EV fleet charging glossary

Glossary

The terms you will hear when planning charging for a fleet, explained in plain words.

§1 term

§14a EnWG: A rule in the German Energy Industry Act. Since 2024, new controllable devices such as wallboxes above 4.2 kW on a low-voltage connection must let the grid operator reduce their power in a grid emergency, down to at least 4.2 kW. In return the site pays lower grid fees. Smart charging and load management

AC charging: Charging with alternating current. The charger in the vehicle converts AC to DC for the battery, so charging power is limited by that on-board charger, typically 11 kW or 22 kW. Most depot and workplace wallboxes are AC.
AFIR: Alternative Fuels Infrastructure Regulation, EU Regulation 2023/1804, in force since April 2024. It sets rules for public charging, such as paying without a contract and clear prices. Chargers only your own fleet uses are generally not public, but company car parks open to visitors can be.

BEV: Battery electric vehicle. A vehicle that runs only on electricity stored in its battery, with no combustion engine.
Bidirectional charging: Charging that can also send energy from the vehicle back to a building or the grid (vehicle-to-home, vehicle-to-grid). It needs a compatible vehicle and charger.

CCS: Combined Charging System. The standard plug for DC fast charging in Europe. It adds two DC pins below a Type 2 plug, so one inlet handles both AC and DC.
Charge point operator (CPO): The company that runs charging stations: keeping them online, setting prices and handling sessions. A fleet running its own depot chargers is its own CPO.
Charging losses: Energy lost as heat between the grid and the battery, often around 10% for AC charging. You pay for the energy at the meter, so losses belong in any cost calculation. Fleet TCO calculator
Charging profile: Rules for how a vehicle or group of vehicles charges: when, at what power, and to what battery level. Profiles let you favour low cost, speed or a balance of both. Charging schedules
Charging session: One charge from plug-in to unplug, with its start and end time, energy and charger. Session data is the basis for cost reports, reimbursements and spotting faults. Charging monitoring

DC charging: Charging with direct current. The conversion happens in the charger, so power can be much higher than AC, commonly 50 kW and above. Used where vehicles have little time to charge.
Demand charge: A grid fee based on your highest power draw in a billing period (in Germany: Leistungspreis), charged per kW. One short peak can raise the bill for the whole year, which is why depot peaks matter. Load management
Depot charging: Charging fleet vehicles at the company’s own site, usually overnight or between shifts. It is normally the cheapest way to charge a fleet and the easiest to plan. Smart charging and load management
Dynamic load management: Software that shares the available power across chargers in real time, based on the site limit, other consumption and when each vehicle leaves. It keeps the site below its peak without fixed power caps. Load management

Eichrecht: German calibration law. Chargers used to bill energy to someone else, for example drivers or customers, need calibration-law compliant metering so the kWh on the invoice can be verified.

GEIG: Gebäude-Elektromobilitätsinfrastruktur-Gesetz, the German law on charging infrastructure in buildings. It requires cabling for future charge points in new and heavily renovated buildings with larger car parks, and at least one charge point at existing non-residential buildings with more than 20 parking spaces from 2025.
Grid connection: The power capacity your site is allowed to draw from the grid operator. Charging many vehicles at once can exceed it; increasing it can take months and involve significant cost. Smart charging and load management

Home charging reimbursement: Paying back an employee for the electricity used to charge a company car at home. In Germany this can be tax-free, either based on the measured kWh or on a flat rate, under rules that have changed over time. Check the current rules with your tax adviser. Cost and CO₂ reporting

kW and kWh: Kilowatt (kW) is power, how fast energy flows. Kilowatt-hour (kWh) is energy, how much flows. An 11 kW charger running for 2 hours delivers up to 22 kWh. Battery size and electricity bills are in kWh; chargers and demand charges are in kW.

OCPP: Open Charge Point Protocol. The open standard chargers use to talk to a management backend. Versions 1.6 and 2.0.1 are widely used. OCPP lets you control chargers from different manufacturers in one system. Charger control

Peak load: The highest power a site draws at one time. Without load management, peak load is roughly the number of chargers times their power, even if vehicles could charge more slowly.
PHEV: Plug-in hybrid electric vehicle. Has both a combustion engine and a battery that can be charged from the grid, with a shorter electric range than a BEV.
Plug & Charge (ISO 15118): A standard that lets a vehicle identify itself to the charger through the cable, so charging starts without a card or app. It needs a vehicle and charger that both support it.

RLM metering: Registrierende Leistungsmessung: a meter that records your power draw every 15 minutes. Sites using more than 100,000 kWh a year usually have one, and their grid fees then include a demand charge based on the highest 15-minute peak. Load management

Smart charging: Charging that is scheduled and controlled by software instead of starting at full power on plug-in. It takes departure times, energy prices and site limits into account. Charging schedules
State of charge (SoC): How full the battery is, as a percentage. Fleet charging usually targets a minimum state of charge at departure.

TCO: Total cost of ownership. All costs of a vehicle over the time you keep it: purchase, energy, maintenance, tax and incentives. Used to compare electric and combustion vehicles fairly. Fleet TCO calculator
THG quota: Greenhouse gas reduction quota (THG-Quote). In Germany, owners of registered electric vehicles can sell the CO₂ savings of their vehicles each year, usually through a quota trader. The payout changes with the market.
Type 2: The standard AC charging plug in Europe, also called Mennekes. Supports single-phase and three-phase charging, typically up to 22 kW.

Uptime: The share of time a charger is working and available. For a fleet, the uptime that matters most is during the hours vehicles are parked and need to charge. Charging monitoring

Wallbox: A wall-mounted AC charger, common at homes, workplaces and depots. Depot wallboxes are usually 11 kW or 22 kW.

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