EV Charging Glossary

Plain-language definitions for the terms that matter.

A

Ampere (Amp): A unit of electrical current. In EV charging, amperage determines how much power flows through the circuit. A 48-amp Level 2 charger on a 240V circuit delivers about 11.5 kW (48A × 240V). Common residential EV charging circuits are 30A (for 24A chargers), 40A (for 32A chargers), or 60A (for 48A chargers) — the circuit breaker is sized at 125% of the charger's rated draw per NEC requirements. Higher amperage means faster charging.

C

CCS: Combined Charging System. A DC fast charging connector standard that combines a J1772 AC port with two additional DC pins below it, enabling both Level 2 AC and DC fast charging through a single port. CCS1 is the North American variant. Prior to the NACS transition, CCS was the DC fast charging standard used by most non-Tesla automakers in the US. Many newer EVs are switching from CCS to NACS, though existing CCS infrastructure remains widely deployed.
CFI: Charging and Fueling Infrastructure grant program. A federal competitive grant program administered by the Federal Highway Administration (FHWA) that funds EV charging in communities and along corridors. CFI is broader than NEVI — it covers community locations (schools, parks, transit hubs), workplace sites, and properties serving underserved communities. The program runs in annual solicitation rounds, with up to 80% cost coverage and matching requirements. Government entities, nonprofits, and private property owners in qualifying communities are eligible.
Circuit Breaker: An automatic electrical switch that interrupts current flow when a fault or overload is detected. EV charger circuits require a dedicated circuit breaker sized at 125% of the charger's rated amperage — a 48A charger requires a 60A breaker. The National Electrical Code (NEC) requires this oversizing because EV charging is a continuous load (running for 3+ hours). The breaker lives in your electrical panel and is the last line of defense against overloaded wiring.

D

DC Fast Charging: High-power public charging that delivers direct current (DC) electricity at 50–350+ kilowatts, adding 150–250+ miles of range in 20–40 minutes. Unlike Level 1 and Level 2 chargers (which supply AC power that the car's onboard charger converts to DC), DC fast chargers bypass the onboard charger and push DC directly into the battery pack. Also called Level 3 charging or DCFC. Not available for home installation — requires utility-grade electrical infrastructure.
Demand Charge: A component of commercial electricity billing that charges based on the peak power draw (in kilowatts) during a billing period, rather than just total energy consumed. A cluster of EV chargers starting simultaneously can spike peak demand significantly, generating a large demand charge that dwarfs the actual energy cost. Load management software mitigates this by staggering charger start times and capping simultaneous draw. Demand charges are a major consideration in commercial EV charging economics but do not apply to most residential electricity customers.

E

Electrical Panel: The metal enclosure in your home or building that distributes electricity from the utility to individual circuits through circuit breakers. Also called a breaker panel, load center, or service panel. The panel's amperage rating (typically 100A, 150A, or 200A in residential settings) determines total electrical capacity. Installing a Level 2 EV charger requires an available circuit breaker slot and sufficient panel capacity. A 200A panel with modern appliances typically has headroom for a 48A EV charger; a 100A panel may not.
EVSE: Electric Vehicle Supply Equipment. The technical term for what most people call an EV charger. Strictly speaking, the EVSE doesn't actually charge the battery — it safely supplies AC electricity and communicates with the vehicle via a pilot signal. The onboard charger inside the vehicle converts the AC power to DC and manages the charging process. The EVSE handles safety functions: it doesn't energize the cable until a vehicle is properly connected, and it cuts power immediately if the connection is broken.

G

GFCI: Ground Fault Circuit Interrupter. A safety device that monitors current flowing through a circuit and cuts power within milliseconds if it detects current leaking to ground — preventing electrocution. The NEC requires GFCI protection for EV charging equipment in certain locations, particularly outdoor installations and garages. GFCI protection can be built into the outlet, the circuit breaker, or the EVSE itself. Most UL-listed Level 2 chargers include integrated GFCI protection.

I

IRA: Inflation Reduction Act. The 2022 federal legislation that significantly expanded clean energy tax credits, including EV charging incentives. Key IRA provisions for EV charging: (1) Extended and expanded the 30C tax credit through 2032, raising the commercial per-port cap to $100,000; (2) Created bonus credit adders of 10–20 percentage points for projects in low-income communities and energy communities; (3) Made energy credits transferable, allowing entities without sufficient tax liability to sell credits to investors; (4) Created direct pay (cash equivalent) for tax-exempt organizations.

