A deadly accident involving a Xiaomi SU7 on March 29 in eastern Anhui province, which claimed the lives of all three young passengers, has raised important questions about the battery safety and emergency response design of the Chinese electric car startup’s autos and the maturity of its smart driving technology. The families of the victims are still waiting for answers.
The car was in Navigation Assisted Driving mode, traveling at 116 kilometers an hour along the Tongling section of the Anhui highway at the time of the crash, according to Xiaomi’s official statement. The system detected a construction barrier ahead and warned the driver to slow down. After the driver took over the vehicle, he swerved at around 97 km/h and crashed into a cement barrier.
The vehicle caught fire and the two people in the front seats were unable to open the doors, which appear to have locked after the collision, and they died inside in the auto. The person sitting in the back was rescued by passersby who broke the window but he couldn’t be saved. Families of the victims are asking why the doors jammed after the collision.
Xiaomi is cooperating with the police and has provided all the car’s data, but it has not yet examined the damaged vehicle, it said. But the Beijing-based company has yet to address concerns among the public about whether the car's Automatic Emergency Braking system was triggered.
Battery Safety
The Xiaomi SU7 has electronic door handles that are operated by the car’s battery, experts said. If the battery is damaged in a crash, this system might fail. Even though there is an emergency mechanical handle, which is described in the user manual, a strong impact might jam the locks, making it hard to open the doors manually.
Xiaomi autos are equipped with inverted battery cells, which can prevent the battery from rapidly heating up or short-circuiting, even in the case of prolonged immersion, according to official documents. This also reduces the risk of accidental coolant leakage, which is a fire hazard.
But with a major crash like this, even if there was an inverted battery, it would only be a matter of time before the fire spread throughout the vehicle, an industry insider said. The incident serves as another reminder of the risks related to battery safety.
Flawed Algorithms
The car's smart driving technologies and algorithms have also come under scrutiny. The vehicle involved in the accident was the standard version of the SU7, equipped with Xiaomi’s pure visual intelligent driving solution, Xiaomi Pilot Pro, and does not have lidar sensors.
Pure vision systems rely on algorithms to estimate the distance to obstacles, but Xiaomi’s algorithm seems to have trouble recognizing temporary roadblocks, experts said.
The crash exposed flaws in Xiaomi’s perception algorithm, said Huang Song, an investor in autonomous driving firms. At a 200-meter detection range, the system should have been able to stop the car at 120 km/h, but the system only reacted in the final second, which was too late.
Huang also mentioned that Xiaomi's smart driving tech is not in the top tier in China.
The pure-vision solution is cheaper, with hardware costing around USD200, but it needs advanced algorithms to make up for its hardware shortcomings, according to a report by CITIC Securities. An anonymous Xiaomi SU7 user reported issues with the car's Navigation Assisted Driving feature, such as confusing lane-change logic and sudden drops in speed, and rated his smart driving experience as “second-rate.”
Sales Gimmicks
The crash highlights a common problem in the intelligent driving industry. The former Minister of Industry and Information Technology, Miao Wei, recently criticized some companies for misleading consumers with "high-level smart driving" gimmicks while neglecting basic safety features.
Xiaomi has bolstered its smart driving tech by acquiring DeepMotion, an autonomous driving company, but the vehicles' actual performance is still reported to fall short of the hype.
Although Chief Executive Officer Leo Jun said the company will fully co-operate with the investigation, his decision to post pictures of the spring cherry blossoms on social media the next day has sparked a public backlash.
The full details of the crash have not yet been released, and key questions, like whether the inverted battery design was able to withstand a severe impact and whether the coolant leak prevention system was working properly, remain unanswered.
