Major Accident of Xiaomi Cars Triggers Deep Market Concerns: Should the Safety of Low-End Models Be Compromised?

On the night of March 29, the Xiaomi SU7 Standard Edition involved in a collision and explosion on the Chiqi section of the Deshang Expressway in Anhui, resulting in 3 deaths, has pushed Xiaomi Motors into the spotlight of public opinion.

This incident has not only raised market concerns about the safety hazards of Xiaomi Auto, a new entrant in the electric vehicle sector, regarding battery, chassis design, and safety issues in the intelligent driving system under extreme scenarios, but also sparked consumer doubts about the differences in safety features between the standard and base models of Xiaomi Auto compared to the Max and Ultra high-end models.

Question 1: Is there a difference in battery safety between the standard and high-end versions?

The market is generally concerned about whether the power battery of the involved vehicle has safety risks. On the morning of April 2, Xiaomi customer service responded that the Xiaomi SU7 is divided into standard, Pro, and Max versions, with the standard version equipped with BYD Blade batteries.宁德时代 CATL(249.140, 0.08, 0.03%)Batteries, two different types of batteries are randomly installed, and the car buyer cannot choose when purchasing the car.

However, the explanation clearly fails to dispel market concerns.

It is understood that the accident vehicle is the Xiaomi SU7 standard version, equipped withBYD(360.500, -5.00, -1.37%)The 73.6kWh lithium iron phosphate battery produced by BYD Power has a battery pack shell compressive strength of 1500MPa, which is lower than the 2000MPa of the high-end version of CATL's battery.

Not only that, the standard version of Xiaomi adopts BYD's CTP technology and does not come equipped with the "inverted cell technology" featured in the high-end version. The latter can, in extreme cases, direct high-temperature gases and flames downward for expulsion instead of allowing them to invade the passenger compartment upward, theoretically extending escape time.

There is an analysis suggesting that the battery of the involved Xiaomi SU7 exploded and caught fire within 3 seconds after the collision, which may be related to the insufficient number of thermal insulation layers (aerogel) between the battery cells, as the standard version is only equipped with 14 layers of physical protection, while the high-end version has 17 layers.

In addition, the standard version of the battery has an ordinary coating on the bottom, while the high-end version uses "bulletproof coating," with a 13-fold increase in puncture resistance, and the bottom protection is also different.

Industry experts pointed out that the national standard only requires the battery system to not catch fire within 5 minutes after thermal runaway, but the actual high-speed collision scenarios far exceed laboratory conditions. If the battery pack leaks electrolyte due to mechanical deformation, it may still quickly cause an explosion.

In this accident, the vehicle crashed into a concrete pile at a speed of 97 km/h, causing severe compression of the battery pack, which ultimately caught fire, highlighting the shortcomings of the battery protection design in the standard version of the Xiaomi SU7.

Question 2: Is there a design flaw in the door lock mechanism?

The families of the victims questioned whether the locked doors after the accident led to the failure to escape. Xiaomi officially responded that all four doors are equipped with mechanical emergency handles, located below the storage compartment, which can be used to unlock the doors in the event of a power outage.

However, this explanation still failed to dispel market concerns.

It is understood that the Xiaomi SU7 standard version is powered by a 12V low-voltage battery located at the front of the car. In the accident, the severe deformation of the front caused a short circuit in the power supply, resulting in a complete failure of the electronic unlocking function.

In contrast, the Tesla Model 3 is equipped with a 48V lithium battery backup, providing an unlock time of up to 120 seconds. However, the standard version of the Xiaomi SU7 lacks a redundant power design, which may result in the doors being unable to unlock during an accident.

At the same time, the mechanical door handle of the Xiaomi car is hidden at the bottom of the door storage compartment. It requires lifting the anti-slip mat and applying a force of 150N, equivalent to lifting a 15 kg object. The deformation of the storage compartment after a collision may make it difficult for most users to operate in time.

Tsinghua University's collision tests show that when the door deformation exceeds 50mm, the success rate of operating the mechanical pull handle of the Xiaomi SU7 is less than 37%.

Additionally, Xiaomi's sales process lacks sufficient instructions on the use of emergency devices. Multiple car owners have reported not receiving relevant safety training at the time of purchase, and the manual's explanation of the mechanical release handle is easily overlooked. During emergencies, this further increases the difficulty for panicked owners to escape.

Question three: Does the low-equipped model's intelligent driving system fully consider safety factors?

At the time of the accident, the Xiaomi SU7 standard version was in NOA (Smart Assisted Driving) mode, traveling at a speed of 116 km/h. Considering the differences in configurations, the market has also raised concerns about the safety of the intelligent driving systems in Xiaomi's lower-spec models.

It is reported that the standard version of Xiaomi SU7 is only equipped with 11 cameras and 5 millimeter-wave radars, adopting a pure visual perception solution without LiDAR, relying on a single Nvidia Orin chip with a computing power of 84 TOPS.

In contrast, the high-end Max version of the Xiaomi SU7 adds a LiDAR, adopts multi-sensor fusion, and is equipped with dual Orin-X chips with a computing power of 508 TOPS. Whether in terms of the quantity and type of sensors or the processing capability of the chips, there are significant differences compared to the lower-end version.

The accident occurred on a construction site at night, further challenging the recognition capabilities of the pure visual solution.

Currently, the national standard requires AEB to achieve a detection distance of 160 meters at a speed of 100 km/h, while the nighttime recognition distance of the visual solution is only 120 meters, issuing a warning only 2 seconds before a collision. The LiDAR solution, on the other hand, can reach over 200 meters. The Max version has also previously passed the AEB test for stationary obstacles at a nighttime speed of 120 km/h.

Xiaomi has officially stated that the AEB function is only applicable to vehicles, pedestrians, and two-wheeled vehicles, and cannot respond to static obstacles on the road such as cones, stones, and animals. In addition, Xiaomi has collaborated with Waymo to develop an end-to-end neural network model that supports high-speed NOA, but its ability to recognize static obstacles is relatively weak.

Previously, Tesla's Autopilot had experienced multiple static obstacle collision accidents in similar scenarios due to its pure vision solution. However, systems like Xiao鹏's XNGP and Huawei's ADS, which employ LiDAR solutions, have higher recognition rates.

In fact, in this accident, the AEB of the standard version of Xiaomi SU7 did not clearly trigger emergency braking. After the driver took over, the braking was insufficient, which eventually led to the vehicle collision and casualties.

Conclusion: Cost reduction and marketing should be moderate, and safety must not be compromised.

It is undeniable that different products have different configurations at different prices, which is reasonable. However, in the case of passenger cars, which are closely related to personal safety, manufacturers should be especially cautious when deciding on the extent to which low-end models compromise on safety.

If the aforementioned issue is ultimately proven, Xiaomi Auto, as a newcomer to the new energy vehicle market, may face a severe trust crisis. To regain its reputation, Xiaomi needs to promptly cooperate with relevant departments to publicly release the complete accident data and accelerate technological iterations, tilting its R&D investments toward safety areas.

It is worth mentioning that in 2024, Xiaomi's automotive business R&D expenses reached approximately 9.6 billion yuan, a year-on-year increase of 68.4%, while sales expenses were about 5.1 billion yuan, a year-on-year increase of 75.9%, exceeding the growth rate of R&D during the same period.

For consumers, when choosing new energy vehicles, they need to rationally view the marketing gimmicks in the promotion and pay more attention to the safety configurations in actual scenarios, because safety is the foundation of everything.