DC (Direct Current) chargers are the largest and fastest EVSE (Electric Vehicle Supply Equipment) for charging an electric vehicle (EV).
To put EVSEs in context, figure 1 shows the main features of the four main modes of EV charging – where mode 4 is direct current (DC) fast charging.
In DC fast-charging, the EV battery (which is also DC) is directly connected to an external AC to DC power supply.
That power supply has a large, three phase connection to the power grid – and depending on the size of that connection, a DC fast charger can currently deliver anything from 50 to 150kW (kW = kilowatts) of power to charge the vehicle battery, depending on the size of the DC charging equipment and charging standard used.
It is worth noting that the average house electrical supply can deliver, IN TOTAL, no more than 15kW – so you can see that DC fast charging is not a practical solution for home EV charging!
(By the way, the charging kW rate depends on the size of the charger as well as the standard chosen. As high kW capable DC chargers are much more expensive to buy and install than smaller ones, 50kW is currently the norm for most installed DC fast-chargers).
DC fast charging requires different plugs and communications with the car than the AC charging modes of 1, 2 or 3.
However, unlike AC EVSEs (i.e. modes 1 – 3: which have generally settled on the Mennekes standard plug for all but the North American and Japanese markets), there are several competing standards for a DC fast-charge plug.
These are listed below: (Click on each name to take you to a more detailed FAQ about them).
- CHAdeMO (CHArge de Mode),
- CCS (Combined Charging System),
- Tesla Supercharger and