EV Charging Standards & Protocols

Technical overview of communication protocols, power delivery specifications, and charging standards

📡 ISO 15118

V2G Communication
Full Name Road Vehicle to Grid Communication Interface
Purpose Plug & Charge, Smart Charging, V2G
Transport PLC (Power Line Communication)
Security PKI-based authentication

Key Features

  • Plug & Charge (PnC) authentication
  • Vehicle-to-Grid (V2G) capability
  • Smart charging schedules
  • Wireless charging support
  • Bidirectional power flow

Status: Industry standard for advanced charging communication. Enables seamless charging experience without cards or apps.

⚡ IEC 61851

AC Charging
Full Name Electric Vehicle Conductive Charging System
Scope AC charging infrastructure
Power Levels 3.7kW to 43kW
Communication PWM signaling

Charging Modes

  • Mode 1: Domestic socket (not recommended)
  • Mode 2: Domestic socket + EVSE
  • Mode 3: Dedicated charging station
  • Mode 4: DC fast charging

Usage: Fundamental standard for AC charging safety, control, and communication between vehicle and charging station.

🔌 IEC 62196

Connector Specs
Full Name Plugs, Socket-Outlets, Vehicle Connectors
Scope Physical connector specifications
Types Type 1 (J1772), Type 2 (Mennekes)
Regions Global connector standards

Connector Types

  • Type 1: Single-phase, North America
  • Type 2: Three-phase, Europe
  • Type 3: Legacy (rarely used)
  • CCS: Combined AC/DC connectors

Purpose: Defines physical dimensions, electrical characteristics, and safety requirements for EV connectors worldwide.

🏃 CHAdeMO Protocol

DC Fast Charging
Full Name CHArge de MOve (Charge for Moving)
Origin Japan (TEPCO, Nissan, Mitsubishi)
Max Power 150kW (v2.0: 400kW)
Communication CAN bus

Protocol Features

  • Bidirectional charging (V2G/V2H)
  • Real-time communication
  • Battery management integration
  • Emergency stop capabilities
  • Temperature monitoring

Status: First major DC fast charging standard. Being superseded by CCS in most markets but still used by Nissan Leaf.

🌐 OCPP

Network Management
Full Name Open Charge Point Protocol
Purpose Station-to-network communication
Versions OCPP 1.6, 2.0, 2.0.1
Transport WebSocket, SOAP/HTTP

Management Features

  • Remote station monitoring
  • Charging session management
  • Firmware updates
  • Load balancing
  • Smart charging profiles

Usage: Industry standard for communication between charging stations and central management systems.

🚗 Tesla Protocol

NACS Charging
Full Name Tesla Supercharger Protocol
Connector NACS (North American Charging Standard)
Max Power 250kW (V3), 1MW+ (V4)
Communication PLC + proprietary protocols

Unique Features

  • Plug & Charge authentication
  • Dynamic power allocation
  • Pre-conditioning integration
  • Real-time pricing
  • Seamless billing

Evolution: Originally proprietary, now becoming open standard as NACS gains industry adoption in North America.

Charging Communication Flow

1

Physical Connection

Vehicle connector inserted into charging station. Pilot signal establishes basic communication.

2

Protocol Negotiation

Vehicle and station negotiate supported protocols (ISO 15118, CHAdeMO, etc.) and communication parameters.

3

Authentication

User authentication via RFID, credit card, mobile app, or Plug & Charge (ISO 15118).

4

Power Negotiation

Vehicle communicates battery state, charging limits, and preferred charging curve to station.

5

Charging Control

Station delivers power according to vehicle requirements. Continuous monitoring and adjustment.

6

Session Termination

Charging stops when complete, by user request, or error condition. Billing and session data recorded.

Power Delivery Standards

🔋 AC Charging Levels

Level 1
120V, 12-16A, 1.4-1.9kW
Level 2
240V, 16-80A, 3.8-19.2kW
Level 3
Three-phase, up to 43kW

Use Cases: Home charging (L1/L2), workplace charging (L2), public AC charging (L2/L3)

⚡ DC Fast Charging

Standard
50kW CCS/CHAdeMO
High Power
150-350kW CCS
Ultra Fast
350kW+ next-gen

Use Cases: Highway corridors, urban fast charging, commercial fleets

Emerging Standards & Future Trends

Wireless Charging (WPT)

  • SAE J2954: Wireless Power Transfer standard for light-duty vehicles
  • Power Levels: WPT1 (3.7kW), WPT2 (7.7kW), WPT3 (11kW)
  • Efficiency: 85-90% for modern systems
  • Applications: Static charging, dynamic charging (road-embedded)

Megawatt Charging System (MCS)

  • IEC 62196-6: Standard for heavy-duty vehicle charging
  • Power Range: 350kW to 4.5MW
  • Voltage: Up to 1500V DC
  • Target: Commercial trucks, buses, marine vessels

Vehicle-to-Everything (V2X)

  • V2G: Vehicle-to-Grid energy trading
  • V2H: Vehicle-to-Home backup power
  • V2L: Vehicle-to-Load portable power
  • Standards: ISO 15118-20, IEC 61980 series