Charging an electric car at home: cost, time and price per 10 km
Charging cost depends on the battery, the losses and your all-in price per kWh. All of it can be worked out.
Checked by Radif Partners · Editorial policy · Method and sources
A home charge costs the energy drawn from the grid times your all-in price per kWh. With the calculator’s example values, a 60 kWh battery charged from 20 to 80 percent with 10 percent charging losses, it takes 40.0 kWh from the grid to put 36 kWh into the battery. In a house in E.ON’s Stockholm area with a 20 A fuse, at the Statistics Sweden average variable price for SE3, a kWh costs 176.4 öre/kWh with grid fee, tax and VAT. The charge then costs SEK 71. At 1.8 kWh per mil (Swedes count in mil, 10 km) it covers 20.0 mil, at SEK 3.53 per mil. At 11 kW the charge takes 3 h 38 min, at 3.7 kW 10 h 49 min. All car values are examples to replace with your own.
Cost of this charge
SEK 68
SEK 3.38 per 10 km, 3 h 38 min of charging
| Energy into the battery | 36.0 kWh |
| Energy from the grid (with losses) | 40.0 kWh |
| Charging time | 3 h 38 min |
| All-in price per kWh | 169.0 öre/kWh |
| Range added | 20.0 mil (10 km) |
| Cost per mil (10 km) | SEK 3.38 |
Assumptions
Defaults are examples for you to change: 60 kWh battery, 10% losses, 1.8 kWh per 10 km. Constant-power charging; in reality power tapers over the last few per cent. Method and sources
Charging cost per year by distance
| Distance per year | Power from the grid | Cost per year |
|---|---|---|
| 500 mil (5,000 km) | 1,000 kWh | SEK 1,764 |
| 1,000 mil (10,000 km) | 2,000 kWh | SEK 3,528 |
| 1,500 mil (15,000 km) | 3,000 kWh | SEK 5,291 |
| 2,000 mil (20,000 km) | 4,000 kWh | SEK 7,055 |
The table assumes every charge happens at home at the same price. Charging partly at work or at fast chargers changes the cost. Replace consumption, losses and battery with your own car’s values in the calculator above.
Charging power, fuse and power charges
An 11 kW wallbox draws a lot of power for several hours. In a 16 or 20 A house, together with the hob and laundry, that can approach what the main fuse allows, so an electrician should assess the installation. If your grid company has a power charge, charging can become the month’s peak. Charging at lower power, say 3.7 kW, takes longer but gives a lower peak, while the energy, and so the energy cost, stays the same.
The cheapest charging time
On a quarter-hour contract you can paste tomorrow’s prices into the calculator. It derives the charging time from the battery and power and finds the cheapest continuous window of that length. Tomorrow’s prices are known after the 12:00 auction; see electricity price tomorrow. Then set the start time in the car or wallbox. The grid fee per kWh and energy tax are the same whatever the time, unless your grid has peak and off-peak rates.