Your EV Has Been Flooded — What Now? 6 Steps and the Things You Must Not Do

The short answer: if your electric car has been flooded or submerged, never press start or power up the vehicle, never plug it in to charge, and never tow it on its own wheels. Call a flatbed truck to lift the whole car to an open area away from buildings, then notify your service center and insurer immediately. Even if the car seems to work normally, a technician must check the electrical system before you drive it again.

First, assess how high the water reached

The water level tells you how serious the damage is likely to be and what you need to do next.

• Below the cabin floor — mostly the underbody, wheels and brakes are affected, and the risk to the electrical system is low, but a service check is still advisable

• Up to the cabin floor or carpet — water has reached control units and low-mounted wiring, so a technician must inspect it before any further use

• Up to the seats or center console — this counts as severe damage, with most electrical and electronic components affected

• Fully submerged — do not touch the car yourself under any circumstances; leave it to specialists

Five things you must not do

• Do not press start or power up the vehicle, even if the screen still lights up

• Do not plug the car in to charge, at home or at a station, until a technician has checked the electrical system

• Do not tow the car on its wheels — only a flatbed truck lifting the whole car is acceptable

• Do not open the bonnet to remove high-voltage parts yourself; the orange components are high-voltage cabling and must not be touched

• Do not park a flooded car in a garage, under a building, or near anything flammable

Six steps to take

1. People come first. If the water is still high or moving fast, get everyone to safety and do not go back for belongings.

2. Photograph and film everything as evidence — the water level against the car, the number plate, and the surroundings. You will need it for the insurance claim.

3. Notify your insurer straight away. The sooner the better, and ask which service center to use and whose flatbed truck to call.

4. Contact BYD Roadside Assistance, available 24 hours on 02-045-8888, to arrange a flatbed and get initial guidance.

5. Move the car to an open area, away from houses, buildings and anything flammable, and leave it there until a technician has inspected it.

6. Book a service center inspection, even if the car still drives normally. Water damage often shows up later.

Why you must not start or charge it

Floodwater is not clean water. It carries mud, sediment and minerals that conduct electricity well, and even once dry it leaves deposits on connectors and circuit boards. Powering up the system in that condition can cause short circuits, heat build-up, and damage that spreads to parts that were still intact.

There is a second reason: damage to a lithium battery may not show immediately, but can develop over hours or days. Leaving the car in an open area with no power going through the system is the safest approach while you wait for an inspection.

What the service center will check

• Insulation resistance of the high-voltage system, to detect moisture inside it

• The battery pack, its seals, and the connection points under the car

• Electronic control units and low-mounted wiring harnesses

• Motor, drivetrain and wheel bearings

• Brakes, suspension and cabin drainage

• Stored fault codes, and a software update where needed

How insurance claims work

First-class motor insurance generally covers natural-disaster damage including flooding, though terms vary between policies. Other classes of cover may not include it, so check directly with your insurer.

Have your evidence ready: photos and video from the scene, a copy of the policy, your driving licence, the vehicle registration, and the flatbed receipt if you paid up front.

If it can be shown that the driver deliberately drove into an area under a flood warning, cover may be disputed — another reason not to push through a route you are unsure about.

Is a DM-i plug-in hybrid any different?

The rules are the same: do not start it, do not charge it, do not tow it on its wheels. But a DM-i also has a petrol engine, which adds one more risk — water entering the engine's air intake. Trying to start it in that state causes severe engine damage immediately.

Prevention is better

• Follow local flood warnings and move the car to higher ground early, rather than waiting for the water to arrive

• Keep the battery charged, in case you need to move the car or use it in an emergency

• If water reaches your Home Charger, switch off its circuit breaker and stop using it until an electrician has checked it

• Save the Roadside Assistance and insurance numbers in your phone where you can find them instantly

• If the power goes out during a flood, a BYD can run essential appliances such as a fridge, fans and lighting through its V2L function — used only in a dry, safe spot

Frequently asked questions

Can a submerged EV electrocute someone standing near it? No. The high-voltage system is sealed and cuts out automatically when a fault is detected, so approaching or touching the body will not shock you. Even so, do not power it up, do not charge it, and never touch the orange high-voltage cabling.

The car drove through water and still works fine — does it need a service visit? Yes, if the water reached the cabin floor or higher. Damage from moisture and corrosion often appears days or weeks later.

Does a submerged car always need a whole new battery? Not necessarily. It depends on the insulation resistance readings and the condition of the pack's seals. In many cases where water did not reach inside the pack, the car can be used again after cleaning and inspection.

Does first-class insurance cover flooding? It generally covers natural-disaster damage including floods, but terms differ between policies, so check directly with your insurer.

Information correct as of October 2026 and intended as general guidance. Every case differs, so follow the instructions of your service center and insurer. The BYD NOVA team is on hand at all branches: Salaya, Korat, Phetchaburi and Pranburi.