5 Rules for Using an Extension Cord With an EV Charger

Don’t use an extension cord at all Most EV manufacturers explicitly warn against them. A standard cord will heat up, melt, or start a fire during hours of high-amperage charging.

Use only a 10-gauge cord for Level 2 charging A 12-gauge cord is risky for a 32-amp Level 2 charger. For Level 1 at 12 amps max, 12-gauge is the minimum.

Keep the cord as short as possible Limit it to 25 feet max. Longer cords increase resistance and heat buildup.

Choose an outdoor-rated, 100% copper cord Avoid copper-clad aluminum, which is less conductive and more prone to overheating. Plug directly into a GFCI outlet—no daisy-chaining.

Check the cord temperature after 30 minutes If it feels warm, stop using it immediately. Warmth means you’re exceeding the cord’s safe capacity and risking a fire.