Direct reasons: Insufficient battery production and manufacturing technology capabilities, battery storage time, temperature difference during battery pack charge and discharge, charge and discharge current, etc. Failure analysis: There are specific technical indicators for consistency. Once the consistency is lower than the specification, it indicates that the production line quality assurance system has serious problems and improvement measures must be taken. Improving product capacity consistency is a process of continuous improvement. Safety technical measures: Strengthen process management and review measures to continuously improve the capabilities of the enterprise's quality management system. Danger: The danger will not occur immediately. Due to poor capacity consistency, manufacturers must promptly improve quality and strictly prohibit unqualified products from leaving the factory. Analysis of safety failure mode of dry goods power battery cells and BMS Safety failure mode analysis of dry goods power battery cells and BMS 1. Short circuit of positive and negative poles inside the battery core, the production equipment support capability is the key direct cause: defects in the battery production process lead to or It is caused by long-term vibration and external force that deforms the battery core. Failure analysis: During the production process, the elimination of short-circuit defects in the positive and negative poles inside the battery core is ensured by the relevant equipment of the production line. If the equipment cannot guarantee this, batch product quality problems will occur. This is a basic requirement for battery manufacturers. Our country has implemented catalog management for power battery manufacturers, which can basically ensure that compliant battery manufacturers will not have batch product quality problems. Safety technical measures: Screen out unqualified (positive and negative poles inside the battery core are short-circuited) batteries, and the target value is greater than 99.999%. Danger: Once a serious internal short circuit occurs, control cannot be prevented, external insurance does not work, and smoke or burning will definitely occur. However, if the battery manufacturer has sufficient support capabilities, the probability of occurrence is very low. Even if it does happen, the vehicle manufacturer and the automatic fire extinguishing device must play a protective role. 2. Battery cells leak, and the implementation of process discipline is the key direct cause: external force damage; collision and improper installation causing damage to the sealing structure; welding defects and insufficient sealing glue causing poor sealing performance, etc. Failure analysis: Compared with soft-packed and plastic-cased batteries, metal-cased cells are more prone to leakage, leading to insulation failure. After the battery leaks, the insulation of the entire battery pack will fail. Single-point insulation failure is not a big problem. If there are two or more insulation failures, an external short circuit will occur. Safety technical measures: Strict process discipline and improve production automation level. Risk: Very dangerous; the probability of a car fire caused by battery leakage is several orders of magnitude greater than the probability of a short circuit between the positive and negative poles inside the battery cell. For this kind of external short circuit, external insurance must play a role. 3. The battery core is bulging and the environment (air) indicators at the production site are not up to standard. This is the key direct reason: it is mainly because side reactions occur inside the battery to produce gas, the most typical side reaction is with water. Failure analysis: The production line environment deviates from specified requirements. Safety technical measures: Strict control of moisture during the battery production process can be avoided. Risk: Once the battery is inflated, leakage and other situations may occur. This is a serious quality problem in product production quality. Preventive measures can be formulated, and unqualified products are strictly prohibited from leaving the factory.

Read recommendations:

601248 300mAh 3.7V

-20 C Lithium battery with low temperature charging.cabinet type energy storage battery Factory

Open circuit voltage and resistance of lithium batteries.3.7 volt 18650 lithium battery

801738 battery

NiMH No.7 battery