How Chinese EVs Achieve One-Meter Wading Depth in Storms

Storms highlight EV wading capabilities

Heavy rains from Typhoon White Dolphin struck eastern and northern China on August 9, with Shanghai recording nearly 300mm of rainfall and thousands of vehicles submerged in Zhejiang province. In Beijing's Chaoyang district, some cars required forklift rescue from flooded roads. The incidents reignited public debate over vehicle wading safety.

Xiaomi founder and CEO Lei Jun took to social media to remind drivers to pay attention to wading capability, sharing performance data for the Xiaomi Pengcheng N90 Max: a maximum wading depth of 750mm, with the battery pack rated IPX8 and IPX9K for waterproofing.

National standard vs. real-world capabilities

Under the Electric Vehicle Safety Requirements (GB18384-2025), effective July 1, 2026, EVs must pass a 150mm wading test — a significant increase from the previous 100mm threshold. But several Chinese models far exceed that minimum.

• NIO ES9: 810mm wading depth
• Xiaomi Pengcheng N90 Max: 750mm with air suspension at maximum ride height
• Stelato G9 (HIMA): 900mm
• Yangwang U8 (BYD): ~1,000mm with emergency floating support
• Jetour Zongheng G700 (Chery): ~1,000mm

Sealed three-electric systems are the key

The core difference lies in the powertrain. Conventional fuel vehicles are limited by engine air-intake height — water entering the cylinders causes immediate stalling. EVs have no such bottleneck; instead, their vulnerability centers on the battery pack, drive motor, and electronic control unit.

Most mainstream battery packs now use aluminum alloy housings joined by die-casting or friction-stir welding, sealed with multi-layer rubber gaskets and fitted with pressure-equalizing vents. Battery waterproof ratings of IPX8 and IPX9K are common — capable of withstanding submersion at one meter for 48 hours and high-temperature, high-pressure water jets.

Drive motors increasingly use magnetic fluid seals at the shaft, where a magnetically held liquid seal achieves near-zero leakage even at high rotational speeds. High-voltage harness connectors include water-detection sensors that trigger the battery management system to cut high-voltage output upon detecting intrusion.

System-level waterproof design

Beating the limits of individual component sealing requires a holistic approach. Xiaomi notes that the Pengcheng N90 Max raises its range-extender air intake to 1,109mm above ground, positioned below the front windshield. A cabin pressure-relief valve sits at 950mm — 250mm higher than conventional placement. When wading mode activates, the air suspension rises to its maximum height, the climate system switches to recirculation, windows lower slightly for occupant breathing, and the infotainment screen displays real-time water-depth sensor readings.

The brand also claims 27 upgraded high-waterproof sealing plugs and dual-layer EPDM/EVA seals in pillar cavities to slow cabin water ingress and extend the evacuation window in worst-case scenarios.

Emergency floating and active water propulsion

The Yangwang U8 takes the concept further with an emergency floating function, using four independent wheel motors to paddle through water. The vehicle features over 3,000 sealing points and 161 waterproof-specific components across its body. BYD recommends limiting float-duration to 30 minutes, positioning the feature as a passive safety measure akin to airbags.

The Jetour Zongheng G700 pursued a different path entirely, equipping two rear-mounted water thrusters for active propulsion at up to 7km/h with over one hour of range — a departure from purely emergency-oriented design.

Caution remains warranted

After posting the wading data, Lei Jun added a clear warning: unknown water depth requires careful driving. Regardless of whether a vehicle carries a fuel engine or a battery pack, the safest response to unfamiliar floodwater remains to turn around and find an alternative route.