What does it really cost to charge an EV?

Petrol is priced per litre; electricity is priced per kilowatt-hour. To compare charging options, and to compare an EV against a combustion car, translate that into cost per 100 km: multiply the price per kWh by how many kWh your car uses to travel 100 km.

A typical electric car uses somewhere around 15 to 20 kWh per 100 km. So the same journey can cost very different amounts depending only on the price of the electricity you put in.

Home is almost always the cheapest, especially on an overnight or off-peak tariff. You charge slowly on AC while you sleep and pay your household rate, with no session or connection fees.

Public AC chargers, the slower street and car-park posts, sit in the middle: more than home, but usually much less than rapid charging.

Public DC rapid and ultra-rapid chargers are the expensive convenience. They refill in minutes instead of hours, and you pay for it: often two to four times the home rate per kWh, sometimes with an extra session or idle fee on top.

Take a car that uses 18 kWh per 100 km. Charge it at home at 0.15 per kWh and 100 km costs about 2.70. Use a rapid charger at 0.55 per kWh and the same 100 km costs almost 10. Same car, same road, more than three times the price, decided entirely by where you plugged in.

These figures are only an illustration; your tariff, your car and the network you use will shift them. But the shape is always the same: home cheap, public AC moderate, DC rapid dear. Knowing that shape is most of the battle.

• Charge at home or work whenever you can. Slow AC on a good tariff is the cheapest energy your car will ever see. Treat rapid charging as top-ups, not routine.
• Use AC when you have time. Parked for a few hours anyway? A slower public AC point is usually far cheaper than the rapid charger next to it.
• Compare networks before you plug in. Prices per kWh vary a lot between operators at the same power. Check what each one costs rather than pulling into the first charger you see.
• Mind the extra fees. Some networks add a session fee, and many charge idle fees if you leave the car plugged in after it is full. Move on promptly.
• Plan longer trips. Know where you will charge before you set off, so you are choosing on price and availability, not charging in a panic at whatever is nearest.

Is an EV still cheaper to run than petrol or diesel?

Charged mostly at home, almost always, and by a wide margin. If you rely only on public rapid charging the gap narrows, and on the priciest networks it can shrink a lot. Where you charge decides it.

Why is rapid charging so expensive?

Rapid chargers cost far more to install and to feed with high-power grid connections, and you are paying for speed and convenience. That premium is built into the price per kWh.

Does cold weather cost more?

Yes, a little. In the cold a car uses more energy for heating and the battery is less efficient, so your kWh per 100 km rises and each charge does slightly less.

Can I compare charger prices before I go?

That is exactly what Fillz is for. It shows the charging points around you with their prices and, where the network provides it, how many connectors are free right now.