EV Charging Glossary (A–Z)

November 24, 2025

Vasine Wang is the Marketing Director at Workersbee, focusing on overseas EV charging markets, customer requirements, and charging connector applications. Drawing on market research, customer questions, and close collaboration with Workersbee’s product and engineering teams, he creates practical content to help charging equipment manufacturers and project teams better understand their options and make informed decisions.

Vasine Wang - Marketing Director at Workersbee

A quick reference for common EV charging terms used in hardware selection, site engineering, compliance, and backend operations. Each entry is a one-line meaning. Terms are sorted alphabetically, with the related topic shown in parentheses. Only letters that appear in this glossary are listed below. To find a specific term fast, use Ctrl+F (Windows) or Cmd+F (Mac).

A–Z Index (scan-only)

A: AFIR

C: Cable sizing / voltage drop; CAN bus; CCS1; CCS2; CDR / Session record; CE / UKCA; CHAdeMO; Contactor / Relay; Current transformer (CT)

D: DCFC; Dedicated circuit; Derating curve; DIN SPEC 70121; Dynamic Load Management (DLM)

E: Earthing / Grounding; Eichrecht / PTB-A; Emergency stop (E-stop); Ethernet / 4G/5G; EVSE controller (CSU)

G: GB/T AC; GB/T DC; GFCI

H: Harmonics / THD; HMI; HomePlug Green PHY (PLC); HPC / Ultra-rapid

I: IEC 62196-2 Type 2; IK rating (IK08/IK10); Inlet / Coupler; Interlock; IP rating (IP54/IP65/IP66); IPxxK; ISO 15118-2; ISO 15118-20; Isolation monitoring (IMD)

L: Level 1; Level 2; Liquid-cooled cable

M: MCS; MID meter; Mode 1; Mode 2 (IC-CPD); Mode 3; Mode 4; MQTT / HTTP(S)

N: NACS / J3400

O: OCPI; OCPP 1.6J; OCPP 2.0.1; OICP; Operating temperature; OTA update; Overcurrent protection (MCB)

P: Pattern approval; PEN fault detection; Phase balancing; PKI / V2G PKI; Plug & Charge (PnC); PME (UK)

Q: QR/app start

R: RCM 6 mA; RED / EMC / LVD; RF module; RFID / NFC; Roaming; RS-485 / UART

S: SAE J1772 (Type 1); SAE J2954; Salt spray; Secure boot / TPM; Shunt resistor; Strain relief / Backshell; Surge protection (SPD)

T: Tariff / TOU; Temperature sensor (NTC/PTC); TLS / Certificates; Type A RCD; Type B RCD

U: UL / cUL; Uptime / Availability; UV resistance

V: V2G / BPT; V2H; V2L

AFIR (Metering & compliance)

EU regulation setting deployment, uptime, and payment requirements for public EV charging.

Notes: Focus on TEN-T corridors.

Cable sizing / voltage drop (Installation & grid)

Selecting conductor size to keep voltage drop within limits.

Notes: Long runs need larger gauge.

CAN bus (Communication & protocols)

Vehicle network standard sometimes used for DC charging handshake.

Notes: Legacy controller communications.

CCS1 (Connectors & standards)

DC fast charge interface in North America (Type 1 AC + DC pins).

Notes: Also called SAE Combo 1.

CCS2 (Connectors & standards)

DC fast charge interface in Europe (Type 2 AC + DC pins).

Notes: Also called Combo 2. See also: Workersbee CCS2 DC charging connectors.

CDR / Session record (Smart/UX/Operations)

Charge Detail Record used for billing and audit.

Notes: Shared via OCPI and OCPP.

CE / UKCA (Metering & compliance)

Regulatory conformity marking for EU and UK markets.

Notes: Based on LVD, EMC, and RED directives.

CHAdeMO (Connectors & standards)

Legacy DC charging standard from Japan.

Notes: Early V2H support.

Contactor / Relay (Hardware components)

Switching devices that turn charging power on or off under control.

Notes: AC and DC variants.

Current transformer (CT) (Hardware components)

Current measurement device for protection or metering.

Notes: Alternative to shunt sensing.

DCFC (Charging modes & power levels)

Generic term for DC fast charging (about 50–150 kW+).

Notes: Also called rapid charging.

Dedicated circuit (Installation & grid)

An EVSE-only breaker and wiring run.

Notes: Avoids nuisance trips.

Derating curve (Charging modes & power levels)

Output current or power reduced versus temperature to protect hardware.

Notes: Driven by cable and connector limits.

DIN SPEC 70121 (Communication & protocols)

Early CCS DC communication specification between EV and charger.

Notes: Still used by many vehicles.

Dynamic Load Management (DLM) (Installation & grid)

Adjusts current across chargers to stay within a site power cap.

