EV Charging and BMS Terms Explained

10BASE-T1S

A single-pair Ethernet physical layer designed for multidrop communication. ISO 15118-10:2025 specifies its use for communication between MCS controllers.

AC charging

The vehicle receives alternating current and converts it into battery-side DC.

Conductive charging in which alternating current is supplied to the vehicle and the on-board charger converts it for the traction battery.

Example: the onboard charger controls the conversion during an AC charging session.

Accreditation

Formal recognition that a conformity-assessment body is competent to perform defined activities within a stated scope. Laboratory accreditation is not product certification.

Active balancing

Energy is transferred to reduce differences between cells.

Cell balancing that transfers energy through controlled conversion or switching rather than dissipating most of it as heat.

Example: observe the current transferred during a supported balancing sequence.

Adjustment

Change an instrument to reduce a measurement deviation.

An intervention that changes an instrument so its indication better matches the desired value. Adjustment is separate from calibration and can require a new calibration afterwards.

Example: adjust a supported output, then check it against the reference again.

AFIR

Regulation (EU) 2023/1804 on the deployment of alternative fuels infrastructure. AFIR creates regulatory obligations for infrastructure, access, payment, data and interoperability. It is not one charging protocol or one test case.

Amendment

A formally published change to an existing standard. The base edition and applicable amendments must be stated together when defining a test scope.

Analogue front end (AFE)

This is the measurement circuitry connected to battery-cell signals.

The battery-monitoring electronics that measure cell voltages and related analogue signals and provide protected, conditioned data to the battery controller.

Example: compare a simulated cell voltage with the value reported by the controller.

Annex

A section attached to a standard or regulation. An annex can be normative or informative, so its status must be checked before deriving an acceptance criterion.

Application layer

The protocol layer that defines service messages, state-dependent exchanges and application behaviour above transport and lower communication layers.

Artificial network (AN / LISN)

A defined impedance network inserted between a power or signal port and the test environment to stabilise impedance and provide a measurement connection for conducted disturbances.

Asymmetric artificial network (AAN)

A network used to establish a defined asymmetric impedance and coupling condition for certain communication or signal ports during EMC testing.

Automated standards analysis

Software-supported evaluation that compares measured behaviour with encoded limits, sequences or state rules and highlights deviations. It goes beyond displaying decoded data.

Balancing current

The current used to change the relative state of charge of individual cells during balancing. Its direction, range and measurement method depend on active or passive architecture.

Battery Cell Simulator (BCS)

A test instrument supplies controlled electrical signals in place of real cells.

A test system that creates configurable virtual cell voltages and related sensor signals for BMS validation without using real cells as the primary stimulus.

Example: vary one cell voltage while observing the BMS response.

Battery energy storage system (BESS)

A battery system stores energy for later use.

A stationary or mobile system that stores electrical energy in batteries and includes the battery, BMS, power conversion, protection and supervisory functions required by the application.

Example: test the battery controller with simulated cell and sensor inputs.

Battery management system (BMS)

The controller monitors the battery and manages its operating limits.

The electronic and software system that monitors battery cells, estimates operating states, controls protection and balancing functions, and communicates with the surrounding vehicle or energy-storage system.

Example: a temperature condition leads to the specified charging-current limit.

Battery pack

Cells are assembled into a battery with the required connections and supervision.

An assembled battery system containing cells or modules plus interconnections, sensing, protection, thermal functions and control electronics.

Example: the BMS monitors individual cell signals within the pack.

Bidirectional power transfer (BPT)

A charging capability in which electrical energy can flow both to and from the vehicle under controlled conditions. The use case, grid interface, security and power-electronics capabilities must all support it.

Bulk current injection (BCI)

An immunity method that injects radio-frequency current into a cable harness through a current-injection probe to evaluate susceptibility.

Calibration

Compare a measurement with a reference and report their relationship.

An operation that establishes the relationship between values provided by measurement standards and indications from an instrument under specified conditions. Calibration does not automatically include adjustment.

Example: compare a station’s recorded energy with the reference over the same interval.

