Testing Principle: Lithium-ion battery aging is essentially the performance degradation process of a chemical system under cyclic charge-discharge or high-temperature environments. This includes electrode material structure damage, electrolyte decomposition, and SEI film thickening. Aging testing accelerates these reactions, shortening the evaluation cycle. For example, high-temperature environments (such as 55℃-85℃) can accelerate side reaction rates, making several weeks of testing equivalent to several years of actual use.
After assembly, lithium-ion battery packs must undergo aging testing in an aging chamber before shipment. This is a fundamental and core step in ensuring the safety, reliability, and performance stability of the battery pack. Through tests such as cycle life, high/low temperature, storage, and simulated comprehensive environments, potential defects are revealed early, eliminating defective products and stabilizing the overall performance of the battery pack.
ACEY-BA3020-18 battery aging machine is designed for evaluating the aging characteristics of various battery types, including ternary, lithium iron phosphate, lead-acid, and nickel-metal hydride/nickel-cadmium.Test items include charge protection voltage, discharge protection voltage, and capacity measurement. The system supports four types of test phases: charging, discharging, shelving (rest periods), and cycling.
A lithium-ion battery pack consists of multiple parts, including cells, BMS/protection board, connectors, casing, and auxiliary materials. Hidden defects may occur during manufacturing. These hidden problems are difficult to detect initially but can quickly lead to malfunctions during product application. The key to aging testing is to expose all defects before battery packs are shipped. For example, at the cell level, hidden problems such as micro-short circuits, separator damage, and active material shedding may appear normal in initial testing, but can easily lead to capacity drops, abnormal voltage, or even leakage or bulging under cyclic charge-discharge or high-temperature conditions. At the structural and connection level, issues such as poor welding, loose connections, or excessive contact resistance can accumulate heat during aging, potentially causing interface melting, localized overheating of the battery pack, and in severe cases, localized ablation or thermal runaway. The BMS protection board may also have parameter deviations, abnormal equalization, or communication interruptions, which can be triggered by abnormal charge-discharge cycles during aging. By using multi-condition composite testing, including high-temperature, multi-cycle charge-discharge, and static placement, the aging process amplifies these early failure risks, enabling precise screening of defective products and preventing substandard products from entering the market and causing safety accidents or performance abnormalities.
In the initial stages, lithium-ion battery packs often exhibit unstable performance, particularly since the SEI film of the cells may not be fully formed. After pack assembly, slight performance differences between cells are inevitable, and the aging process effectively improves performance. The SEI film formed after the first charge and discharge cycle of a cell may be loose and uneven. Aging cycles using low-current charge and discharge can stabilize the SEI film, reducing capacity decay during subsequent use (preventing rapid power loss immediately upon user activation). Even after initial screening, multiple cells in a pack may still have slight differences in capacity and internal resistance. During aging, charge and discharge cycles will cause weaker cells to show faster capacity decay, facilitating further calibration using the BMS's balancing function. This reduces the risk of a single cell causing the entire battery pack to fail during subsequent use.
Lithium-ion battery packs need to withstand diverse application environments. Aging tests simulate high/low temperatures, continuous operation, and comprehensive usage scenarios to verify the battery pack's adaptability under different conditions. For example, automotive batteries need to withstand high/low temperatures. Aging chambers can cycle at high/low temperatures to test the battery pack's charge/discharge efficiency, capacity retention, and BMS adaptability under extreme temperatures (e.g., whether low-temperature protection is falsely triggered). Energy storage batteries, on the other hand, require long-term voltage stability and self-discharge control under float charging to ensure that they do not experience excessively rapid power loss or overcharging in actual use.
Both international and domestic standards, such as IEC 62133, UN38.3, and GB/T 31467.3, clearly stipulate that lithium battery packs must undergo aging tests before leaving the factory. This is not only a mandatory standard requirement but also a crucial measure for companies to assume product quality responsibility and ensure user safety.
In summary, aging chamber testing is the "ultimate checkup" for lithium battery packs before they leave the factory: although this step requires an additional 1-3 days, it can prevent end-product failures and safety risks from the source and is an indispensable quality control and core step in the lithium battery industry's manufacturing system.
