EV charging glossary
The terms you run into around EV chargers and charging software, defined in plain language. From OCPP and roaming to load balancing and dynamic tariffs.
A
- AC charging
- Charging with alternating current, the standard for home and workplace chargers. The car's onboard converter turns AC into DC for the battery, which limits speed to roughly 3.7 to 22 kW depending on the car and the connection.
- AFIR
- The EU Alternative Fuels Infrastructure Regulation. It sets requirements for public charging infrastructure, such as ad-hoc payment options and price transparency at charge points.Read more
- Autostart
- Starting a charging session automatically when the cable is plugged in, without scanning a card. The charger presents a stored card ID on the driver's behalf. Not the same as ISO 15118 Plug & Charge, which authenticates through the car itself.
- Available (charger status)
- The connector is idle and ready to use: no active session, no car connected, no card scanned.
C
- Card UID
- The unique chip code a charge card carries internally. It is what the charger's card reader actually scans, and it is usually not printed on the card itself.
- CCS (Combined Charging System)
- The dominant DC fast-charging connector standard in Europe. It combines the Type 2 AC plug with two extra DC pins, so one inlet on the car covers both.
- Charge card (RFID)
- A card or key fob with an RFID chip used to authorize charging sessions. The charger reads the card's unique ID and checks it against a whitelist or a billing provider.
- Charge point operator (CPO)
- The party that operates charge points: it monitors them, keeps them online, and often sets the price per kWh at public locations. One charger can be operated by a CPO while being owned by someone else.Read more
- Chargepoint ID
- The identifier a charger uses to announce itself to a charging platform over OCPP. Every charger connected to a backend has one, and it is the key to finding the right device in a portal.
- Charging session (transaction)
- One complete charge, from authorization to unplugging, recorded with its start and stop time and the energy delivered in kWh. Charging platforms list sessions as transactions for billing and reporting.
- Connection status
- Whether a charger currently has an internet connection to its platform: online or offline. An offline charger usually keeps charging, but it cannot be monitored or controlled remotely until it reconnects.
- Connector
- The individual outlet or fixed cable on a charger. A charge point can have more than one connector, each with its own status and transactions.
- CSMS (charging station management system)
- The backend software chargers connect to over OCPP: it monitors status, manages sessions, and handles billing and smart charging. Also called a charging platform or backoffice.Read more
D
- DC fast charging
- Charging with direct current from a converter built into the charging station, bypassing the car's onboard charger. Typical along highways, at powers from 50 kW up to several hundred kW.
- Dynamic energy tariffs
- Electricity prices that change per hour (or shorter), following the wholesale market. With a dynamic contract, a smart charger can shift charging to the cheapest hours automatically.Read more
- Dynamic load balancing (DLM)
- Load balancing that reacts to live consumption. A meter watches how much the building is using, and the charger scales up or down so the total stays within the main fuse. Also called dynamic load management.Read more
E
- eMSP (e-Mobility Service Provider)
- The party the driver has the contract with: it issues the charge card or app and sends the invoice. The eMSP pays the charge point operator for the energy, usually settled over OCPI roaming connections.
- EPBD
- The EU Energy Performance of Buildings Directive. Among other things it requires charging points and pre-cabling for parking spaces in new and renovated buildings.Read more
- ERE (green energy certificates)
- Turning charged kWh into tradeable renewable-energy certificates. Charging data is reported to a booking service provider, who registers the certificates; the charger owner or CPO earns a share of their value.Read more
F
- Faulted (charger status)
- The charger or connector is reporting an error, usually with an error code that points at the cause. Common triggers are grid problems, a tripped breaker, or a hardware fault.
I
- ISO 15118 and Plug & Charge
- The standard for communication between car and charger. Its best-known feature is Plug & Charge: the car identifies itself cryptographically, so a session starts and bills without a card or app.
K
- kW vs kWh
- Kilowatt (kW) is power: how fast energy flows at this moment. Kilowatt-hour (kWh) is energy: how much has been delivered in total. A session at 11 kW for two hours delivers 22 kWh.
L
- Load balancing
- Dividing the available electrical capacity intelligently across one or more chargers, so everyone charges as fast as possible without overloading the connection.Read more
M
- Main fuse capacity
- The maximum current the location's main fuse allows, per phase, in amperes. It is the hard limit that load balancing protects: everything in the building plus the chargers must stay below it.
- MID meter
- A kWh meter certified under the EU Measuring Instruments Directive. Required when charged energy is billed to someone, for example reimbursing an employee who charges a lease car at home.
O
- OCPI
- The Open Charge Point Interface: the protocol charge point operators and e-Mobility Service Providers use to exchange locations, tariffs, and sessions. It is what makes roaming between charging networks work.
- OCPP
- The Open Charge Point Protocol: the open standard chargers use to talk to a management platform. It carries statuses, transactions, configuration, and smart-charging commands, and it is why chargers and platforms from different vendors work together.Read more
- OCPP proxy
- A service that sits between a charger and one or more OCPP platforms, forwarding the connection. It lets a single charger serve multiple backends at once, for example one for billing and one for energy management.Read more
- Operator
- In charging software: an OCPP platform a charger's connection is forwarded to, for billing, monitoring, or public charging. One charger can be connected to several operators at once.Read more
P
- Peak shaving
- Capping a site's total consumption below a set peak, by temporarily limiting charging power. Used to avoid expensive peak-demand charges or to stay within a constrained grid connection.Read more
- Phase (single and three-phase)
- One of the individual AC power lines in an electrical connection. A single-phase connection charges at up to 7.4 kW; a three-phase connection at up to 22 kW, if the car's onboard charger supports it.
- Power sharing
- Load balancing across multiple connectors or chargers: the available capacity is divided over all active sessions, instead of the first car taking everything.Read more
- Preparing (charger status)
- The charger is connected to a car or a card has been authorized, but not both yet. The session starts once the second step happens.
R
- Roaming
- Charging on another operator's network with your own charge card or app. Behind the scenes, the operator and your provider settle the session through OCPI, directly or via a roaming hub.
S
- Scheduled charging
- Restricting charging to set time windows, for example only outside peak hours or only at night. A simpler alternative to charging on dynamic tariffs.Read more
- Smart charging
- The umbrella term for charging that adapts to circumstances: available capacity, solar production, energy prices, or a schedule. In practice it combines power management and tariff-based charging.Read more
- Smart meter (P1)
- The utility meter that measures a building's consumption and, in the Netherlands and Belgium, exposes live readings through its P1 port. A P1 dongle feeds those readings to the charger for dynamic load balancing and solar charging.
- Solar charging (solar balancing)
- Charging with the solar power that would otherwise be exported to the grid. A meter measures the surplus and the charger follows it, optionally topping up from the grid when production dips.Read more
- State of charge (SoC)
- How full the car's battery is, as a percentage. Charging typically slows down at a high state of charge, especially during DC fast charging.
- Suspended (waiting for car or power)
- An active session where no energy flows. Waiting for car: the car is not requesting power, for example because its battery is full or its own schedule paused. Waiting for power: the charger is offering none, usually because smart charging is holding it back.
T
- Type 2 connector
- The standard AC charging plug in Europe, required on public AC charge points in the EU. Supports single and three-phase charging up to 22 kW (43 kW in rare cases).
V
- V2G (vehicle-to-grid)
- Bidirectional charging: the car can feed energy back, to the building (V2H) or the grid (V2G). It requires a bidirectional charger and a car that supports it; adoption is still early.