Calibration certificate

A controlled document reporting the calibration object, method, conditions, results, uncertainty and traceability information within the issuing laboratory’s scope.

Cell balancing

Manage differences in charge between battery cells.

The BMS function used to reduce differences between individual cell states. It can be implemented through passive dissipation or active energy transfer.

Example: check whether the controller activates balancing on the intended cells.

Cell management controller (CMC / CSC)

A controller supervises a group of battery-cell signals.

A distributed battery controller located close to a group of cells. It measures cell voltages and temperatures, can support balancing, and exchanges data with the central BMS.

Example: supply controlled inputs to one cell-monitoring unit before testing the complete BMS.

Cell short circuit

A fault condition in which a cell path is connected with very low resistance. In a simulator, it is introduced in a controlled manner to test BMS diagnostics and reaction.

Cell voltage simulation

Set the voltage that a controller sees as a battery-cell input.

Controlled generation of the voltage seen by a BMS cell input. Channels must support the required range, accuracy, dynamics, isolation and current behaviour.

Example: lower one simulated cell through the diagnostic threshold.

Certificate chain

An ordered set of digital certificates used to connect an end-entity certificate to a trusted root. Validation includes signatures, validity periods, identities and policy constraints.

Certification

A formal third-party attestation that a defined object meets specified requirements under a certification scheme. A test result, laboratory accreditation or test-system validation is not automatically product certification.

CHAdeMO

A DC charging system with its own connector, communication and charging-control specifications. CHAdeMO communication is commonly based on CAN.

Charge Cycle Automation

Run a series of saved charging configurations.

Automated execution of multiple charging configurations or sessions with controlled parameters, sequencing and result capture.

Example: repeat the same normal-start and stop cases after an update.

Charge Enable (CE)

An MCS low-level signal used as part of the safety-related coordination between vehicle and supply equipment. Its exact states and timing belong to the applicable MCS specifications.

Charge Playback

Use supported recorded behaviour to create a charging partner for another test.

Active physical reproduction of recorded EV or EVSE charging behaviour at the charging interface. It is used to recreate relevant protocol-level behaviour, not merely to reopen a trace file.

Example: reproduce relevant vehicle behaviour after the original vehicle has left.

Charge point operator (CPO)

The organisation responsible for operating charging infrastructure. Its responsibilities can include availability, maintenance, tariffs, access, backend integration and regulatory obligations.

Charging mode

A classification used in IEC 61851 to describe how an EV is connected to the supply and which control and protection functions are involved. Mode numbers are not power classes.

Charging station management system (CSMS)

A backend platform used to monitor, configure and manage charging stations. The CSMS communicates with the charging infrastructure, commonly through a backend protocol such as OCPP.

CharIN Conformance Test System (CCTS)

A test system validated by CharIN for a stated Charging System application profile and approved setup. The validation applies to that defined profile and does not certify the customer DUT.

Combined Charging System (CCS)

A charging system architecture that combines connector arrangements, low-level signalling, high-level communication and AC or DC power transfer. CCS is an ecosystem of specifications, not a single protocol.

Combo 1 and Combo 2

CCS vehicle-coupler arrangements that extend the regional AC connector geometry with additional DC contacts. Combo 1 is associated with Type 1. Combo 2 is associated with Type 2.

Commissioning

Check an installed system before putting it into service.

The structured verification performed when a system is installed or placed into service. It confirms installation, safety, configuration and functional operation against the applicable project requirements.

Example: follow the applicable field procedure and retain the charging-point record.

Conducted disturbance

Unwanted electromagnetic energy that propagates along cables or conductors rather than primarily through radiation.

Conformance

Check whether defined requirements are met for the selected scope.

The degree to which an implementation satisfies defined requirements for a stated standard, edition, role, profile and test scope.

Example: compare a message response with the criterion of a specific test case.

Conformance Test Library

Versioned, executable test logic that turns defined normative requirements into controlled preconditions, actions, observations, verdicts and reports for a released scope.

Controller Area Network (CAN)

A robust serial bus used in vehicles and several charging systems. CHAdeMO and GB/T DC use CAN-based communication, while CCS high-level communication uses other protocol stacks.

