How much will it cost to charge your electric car?

How it works

A battery stores less energy than the grid supplies: some of it turns into heat in the charger, the cable and the battery. So the energy from the grid is the energy into the battery divided by (1 − losses), and the cost is that grid energy times your price per kWh. Typical losses are about 10 % on AC and 8 % on DC, from published measurements (Idaho National Laboratory, the California ETCC, ADAC) that range from about 5 % to 20 %.

The car and the charger share the work, so charging runs at the lower of the charger's power and the car's limit (its onboard charger on AC, its DC peak on DC). On AC the power is held constant. On DC it is held up to 80 %, the point makers quote as "10–80 %", and then falls steadily to a fifth of the power at 100 %. Time is the energy divided by the power, added up over the charge.

Real curves differ by car, battery temperature and state of charge, and chargers may share power between cars. Treat the time as a fair guess, not a promise, and the cost as the energy you pay for at the price you enter. Fixed fees, parking and idle charges are not included.