With the booming development of the new energy vehicle market, the safety performance testing of new energy batteries has become the focus of attention. As the power source of vehicles, the safety of new energy batteries is directly related to the life and property safety of drivers and passengers as well as the traffic safety of the entire society.

Safety performance testing mainly includes a series of rigorous test items such as overcharge test, short circuit test, puncture test, extrusion test and hot box test. The overcharge test is designed to simulate the overcharge situation that may occur during the charging process of the battery and to verify whether the overcharge protection mechanism of the battery is effective. When the battery charging voltage exceeds the set value, a good battery management system should be able to cut off the charging circuit in time to prevent the battery from thermal runaway, fire or even explosion due to overcharging.

The short-circuit test directly short-circuits the positive and negative electrodes of the battery to simulate a short-circuit failure of the battery under extreme conditions. By observing the battery's reaction at the moment of short circuit and the subsequent state changes, the short-circuit protection capability and safety of the battery are evaluated. High-quality new energy batteries should be able to quickly cut off the current when a short circuit occurs to avoid generating a lot of heat and dangerous situations.

The puncture test is to pierce the battery with a sharp object to test the safety of the battery when it is physically damaged. During the puncture process, short circuits and thermal runaway may occur inside the battery, but qualified batteries should be able to effectively control the spread of these dangerous situations to ensure that no serious safety accidents will occur.

The extrusion test applies a certain amount of pressure to the battery to simulate the stress on the battery during a vehicle collision or extrusion. The battery's anti-extrusion ability and safety are evaluated by detecting the degree of deformation, leakage, and changes in electrical properties during the extrusion process. A good battery structure and material should be able to withstand extrusion stress to a certain extent and maintain the integrity and safety of the battery.

The hot box test places the battery in a high temperature environment to observe the battery's performance and safety at high temperatures. During the hot box test, the battery temperature will gradually rise. When it reaches a certain temperature, it will be tested to see if the battery will experience dangerous situations such as thermal runaway, fire or explosion. At the same time, the changes in battery parameters such as voltage and current at high temperatures will be monitored to evaluate the battery's thermal stability and safety.

Although these safety performance testing items are strict, they are necessary means to ensure the quality and safety of new energy batteries. Only new energy batteries that have passed these strict tests can provide reliable power support for the safe driving of new energy vehicles, allowing consumers to safely choose new energy vehicles as a tool for green travel.