CP

A charging-control signal helps the vehicle and station coordinate connection and charging.

The low-level pilot signal used to indicate connection and charging states and, in relevant charging modes, to communicate available current through pulse-width modulation.

Example: record the Control Pilot (CP) state together with the charging messages.

Coulomb counting

Track current over time to determine transferred electric charge.

Estimation of charge movement by integrating current over time. It is commonly used as one input for state-of-charge estimation and balancing validation.

Example: a changing balancing current must be sampled over the relevant interval.

Coupling / decoupling network (CDN)

A network used to couple an EMC test signal into a cable while decoupling auxiliary equipment and establishing a defined impedance.

Cross-Layer State Monitoring

Standards-aware correlation of low-level signals, protocol messages, state transitions, timing and electrical values on one time base. It evaluates whether the combined state is permitted.

DAkkS

Deutsche Akkreditierungsstelle GmbH. Germany’s national accreditation body, responsible for accrediting conformity-assessment bodies within its legal mandate.

Data replay

Offline re-use of recorded measurement or protocol data for visualisation, filtering or analysis. Data replay does not necessarily reproduce the behaviour physically at the DUT interface.

DC charging

The station supplies direct current for charging the vehicle battery.

Conductive charging in which the EVSE supplies controlled direct current to the vehicle battery. The EV and EVSE coordinate limits, safety and charging progression.

Example: compare the requested DC current with the station’s measured output.

Device under test (DUT)

The device you are testing.

The specific device, subsystem or complete product being evaluated. The DUT boundary must be stated because it determines the simulated counterpart, interfaces, measurements and acceptance criteria.

Example: in a charger test the station is the DUT and a simulator can act as the vehicle.

Digital twin

A digital representation of a physical system or behaviour. In testing, the term is meaningful only when the represented boundary, inputs, fidelity and update method are defined.

DIN SPEC 70121

A communication specification used for DC charging in early CCS implementations. It defines EVCC-to-SECC network and application communication for its stated scope.

Edition

A formally identified version of a standard. Edition, publication year and amendments are part of the test identity because requirements can change between releases.

Efficient XML Interchange (EXI)

A compact binary representation of XML information used in ISO 15118 message exchange to reduce bandwidth and processing overhead.

Eichrecht

The German legal-metrology framework for measuring instruments used in regulated applications, including billing-relevant energy measurement at charging infrastructure where applicable.

Electric vehicle communication controller (EVCC)

The vehicle-side controller for the charging conversation.

The vehicle-side controller that performs high-level charging communication with the SECC. Its functions depend on the applicable ISO 15118, DIN or related communication profile.

Example: observe how it communicates a changed battery limit.

Electric vehicle (EV)

The electric vehicle receiving or supplying energy through the charging connection.

The vehicle-side system connected to charging equipment. In a test definition, EV can mean the complete vehicle or a controlled vehicle-side subsystem such as the OBC and EVCC.

Example: test a real EV against a simulated charging station.

Electric vehicle supply equipment (EVSE)

The equipment that provides the vehicle’s charging connection and associated functions.

The equipment that supplies electrical energy to an EV and manages the conductive charging interface. EVSE is a technical equipment boundary and is not automatically identical to an entire charging site.

Example: test a charging station with a simulated vehicle.

Electromagnetic compatibility (EMC)

Equipment must work in its electromagnetic environment without causing unacceptable disturbance.

The ability of equipment to operate satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbance to other equipment.

Example: investigate charging behaviour while a defined disturbance is applied.

Electromagnetic interference (EMI)

Electromagnetic disturbance that degrades the performance of equipment, a transmission channel or a system. EMI describes the interference phenomenon. EMC describes compatible operation.

EMC Link

A fibre-optic transmission system that carries selected charging signals and communication transparently across an EMC chamber boundary. It does not create the RF disturbance or replace laboratory EMC equipment.

Emissions

Disturbances produced by the equipment.

Electromagnetic energy produced by equipment and evaluated against limits for conducted or radiated disturbance.

Example: measure disturbances from the charging system under the selected test method.

