Glossary
EV charging glossary
CMS, CPMS, CSMS, CPO, eMSP, OCPP, OCPI, Plug & Charge, V2G: the terms and abbreviations used across EV charging software, explained in plain language. Each term has its own page with more detail.
- CMSCharging Management System
A charging management system connects chargers to a central platform so operators can manage stations, connectors, sessions, tariffs, billing and driver services from one place. It is the same kind of system as a CPMS or CSMS, and CMS is the term most operators use day to day.
Also called: CPMS, CSMS, EV charging management system, charging station management system, charger management system, electric vehicle charging management system
- CPMSCharge Point Management System
A CPMS is the software a charge point operator uses to run its chargers remotely: it connects every charger to one platform to monitor status, start and stop sessions, set tariffs, bill drivers, push firmware updates and fix faults. CPMS, CMS (charging management system) and CSMS all name the same kind of system; CMS is the most common in everyday use.
Also called: CMS, CSMS, charging management system, charging management software, EV charging management platform
- CSMSCharging Station Management System
CSMS is the name the OCPP specification uses for the central system that chargers connect to. In practice it means the same thing as a CPMS or CMS: the back office that monitors and controls a network of EV chargers.
Iris Network acts as the CSMS for OCPP 1.6J and 2.0.1 chargers.
- CPOCharge Point Operator
A CPO owns or operates EV charging stations: it keeps them running, sets prices and earns revenue from charging sessions. A CPO runs its network on a CMS (CPMS) and often shares it with other networks through roaming.
- eMSPeMobility Service Provider
An eMSP gives EV drivers access to charging, usually through an app or charging card, and bills them for it. Through roaming, an eMSP can offer charging on chargers run by many different CPOs. One company can be both a CPO and an eMSP.
Also called: EMSP, MSP, mobility service provider
- OCPPOpen Charge Point Protocol
OCPP is the open protocol that EV chargers use to talk to a CMS (CPMS). It covers starting and stopping sessions, authorising drivers, reporting meter values and faults, remote commands and firmware updates. OCPP 1.6J (JSON over WebSocket) is the most widely deployed version; OCPP 2.0.1 adds device management, better security and smart charging features. It is maintained by the Open Charge Alliance (OCA).
Iris supports OCPP 1.6J and 2.0.1 and is integrated with chargers from 35+ manufacturers.
- OCPIOpen Charge Point Interface
OCPI is the open protocol for EV roaming: it lets a CPO and an eMSP exchange charger locations, live availability, tariffs, sessions and billing records, so drivers can charge on networks they have no contract with. OCPI 2.2.1 is the current widely used version.
Iris Network roams over OCPI 2.2.1 in both the CPO and eMSP role.
- EV roaming
Roaming lets a driver charge on another operator’s network with their usual app or card. The networks connect directly over OCPI, or through a roaming hub that connects many operators at once, and settle payments between themselves.
- EVSEElectric Vehicle Supply Equipment
EVSE is the technical term for the charging equipment that delivers power to an electric vehicle. In OCPI, an EVSE is one charging point at a location that can charge one vehicle at a time, and it can have several connectors.
- Charge point
A charge point is the physical charger. One charge point can have one or more EVSEs and connectors, and it connects to a CMS (CPMS) over OCPP.
Also called: charging station, charger
- AC and DC charging
AC chargers supply alternating current that the vehicle’s on-board charger converts, typically at up to 22 kW, and suit homes, workplaces and destinations. DC fast chargers convert power in the charger and deliver it straight to the battery, at 50 kW to 350 kW or more, for highways and quick top-ups.
- ISO 15118
ISO 15118 is the standard for communication between an electric vehicle and a charger. It enables Plug & Charge, where the car identifies itself and charging starts without an app or card, and it is the basis for bidirectional charging.
- Smart charging
Smart charging adjusts when and how fast vehicles charge, to stay within a site’s grid connection, use cheaper or cleaner energy, or have fleet vehicles ready before departure. OCPP carries the charging limits from the management system to each charger.
- Charger uptime
Uptime is the share of time a charger is available and able to charge. It is the main reliability measure for a charging network, and many public funding programmes set a minimum.
- Predictive maintenance
Predictive maintenance uses charger telemetry, fault codes and session data to forecast which chargers will fail before they do, so operators can fix them on a planned visit instead of after drivers find them broken.
More about Predictive maintenance
Iris R-One predicts EV charger failures up to 3 weeks ahead with up to 97% accuracy.
- EV charger asset management
Charger asset management keeps one record per charger across its whole life: inventory, installation, commissioning, maintenance, faults and replacement parts, so operators know what they own, where it is and what state it is in.
- White-label charging platform
A white-label platform is software a CPO or eMSP runs under its own brand: the driver app, website and receipts carry the operator’s name and design, while the software vendor maintains the platform.
More about White-label charging platform
Iris Network is fully white-label, including the driver app.
- Plug & Charge
Plug & Charge lets an electric vehicle start a charging session just by being plugged in: the car identifies itself to the charger with a digital certificate, and the session is authorised and billed to the driver’s contract with no app or card. It is defined in ISO 15118.
Also called: Plug and Charge, PnC
- Autocharge
Autocharge starts a charging session automatically when a registered vehicle is plugged in, by recognising the vehicle’s unique identifier (its MAC address, or EVCCID) at a DC charger. The driver links the vehicle to their account once, and after that needs no app or card.
Also called: Auto charge, Autocharge (MAC address authorisation)
- V2GVehicle-to-Grid
V2G lets an electric vehicle send power from its battery back to the grid as well as charge from it. Parked vehicles can then help balance the grid at peak times, and their owners can be paid for it.
Also called: V2X, V2H, vehicle to grid, bidirectional charging
- Load management
Load management shares the power available at a site between the vehicles charging there, so the total never exceeds the site’s grid connection. Static load management uses a fixed limit; dynamic load management adjusts it in real time to the building’s other consumption.
Also called: dynamic load management, load balancing, DLM
- Demand-side response
Demand-side response means reducing or shifting electricity use when the grid is under strain, usually in return for payment. EV charging suits it well, because many sessions can be slowed or paused for a short time without the driver noticing.
Also called: demand response, DSR, automated demand response
- CCSCombined Charging System
CCS is the charging connector standard that combines AC charging pins with two large DC pins in one inlet, so the same socket on the car takes both slow AC and fast DC charging. CCS2 (Combo 2) is the standard in Europe; CCS1 is used in North America.
Also called: CCS2, CCS Combo 2, CCS1