Electric Vehicle Charging Cable Extensions
The International Electrotechnical Commission (IEC) standard is clear on the matter; “A cord extension set or second cable assembly shall not be used in addition to the cable assembly for the connection of the EV to EVSE.”
Therefore any EV extension cable will sit outside of the standards and will affect your vehicle warranty in the event of a claim. If you just plug in any extension, it could overheat, cause a fire, or damage the car or charger.
However, if you are looking to extend the reach of your EV charging set up, you do still have some options available...

Purchase A Longer, Custom-Length EV Cable
You can simply purchase a custom-length EV cable that meets your setup needs (and use your existing cable as a spare):
Standard Untethered (Plug to Plug) Cable: Purchase a Type 1 or Type 2 cable for the full length you require.
Tethered Charge Point Cable: Purchase a Type 1 Tethered Cable or Type 2 Tethered Cable for the full length you require.

Portable (Granny) Charger Extension Cables
If you are charging from a portable EV charger cable, you can extend its' reach with our purpose build weatherproof extension lead. They're specially made for EV chargers with thicker wiring and a built in RCD.