EV charging cable in cold and heat: what happens to it?

Cold makes a charging cable stiffer and heat ages it, and the jacket material decides how much. A charging cable built to the European standard is rated for handling down to about −35 °C, while an ordinary PVC cable should not be bent below −5 °C. Voldt® cables are rated for use from −30 °C to +50 °C, and a few habits keep them flexible in January and safe in August.

Published 06/11/2026 · By Voldt® product team

−30 to +50 °C

the range Voldt® cables are rated for

Every cable jacket is a plastic or rubber compound that hardens as it cools. How cold it can get before it stops bending depends on the compound. A standard flexible PVC cable (H05VV-F) is rated for bending only down to −5 °C, which is why a cheap extension lead turns as stiff as a garden hose on a frosty morning. Charging cables built to EN 50620, the European standard for them, use a polyurethane jacket that cable makers rate for movement down to −35 °C.

Stiffness on its own is a nuisance. The risk comes when a cold jacket is forced into a tight bend, because the strain gathers on the outside of that bend. It happens most where the cable leaves the plug, in tight loops and folds, and over hard edges such as a kerb or a doorstep. Driving over a cold cable or shutting a door on it is worse still.

A crack in the jacket lets water in, and keeping water away from the cores is what the IP67 rating of a charging cable is about. Our article on IP ratings explains what that rating proves.

A charging cable warms up from two sides. The current heats the copper from the inside, and on a summer afternoon the sun heats the jacket from the outside. A dark cable lying on dark tarmac gets noticeably warmer than the air. The current ratings in EN 50620 are set so the outside of the cable stays below 50 °C, and our article on cable cross-section shows how much margin a 6 mm² cable keeps on a hot day.

Heat does its damage slowly. Plastics and rubbers age faster the warmer they are kept, and the ultraviolet in sunlight breaks down jackets that are not made for it. Charging cable jackets built to EN 50620 are tested for resistance to UV light and ozone, which an indoor PVC extension lead is not. A cable left coiled in a hot car summer after summer ages faster than one stored in the shade.

The UK sits comfortably inside a cable’s rated range. In London an average January night bottoms out at 2,7 °C, with about 27 frosty nights a year, and an average July afternoon reaches 23,9 °C. Across the UK as a whole there are about 53 frosty nights a year. The days that test a cable are the cold snaps and heatwaves at the edges, which is when handling matters most.

Three jacket families turn up on charging cables and extension leads. PVC is cheap and fine indoors, but a standard flexible PVC cable is rated for bending only between −5 °C and +70 °C. Rubber (H07RN-F) handles the cold far better, down to −25 °C when moved, but tops out at +60 °C. Polyurethane jackets on EN 50620 charging cables cover −35 °C to +80 °C when moved, according to cable makers’ datasheets.

For a cable that lives in a car and gets used outdoors all year, the low end matters most. A PVC cable that behaves well in the garage can crack the first time you unroll it on a frosty driveway, while a polyurethane jacket still bends. Our 22 kW cable has a jacket of TPU, thermoplastic polyurethane.

Voldt® charging cables and portable chargers are rated for use from −30 °C to +50 °C. That range is narrower than the jacket’s own, because it covers the whole product: the plugs, the contacts and, on a portable charger, the control box as well.

Copper’s resistance rises by about 0,4% for every degree it warms up (0,00393 per °C, EN 60228). A cable at −10 °C therefore has about 12% less resistance than the same cable at +20 °C, so it loses a little less energy as heat. The effect on charging speed is too small to notice.

The changes you do notice come from the car and the charger. A cold battery accepts less power until it has warmed up, which is why many cars warm the battery before a fast charge. In the heat, chargers protect themselves: our portable chargers have temperature sensors that turn the current down, or pause the charge, if they get too warm, and their screen shows the charger’s temperature.

In winter, unroll a cold cable slowly in wide loops rather than shaking it straight, and avoid folding it double to fit it in a bag. Keep it out from under the wheels and away from closing doors. If the plug has frozen into the car’s inlet, let it thaw rather than pulling hard. Our guide to freeing a stuck charging cable explains how to do that safely.

In summer, the thing to avoid is long hours in direct sun. Store the cable in the boot or in a bag rather than on the driveway, and during a long charge lay it out in a loose loop, in the shade where you can, so the copper’s own heat can escape.

Whatever the season, coil the cable along its natural curve. Tight loops and twists set into a cold jacket and come back as kinks, and a kink is where the next crack starts.

• Stop using a cable with a cracked or split jacket.
• Let a frozen plug thaw instead of forcing it.
• Where your car’s manual differs from this guide, follow the manual.

Voldt® cables are CE and UKCA marked and TÜV certified, with a 3-year warranty. Terms and exclusions are on the warranty and complaints page.