Many electric vehicle manufacturers provide a Level 1 charging cord when you buy an EV or a plug-in hybrid (PHEV). These “trickle chargers” don’t require special equipment to use and connect to a standard 120-volt electrical outlet at home or elsewhere. Similarly, portable Level 2 chargers on the market plug into 240-volt receptacles — the type used for dryers. The cable length on these portable chargers can range from six to 20 feet or more, depending on the manufacturer.
If that charging cable isn’t long enough to plug into a nearby outlet and reach the car, you may be tempted to use an extension cord. Here’s why you shouldn’t.
Is it safe to charge an EV or PHEV using an extension cord? Carmakers say no, and we don’t recommend using one. Charging an electric car requires more electricity than the amount common home appliances need. Therefore, electric car chargers contain thicker wires that can handle more power than smaller gauge wires in typical extension cords.
“While some electric car owners have reported using a typical extension cord, we don’t recommend it,” says Brian Moody, a senior editor at Kelley Blue Book. “In fact, Kia and other automakers specifically say not to use an extension cord in the owner’s manual. An electric car pulls more power than a typical home appliance, and using a typical extension cord when charging can harm your home and car.”
Owner manuals are explicit with warnings, such as this one from Chevrolet to Bolt owners: “Do not use extension cords, multi-outlet power strips, splitters, grounding adaptors, surge protectors, or similar devices.”
A Level 1 cable offers a slower “trickle” charge and supplies a few miles of range per hour, which is suitable for many PHEV owners. Pairing an extension cord with the charger restricts the voltage transfer. This setup will take even longer to boost your battery, in addition to creating safety concerns.
We suggest upgrading to Level 2 charging for regular home use, which is standard for most EV drivers in 2025.
So what happens if you charge with an extension cord? Since charging an electric vehicle draws a large amount of power, an extension cord may overheat if you connect it to the charging cable. The chance of fire increases because the extension cord attempts to transmit more energy than it was made to carry. Overheating cords can melt plugs and receptacles, and the fire danger is greater when left unattended overnight or while you’re not home.
Another safety risk is electric shock. An EV charging cable is more vulnerable when connected to an extension cord. Rerouting the power supply from your electrical outlet through an extension compromises the stability of this power transfer. Inserting and removing the plug then becomes a riskier task.
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Consult a licensed electrician if you’ll be connecting an EV or PHEV to a Level 1 charging cable for long-term, at-home charging. An electric vehicle supply equipment (EVSE) professional can ensure you have a dedicated circuit to support the power load.
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Using an extension cord when charging an EV at home is unsafe. Consider these solutions:
Check for incentives and rebates from your electricity provider for installing home charging equipment.
Editor’s Note: This article has been updated since its initial publication.
