Xiaomi's Lei Jun tests the SU7 Ultra battery coating strength with 6th floor watermelon fall

The ever innovative Xiaomi CEO Lei Jun demonstrated the tough coating of the company's SU7 Ultra sports car by dropping a watermelon covered in said coating from the 6th floor of the car factory.

The 94 kWh NMH battery pack that powers SU7 Ultra runs from 0-60 mph in under two seconds is made by CATL, and Xiaomi tried to make the ternary nickel pack as safe as it can be upon impact. The structural chassis pack is protected by a tough multilayer shell of high-strength steel beams, as well as an active cooling system with wide surface and aerogel insulation.

As part of the latest generation of CATL Qilin batteries, the Xiaomi SU7 Ultra pack has dual large-surface active cooling, similar to what BYD recently demonstrated for its 1MW system in the Han L sedan. This helps with heat dissipation and ensures safety during the fast 5C charging sessions, as well as the longevity of the battery cells that stay cool under pressure.

The aerogel on the side of each cell inhibit cell to cell propagation, while the 7.8 m2 active cooling system has its plates running on each side of the prismatic cells, thus increasing the total cooling surface significantly. Since this dual-surface system may suffer in a side impact, the CATL Qilin battery pack is structurally reinforced and covered with the so-called "bulletproof" coating. 

In the Xiaomi SU7 Ultra pack, this reinforces the scratch and tear resistance ten times, and the puncture resistance thirteen times.

Xiaomi, which is mainly known for making phones, home electronics, and consumers gadgets like Bluetooth speakers, is now using its earned value-for-money street cred to make electric cars with quite the market acceptance. Lei Jun's work ethic and go-getter attitude has earned him somewhat of a cult status among Chinese entrepreneurs, who consider him to be the local version of Elon Musk.

The pedigree is seemingly there, since Lei Jun got on the 6th floor of Xiaomi's car factory, and threw a watermelon covered with the same SU7 Ultra battery coating. Needless to say, the watermelon bounced from the asphalt down below without bursting into pieces, and that's the kind of safety Xiaomi wants from its race car battery upon impact.