EV charging is described as either AC or DC, and the difference affects how fast a car charges and where the equipment is installed. Home Level 2 chargers use AC, while most public fast chargers use DC. This article explains what each term means and why it matters when you choose a home charger.
What alternating current (AC) means
Alternating current reverses direction many times per second. It is the form of electricity delivered to homes and businesses by the utility grid. A Level 2 home charger takes AC from your electrical panel and passes it to the car.
What direct current (DC) means
Direct current flows in one direction. Batteries store and release energy as DC. Fast public chargers convert grid AC into DC inside the charging station and supply that DC directly to the car's battery.
Where the conversion happens
With AC charging, the car converts AC to DC using its onboard charger, and that component has a limited power rating. With DC charging, the conversion takes place in a large unit at the station, so the delivered power can be much higher. This is why DC fast charging adds range far faster than home Level 2 charging.
AC and DC compared
| Feature | AC Level 2 at home | DC fast charging at stations |
|---|---|---|
| Type of current delivered | Alternating current | Direct current |
| Where the conversion happens | Onboard charger in the car | Charger cabinet at the station |
| What limits the speed | The car's onboard charger | The station and the car's battery |
| Typical use | Overnight charging at home | Quick top-ups on longer trips |
| Installation | Wall-mounted, hardwired or plug-in | Commercial site |
Why home charging uses AC
A home has AC supply, and a home charger that uses AC is far simpler to install than a DC fast charger. DC fast chargers are large commercial units, so they are not practical for typical home installations. For most owners, an AC Level 2 charger at home is the right tool for overnight charging, and public DC stations fill the gap on trips.
Connectors
AC and DC charging use different connectors. The J1772 is the standard AC connector for most non-Tesla EVs in North America. Tesla uses NACS (SAE J3400), and many other makers have announced a move to it. DC fast chargers use their own connector designs, so a home AC connector will not plug into a DC station. Adapters exist for some combinations, but they do not change how the charging power is delivered.
How this applies to EVIQO chargers
EVIQO sells AC Level 2 chargers for home installation. All five models run on 240 volts, include a 25 ft cable, and carry a 3-year warranty, and a 4-year extended warranty is available for an extra charge. The J1772 models are for non-Tesla EVs, and the NACS models are for Tesla. Because these are AC chargers, the car's onboard charger sets the speed, so check the car's AC rate when choosing a model.