EV Charging Glossary

Alternating current charging. Power from the grid is delivered as AC to the vehicle's on-board charger (OBC), which converts it to DC internally before storing it in the battery. AC chargers are simpler and lower cost than DC fast chargers, and are suited to applications where vehicles dwell for 2–10+ hours.

An AC charger operating at 208–240 V, typically delivering 7 kW, 11 kW, or 22 kW. The standard product category for residential complexes, workplace parking, and commercial parking applications. Uses a Type 2 connector in Europe or J1772 in North America.

Electronics embedded in the EV battery pack that monitor cell voltage, temperature, and state of charge. During DC fast charging, the BMS communicates directly with the charger via the charging cable to set the optimal charging profile and protect battery health.

A DC fast-charging connector standard that adds two DC power pins below a standard AC socket. CCS1 is used in North America (below J1772); CCS2 is used in Europe and most global markets (below Type 2). The dominant DC standard in Europe and North America, supporting up to 350 kW.

A DC fast-charging connector standard originally developed in Japan. Supports bidirectional charging (V2G). Widely deployed in Japan and historically common globally; being replaced by CCS2 in most new European and North American deployments but remains important for legacy Nissan and Mitsubishi vehicles.

The handheld connector assembly at the end of a charging cable that plugs into the vehicle's inlet socket. DC fast charger guns are larger and heavier than AC guns due to higher power requirements and, on ultra-fast units, liquid-cooled cable technology.

An industry term for an EV charging unit, widely used to describe any charging post or station. Covers both AC and DC products — from 7 kW residential wall boxes to 720 kW liquid-cooled superchargers.

Cloud-based software that manages a network of EV charging stations. Provides remote monitoring, user authentication, load management, billing, energy reporting, and firmware updates. Communicates with chargers via OCPP.

A signal line in the charging cable, defined by IEC 61851, used to communicate between the EVSE and the vehicle. Controls charging start and stop, communicates available current to the vehicle, and detects proper cable connection and vehicle presence.

A company or entity that owns and operates EV charging stations. CPOs install and maintain the hardware, use a CMS to manage their network, and may provide payment services directly to drivers. Distinct from the EMSP, which provides driver-facing accounts and billing.

A mandatory certification marking for products sold within the European Economic Area, indicating conformity with EU safety, health, and environmental standards. EV chargers require CE marking under the Low Voltage Directive (2014/35/EU), EMC Directive (2014/30/EU), and RoHS Directive (2011/65/EU).

Direct current fast charging. Power is converted from AC to DC inside the charger and delivered directly to the vehicle battery, bypassing the OBC. Enables much higher power delivery — typically 30 kW to 360 kW+ — compared to AC charging, and is suited to public charging hubs and fleet depots.

A smart charging feature that automatically distributes available electrical capacity across multiple charging points at a site in real time. Prevents grid overload while maximising the number of vehicles that can charge simultaneously, reducing the cost of grid connection upgrades.

The ability of electrical equipment to operate without causing or being affected by electromagnetic interference. EMC compliance is mandatory for CE marking under EU Directive 2014/30/EU and is tested by accredited third-party laboratories.

A company that provides EV charging access to drivers — including network access, RFID cards, mobile apps, billing, and roaming agreements with other networks. Drivers subscribe to an EMSP; the EMSP then authorises sessions at CPO-operated charging stations.

The formal technical term for EV charging equipment. An EVSE includes the charging unit, cable, connector, and all associated electronics. The term covers all forms of EV charging infrastructure, from simple Level 1 units to multi-gun ultra-fast charging stations.

China's national standard for EV charging connectors and communication interfaces. GB/T 20234.2 covers AC charging; GB/T 20234.3 covers DC charging. All public charging stations in China must use GB/T connectors, and GB/T is also required for any equipment connecting to Chinese charging networks.

The core international standard for electric vehicle conductive charging systems. Defines four charging modes (Mode 1–4), the control pilot communication protocol, and safety requirements for both the EVSE and the vehicle interface. Forms the technical basis for CE-marked EV chargers in the EU.

