Glossary
Charging and interoperability terminology used across this guidance — vendor-neutral, standards-sourced definitions, not marketing language.
A
- AC charging
- Alternating Current charging — the slower charging type (typically up to ~22 kW) that uses the vehicle's onboard charger to convert AC from the grid to DC for the battery.
- AutoCharge
- An automatic-authentication method that identifies a vehicle by its charging-cable communication signature rather than an app, card, or RFID tap. A precursor to ISO 15118 Plug & Charge, still used by some networks and vehicles that don't yet support the newer standard.
B
- BEV
- Battery Electric Vehicle — powered solely by a battery and electric motor, with no internal combustion engine. Must be recharged from a cable or charging station.
- Bidirectional charging
- Charging capable of flowing power in both directions — from the grid into the vehicle and back out again — covering Vehicle-to-Grid (V2G), Vehicle-to-Home (V2H), and Vehicle-to-Load (V2L) use cases.
C
- CPMS
- Charge Point Management System — the backend software that monitors, controls, and bills charging stations, and coordinates with a CPO's operations.
- CPO
- Charge Point Operator — owns and operates physical charging stations.
- CCS
- Combined Charging System — a DC fast-charging connector standard that adds two DC pins to the Type 1 (CCS1, North America) or Type 2 (CCS2, Europe and most of Africa) AC connector.
- CHAdeMO
- A Japanese-originated DC fast-charging connector standard, largely superseded elsewhere by CCS and NACS but still found on some legacy vehicles.
- Carbon credits (EV charging)
- Tradeable certificates representing verified emissions reductions from switching to electric transport, which charging operators or fleets can generate and sell as a revenue stream alongside charging fees.
D
- DC fast charging
- Direct Current fast charging — delivers DC power straight to the battery, bypassing the onboard charger, enabling much higher power and shorter charging times than AC.
- DSO
- Distribution System Operator — the utility responsible for the local electricity grid a charging site connects to.
- Demand response
- A program letting a utility or grid operator send signals to connected equipment, including chargers, to reduce power draw during periods of grid stress.
- Destination charging
- Charging that happens while a vehicle is parked for another purpose — at a hotel, shopping centre, or workplace — rather than as the primary reason for the stop.
E
- eMSP
- eMobility Service Provider (also written EMSP) — sells charging access to drivers, often across multiple CPO networks through roaming agreements.
- EVSE
- Electric Vehicle Supply Equipment — the formal term for the physical charging unit itself, covering both AC and DC hardware.
- Energy management system (EMS)
- Software that monitors and optimises a site's overall power use across multiple loads, including EV chargers, rather than managing chargers in isolation.
- En-route charging
- Charging undertaken specifically to continue a journey, typically at higher power and for a shorter dwell time than destination charging — the primary use case for DC fast charging along travel corridors.
- EV Charging for Apartments
- Charging serving residents of apartment or multi-unit buildings — a subset of multi-unit dwelling (MUD) charging distinguished by needing per-resident billing, access control, and often retrofit into existing parking.
G
- GB/T
- The Chinese national charging connector and communication standard (Guobiao), distinct from CCS and Type 2 — relevant wherever Chinese-made vehicles or chargers are deployed.
I
- ISO 15118
- The international standard governing communication between an electric vehicle and a charging station, including Plug & Charge authentication.
- ICE
- Internal Combustion Engine — a vehicle powered by burning fuel rather than electricity; the baseline technology being displaced by BEVs and PHEVs.
- ISO 15118-20
- The second-generation extension of ISO 15118, adding bidirectional charging (V2G) support to the original standard's vehicle-to-charger communication and Plug & Charge capability.
K
- kW / kWh
- Kilowatt (kW) measures charging power — how fast energy is delivered. Kilowatt-hour (kWh) measures energy itself — how much a battery holds or a session delivers.
L
- Level 1 / Level 2 / Level 3 charging
- Informal charging-speed tiers: Level 1 (a standard household outlet, slowest), Level 2 (208–240V AC, typical for home and workplace charging), and Level 3 (another name for DC fast charging).
- Load management
- Distributing available electrical capacity across multiple chargers at a site — also called load balancing or dynamic load management — to avoid exceeding the site's grid connection limit.
- Load shifting
- Moving charging demand from peak hours to off-peak hours, typically to reduce cost or ease strain on the grid, rather than reducing total demand outright.
M
- Make-ready infrastructure
- Wiring, panel capacity, and conduit installed ahead of an actual charger, in three stages: EV Capable (panel capacity and conduit only), EV Ready (plus wiring to a junction box), and EV Installed (charger fully installed and commissioned).
