About this tool
How long does the car need at the wallbox to get back to 80 %? The calculator takes the usable battery capacity, start and target state of charge and the charging power and shows the charging time, energy charged, cost and added range.
At a wallbox (AC) the car charges at constant power – limited by the wallbox or the car’s onboard charger, whichever is lower. At a fast charger (DC) the power drops as the battery fills up; the calculator models this with a simplified curve. Charging losses are added to the energy from the grid, because that is what you pay for.
How it works
- Choose AC (wallbox, charging station) or DC (fast charger) and enter the usable battery capacity.
- Set the start and target charge level and enter the power of the charger and your car’s maximum charging power.
- With the electricity price and consumption you also see the cost and the added range.
Frequently asked questions
Why does my car charge at only 11 kW on a 22 kW wallbox?
On AC the onboard charger of the car limits the power. Many cars have an 11 kW charger; a 22 kW wallbox brings no benefit then. So always enter your car’s maximum AC power too.
Why does charging from 80 to 100 % take so long?
When fast charging, the power drops as the charge level rises to protect the battery. The last 20 % often take as long as the 50 % before. On the road it is usually worth charging only to about 80 %.
How high are the charging losses?
Typically about 10 % at a wallbox and about 5 % at a fast charger (part of the losses already happen inside the station). In the cold and with very low charging currents, e.g. on a household socket, they can be much higher.
What does a trip in an electric car cost?
Calculate the cost per trip and per 100 km with the Fuel Cost Calculator. What a household appliance costs in electricity is shown by the Electricity Cost Calculator.