Please see our article on safely charging electric vehicles for advice on extension leads. It is the responsibility of the EV user to consider the manufacturers guidance, the safety of the supply and any other risks, before deciding whether to use an extension lead with an EV charger. Given varying advice from manufacturers and varying risks in a whole myriad of charging scenarios, we cannot make a blanket recommendation that an extension lead should be used. Tough Leads simply supply high quality extension leads; it is down to the user to determine what applications they are used for. If in any doubt, consult an electrician.