charging efficiency and capacity of lead-acid batteries in low-temperature environments. First, the charging voltage can be slightly increased to compensate for the increase in battery internal resistance caused by the decrease in temperature. According to the standard, the charging process is designed for a temperature of 25°C, and the voltage adjustment coefficient is 18mV/°C as the temperature decreases. Second, single-pulse charging can be adopted. Single-pulse charging can significantly reduce the impact of polarization and improve charging efficiency. For example, in low-temperature environments, single-pulse charging allows the positive ions within the battery to diffuse more rapidly under the influence of the single pulse, thereby improving the battery's charging performance. Furthermore, the battery can be preheated to bring the temperature to a suitable range before charging.

Process Improvements in High-Temperature Environments: In high-temperature environments, controlling the charging temperature is crucial. Cooling measures can be implemented to reduce battery temperature, such as central air conditioning, ventilation, cooling water tanks, cooling circulating water, and heat exchangers. At the same time, the charging current must be appropriately adjusted to reduce heat generation within the battery's internal structure. In high-temperature environments, the battery's acceptable charging current decreases. If the charging current is unstable, the internal battery temperature can rise excessively, affecting battery performance and lifespan. Furthermore, the charging curve can be optimized, employing a staged charging method, selecting different charging currents and operating voltages at different charging stages to prevent overcharging and overheating.

Advantages of Processing at Room Temperature: The internal formation charging process for lead-acid batteries offers certain advantages at room temperature (generally around 25°C). Within this temperature range, the battery's internal chemical reaction rates are moderate, polarization is minimal, the battery can accept a large charging current, and charging efficiency is high. Furthermore, at room temperature, battery capacity is well maintained, and charging times are shortened. Therefore, performing the internal formation charging process at room temperature can improve battery production efficiency and performance.

Temperature control methods used in the internal formation and charging process of lead-acid batteries. Common temperature control methods in the internal formation and charging process of lead-acid batteries include physical cooling and charging parameter adjustment. Physical cooling methods, as mentioned above, include heating, air cooling, cooling water tanks, cooling water tanks with circulating water, and cooling water tanks with heat exchangers. Central air conditioning regulates battery temperature by adjusting the ambient temperature and is suitable for small and medium-sized production lines. Air cooling uses fans and other devices to blow air over the battery surface, removing heat. Cooling water tanks immerse the batteries in water, reducing the battery temperature through the water's heat dissipation. Cooling water tanks with circulating water cooling and cooling water tanks with heat exchangers further enhance the cooling effect, maintaining the water temperature within a stable range.

Choosing the right temperature control method requires considering several factors, such as scale, ambient temperature, and battery type. Large-scale production companies may need to employ efficient cooling strategies such as cooling water tanks, circulating water cooling, or cooling water tanks and heat exchangers to ensure the battery temperature is controlled during charging. For smaller manufacturing companies, central air conditioning or daytime cooling may be a more cost-effective option. Furthermore, different types of lead-acid batteries have varying degrees of temperature sensitivity, and some high-performance lead-acid batteries may require more precise temperature control methods.

The effectiveness of temperature control methods can be evaluated from multiple perspectives. First, the cooling effect can be evaluated by monitoring the temperature changes of the battery. If the battery temperature can be maintained within an appropriate range during the charging process, it indicates that the temperature control method is effective. Secondly, the impact of the temperature control method on the battery can be evaluated by examining the battery's charging efficiency and capacity. If the battery's charging efficiency increases and its capacity increases after the temperature control method is used, it indicates that the temperature control method has a significant impact on the battery's characteristics. In addition, the long-term effectiveness of the temperature control method can also be evaluated by observing the battery's service life. If the battery's service life increases after the temperature control method is used, it indicates that the temperature control method can effectively control the battery and improve its stability.

A specific classic case study: Verifying the relationship between temperature and internal charge processing. Case study 1: Ultra-low temperature charging test at a battery manufacturer. A battery manufacturer conducted internal charge testing of lead-acid batteries in winter. The experimental environment was relatively low, with an average temperature of approximately 5°C. The company used conventional charging processes and found that charging time increased significantly and battery capacity decreased. The company then upgraded the charging process, appropriately increasing the charging operating voltage and adopting a single-pulse charging method. After optimization, charging time was shortened by approximately 20%, and battery capacity was also restored to a certain extent. This example demonstrates the impact of temperature on charging time and battery capacity in low-temperature environments, and how these issues can be effectively improved by adjusting the charging process.

Case 2: Battery Production in a Consistently High-Temperature Region. In a region with consistently high temperatures, summer ambient temperatures often exceed 35°C. A battery manufacturer, employing an internal formation charging process, encountered numerous issues, including high battery temperatures and low charging efficiency. The company implemented a cooling system using a cooling trough to cool the circulating water and appropriately adjusted the charging current. After a period of practical application, the company found that battery temperature was effectively controlled, charging efficiency increased by approximately 15%, and the battery life was also extended. This example demonstrates that, in high-temperature environments, effective temperature control methods and rationally tailored charging parameters can significantly improve the effectiveness of internal formation charging processes for lead-acid batteries.

Example 3: Efficient Production at Room Temperature. A battery manufacturer manufactures lead-acid batteries under room temperature (average temperature approximately 25°C). Due to the advantages of room temperature, the company uses a simpler charging process, resulting in higher charging efficiency and relatively stable battery quality. Compared to batteries manufactured at high and low temperatures, batteries manufactured at room temperature demonstrate significant advantages in terms of capacity, charging time, and service life. This example further demonstrates the positive impact of room temperature on the internal formation charging process for lead-acid batteries.

In general, there's a close relationship between the internalization and charging process of lead-acid batteries and temperature. Temperature significantly impacts the polarization state of the charging process, battery size, and charging methods. Scientifically sound temperature control methods and charging process improvements can effectively address these issues and enhance the performance and quality of lead-acid batteries. In actual production, companies should select appropriate temperature control methods and charging processes for different temperature environments to ensure lead-acid battery production efficiency and product quality.