Charging an electric vehicle (EV) depends on many factors, such as battery capacity, type of charging station, vehicle energy efficiency, and environmental conditions. In this article, we will look at the key aspects that affect the number of kilowatt-hours (kWh) of electricity needed to charge an electric vehicle, as well as discuss the different options for charging stations.
1. Battery capacity
The main factor that determines how much energy is required to fully charge an electric vehicle is its battery capacity, which is measured in kilowatt-hours (kWh). Average batteries have the following parameters:
Small electric cars (Nissan Leaf, BMW i3): from 30 to 40 kWh.
Medium electric cars (Tesla Model 3, Chevrolet Bolt): from 50 to 75 kWh.
Large electric cars (Tesla Model S, Audi e-tron): from 80 to 100 kWh and more.
2. Types of charging stations
There are different types of charging stations that provide different charging speeds:
Level 1 charging (regular outlet): This option uses a household outlet with a capacity of 1.5-2 kW. For an electric car with a battery capacity of 40 kWh, such charging can take from 20 to 30 hours.
Level 2 charging (domestic or public station): This type uses power from 7 to 22 kW. For example, a 40 kWh battery will be charged in 4-6 hours.
Level 3 fast charging (DC Fast Charging): These stations have a capacity of 50 to 350 kW. They are able to charge the battery to 80% in 20-30 minutes (depending on the battery capacity).
3. Energy losses during charging
No charger is 100% efficient, so you need to take into account energy losses, which are usually between 10% and 15%. This means that if 40 kWh are required to charge an electric vehicle, approximately 44-46 kWh of electricity will actually be consumed.
4. Energy efficiency of the car
Another important factor is the car’s energy efficiency, which is measured in kilometers per 1 kWh. For example, a Tesla Model 3 can travel about 6 km per 1 kWh, while large electric cars such as the Audi e-tron can have a figure of 4-5 km per 1 kWh. Thus, more energy efficient cars require less energy to travel the same distances.
5. Calculation example
It takes about 8-9 hours to charge an electric vehicle with a battery capacity of 60 kWh at a standard level 2 station (for example, with a capacity of 7 kW). If the energy loss is 10%, then the total electricity consumption will be about 66 kWh.
