EVs, Floods and Monsoon Season: Staying Safe in Deep Water

EVs in water: the basics

An EV has no air intake to flood and no exhaust to fill with water, so it will drive through shallow standing water more calmly than a petrol car. The battery pack is a sealed, waterproof unit tested by immersion, and the high-voltage system is isolated from the body. The limits are the same as for any car — the depth the manufacturer specifies for wading, usually around the bottom of the doors — and the danger is water getting past those seals over time.

How deep is too deep?

• Puddles and water below the wheel hubs: fine.
• Up to the manufacturer's stated wading depth (check the handbook): drive slowly and steadily.
• Above the door sills or moving water: do not attempt. Moving water only 30 cm deep can float a car.
• Never drive into water when you can't see the road surface — hidden potholes and debris can damage the underside of the battery pack.

Why you must not charge a flooded EV

If floodwater — especially salty or dirty water — gets inside the battery pack or high-voltage components, it can corrode connections and create short circuits. The danger is that this can lead to a fire days or even weeks later, sometimes triggered by charging. Any EV that has been submerged, or has had water above the sill line for a period, should be treated as potentially damaged.

After a flood: step by step

1. If the car was in deep water, do not start it or plug it in.
2. Move it (towed if needed) to an open area away from buildings and other vehicles.
3. Contact the manufacturer, dealer or a qualified EV technician for an inspection of the battery and high-voltage system.
4. Inform your insurer; flood damage to the battery is usually a serious claim.
5. Only charge again once the pack has been inspected and cleared.

Monsoon-season tips

• Check flood-prone routes and underpasses before setting out; use the map to plan charging away from low-lying areas.
• Park on higher ground when heavy rain is forecast; basements and low car parks flood first.
• Keep the charge port cap closed and the car's seals in good condition.
• Keep the battery reasonably topped up before storms in case of long detours or power cuts at chargers.
• Charging in ordinary rain is completely safe — it is only submersion that matters.