Tesla Cybertruck lead engineer Wes Morrill has shared a warning about the use of extension cords for Supercharger stalls. As per the Tesla lead engineer, using North American Charging Standard (NACS) extension cords could present safety issues.
Morrill’s comment came as a response to an electric vehicle enthusiast who discussing an aftermarket NACS DC extension cord. By using a NACS extension cord, non-Tesla vehicles like Rivian’s R1T and R1S could avoid using up two charging spaces when they use the Supercharger Network.
As per the Cybertruck lead engineer, however, using an extension cord on a Supercharger or any other DC charging station is not preferable at all. Morrill noted that he has seen several instances of cable overheating with the use of such items.
“Would recommend AGAINST using an extension cord on a supercharger (or any DC charging station with a liquid cooled cable). Have seen multiple instances of the cable overheated and shorting DC +/-.
“There’s a temperature measurement in the handle and the supercharger derates based on that temperature. With the extension cable that safety goes away. On top of adding an additional junction which generates heat making matters worse,” Morrill wrote in his post on X.
While the use of extension cords for Tesla Superchargers may seem convenient, drivers should keep in mind that each aspect of a Supercharger is built by design. This includes the cable length of existing Superchargers, which is likely optimized for reliability and safety. Effectively modifying the length of a Supercharger cable through an extension cord may then present some safety risks.
Tesla is known for prioritizing safety in both its vehicles and its charging infrastructure. This is one of the reasons why the company has issued warnings against some popular charging practices in the past, such as the use of a wet towel on a NACS handle to push more power into a vehicle. As per Tesla back in July, using a wet cloth on a Supercharger cable creates a risk of overheating.
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