It is tempting. The car is parked a few metres from the power point, and there is an extension lead in the shed. But charging an EV through a household extension lead or power board is one of the most common causes of melted plugs, and it is a fire risk we would rather you avoided.
Why EV charging is different
Most appliances draw high current for minutes. An EV draws its maximum current continuously for hours. Every connection in the path generates a little heat, and with an extension lead you add more connections, more length and often thinner wire.
- A slightly loose or worn plug heats up under constant load.
- Coiled leads trap heat.
- Cheap power boards and double adaptors are not built for sustained 10A loads.
- Outdoor connections can let in moisture.
The result can be a scorched plug, a melted power point, or worse, often after weeks of apparently working fine.
What manufacturers say
EV makers and charger manufacturers, including us, tell you not to use extension leads or adaptors that are not designed for EV charging. Using one may also affect your warranty and could be an issue with insurance if something goes wrong.
Safe alternatives
- Park closer. Most portable chargers have a long cable to reach the car.
- Install an outlet where you park. A licensed electrician can add a weatherproof 10A, 15A or 32A outlet on its own circuit near your driveway or carport.
- Use proper adapters only. Purpose-made EV adapters, like the bonus adapter included with Evtronix chargers, are designed for the job. Set the charger to the adapter’s rating (10A for a 10A outlet).
- Lower the current if you are unsure about a circuit, and get it checked.
Warning signs to look for
Stop charging and get an electrician to check if you notice:
- A plug or outlet that feels hot to touch
- Discolouration, a burning smell or crackling
- The charger repeatedly stopping with a fault
Our chargers watch for over-temperature and other faults and will stop safely, but they cannot see inside your wall or a lead plugged in between.
Frequently asked questions
Can I use a heavy-duty extension lead?
We still advise against it for EV charging. A dedicated outlet where you park is the safe fix.
Is a 15A extension lead OK?
The same principle applies: extra connections under continuous load add risk. Install an outlet instead.
Are EV charger adapters different from extension leads?
Yes. Purpose-built EV adapters are short, rated for the load, and used with the charger turned down to the outlet’s rating.
Key takeaways
- EVs draw high current for hours, unlike most appliances
- Extension leads and power boards add heat-generating connections
- Park closer or have an electrician install an outlet where you park
- Hot, discoloured or smelly plugs mean stop and get them checked