AC vs DC charging: what's the difference?

An EV battery stores direct current (DC), but the grid supplies alternating current (AC). The difference between AC and DC charging comes down to where the conversion happens, and that affects speed, cost and which buildings each one suits.

How AC charging works

An AC charger sends alternating current to the car, and the car's on-board charger converts it to DC for the battery. So the car sets the speed limit. Many cars accept around 7 kW on single-phase power and 11 kW or 22 kW on three-phase. The 22 kW AC chargers EVC installs deliver whatever each car can take (more on charging times).

How DC charging works

A DC charger has a large power converter inside and feeds direct current straight into the battery through a CCS2 connector, from around 30 kW to several hundred kW depending on the charger and car. It suits topping up during a journey, at places like petrol stations and shopping malls.

AC vs DC compared

How long does AC charging take?

A rough estimate is energy needed (kWh) ÷ charging power (kW). For example:

• A 40 km daily commute uses about 6–8 kWh, which takes about 1 hour on a 7 kW AC charger.
• Filling a 60 kWh battery from nearly empty on 7 kW AC takes about 8–9 hours, which fits an overnight stay.

Real times depend on the car, temperature and battery level, since cars slow down near full to protect the battery.

Which should a condo choose?

For condos, AC is the better choice in almost every case. Residents already park for hours, the building's electrical system can support it without a major upgrade, and the budget for one DC charger covers several AC charging points. That's why EVC installs mainly AC chargers in condos. Read about safety in what are IEC 61851 and TIS 62196.