Can I use a regular extension cord for my EV?

Generally, no. Standard extension cords aren’t built for the continuous high load an EV pulls for hours — they overheat, cause voltage drops, and can start fires. If you absolutely must, use a short (10 feet max), heavy-duty cord rated for at least 15 amps continuous (12-gauge minimum, 10-gauge safer), outdoor-rated (marked W or SJTW), with a three-prong grounded plug. Even then, monitor for heat and never coil it while in use. But the best move is to install a proper Level 2 charger or use a dedicated outlet.