There are rumors online about cases where the Xiaomi SU7 emitted smoke from the undercarriage after a collision. Is this true? What are the specific details?
We can only consider this case as an extremely low-probability extreme condition caused by extreme external force under extremely accidental circumstances.
The day before yesterday, we received a report from the vehicle driver stating that there was a short-term local smoking phenomenon after the vehicle collided. Xiaomi Auto store service personnel rushed to the scene immediately. After communicating with the user and conducting an on-site inspection, the situation was confirmed as follows:
The vehicle chassis had obvious severe damage caused by external force, but the battery pack only experienced brief pressure relief and venting, with no thermal runaway or fire. Additionally, the backend data networking function of the accident vehicle was actively turned off at the vehicle end at the time of the incident.
The bottom of the accident vehicle's battery is suspected to have suffered extreme external force collision. Based on the on-site analysis, the inferred cause of the extreme condition (it is currently impossible to confirm whether the chassis had been bumped before) is loose concrete tiles mixed with marble (300*300*20mm), which lifted up on one side after being run over by tires, striking the bottom of the battery pack violently at a sharp intrusion angle and causing it to tear (maximum opening exceeding 350mm). Ultimately, the bottom of the battery pack was severely depressed (maximum depth exceeding 30mm), internal cells were damaged and exposed, with a deformation of approximately 14.3mm.
The Xiaomi CTB battery pack was developed according to the highest safety standards, and comprehensive and rigorous tests were conducted for bottom collision safety, such as placing a solid hemisphere with a diameter of 150mm on the ground and performing a scraping test at a speed of 30km/h, where the cell deformation was only 1mm. Even when facing the industry's most rigorous bottom impact test, the battery deformation was only 5.4mm. In this accident, the cell deformation exceeded 14mm, which is 2.6 times greater than the most rigorous test, constituting an extreme condition. However, due to a series of protective measures of the Xiaomi SU7 battery pack, no more cells caught fire due to thermal runaway, and only brief pressure relief and venting occurred.
Some reports, without understanding the true situation, used descriptions like "spontaneous combustion" and "fire," which are completely inaccurate. We earnestly request everyone not to believe or spread rumors. Currently, we are also assisting the user in properly handling subsequent matters.