Notes: Also called load balancing.

Earthing / Grounding (Installation & grid)

TN, TT, or IT earthing arrangements that ensure shock protection.

Notes: Impacts safety detection methods.

Eichrecht / PTB-A (Metering & compliance)

German calibration law for public charging billing.

Notes: Requires signed metering data.

Emergency stop (E-stop) (Electrical safety & protection)

Immediate stop that de-energizes the system for safety.

Notes: Common on DC cabinets.

Ethernet / 4G/5G (Communication & protocols)

Backhaul links from charger to CSMS or cloud.

Notes: WAN connectivity options.

EVSE controller (CSU) (Hardware components)

Main control board that manages switching, communications, and HMI.

Notes: The charger’s control core.

GB/T AC (Connectors & standards)

Chinese national standard AC charging connector.

Notes: GB/T 20234.2.

GB/T DC (Connectors & standards)

Chinese national standard DC fast-charging connector.

Notes: GB/T 20234.3.

GFCI (Electrical safety & protection)

US term for ground-fault leakage protection.

Notes: Referenced in NEC 625.

Harmonics / THD (Installation & grid)

Power-quality distortion caused by rectifiers and inverters.

Notes: Managed with filters and standards.

HMI (Hardware components)

Display, LEDs, or buttons for user interaction.

Notes: User interface panel.

HomePlug Green PHY (PLC) (Communication & protocols)

Physical layer carrying ISO 15118 data over power lines.

Notes: Used in CCS systems.

HPC / Ultra-rapid (Charging modes & power levels)

High-power DC charging at 150 kW and above, often up to 350 kW.

Notes: Liquid cooling is common.

IEC 62196-2 Type 2 (Connectors & standards)

AC connector used in Europe and many other regions.

Notes: 7-pin AC interface.

IK rating (IK08/IK10) (Env & mechanical)

Mechanical impact resistance rating for enclosures.

Notes: Defined in EN 62262.

Inlet / Coupler (Connectors & standards)

Vehicle inlet and the handheld plug assembly.

Notes: Vehicle-side vs cable-side parts.

Interlock (Electrical safety & protection)

Safety interlock between connector engagement and power switching.

Notes: Prevents arcing under load.

IP rating (IP54/IP65/IP66) (Env & mechanical)

Ingress protection against dust and water.

Notes: Defined in EN 60529.

IPxxK (Env & mechanical)

High-pressure water-jet protection rating.

Notes: Defined in ISO 20653.

ISO 15118-2 (Communication & protocols)

High-level EV-charger communication enabling Plug & Charge.

Notes: Runs over PLC.

ISO 15118-20 (Communication & protocols)

Next-gen standard adding bidirectional power transfer and advanced smart charging.

Notes: Includes V2G features.

Isolation monitoring (IMD) (Electrical safety & protection)

Monitors insulation resistance in DC systems.

Notes: Defined in IEC 61557-8.

Level 1 (Charging modes & power levels)

120 V AC charging up to about 1.9 kW.

Notes: Slow home charging in North America.

Level 2 (Charging modes & power levels)

208–240 V AC charging up to about 19.2 kW.

Notes: Standard home and workplace level.

Liquid-cooled cable (Hardware components)

DC cable with coolant channels for higher continuous current.

Notes: Used for HPC and MCS.

MCS (Connectors & standards)

Megawatt Charging System standard for heavy-duty EV charging above 1 MW.

Notes: Targeted at trucks and buses.

MID meter (Metering & compliance)

EU MID-compliant meter approved for billing.

Notes: Legal metrology requirement.

Mode 1 (Charging modes & power levels)

AC charging from a socket with no EVSE control.

Notes: Generally not recommended.

Mode 2 (IC-CPD) (Charging modes & power levels)

AC charging with an in-cable control and protection device.

Notes: Portable charging mode.

Mode 3 (Charging modes & power levels)

AC charging via a dedicated EVSE with control pilot.

Notes: Typical wallbox or public AC.

Mode 4 (Charging modes & power levels)

DC charging with off-board rectification in the charger.

Notes: Used for fast charging.

MQTT / HTTP(S) (Communication & protocols)

Common telemetry and API protocols used by chargers.

Notes: Typical IoT backends.

NACS / J3400 (Connectors & standards)

North American Charging Standard formalized as SAE J3400.

Notes: Supports both AC and DC charging.

OCPI (Communication & protocols)

Roaming protocol between CPOs and eMSPs.

Notes: Handles tariffs, tokens, and CDRs.

OCPP 1.6J (Communication & protocols)

WebSocket/JSON protocol between charger and CSMS.

Notes: Widely deployed version.