Emulation

Reproduction of the externally visible behaviour of a real component or system, often with higher interface fidelity than a purely mathematical model.

End-of-line (EOL) testing

Repeatable verification performed at the end of a production process to detect assembly, configuration and functional defects before release.

Environmental conditions

Temperature, humidity, supply conditions and other influences that can affect a measurement or test. Relevant conditions must be controlled, monitored or included in the uncertainty assessment.

External Identification Means (EIM)

A charging authorisation route in which the user is identified by a mechanism outside the automatic Plug & Charge certificate flow, for example an app, card or payment interaction.

Fault injection

Deliberately create a supported fault condition for a controlled test.

Deliberate introduction of a controlled electrical, signal, communication or sensor fault to verify detection, reaction, safety and recovery behaviour.

Example: simulate a sensor-wire interruption with suitable test hardware.

Fault Simulation Unit (FSU)

A controlled switching unit used to introduce defined faults such as open wires, short circuits or polarity conditions into BMS test paths.

Flicker

Perceptible or measurable voltage fluctuation effects associated with changing loads. Flicker assessment belongs to power-quality and grid-interaction testing.

Gateway

A system positioned between communication participants that forwards, translates, records or controls traffic. The exact transparency and manipulation capability must be stated.

GB/T DC

A Chinese DC charging system defined through the relevant GB/T standards. It uses its own coupler, low-level behaviour and CAN-based communication sequence.

Hardware-in-the-loop (HiL)

Connect a real controller to simulated surroundings.

A test method in which real hardware interacts in real time with simulated components or environments through controlled interfaces.

Example: the BMS receives simulated cell values while its actual software runs.

Harmonic current emissions

Current components at integer multiples of the fundamental frequency produced by non-linear loads. They are evaluated under the applicable power-quality requirements.

High-level communication (HLC)

The structured digital conversation used to coordinate charging.

Structured digital communication between EVCC and SECC for services such as parameter negotiation, charging control, authentication and scheduling. HLC describes the logical exchange, not the physical carrier alone.

Example: compare a requested charging value with the corresponding response.

High-power charging (HPC)

A market term for charging at elevated power. It does not by itself define one connector, protocol or normative power threshold, so the actual interface and ratings must be stated.

High-voltage interlock loop (HVIL)

A low-voltage monitoring loop used to detect whether high-voltage connectors, covers or service points are correctly closed.

HomePlug Green PHY

A power-line communication technology used as a lower communication layer in CCS charging. It supports link establishment through mechanisms including SLAC.

IEC 61851-21-1

The IEC standard for EMC requirements of an EV on-board charger, tested at vehicle or electronic-subassembly level while conductively connected to the supply.

IEC 61851-21-2

The IEC standard for EMC requirements of off-board conductive charging equipment, including defined ports, operating modes and test setups.

Immunity

The ability to continue the required operation when disturbances are applied.

The ability of equipment to maintain acceptable performance when exposed to a defined electromagnetic disturbance.

Example: observe the specified response during an EMC test.

Implementation guideline

A document that explains how standards should be combined or applied within an ecosystem. Its authority and normative status must be checked separately from the referenced standards.

Insulation monitoring device (IMD)

A device that monitors insulation resistance between a high-voltage system and protective earth or chassis.

Interoperability

Different products work together as intended.

The ability of independently developed implementations to work together under defined conditions. Interoperability testing complements conformance testing by exposing integration behaviour across real counterparts.

Example: investigate a vehicle and station that each work elsewhere but fail as a pair.

ISO 15118

A family of standards for communication between EVCC and SECC. Different parts define use cases, network and application communication, lower layers, security-related functions and conformance testing.

ISO/IEC 17025

The international standard specifying competence, impartiality and consistent operation requirements for testing and calibration laboratories. Accreditation applies to the published laboratory scope.

Leakage current

Unintended current flowing through a path that should ideally be non-conductive or inactive. In BMS testing, small leakage currents can reveal faulty outputs or deactivation behaviour.

Legal metrology

Regulatory control of measurements and measuring instruments used where accuracy has legal, economic, health or public-interest consequences.

Man-in-the-Middle (MitM)

A position between communicating partners used here for charging measurement or supported intervention.

