DC Fast Charging Guide: CCS, CHAdeMO, NACS & How It Works

DC fast charging is what makes long-distance EV travel practical. While home charging overnight is fine for daily use, DC fast chargers can add 200+ km of range in 20–30 minutes — comparable to a fuel stop. Understanding how DC fast charging works, which standards exist, and what to expect at a charger helps you plan trips and choose the right EV.

AC vs DC Charging: The Key Difference

AC Charging (Level 1 & Level 2)

• The charger delivers AC power to the vehicle
• The vehicle's onboard charger converts AC to DC to charge the battery
• Speed is limited by the onboard charger capacity (typically 7.4–22 kW)
• Connectors: J1772 (North America), Type 2 (Europe/AU)

DC Fast Charging (Level 3)

• The charger converts AC to DC externally — the conversion happens in the charging station, not the vehicle
• DC power is delivered directly to the battery, bypassing the onboard charger
• Speed is limited by the battery's maximum charge rate and the charger's output
• Connectors: CCS1, CCS2, CHAdeMO, NACS, GB/T

This is why DC fast charging is so much faster — the large, powerful conversion electronics are in the charging station, not constrained by the vehicle's size and weight limits.

DC Fast Charging Standards

CCS1 (Combined Charging System Type 1)

• Region: North America, South Korea
• AC base: SAE J1772 (Type 1)
• Max power: 350 kW
• Communication: ISO 15118 / DIN 70121
• Used by: Most non-Tesla US/Canadian EVs (Ford, GM, Hyundai, Kia, VW Group)

CCS2 (Combined Charging System Type 2)

• Region: Europe, Australia, growing globally
• AC base: IEC 62196-2 (Type 2 / Mennekes)
• Max power: 350 kW+
• Communication: ISO 15118 / DIN 70121
• Used by: All European EVs, Australian EVs, Tesla (Europe/AU)
• Mandated: EU regulation requires CCS2 on all new public chargers

CHAdeMO

• Region: Japan, some global presence
• Max power: 400 kW (CHAdeMO 3.0)
• Communication: CAN bus
• Used by: Nissan Leaf (older), Mitsubishi Outlander PHEV, some Kia/Hyundai (older)
• Status: Declining — most new EVs use CCS or NACS

NACS (SAE J3400 / Tesla Connector)

• Region: North America (rapidly expanding)
• Max power: 250 kW (current Supercharger V3)
• Communication: ISO 15118
• Used by: Tesla (all models), Ford (2024+), GM (2024+), Rivian, Honda, Toyota, Nissan (adopting)
• Status: Becoming the North American standard — SAE standardized as J3400 in 2023

GB/T (Chinese Standard)

• Region: China
• Max power: 250 kW (current), 900 kW (ChaoJi, next-gen)
• Communication: GB/T 27930
• Used by: All EVs sold in China
• Notes: Separate AC (GB/T 20234.2) and DC (GB/T 20234.3) connectors

DC Fast Charging Power Levels

Actual charging speed depends on:

1. Charger output: The station's maximum power
2. Vehicle acceptance rate: The battery's maximum charge rate (varies by vehicle and state of charge)
3. Battery temperature: Cold batteries charge slower; thermal management systems help
4. State of charge (SoC): Charging slows significantly above 80% SoC

The Charging Curve

DC fast charging doesn't maintain peak power throughout the session. The charging curve shows how power varies with state of charge:

• 0–20% SoC: Power may be limited to protect a cold or depleted battery
• 20–80% SoC: Peak power — this is the fast part
• 80–100% SoC: Power tapers significantly to protect the battery

This is why EV manufacturers recommend charging to 80% for fast charging stops — the last 20% takes as long as the first 80%.

Liquid-Cooled Cables

At 150 kW+, the charging cable carries 300–500 A of DC current. Standard cables become heavy and stiff at these ratings. Liquid-cooled cables solve this:

• Coolant circulates through the cable jacket
• Allows thinner, more flexible cables at high current
• Required for 350 kW stations
• The cooling system is in the charging station, not the vehicle

Plug & Charge (ISO 15118)

Plug & Charge is an automatic authentication system defined by ISO 15118:

1. Plug in the cable
2. The vehicle and charger exchange digital certificates
3. Authentication and billing happen automatically — no app, RFID card, or credit card needed
4. Charging starts

Plug & Charge is supported by Tesla Superchargers, Ionity, and growing numbers of public networks. It requires both the vehicle and charger to support ISO 15118.

V2G: Vehicle-to-Grid

V2G (Vehicle-to-Grid) uses the EV battery as a grid storage resource:

• The EV exports power to the grid during peak demand
• The grid operator pays the EV owner for the exported energy
• Requires a bidirectional DC charger and a compatible vehicle

V2G is commercially available in some markets (Japan with CHAdeMO, Europe with CCS2 via ISO 15118-20). It's expected to become more widespread as EV adoption grows.

Choosing a DC Fast Charger Network

Summary

DC fast charging delivers power directly to the EV battery, bypassing the onboard charger for much faster charging speeds. Key points:

• CCS2 is the dominant standard in Europe and Australia (EU-mandated)
• NACS is rapidly becoming the North American standard
• CHAdeMO is declining — mainly legacy Nissan and Mitsubishi vehicles
• Peak charging speed occurs between 20–80% SoC — charge to 80% for fast stops
• Plug & Charge (ISO 15118) enables automatic authentication — no app needed
• Liquid-cooled cables are required for 150 kW+ stations

CZT supplies EV charging connectors and components for CCS, NACS, and other charging standards. Browse our EV charging connector range for compatible products.