OCPP 2.0.1 (Communication & protocols)

Newer OCPP adding device model, security, and richer smart charging.

Notes: Modern feature set.

OICP (Communication & protocols)

Hubject roaming protocol for inter-network charging.

Notes: eRoaming integration.

Operating temperature (Env & mechanical)

Ambient range where the charger operates safely.

Notes: Often specified as a class like −30 to +50°C.

OTA update (Communication & protocols)

Remote firmware or configuration updates.

Notes: Enables ongoing maintenance.

Overcurrent protection (MCB) (Electrical safety & protection)

Protection against overload and short circuits.

Notes: Breaker curve selection matters.

Pattern approval (Metering & compliance)

Legal metrology approval process for revenue metering.

Notes: Required in many regions.

PEN fault detection (Electrical safety & protection)

Detects loss of Protective Earth and Neutral in TN-C-S systems.

Notes: UK PME rule.

Phase balancing (Installation & grid)

Distributes load across three phases to reduce imbalance.

Notes: Helps power quality.

PKI / V2G PKI (Cybersecurity)

Certificate infrastructure for Plug & Charge and device trust.

Notes: Enables secure authentication.

Plug & Charge (PnC) (Communication & protocols)

Automatic authentication and billing via certificates when plugged in.

Notes: ISO 15118 feature.

PME (UK) (Installation & grid)

Protective Multiple Earthing system used in the UK.

Notes: Special EVSE requirements.

QR/app start (Smart/UX/Operations)

Starting a charging session via app or QR code.

Notes: Common at public sites.

RCM 6 mA (Electrical safety & protection)

Monitors DC leakage and trips upstream Type A RCD at 6 mA or higher.

Notes: Often built into EVSE.

RED / EMC / LVD (Metering & compliance)

EU directives for radio, electromagnetic compatibility, and electrical safety.

Notes: Core basis for CE marking.

RF module (Communication & protocols)

Wireless connectivity module such as Wi-Fi, BLE, LTE, or NR.

Notes: Used for remote operations.

RFID / NFC (Smart/UX/Operations)

Card or tap authentication to start charging.

Notes: Widely used in public charging.

Roaming (Smart/UX/Operations)

Cross-network charging access through interoperability hubs.

Notes: Connects eMSPs and CPOs.

RS-485 / UART (Hardware components)

Serial links for meters and peripherals.

Notes: Modbus RTU is common.

SAE J1772 (Type 1) (Connectors & standards)

AC connector used in North America and Japan.

Notes: 5-pin AC interface.

SAE J2954 (V2X & wireless)

Wireless charging standard for EVs.

Notes: Defines coil alignment and power classes.

Salt spray (Env & mechanical)

Corrosion resistance test method for outdoor products.

Notes: IEC 60068-2-11.

Secure boot / TPM (Cybersecurity)

Hardware-rooted firmware integrity and trust.

Notes: Blocks tampered code.

Shunt resistor (Hardware components)

DC current sensing element using voltage drop across a resistor.

Notes: High precision method.

Strain relief / Backshell (Env & mechanical)

Mechanical support at the cable-handle interface.

Notes: Extends cable life.

Surge protection (SPD) (Electrical safety & protection)

Protection against transient overvoltage events.

Notes: Type 1 and Type 2 per IEC 61643.

Tariff / TOU (Smart/UX/Operations)

Pricing schemes including time-of-use rates and demand components.

Notes: Drives billing logic.

Temperature sensor (NTC/PTC) (Hardware components)

Measures handle or cable temperature to control derating.

Notes: Protects contacts.

TLS / Certificates (Cybersecurity)

Encrypted communication and mutual authentication.

Notes: Used by OCPP and ISO 15118.

Type A RCD (Electrical safety & protection)

Detects AC and pulsed DC leakage, commonly used for AC EV charging.

Notes: Usually paired with 6 mA DC monitoring.

Type B RCD (Electrical safety & protection)

Detects AC, pulsed DC, and smooth DC leakage, common for DC chargers.

Notes: Covers higher DC leakage.

UL / cUL (Metering & compliance)

North American safety certification for EVSE.

Notes: Examples include UL 2594 and UL 2202.

Uptime / Availability (Smart/UX/Operations)

Percentage of time a charger is operational and usable.

Notes: Key public-site KPI.

UV resistance (Env & mechanical)

Material durability against long-term sunlight exposure.

Notes: Important for outdoor plastics.

V2G / BPT (V2X & wireless)

Bidirectional power transfer between vehicle and grid.

Notes: Defined in ISO 15118-20.

V2H (V2X & wireless)

Vehicle powering a home through a bidirectional charger.

Notes: Backup or self-consumption use.

V2L (V2X & wireless)

Vehicle powering external loads or devices.

Notes: Portable power use.

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