A measurement or test position between two real communication participants. Depending on implementation it can passively observe or actively influence the exchange.

Example: record the real vehicle and station without substituting either partner.

Manipulating Gateway

An active gateway that can modify, suppress or replace selected communication content while the participants remain connected. It is used to validate suspected causes without immediate DUT firmware changes.

Measurement result

The reported quantity value together with the information needed to interpret it, including unit, uncertainty or decision rule where relevant, and measurement conditions.

Measurement trace

A time-ordered record of measured values, messages, events or states. A useful trace retains units, channels, timestamps, configuration and source identity.

Measurement uncertainty

The reported result has a quantified uncertainty, not an infinitely precise value.

A non-negative parameter that characterises the dispersion of quantity values attributed to a measurement result. It expresses measurement doubt, not a mistake correction.

Example: include the reference uncertainty when judging an energy comparison.

Megawatt Charging System (MCS)

A charging system developed for very high-power vehicle charging.

A charging system for high-power heavy-duty applications. Current normative routes combine the MCS coupler, low-level signals, ISO 15118-10 communication and ISO 15118-20 application-layer functions.

Example: specify truck-side communication, current, voltage and cooling together.

Metrological traceability

A property of a measurement result whereby it can be related to a reference through a documented, unbroken chain of calibrations, each contributing to measurement uncertainty.

Metrological verification

Evaluation that a measuring instrument satisfies specified legal or technical metrological requirements. It is distinct from calibration, even when calibration data supports the decision.

Mobility service provider (eMSP)

A service provider that gives drivers access to charging services, contracts, authentication and billing across one or more charging networks.

NACS / SAE J3400

The North American Charging System standardisation route for conductive AC and DC power transfer through a compact coupler. SAE J3400 covers more than connector shape and includes electrical, functional, safety and performance requirements.

Normative and informative

Normative content contains requirements or provisions needed for compliance with the document. Informative content explains, illustrates or guides and is not itself a mandatory requirement unless referenced normatively.

NTC / PTC sensor simulation

Represent temperature-dependent sensor resistance with a controlled electrical input.

Electrical emulation of negative- or positive-temperature-coefficient sensor behaviour so that BMS temperature inputs can be tested over valid and faulty conditions.

Example: simulate a high-temperature indication and observe the BMS diagnostic response.

OIML G 22

An OIML guide for electric vehicle supply equipment intended to support harmonised legal-metrology treatment of EV charging measurements. It is being used as a basis for further OIML recommendation work.

On-board charger (OBC)

The vehicle equipment that converts AC input into DC for the battery.

Vehicle power electronics that convert external AC power into the DC power required by the traction battery. During DC charging, the external EVSE normally performs the main power conversion.

Example: check whether its electrical response follows the battery’s charging limit.

Open Charge Point Protocol (OCPP)

A protocol between charging stations and a management backend. OCPP is not the EV-to-EVSE charging-interface protocol and must be tested at a different system boundary.

Open-circuit voltage (OCV)

The voltage of a cell or battery measured without an applied load after the relevant settling conditions. OCV can be related to state of charge, chemistry and temperature.

Open-wire fault

A measurement or sensor connection is interrupted.

A broken or disconnected sensing path between a cell and the BMS measurement input. Test systems reproduce this fault to verify diagnostics and safe reaction.

Example: check whether the controller detects the simulated missing connection.

PASS / FAIL / inconclusive

Verdict classes for a test case. PASS means the observed result met the defined criterion. FAIL means it did not. Inconclusive means the available evidence cannot support either conclusion for the stated case.

Passive balancing

Energy is removed from selected cells to reduce their imbalance.

Cell balancing that removes energy from higher-voltage cells, commonly by dissipating it through resistive paths.

Example: measure the balancing current and how long it flows.

Physical layer

The layer that transports raw signals over the physical medium. Examples include PLC for CCS and 10BASE-T1S for MCS controller communication.

Plug & Charge (PnC)

Certificate-based identification and authorisation defined within the ISO 15118 ecosystem. It requires coordinated certificate, PKI, EV, EVSE and backend functions.

