Why Is My EV Charging Cable Getting Warm?

Some warmth in an EV charging cable during a session is normal: current flowing through any conductor generates a small amount of heat, and a cable carrying the sustained load of EV charging will feel noticeably warm to the touch, particularly near the plugs. What you should not feel is significant heat, a burning smell, or a cable that is too hot to hold comfortably. If that is what you are experiencing, stop charging and investigate before continuing. Browse our EV charging cables if you need a replacement or a higher-rated cable for your setup.

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

Yes, moderate warmth is entirely normal and expected. Electrical resistance in the cable's conductors converts a small fraction of the energy being transferred into heat. The higher the current being carried, the more heat is produced. A 32 A cable carrying a full 7 kW charge will feel warmer than the same cable at a lower charge rate. You would expect a similar warmth from a cable powering any high-current electrical device. Warm is fine; hot is a warning sign that needs attention.

What makes a cable get excessively hot?

Several things can cause a cable to run hotter than it should:

• Undersized cable: If the cable's current rating is lower than the charge rate being drawn, the conductors are working harder than they should. This is the most common cause of excessive heat, particularly if you have upgraded a charger or wallbox without checking the cable rating.
• Poor or dirty connections: Resistance at the plug contacts is higher if the pins are corroded, dirty, or not making a clean contact with the socket. Increased resistance at the connection point causes localised heating, often most noticeable at the plug end.
• Damaged or kinked cable: Physical damage to the cable's internal conductors reduces their effective cross-section, increasing resistance and heat in that section.
• Cable coiled during charging: A coiled cable cannot dissipate heat as effectively as one laid flat. Always uncoil the full cable during a charging session rather than leaving it bundled up.
• Hot ambient conditions: In very warm weather, a cable in direct sunlight gets less help from the surrounding air to dissipate heat, making it run somewhat warmer than in cooler conditions.

How do I check if my cable is rated for my charge rate?

The cable's current rating (in amperes) should be marked on the plug or listed in the product documentation. Divide the charger's output in watts by 230 (the UK mains voltage) to get the current in amperes. A 7 kW wallbox, for example, draws approximately 30 A, so you need a cable rated for at least 32 A. If your cable is rated for 16 A and you are charging at a rate that requires 32 A, the cable is being overloaded and will overheat. Replacing it with a correctly rated cable resolves the problem. Our Type 2 cables are available in 16 A and 32 A ratings, so it is straightforward to choose the right one.

What should I check at the connector?

The connector end (the part that goes into the car and the part that plugs into the charger or socket) is where heat problems often concentrate. Check for:

• Visible corrosion or discolouration on the pins
• Any melting, deformation, or discolouration of the plastic housing
• Grit, moisture, or debris inside the connector that could be increasing resistance
• A connector that does not lock positively into the car's charge port (loose or intermittent contact increases heat)

If you notice any of these, do not continue using the cable until it has been cleaned or replaced. A connector showing signs of heat damage should be replaced rather than cleaned and reused.

Could the car's charge port or wallbox be the cause?

Yes. If the cable is fine but you still notice heat at the plug end, the problem may be on the car or charger side rather than the cable itself. A damaged or worn charge port on the car can create a poor connection. If you suspect this, try a different cable first to rule out the cable as the cause. If the problem persists with a known-good cable, consult your dealer or the charger's manufacturer. For a tethered wallbox charger, the cable is fixed and you would need the installer or manufacturer to inspect the unit.

When should I replace my charging cable?

Replace your cable if you notice any of the following:

• Burn marks, melting, or discolouration at either connector
• Cracked, frayed, or otherwise damaged outer sheath
• A burning or acrid smell during charging
• The cable running very hot under load at a current within its rated limit
• Intermittent charging (the car starting and stopping) when the connector is not being disturbed

A cable showing these signs should not be used again. EV charging cables are a safety-critical component and a worn or damaged one is not worth the risk.

Frequently asked questions

Is it normal for the plug end to be hotter than the cable itself?

Yes, to a modest degree. The connector pins and their housing have more complex geometry than the cable, which can mean slightly more localised resistance. A connector that is noticeably hotter than the rest of the cable, however, especially if it is uncomfortably hot or shows discolouration, is a sign of a connection problem that needs attention.

Will a longer cable get hotter than a shorter one?

A longer cable has more total resistance, so it will dissipate slightly more heat along its length. For typical domestic charging cable lengths, the difference is small. Where cable length matters more is in the voltage drop along the cable, which can marginally reduce the effective charge rate. For very long runs (for example, a cable stretched across a drive to reach an awkward parking spot), a shorter cable used with a proper wallbox installation is preferable.

Should I store my cable coiled or flat?

During charging, always uncoil and lay the cable flat or loosely draped rather than coiled tightly. When storing the cable, a loose coil is fine. Tight repeated bending at the same point can damage the internal conductors over time. Most cables come with a storage bag or holder; keeping the cable off the ground and away from sharp edges prolongs its life.

Can I use a cable that has been warm with no other problems?

If the cable felt warm (not hot), the connector shows no discolouration, there is no burning smell, and the cable is correctly rated for the charge rate, there is no reason to stop using it. Monitor it during the next session. If the warmth increases or you notice any of the warning signs above, stop and investigate. Warm is normal; hot or smelly is not.

Does using a cable in cold weather affect how warm it gets?

Cold ambient temperatures can actually help the cable dissipate heat, since the temperature difference between the cable and the surrounding air is larger. A cable that runs warm in summer may run cooler in winter at the same charge rate. The exception is very cold temperatures, where the cable's insulation material becomes stiffer and the cable is slightly more prone to cracking under repeated bending.

Are cheaper cables more likely to overheat?

A cable that does not meet the relevant standards (IEC 62196 for EV connectors) may use thinner conductors or lower-grade insulation, which increases the risk of overheating. Always buy from a reputable supplier who can confirm the cable's standards compliance and rating. Our charging cables are rated and tested to the appropriate standards.

Moderate warmth in a charging cable during a session is nothing to worry about: it is physics working as it should. Excessive heat, burning smells, or discolouration at the connector are the warning signs that need action, and in those cases a replacement cable is the right call. Browse our full range of EV charging cables in both 16 A and 32 A ratings, and visit our Guides section for more on cable care, home charging setup, and getting the most from your charger.