Some aftermarket electric vehicle (EV) charging cables pose a risk of overheating and electric shocks for users, an investigation by consumer champion and new car buying platform What Car? has found.

What Car? bought three ‘Mode 2’ chargers, which allow EV owners to charge their vehicle using a three-pin domestic socket. They were tested in an electrical laboratory and assessed for conformity with British and European safety standards.

Each cable was subjected to five different Residual Current Device (RCD) tests. Two cables failed all five RCD tests, and one cable passed only one of the tests. The RCD’s job is to switch off the electricity automatically if a fault is detected. If the system doesn’t react quickly enough or appropriately, there is a serious risk of electric shock to anyone using it. 

The lab also tested each cable’s plug to ensure it fitted properly into a socket. If the connection isn’t good enough there is a risk of it overheating, especially if the cable is left plugged in for many hours. None of the three plugs fitted into the socket securely. 

In addition, it was noted that all three cables were designed to run at more than 13 amps, whereas the plugs were only rated up to 13 amps. While this additional current is unlikely to blow a fuse, it will generate extra heat and, over prolonged periods, could make the plug get hot enough to burn someone. 

Visual tests were conducted to assess the safety labelling and resistance to tampering. All three cables featured data panels on their control units, but the information was poorly worded and did not clearly state the safety regulations that each device adhered to. All also had unclear labelling relating to their level of water resistance. As these units are likely to be used outside, water resistance is an essential safety feature. 

The cables were bought from two online marketplaces: Amazon and componentauthority.com. Online third-party sites are not legally obliged to check the safety of the products they sell in the same way as high street retailers, so it can be easy for sellers to offer sub-standard products via them. What Car? believes there should be stricter regulations on the sale of electrical goods, such as EV charging cables, via online marketplaces.

What Car? informed the online retailers of its investigation. Amazon said it had removed the charging cables from sale while it investigated What Car?’s findings, but componentauthority.com did not offer to do so.

What Car? consumer editor Claire Evans said: “Our tests show how easy it is to buy unsafe EV charging cables online. Our investigation highlights the importance of choosing electrical products with care and we recommend buying from reputable high street or online retailers. We believe stricter regulations for third-party sellers are needed. They should check that products meet the relevant standards up front, rather than retrospectively, following a complaint or investigation.”