Polarity reversal

A condition in which a simulated cell or sensor connection is applied with reversed polarity. It is used to verify input protection, diagnostics and assembly-fault handling.

Power line communication (PLC)

Communication transmitted over conductors that also serve another electrical function. In CCS, PLC carries the lower-layer communication used by HLC.

Power quality

Characteristics of voltage and current at the grid interface, including harmonics, power factor, fluctuations and flicker, as applicable to the equipment and installation.

Power transfer interface

The physical and electrical boundary through which charging energy flows. It includes rated voltage and current, contact arrangement, protection, isolation and connection conditions.

Pre-compliance testing

Testing performed before formal certification or scheme testing to find implementation gaps and reduce the risk of later failure. It does not replace the formal process.

Profile

A defined subset or combination of standards, functions and options used for a particular application or test programme. Profile identity prevents ambiguous claims of general compliance.

Protocol stack

The coordinated set of communication layers used by an implementation, from physical and data-link functions through transport, security and application behaviour.

PP

A signal associated with the charging connection and cable context.

A low-level circuit used for connection and cable-related information. Its implementation and interpretation depend on the coupler system.

Example: observe the relevant Proximity Pilot (PP) state along with the connection sequence.

Pulse-width modulation (PWM)

A method that encodes information through the duty cycle of a periodic signal. At the charging interface, CP PWM is used in defined IEC 61851 charging states.

Quiescent current

The current consumed by a device in a defined inactive or low-power state. BMS quiescent-current measurement helps detect excessive drain during shutdown.

Radiated disturbance

Electromagnetic energy that propagates through space and is measured or applied using antennas and defined field conditions.

Radio-frequency immunity

Testing that exposes equipment or cables to a defined RF field or injected RF current to evaluate functional resilience.

Reference standard

A measurement standard used as a reference for calibrating other instruments or standards. Its status, uncertainty and traceability must be controlled.

Regression test

Repeat established tests after a change.

A repeated test used to detect unintended changes after software, firmware, hardware or configuration updates.

Example: run the same charging configurations before and after a firmware update.

Reproducibility

The ability to obtain consistent results when a defined test is repeated under stated conditions, potentially with changed operators, systems or locations.

REST API

A software interface lets programs exchange commands and data using web-style requests.

A web-style application programming interface used to control functions or exchange data between systems. In a test environment it can connect external automation with comframe and supported hardware functions.

Example: a test application selects a configuration and retrieves its result through supported commands.

Robustness

The ability of a system to continue operating safely and predictably when inputs, timing, counterparts or environmental conditions vary within and beyond expected ranges.

Safety inspection

A structured examination and test of safety-relevant installation and equipment conditions. It is not identical to metrological calibration or protocol conformance testing.

SECC Discovery Protocol (SDP)

The discovery procedure used by an EVCC to obtain communication parameters for the SECC before the main high-level communication session begins.

Signal Level Attenuation Characterization (SLAC)

A HomePlug Green PHY procedure used to match the EV and EVSE communication endpoints based on measured signal attenuation.

Simulation

Create controlled behaviour to stand in for part of the real environment.

Controlled generation of modelled signals, states, messages or electrical behaviour to represent a counterpart or environment for the DUT.

Example: a charging tester acts as a vehicle while the real station is tested.

Sniffer

A passive observation function that captures communication without intentionally changing the exchange. Decryption or application-level visibility depends on the protocol and access method.

Standard

A consensus document published by a recognised standards organisation. A standard must be identified by number, part, edition and amendments before it can be converted into a test scope.

State of charge (SOC)

An estimate of how much charge remains relative to the battery’s defined capacity.

An estimate of the remaining usable charge relative to a defined full-charge reference. SOC is calculated, not directly measured as one physical quantity.

Example: observe how the BMS estimate changes with the simulated current history.

State of health (SOH)

An estimate of battery condition relative to a defined reference, often considering capacity, resistance, power capability or ageing indicators.

State of power (SOP)

An estimate of the charge or discharge power that can be delivered or accepted under current limits, temperature, SOC and system constraints.