A two-digit code (per IEC 60529) indicating a product's protection against solid particles and liquids. The first digit (0–6) indicates dust protection; the second (0–9) indicates water protection. IP54 is the minimum for outdoor EV chargers; IP65 or IP66 is recommended for exposed locations.

An ingress protection rating indicating dust protection (no harmful ingress) and resistance to water splash from any direction. The minimum acceptable protection level for outdoor-installed EV charging equipment under IEC 61851.

IP65 provides dust-tight protection and resistance to low-pressure water jets from any direction. IP66 adds resistance to high-pressure water jets. Recommended for EV chargers in exposed outdoor locations, coastal environments, or sites subject to regular hosing.

International standard enabling "Plug & Charge" — a communication protocol between vehicle and charger that enables automatic authentication and billing via digital certificates embedded in the vehicle, without RFID cards or app interaction. Requires compatible hardware and a PKI certificate infrastructure.

The AC Level 1 and Level 2 charging connector standard for North America and Japan. A 5-pin connector supporting up to 19.2 kW for AC charging. The lower portion of the CCS1 DC fast-charging connector, meaning CCS1-capable vehicles accept J1772 AC charging.

A unit of electrical power equal to 1,000 watts. The standard measure of a charger's output rate. A 22 kW charger delivers 22 kilowatts of power while active. Power determines how quickly energy is transferred to the vehicle battery.

A unit of electrical energy equal to 1 kilowatt of power sustained for one hour. Used to measure battery capacity and total energy delivered in a charging session. A 60 kWh battery at 20% SOC needs approximately 48 kWh to reach 100%.

AC charging using a standard household outlet (120 V in North America; ~230 V in Europe). Delivers 1.4–2.4 kW. Adequate for overnight home charging with moderate daily mileage. No dedicated charging equipment required beyond a safety-rated cable.

AC charging using a dedicated 208–240 V connection, delivering 7–22 kW. The standard for residential, workplace, and commercial installations. Provides a full charge overnight for most battery-electric vehicles.

A thermal management method that circulates coolant fluid through the charging cable and connector to dissipate heat at very high power outputs. Enables ultra-fast charging cables to remain physically manageable at 150–720 kW power levels that would otherwise require impractically thick copper conductors.

A temporary reduction of charging power at a site or across a network in response to grid operator signals or local capacity limits. Used in demand response programmes where CPOs agree to reduce load during peak grid periods in exchange for lower energy tariffs.

Measurement and recording of electrical energy consumed during a charging session for billing purposes. Fiscally metered charging — using MID-certified (Measuring Instruments Directive) electricity meters — is required in Germany and several other EU markets to ensure legally compliant, accurate billing to end users.

A compact combined AC/DC charging connector originally developed by Tesla and subsequently standardised as SAE J3400. Rapidly being adopted by major US and Japanese automakers as a replacement for CCS1 and J1772. Supports up to 1 MW.

The AC-to-DC power converter built into an electric vehicle. The OBC rating (e.g. 7.4 kW or 22 kW) sets the maximum AC charging rate the vehicle can accept, regardless of how powerful the external EVSE is. DC fast charging bypasses the OBC entirely.

An open protocol enabling interoperability between different charging networks and service providers. OCPI standardises how session data, tariffs, locations, and authorisation are exchanged between CPO and EMSP platforms, enabling roaming across networks.

An open communication standard between EV charging stations and a central management system. OCPP allows operators to use any OCPP-compliant charger with any OCPP-compliant CMS platform, eliminating vendor lock-in. The most widely deployed protocol in the global EV charging industry.

The current widely deployed version of OCPP. Supports remote start/stop, reservations, RFID authentication, smart charging profiles (SetChargingProfile), and remote diagnostics. Compatible with the majority of commercial EV chargers deployed globally.

The next-generation version of OCPP, adding enhanced TLS security, ISO 15118 Plug & Charge support, improved smart charging, device management, and more granular transaction and energy data. Increasingly specified for new commercial and public charging deployments.

In the EV charging context, an OEM arrangement means the charger hardware is manufactured by a factory but sold under the buyer's own brand. The distributor specifies design, firmware customisation, packaging, and documentation; the factory manufactures and ships under the buyer's brand identity.

