kW - Unit of Power
The kW or kilowatt is a unit of power. It usually indicates a car motor power. However, this unit is also used to define electrical charging power.
It is obtained by multiplying a current (in Amps) with voltage (in Volts).
Example: Standard sockets can provide up to 16A at 230V
16A x 230V = 3680W ≈ 3.7 kW
This is why standard sockets can provide maximum 3.7 kW.
kWh - Unit of Energy
The kWh or kilowatt-hour is a unit of energy. It defines an amount of energy used over time, like charged electricity at a charging station.
It is obtained by multiplying a power (in kW) by time (in h).
Example: charging 2 hours at a standard socket
3.7 kW x 2h = 7.4 kWh
After 2 hours, a total of 7.4 kWh of energy has been delivered.
AC - Alternating Current
This is the typical current available in every home. According to its name, current is alternating inside wires. It can be either single phase (230V) or three-phase (400V).
It is perfect for softly charging electric vehicles:
| Power (P) | Voltage (V) | Current (I) |
|---|---|---|
3.7 kW | 230V | 16A |
7.4 kW | 230V | 32A |
11.1 kW | 400V | 16A |
22.2 kW | 400V | 32A |
DC - Direct Current
EV car batteries are operating on direct current. This means they have a positive (+) and a negative (-) terminal. Fast charging is performed using DC current because power goes directly from the station to the battery. DC EV charging stations of up to 350kW can be found. They are 95 times more powerful than a standard socket.