Supply equipment communication controller (SECC)

The charging-station-side controller for the charging conversation.

The EVSE-side controller that performs high-level charging communication with the EVCC and coordinates the communication-dependent charging sequence.

Example: check its response to a supported vehicle request.

Test automation

Software-controlled preparation, execution, evaluation and documentation of tests. Automation is only reliable when versions, limits, safety conditions and verdict logic remain explicit.

Test case

A defined starting condition, action and expected response.

A defined set of preconditions, stimuli, observations, expected results and verdict logic used to evaluate one requirement or behaviour.

Example: specify the message and timing criterion before running the test.

Test chamber

A controlled environment, commonly shielded or anechoic, used to create repeatable electromagnetic test conditions and reduce external influence.

Test coverage

The defined portion of requirements, states, cases, interfaces or risks exercised by a test programme. Coverage is not implied by the number of executed tests alone.

Test equipment monitoring

Planned control of equipment status, calibration validity, checks, maintenance and environmental suitability to keep test results reliable.

Test report

A controlled document that records the test object, method, configuration, results, deviations and evidence needed to interpret the conclusion.

Test system

The complete controlled setup used to stimulate, measure and evaluate a DUT. It can include hardware, interfaces, software, loads or sources, safety functions, test logic and reporting.

Time correlation

Put measurements and messages on a common time reference.

Alignment of measurements, protocol events and state changes to a common time base so that cause and effect can be analysed across layers.

Example: determine whether a changed request preceded or followed the measured current change.

Traceability

The ability to follow a result back to the DUT, configuration, method, software, equipment, raw evidence and applicable requirement. Metrological traceability is a more specific measurement concept.

Transient immunity

The ability to withstand short-duration electrical disturbances such as bursts, surges or electrostatic discharge under the applicable test method.

Transport Layer Security (TLS)

A security protocol that protects communication through authentication, integrity and encryption where required by the active charging profile.

Trigger

A defined event or condition that starts data capture, a test action or a sequence transition. Accurate trigger definition is essential for time-related analysis.

Type 1 and Type 2

AC vehicle-coupler families used in different regions. Type 1 is associated with single-phase North American and Japanese applications. Type 2 is widely used in Europe and supports single-phase or three-phase charging.

UN Regulation No. 10 (ECE R10)

A UNECE vehicle type-approval regulation covering electromagnetic compatibility of vehicles and electronic subassemblies. It is a separate regulatory route from IEC charging-equipment EMC standards.

Validation

Evidence that a system, method or implementation is suitable for its defined intended use or stated profile. The object and scope of validation must always be named.

Vehicle connector

The part of a vehicle coupler attached to the flexible cable and intended to mate with the vehicle inlet.

Vehicle coupler

The combined connector-and-inlet arrangement that establishes the conductive connection between EV and EVSE.

Vehicle inlet

The vehicle-mounted part of the coupler that receives the vehicle connector.

Vehicle-to-Grid Transport Protocol (V2GTP)

A framing protocol used to carry charging-protocol payloads over the network connection between EVCC and SECC.

Vehicle-to-Grid (V2G)

A broad term for interaction between an EV and the energy system. Depending on context it can mean communication, managed charging or actual bidirectional energy transfer.

Verdict

The evaluation assigned to a particular test result.

The formal result assigned after comparing observed behaviour with the acceptance logic of a test case. A verdict is attributable only to the recorded scope and configuration.

Example: PASS applies to the stated criterion, not automatically to the whole product.

Verification interval

The time or use interval after which an instrument must be reverified, recalibrated or otherwise confirmed according to the governing rule or quality process.

Virtual battery cell

A controlled electrical representation used instead of a real cell in a test.

A programmable electrical representation of a cell used to provide reproducible voltage, current and fault behaviour to a BMS input.

Example: vary its voltage without changing physical battery chemistry.

Voltage fluctuations

Changes in supply voltage caused by varying load demand. Depending on magnitude and repetition, they can be assessed together with flicker.

X.509 certificate

A structured digital certificate that binds an identity or role to a public key and is signed within a public-key infrastructure. It is used in secure charging and Plug & Charge workflows.