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uk Transport & mobility emergencies

What to do if…
your electric vehicle displays a high-voltage or battery system warning

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy UK guide

Short answer

Treat it as a safety warning: slow down smoothly, reach the safest available place, stop, and do not continue driving if the warning is red, says to stop, or the vehicle has limited power.

Do not do these things

  • Don’t keep driving “to see if it clears” if the warning is red, says stop or pull over, or the car limits power.
  • Don’t repeatedly switch the vehicle on and off trying to clear the warning at the roadside.
  • Don’t touch, open, cut, move, or inspect anything labelled high-voltage.
  • Don’t go near damaged wiring or orange cables.
  • Don’t plug in to charge if the warning suggests a battery or high-voltage fault, or if you notice heat, smell, smoke, vapour, hissing, or unusual noises.
  • Don’t park in an enclosed garage or tightly next to other vehicles if you suspect a battery problem.
  • Don’t attempt repairs or let bystanders investigate the vehicle.
  • Don’t let the vehicle be towed or dragged unless a trained recovery operator has checked the manufacturer procedure and says it is safe.

What to do now

  1. Make a safer pause first. Indicate, reduce speed smoothly, and move to the safest available place, such as an exit, service area, emergency area, hard shoulder, lay-by, or other place away from moving traffic.
  2. If you are on a motorway or high-speed road:
    • If you are stopped in a live lane, or it is not safe to get out, keep your seatbelt on, keep hazards on, call 999 and ask for the police, or use your in-car SOS button if you have one.
    • If you can reach a hard shoulder, emergency area, lay-by, or another safer place, stop as far left as possible where safe, leave space to exit, turn the wheels left if appropriate, and switch on hazard lights.
    • If it is safe to leave the vehicle, exit by the side furthest from traffic, move well away from the carriageway, and get behind a barrier if there is one.
  3. Secure the car. Put it in Park, apply the parking brake, switch on hazard lights, and switch the vehicle fully off.
  4. From a safe place, do a no-touch check only. Look and listen for smoke, steam, vapour, popping, hissing, unusual heat, burning or chemical smell, leaking fluid, visible damage, or exposed cabling.
  5. If you see or hear danger signs, or there is fire, move well away, upwind if you can do so safely, keep other people back, and call 999. Say it is an electric vehicle and that there is a battery or high-voltage warning.
  6. If there are no immediate danger signs, read the exact on-screen wording and colour. Treat “Stop safely now”, “Pull over”, “High-voltage fault”, red warnings, or limited power as do-not-continue unless the manufacturer or breakdown provider explicitly tells you it is safe to reposition.
  7. Call your manufacturer roadside assistance or breakdown provider. Tell them:
    • the exact warning text and colour,
    • your location, including whether you are in a live lane, emergency area, hard shoulder, lay-by, or car park,
    • whether there is any heat, smell, smoke, vapour, hissing, visible damage, or exposed orange cabling,
    • whether the warning appeared while driving, after an impact, or during charging.
  8. Take a quick photo of the warning message if it is safe. Note the time and what you were doing, such as driving, rapid charging, slow charging, or restarting after parking.
  9. Until a professional says it is safe, do not charge the vehicle, do not move it unnecessarily, and keep people clear of it.

What can wait

  • You do not need to work out the technical cause now.
  • You do not need to decide whether it is the traction battery, 12V battery, charger, inverter, or battery management system.
  • You do not need to arrange repairs at the roadside.
  • You do not need to clear the warning yourself.
  • The only priorities now are a safe stop, distance from possible hazards, and EV-appropriate help.

Important reassurance

Many EV warning messages are caused by faults that can be diagnosed and repaired, but a high-voltage or battery-system warning is not something to guess about at the roadside. Stopping, keeping clear, and getting trained help is the safer choice.

Scope note

These are first steps only for the moment the warning appears. Later decisions about inspection, recovery, repair, charging, storage, or insurance may need the manufacturer, a trained EV recovery operator, or another suitable specialist.

Important note

This is general safety information, not mechanical, legal, financial, medical, or professional advice. Follow the vehicle’s instructions, emergency service instructions, and advice from your breakdown provider or manufacturer.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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