[Flooded Car Alert] Do Electric Cars Cause Electric Shock When Wheels Are Fully Submerged?

Even When Fully Dried, Maintenance Must Be Done Before Charging
Avoid Places Where Tires Are Submerged More Than Half

On the 9th, when record-breaking heavy rain fell in Seoul and the central region, firefighters were moving to enter the flooded basement of a building near Gangnam Station in Seocho-gu, Seoul. Photo by Jinhyung Kang aymsdream@

[Asia Economy Reporter Kiho Sung] As record-breaking heavy rain pours down in the Seoul metropolitan area, damage from car flooding is also reaching unprecedented levels. In particular, with the recent increase in demand and distribution of electric vehicles, it is known that a significant number of flooded vehicles are electric cars. Experts advise that if an electric vehicle is flooded, it must be serviced before charging.

According to the Korea Electrical Safety Corporation and the automotive industry on the 13th, flooded electric vehicles must be operated and charged only after being completely dried and serviced by professionals.

Typically, electric vehicles are equipped with high-voltage batteries of over 300V. The battery is located at the bottom of the vehicle. If rainwater starts to rise, the battery area will inevitably be submerged first. This raises fears of electric shock accidents.

However, experts explain that the possibility of electric shock due to electric vehicle flooding is very low. This is because a protective system that automatically cuts off the current is installed when water enters the vehicle.

All electric vehicles have a Battery Management System (BMS), which acts as the 'brain' of the battery. When the BMS detects water entering the vehicle body, it activates a protection module that cuts off the current going outside the vehicle and discharges the current flowing inside, fundamentally eliminating the risk of electric shock.

Additionally, electric vehicle batteries have strong waterproof performance to prepare for flooding accidents. Generally, the waterproof performance of battery packs for electric vehicles corresponds to the International Electrotechnical Commission (IEC) international dust and waterproof rating IP67. This rating means the battery pack can operate normally even when submerged in water at a depth of 1 meter for 30 minutes.

However, just because the electric vehicle battery does not get wet does not mean it is safe to drive in flooded areas. The structure outside the battery is no different between conventional internal combustion engine vehicles and electric vehicles, so water can enter the vehicle interior in the same way. Electric vehicles consist of various electrical components such as energy storage systems (ESS), electric motors, circuits, and boards. Therefore, once flooded, there is a high possibility of exposure to malfunction and fire risks.

For this reason, it is best for electric vehicles to avoid passing through areas where more than half of the tires are submerged in water. If signs of flooding appear, for safety, the engine should be turned off as quickly as possible and occupants should evacuate the vehicle promptly. Also, if noise, vibration, or malfunction messages occur while driving an electric vehicle in rainy conditions, the vehicle should be serviced immediately.

If an electric vehicle is submerged in water, do not approach it or operate/charge it. There is an increased risk of fire due to system malfunctions inside the electric vehicle and short circuits between battery electrodes. In particular, attempting to directly check for battery damage should be avoided due to the risk of electric shock.

Song Gilmok, head of the Safety Research Office at the Korea Electrical Safety Corporation, advised, "Due to climate change, sudden heavy rain accompanied by lightning is occurring frequently," adding, "This is a time when special attention to the safe use of electric vehicles is necessary."