Is It Normal for an EV Charging Cable to Get Hot?

A little warmth in your EV charging cable while the car is charging is normal, because any conductor carrying current gives off some heat. What is not normal is a cable that feels genuinely hot, looks discoloured, smells of burning, or shows any sign of melting. If you notice any of those, stop charging straight away, unplug at the source, stop using that cable and socket, and get things checked before charging again.

The good news is that most leads run warm and are working exactly as intended. The sections below help you tell the difference between normal warmth and a warning sign, explain why a correctly rated cable runs cooler, and cover the most common reasons a lead gets too hot.

Is it normal for an EV charging cable to get warm?

Yes. When current flows through the copper conductors inside a lead, a small amount of energy is always lost as heat, so the cable and the connectors can feel slightly warm to the touch during a charge. This is normal and expected, especially on a longer or faster charge.

The key word is warm, not hot. Warm means you can comfortably hold the cable or connector in your hand. Hot means you want to let go, and that is the point where you should stop and investigate rather than carry on.

When should I stop charging because the cable is too hot?

Stop charging immediately if the cable or either connector is hot to the touch, has gone discoloured or brown, smells of burning or hot plastic, or shows any melting, bubbling or deformed areas. Any of these is a sign that something is wrong with the cable, the connection, or the socket.

When that happens, the safest order is simple:

1. Stop the charging session at the car or app if you safely can.
2. Unplug at the source first (the socket or charge point), then remove the lead from the car.
3. Stop using that cable and that socket until both have been checked.
4. Have the cable, charge point or socket inspected by a suitably qualified person before charging again.

Do not try to repair a damaged or burnt cable. A charging lead is not something to patch up with tape or a new plug end: if it is damaged, replace it. A fresh, correctly rated lead from our EV charging cables range is the safe route.

How warm is too warm?

Use this as a rough guide. It is not a substitute for your own judgement or a professional check, but it helps you decide whether to relax or to stop.

Why does a correctly rated cable run cooler?

A charging lead is rated for a certain current in amps, and that rating reflects how thick the conductors inside it are. Thicker conductors carry the same current with less resistance, and less resistance means less heat. That is why a lead that is correctly rated for your charge point tends to run cooler than one that is being pushed near its limit.

If a cable is under-rated for the current it is carrying, it has to work harder and can run hotter than it should. Matching the lead to your setup is the simplest way to keep temperatures sensible. Our guides on what size cable for an EV charger and what size cable for a 7kW EV charger walk through choosing the right current rating, and what length cable you need covers getting the length right without over-stretching.

What makes an EV charging cable get too hot?

When a lead runs hotter than it should, it usually comes down to one of a handful of causes. Here are the most common, roughly from simplest to most serious.

A cable under-rated for the current

If the lead is rated for less current than the charge point is trying to deliver, it can run hot. A lower rated or thinner lead carries the current with more resistance, and that shows up as heat. Replacing it with a correctly rated lead from our charging cables range is the right fix. Buying a longer or thicker cable never beats your car's onboard charging limit, but the correct rating does help the lead run within its comfort zone.

Damaged or corroded pins

Dirty, corroded or damaged pins inside a connector increase resistance at the contact point, and that is exactly where heat tends to build. If a connector looks corroded, pitted or damaged, do not keep using it. Replace the cable rather than trying to clean or bend pins back into shape.

A loose or worn connection

A plug that is not fully pushed home, or a connector that has become loose or worn over time, makes poor contact. Poor contact means more resistance and more heat at that point. Always check the lead is seated firmly at both ends. If a connection still feels loose or the cable still runs hot once it is properly seated, stop using it and have it checked.

A granny charger on a tired 13A socket

Portable chargers, often called granny chargers, draw a steady load from a standard 13A socket for hours at a time. A worn, old or poor quality socket can struggle with that sustained load and get hot, and the heat can transfer to the plug and lead. A hot socket is a warning sign in its own right. Our guide on a granny charger not working covers the warning signs, and you can find portable units in our portable EV chargers range. If the socket itself is getting hot, stop using it and have it checked by a qualified electrician.

What should I never do with a hot or damaged cable?

Never try to repair a damaged, burnt or melted charging cable. Do not tape over damage, swap a plug end, or keep using a lead that has run hot in the hope it settles down. A charging lead carries a serious amount of power for hours at a time, and a compromised cable is a genuine risk.

Equally, do not keep using a socket that gets hot, and do not try to open up a wallbox or do any work on the fixed wiring yourself. Anything involving the socket, the charge point or the house wiring is a job for a suitably qualified electrician or the charger manufacturer.

Where to go next

If your charging is behaving oddly in other ways, these sibling guides may help. If the car is charging more slowly than expected, see why is my EV charging slowly. If it will not start at all, see why your EV will not charge at home. For portable charger issues, see granny charger not working. And if any of the terms here are unfamiliar, our EV charging glossary explains the jargon in plain English.

Frequently asked questions

Is it normal for my EV charging cable to feel warm?

Yes. A charging lead carries current for hours, and current always produces some heat, so warm is normal. Hot to the touch, discoloured or smelling of burning is not, and means you should stop charging and get it checked.

Should I stop charging if the cable is hot?

If the cable or connectors are genuinely hot to the touch, stop charging, unplug at the source, and stop using that cable and socket until they have been checked. Hot is different from the mild warmth that is normal during charging.

Why is my EV charging cable getting hot?

Common causes are a cable under-rated for the current, damaged or corroded pins, a loose or worn connection, or a granny charger on a tired 13A socket. Each raises resistance at some point in the path, and resistance produces heat.

Can I repair a burnt or damaged EV charging cable?

No. Do not repair a damaged, burnt or melted charging lead. Replace it with a new, correctly rated cable. A compromised lead carries serious power for long periods and is not safe to patch up.

Why does the socket get hot when I use a granny charger?

Portable chargers draw a steady load for hours, and a worn or poor quality 13A socket can struggle with that and heat up. Use a sound, dedicated socket, and if the socket itself gets hot, stop and have it checked by a qualified electrician.

Does a thicker cable charge my car faster?

No. A correctly rated or thicker lead can run cooler, but it never beats your car's onboard charging limit or the power of the charge point. The right rating is about safety and running temperature, not extra speed.