- Multi-unit dwelling (MUD) charging
- Charging infrastructure serving residents of apartment buildings or shared housing, where individual driveway or garage charging isn't possible — a distinct planning and access challenge from single-family home charging.
N
- NACS
- North American Charging Standard (SAE J3400) — the connector originally used exclusively by Tesla in North America, opened to other automakers from 2022.
O
- OCPI
- Open Charge Point Interface — the protocol for roaming between CPOs and eMSPs, letting a driver charge on a network they don't hold an account with. Owned and maintained by the EVRoaming Foundation.
- OCPP
- Open Charge Point Protocol — the protocol between a physical charger and its CPMS, covering status reporting, remote control, and firmware updates. Owned by the Open Charge Alliance.
- OICP
- Open InterCharge Protocol — an alternative roaming protocol to OCPI, notably used by Hubject.
- OSCP
- Open Smart Charging Protocol — coordinates charging with local grid capacity constraints, such as a site's connection limit. Owned by the Open Charge Alliance.
- Onboard charger
- The vehicle-side hardware that converts AC power from an EVSE into DC power for the battery — required for AC charging, bypassed entirely during DC fast charging.
- On-Street EV Charging
- Charging installed along public roads or at the kerbside, typically serving residents without private off-street parking — a common access model in dense urban areas.
P
- Plug & Charge
- An ISO 15118 capability that authenticates and starts a charging session automatically when the cable is plugged in, with no app, card, or RFID tap required.
- PHEV
- Plug-in Hybrid Electric Vehicle — combines a combustion engine with an electric motor and a battery that can be recharged from an external power source, unlike a standard (non-plug-in) hybrid.
- Payment gateway
- The system that processes a driver's payment for a charging session, connecting the charger or app to card networks or mobile-money providers.
- Peak shaving
- Reducing the maximum power draw at a site during periods of highest demand, often by pausing or slowing charging, to avoid breaching a grid connection limit or triggering demand charges.
- Private EV Charging
- Charging restricted to a single household, business, or fleet's own vehicles, with no public or third-party access.
R
- Roaming
- The arrangement that lets a driver charge on a network they don't hold a direct account with, settled between the CPO and the driver's eMSP — the function OCPI and OICP exist to standardise.
- Range anxiety
- A driver's concern about running out of charge before reaching a destination or the next charger — an adoption barrier that a denser, more reliable, more interoperable charging network directly addresses.
- Roaming hub
- An intermediary that connects multiple CPOs and eMSPs through a single integration, rather than requiring each to integrate directly with every other — reducing the number of bilateral agreements roaming would otherwise require.
- Retail Charging
- Charging installed at shopping centres, supermarkets, or other retail locations, aimed at drivers already stopping to shop rather than as a standalone destination.
S
- SLA
- Service Level Agreement — a contracted commitment to a measurable operating standard, most often charger uptime, in a CPO or CPMS vendor relationship.
- Smart charging
- Charging that adjusts timing, rate, or power draw automatically — to shift load to off-peak hours, align with renewable generation, or respond to grid signals — rather than charging at a fixed, uncoordinated rate.
- Semi-public charging
- Charging accessible to a defined group rather than the general public or a single private user — for example, a workplace car park open to employees and visitors.
- Site host
- The owner or manager of the physical property where a charging station is installed, distinct from the CPO that may own and operate the equipment itself.
- State of Charge (SoC)
- The current energy level of an EV's battery, expressed as a percentage of full capacity — the EV equivalent of a fuel gauge.
T
- Tariff
- The pricing structure applied to a charging session — commonly per-kWh, per-minute, a flat session fee, or a blend of these.
- Time-of-use (ToU) tariff
- A pricing structure where the cost per kWh changes by time of day, charging more during high-demand periods and less off-peak — used to encourage load shifting.
U
- Uptime
- The share of time a charger is available and working, the headline reliability metric operators and this Alliance track — and the opposite of the broken-charger problem interoperability guidance exists to reduce.
V
- V2G
- Vehicle-to-Grid — technology allowing a charging EV's battery to discharge power back into the grid to help balance supply and demand. Still an emerging capability, not yet standard.
W
- Workplace EV Charging
- Charging provided at an employer's premises for staff and sometimes visitors, typically used during the workday while vehicles are parked for hours rather than minutes.
- What is V2H (Vehicle-to-Home)
- A form of bidirectional charging where a parked EV's battery can power a home directly, commonly during an outage or to offset peak household electricity costs — distinct from V2G, which feeds power back to the grid rather than a single building.
Z
- ZEV
- Zero Emission Vehicle — a vehicle producing no tailpipe emissions, covering both battery-electric and hydrogen fuel-cell vehicles.