EV charging terminology

Glossary

A plain-language guide to common terms used when planning and operating electric-vehicle charging sites.

AC Charging: Charging that supplies alternating current to the vehicle, where the onboard charger converts it to DC for the battery.
CCS: Combined Charging System, a connector standard used for DC fast charging on many electric vehicles.
CPO: Charge Point Operator—the organization responsible for operating, monitoring, and maintaining a charging network.
DC Fast Charging: High-power charging that delivers direct current to the vehicle battery, enabling substantially faster charging than typical AC equipment.
Demand Charge: A utility charge based on a site's highest measured power demand during a billing period.
EVSE: Electric Vehicle Supply Equipment—the equipment that safely supplies electricity to an electric vehicle.
kW: Kilowatt, a measure of instantaneous power. A charger's kW rating describes how quickly it can deliver energy under suitable conditions.
kWh: Kilowatt-hour, a measure of energy delivered or stored over time.
Level 1: Low-power AC charging commonly using a standard 120-volt outlet.
Level 2: AC charging commonly using a 208- or 240-volt supply at homes, workplaces, and public destinations.
NACS: North American Charging Standard, a charging connector used by Tesla and adopted by a growing number of vehicle manufacturers and networks.
Networked Charger: A charger connected to software for payment, monitoring, access control, reporting, support, and remote maintenance.
OCPP: Open Charge Point Protocol, a communications standard used between compatible chargers and charging-management software.
Uptime: The percentage of time charging equipment is available and capable of serving drivers.
Utilization: How frequently or how long chargers are actively used over a defined period.