A floor-standing EV charging unit mounted on a post or pedestal base, as opposed to a wall-mounted unit. Common in open-air parking lots, forecourts, and commercial sites where wall mounting is impractical or where the unit must serve vehicles parked on both sides.

An automatic charging authorisation method where the vehicle and charger exchange digital certificates via the charging cable (ISO 15118), authenticating and starting a session without RFID card or app interaction. Requires ISO 15118-compliant hardware on both the vehicle and the EVSE.

The ratio of real power (kW) to apparent power (kVA) drawn from the grid. A power factor close to 1.0 indicates efficient use of electrical supply. EV chargers with active power factor correction (APFC) minimise reactive power draw, reducing losses and grid infrastructure costs.

A discrete, swappable DC power conversion unit within a DC fast charger. Modular charger designs allow output power to be scaled by adding modules, and faulty modules to be hot-swapped without taking the entire unit offline — reducing maintenance downtime.

A method of identifying and authorising EV charging sessions using contactless RFID cards or key fobs. The driver taps their RFID credential on the charger reader; the charger checks with the CMS before starting a session. A widely deployed, low-friction method for managing access to non-public charging sites.

EU Directive 2011/65/EU restricting the use of hazardous substances (lead, mercury, cadmium, hexavalent chromium, PBB, PBDE, and others) in electrical and electronic equipment. Compliance is required for CE marking and is documented in a Declaration of Conformity.

The ability for an EV driver to charge on a charging network other than their home provider using their existing RFID credential or app account. Enabled by inter-platform protocols such as OCPI. Critical for widespread EV adoption in regions with multiple competing charging networks.

Any charging approach that dynamically adjusts power delivery based on signals from the grid, the CMS, or the vehicle. Encompasses scheduled charging, dynamic load balancing, demand response, and V2G. Requires OCPP-compliant chargers connected to a CMS.

The current battery charge level expressed as a percentage of total capacity (0% = empty, 100% = full). During DC fast charging, the BMS reports SOC to the charger continuously, allowing the charger to adjust output and protect the battery — particularly important above 80% SOC.

A measure of a battery's current capacity relative to its original rated capacity, expressed as a percentage. Degrades gradually over charge cycles and temperature exposure. A battery at 80% SOH retains 80% of its original range. Tracked by fleet operators to inform replacement decisions.

A charging cable permanently attached to the EVSE (as opposed to a socket outlet where the driver supplies their own cable). Tethered cables improve convenience for public and commercial charging but add cost, weight, and a wear/theft exposure point. Standard on all DC fast chargers and many public AC units.

A measure of the distortion introduced into the AC supply by power electronics. High THD from poorly designed chargers can degrade grid power quality and cause interference with other equipment. Low THD is a quality indicator and may be specified in grid connection requirements for large charging sites.

The standard AC charging connector for the European market — a 7-pin plug supporting single-phase (3.7 kW, 7.4 kW) or three-phase (11 kW, 22 kW) charging. Mandated as the standard AC connector for all public charging points in the EU. The upper portion of the CCS2 DC fast-charging connector.

DC charging at 150 kW or above, enabling an EV to recover 100+ km of range in under 10 minutes. Requires liquid-cooled cables, high-power modular electronics, and strong grid connections. Suited to highway charging corridors, fleet depots, and high-throughput public hubs.

A bidirectional energy flow capability enabling an EV to export stored battery energy back to the electricity grid. Allows EVs to act as distributed energy storage assets, providing grid balancing services. Requires bidirectional EVSE hardware and vehicle compatibility. CHAdeMO was the first connector standard to support V2G commercially.

A variation of bidirectional charging where the EV battery supplies power to a home or building rather than the grid. Allows EV owners to use their vehicle battery to power their home during outages or peak-price periods, increasing energy self-sufficiency.

A feature enabling the EV to power external electrical devices directly via a standard outlet integrated into the vehicle or charging port — without requiring dedicated bidirectional EVSE hardware. Common on newer EVs for powering tools, camping equipment, or emergency devices.

A compact AC Level 2 charging unit designed for wall mounting, typically delivering 7 kW or 11 kW. The standard residential and workplace charging product. Smaller and simpler than pedestal or commercial units, and usually installed by an electrician on a dedicated 240 V circuit.