For electric vehicles (EVs), AC chargers and DC chargers differ primarily in the speed of charging, the type of infrastructure, and how the current is converted and delivered to the car’s battery. Here’s a detailed breakdown:
1. Current Type and Conversion
AC Chargers: Supply alternating current (AC) directly to the EV. Since EV batteries store power in direct current (DC), the car’s onboard charger (an internal AC-to-DC converter) changes this AC power into DC to charge the battery. This onboard conversion limits the amount of power the battery can accept, making AC charging slower.
DC Chargers: Supply direct current (DC) directly to the battery. DC chargers bypass the onboard AC-to-DC converter, delivering high-voltage DC power straight to the battery, allowing for much faster charging. This is because DC chargers can supply more power than the car’s onboard charger typically can handle.
2. Charging Speed
AC Charging (Level 1 and Level 2 Charging): AC charging is generally slower due to the power limits of the onboard charger.
- Level 1 AC Charging (120V, like a standard wall outlet) is the slowest option, typically adding about 2-5 miles of range per hour.
- Level 2 AC Charging (240V, often found in public or home charging stations) is faster, adding around 10-60 miles of range per hour, depending on the car’s onboard charger capacity.
DC Fast Charging (Level 3 Charging): DC chargers, often called DC fast chargers, provide very high power (usually 50-350 kW or more). They can add 60-200 miles of range in 15-30 minutes, making them ideal for quickly replenishing range during longer trips.
3. Use Cases
AC Charging: Suitable for daily, overnight, or home charging. AC chargers (especially Level 1 and Level 2) are ideal for regular, slower charging sessions at home, work, or places where the car can stay parked for several hours.
DC Fast Charging: Ideal for quick top-ups during long trips or when fast charging is essential. DC fast chargers are often installed along highways and in public locations to help EV drivers recharge quickly when time is limited.
4. Cost and Infrastructure
AC Chargers: Generally less expensive to install and use. Level 1 charging requires no special equipment beyond a standard outlet. Level 2 chargers are more powerful but can be installed at home or work locations without significant electrical upgrades. AC charging is more affordable for daily use.
DC Chargers: Much more expensive to install and operate due to the high power requirements and infrastructure needed to support them. DC fast-charging stations are typically installed by commercial providers (like Tesla Superchargers or Electrify America) and found at public charging stations. DC fast charging is usually more costly per session due to high installation and operational costs.
5. Connector Types
AC Chargers: Use connectors like Type 1 (J1772) in North America and Japan or Type 2 (Mennekes) in Europe.
DC Fast Chargers: Use connectors like GB/T, CCS (Combined Charging System) or CHAdeMO for fast charging. Tesla has its proprietary Supercharger connector in North America, though it’s shifting toward the CCS standard.
Summary Comparison Table
| Feature | AC Charger | DC Charger |
|---|---|---|
| Power Type | AC (converted in-car to DC) | DC (delivered directly to battery) |
| Charging Speed | Slower (Level 1: 2-5 miles/hr; Level 2: 10-60 miles/hr) | Faster (Level 3: 60-200 miles/30 mins) |
| Best For | Daily, overnight, and home/work charging | Quick recharges on long trips |
| Installation Cost | Lower, often manageable for home setups | Higher, commercial-grade only |
| Location | Home, work, public places | Highways, commercial centers |
| Connectors | Type 1 (J1772), Type 2 (Mennekes) | GBT, CCS, CHAdeMO, Tesla Supercharger |