J

J1772: The SAE J1772 standard defines the connector used for Level 1 and Level 2 AC charging in North America. Often called the J-plug or Type 1 connector. All plug-in vehicles sold in the US have historically included a J1772 port (or an adapter), making it the universal home charging connector before the NACS transition. Vehicles using CCS for DC fast charging have a J1772 port with two additional DC pins added below — called the CCS1 combo connector.

K

Kilowatt (kW): A unit of power equal to 1,000 watts. In EV charging, kilowatts describe the rate at which power is delivered. A 7.2 kW charger delivers energy faster than a 3.3 kW charger. A Level 2 home charger typically operates at 7–11 kW. DC fast chargers operate at 50–350+ kW. The higher the kilowatt rating, the faster a given battery will charge — up to the vehicle's maximum acceptance rate.
Kilowatt-hour (kWh): A unit of energy equal to consuming one kilowatt of power for one hour. In EVs, kilowatt-hours measure battery capacity — a 75 kWh battery holds more energy than a 40 kWh battery. kWh also measures electricity consumption for billing purposes: if your utility charges $0.15/kWh, charging a 75 kWh battery from empty costs about $11.25. A vehicle's efficiency is often expressed in miles per kWh (e.g., 4 mi/kWh) or kWh per 100 miles.

L

Level 1 Charging: EV charging using a standard 120-volt household outlet. Every plug-in vehicle sold in the US includes a Level 1 cable (formally called an EVSE cord set) that plugs into any standard outlet. Level 1 adds approximately 4–5 miles of range per hour, making it adequate for plug-in hybrids and low-mileage drivers but impractical for battery-electric trucks or drivers covering more than 40 miles per day.
Level 2 Charging: EV charging using a 240-volt circuit — the same voltage used by electric dryers and ranges. Level 2 chargers add 15–37 miles of range per hour depending on amperage and the vehicle's onboard charger capacity. Requires a dedicated 240V circuit installed by a licensed electrician. Level 2 is the standard for home EV charging and most commercial workplace, multifamily, and hospitality installations.
Load Calculation: An engineering assessment of how much electrical capacity a home or building currently uses versus what its service can support. Electricians perform load calculations per NEC Article 220 to determine whether a panel can accommodate a new circuit. The calculation applies demand factors — recognizing that not all appliances run simultaneously — which often reveals more available capacity than a simple breaker-count suggests. A load calculation is the definitive answer to whether you need a panel upgrade for EV charging.
Load Management: A system that monitors total electrical load and automatically adjusts EV charging speed to prevent circuit or panel overloads. At the residential level, load management devices (such as the Emporia Vue or Span Smart Panel) can allow a 48A charger to operate on a panel that would otherwise require an upgrade — by reducing charging speed when high-draw appliances like HVAC or the dryer are running. In commercial deployments, load management software prevents clusters of chargers from drawing peak power simultaneously, reducing demand charges.

M

Make-Ready: Utility programs that fund the electrical infrastructure needed for EV charging — panel capacity, conduit, and wiring to junction boxes — separately from the charging hardware itself. Make-ready programs separate infrastructure cost (funded by the utility) from equipment cost (paid by the property owner or funded by grants). This makes the project economics cleaner and allows future hardware expansion without additional electrical work. Major utilities offering make-ready programs include PG&E, SCE, National Grid, Con Edison, Xcel Energy, and Duke Energy.

N

NACS: North American Charging Standard. The connector type developed by Tesla and adopted by most major automakers as the new standard for EV charging in North America. Formerly known as the Tesla connector, NACS was opened to the industry in 2022 and formalized as SAE J3400 in 2023. Most new non-Tesla EVs are transitioning to NACS connectors, and most public charging networks are adding NACS cables.
NEC: National Electrical Code. The benchmark standard for safe electrical installation in the United States, published by the National Fire Protection Association (NFPA 70) and updated every three years. Article 625 of the NEC specifically governs electric vehicle charging equipment installation — covering conductor sizing, GFCI protection requirements, ventilation, and continuous load calculations. Most states adopt the NEC with local amendments. A licensed electrician installing EV charging equipment is required to follow NEC Article 625.
NEMA 14-50: A 240-volt, 50-amp four-prong outlet standard — the same type used for electric ranges. Many Level 2 EV chargers are sold in plug-in versions that terminate in a NEMA 14-50 plug, allowing installation without hardwiring directly to the electrical system. Installing a NEMA 14-50 outlet requires a dedicated 50-amp circuit (with a 50A breaker), which an electrician installs the same way as a hardwired charger circuit. The NEMA 14-50 option provides flexibility to move the charger if needed.
Network Platform: Software that manages commercial EV charging infrastructure — handling session authorization, billing, remote monitoring, usage reporting, and load management. Major commercial network platforms include ChargePoint, EV Connect, Blink, and Greenlots (Shell Recharge). Networked chargers communicate with the platform via OCPP or proprietary protocols. Network platforms typically charge per-port monthly fees ($150–$300/port/year) in addition to hardware costs. For any commercial deployment where billing or access control is required, a networked charger and platform are necessary.
NEVI: National Electric Vehicle Infrastructure Formula Program. A $5 billion federal program created by the 2021 Bipartisan Infrastructure Law to fund DC fast charging along designated highway corridors (Alternative Fuel Corridors). NEVI funds flow to state DOTs, which run competitive grant processes for property owners and operators. Eligible projects must install DC fast chargers rated at minimum 150 kW per port, with at least 4 ports per site, publicly accessible, within 1 mile of a designated corridor exit. NEVI covers up to 80% of eligible project costs.

