Water damage on any used car is a concern. On an electric vehicle, it is in a different category of seriousness because water ingress to the high-voltage battery and electrical systems creates risks that may not be immediately visible and can develop over time.
Why it is more serious on an EV
A petrol car with water damage has corroded electrics, damaged upholstery, and potentially a compromised engine.
Serious, but the risks are largely visible and mechanical.
An EV with water ingress to the high-voltage battery pack or associated electrical systems has a different risk profile.
High-voltage systems and water are a dangerous combination the potential for short circuits, battery degradation, and in serious cases fire is real. Crucially, damage may not be apparent at point of sale a vehicle that passed an inspection yesterday may develop problems as corrosion progresses in the battery management electronics.
Signs to look for
Water marks on interior door sills at floor level the high-water mark of a flood event is often visible here even after the interior has been cleaned.
Grit or silt residue in the boot corners, under the rear seat, or in low areas of the footwells.
Corrosion on electrical connectors in the footwells, under the front seats, or in the boot. An unusual damp or musty smell, particularly in warm conditions.
Water marks on the underside of the dashboard indicating water reached dashboard height.
On the underside of the vehicle, unusual corrosion patterns inconsistent with the vehicle's age, particularly around electrical connectors and the battery pack area.
What to do if you find signs
Walk away, or commission a specialist EV technician to assess the vehicle thoroughly before proceeding not a general mechanic, but an EV-accredited specialist with experience in high voltage system assessment.
This is not a situation where cosmetic repairs and a reduced price are an adequate response to the risk.
A flood-damaged EV at a low price is not a bargain.
It is a vehicle with unknown and potentially serious latent faults in its most safety-critical systems.