O

OCPP: Open Charge Point Protocol. An open communication standard between EV charging hardware and network management software. OCPP allows chargers from different manufacturers to connect to network platforms from different vendors — preventing hardware lock-in. Versions 1.6 and 2.0.1 are the most widely deployed. Commercial charging deployments that use OCPP-compliant hardware can switch network software providers without replacing equipment. OCPP is the commercial EV charging industry's answer to interoperability.
Onboard Charger: The component inside an electric vehicle that converts AC electricity from a Level 1 or Level 2 charger into DC electricity that the battery can store. The onboard charger's maximum power rating (measured in kW) determines how fast the car can charge from AC sources, regardless of how powerful the external charger is. A car with a 7.2 kW onboard charger will charge at 7.2 kW even if connected to an 11.5 kW charger. DC fast charging bypasses the onboard charger entirely.

P

Prevailing Wage: Under the Inflation Reduction Act, EV charging projects that pay construction workers at least the locally prevailing wage (per Davis-Bacon Act standards) and use qualified apprentices earn the full 30% IRA tax credit rate. Projects that do not meet prevailing wage and apprenticeship (PWA) requirements are subject to a reduced base credit rate. For commercial installations where the 30C credit represents significant dollars, meeting PWA requirements is typically worth the compliance overhead. Prevailing wage rates by location and trade are published by the US Department of Labor.

R

Range Anxiety: The concern that an electric vehicle will run out of charge before reaching a destination or charging station. Range anxiety was a significant barrier to EV adoption in the early 2010s when most EVs offered under 100 miles of range and public charging was sparse. Modern battery-electric vehicles with 250–400+ mile range and the expanded Supercharger and Electrify America networks have substantially reduced range anxiety for most driving patterns. Home charging nearly eliminates range anxiety for daily use by ensuring a full battery every morning.

S

Smart Charging: EV charging that uses software to optimize when, how fast, and at what price charging occurs. Smart charging capabilities include scheduled charging (starting at off-peak times), load management (reducing speed when other loads spike), remote monitoring, and dynamic pricing response. Smart chargers require a network connection (Wi-Fi) and a companion app or platform. For residential use, the most valuable smart feature is scheduled charging for time-of-use rate savings. For commercial use, load management to control demand charges is often the most financially significant capability.
State of Charge (SOC): The current charge level of an EV battery expressed as a percentage of its total capacity. A fully charged battery is at 100% SOC; a depleted battery is at 0%. Most EV manufacturers recommend keeping daily charging to 80% SOC to reduce battery stress at the top of the charge range, and avoiding regular deep discharge below 10–20%. Charging from 20% to 80% (the middle of the SOC range) is both faster and gentler on the battery than charging from near-empty to full.

T

Time-of-Use Rate: A utility electricity pricing structure that charges different rates depending on the time of day. Off-peak hours (typically overnight, 9pm–7am) carry lower rates — often $0.07–$0.12/kWh — while peak hours (afternoon and early evening) carry higher rates. EVs are ideal time-of-use customers because overnight charging is natural. Enrolling in a TOU plan and scheduling charging during off-peak windows typically cuts EV electricity costs by 30–50% compared to flat-rate billing.

U

Utilization Rate: In commercial EV charging, the percentage of available charging capacity that is actively in use during a given period. Calculated as: (actual kWh delivered) ÷ (maximum possible kWh if all ports ran continuously). A site with 4 Level 2 ports at 40% utilization is delivering roughly 40% of the electricity it could theoretically deliver. New commercial installations typically start at 15–25% utilization as local EV adoption builds, rising to 50–70% at mature, well-positioned sites. Utilization is the primary variable in commercial EV charging ROI models.

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