OBC Test — On-Board Charger Verification

What Is OBC?

The OBC (On-Board Charger) test verifies the vehicle-resident unit that converts energy taken from the AC mains into direct current to charge the high-voltage battery. Since it is a mains-connected device, power quality (harmonics, power factor) and grid compatibility are additionally important.

Purpose of OBC

The purpose is to verify that the OBC can charge at its declared power and efficiency under different mains conditions, does not emit harmonics beyond acceptable limits into the mains, and maintains the insulation barrier.

Which Products Is OBC Applied To?

Single-phase and three-phase on-board chargers
Bidirectional (V2G/V2L-capable) OBC units
Integrated power-electronics modules (OBC + DC/DC)
Light electric vehicle charging units

In Which Sectors Is OBC Used?

AutomotiveElectrical & ElectronicsEnergy

Standards Related to OBC

IEC 61851-21-1
IEC 61000-3-2harmonic current emission test
IEC 61000-3-12
UNECE R10electromagnetic compatibility in vehicles test
CISPR 25Radio degradation of in-car components test
ISO 6469-3

OBC Conditions

Mains conditions: Within the declared voltage and frequency range; verification at the lower and upper limits
Charging profile: Efficiency and power factor are measured throughout the constant-current and constant-voltage phases
Harmonics: Mains current harmonics per the IEC 61000-3-2 or -3-12 limits

Equipment for OBC

Programmable AC source (mains simulator)
Battery emulator or electronic load
Power analyser and harmonics analyser
Dielectric-strength and insulation tester
EMC test rig
Cooling conditioning unit

Sample Requirements for OBC

OBC unit and wiring harness
Cooling interface
The declared input voltage range, number of phases and output power must be stated
The control interface and charging-protocol definition must be provided

Duration of OBC

Electrical performance and power-quality verification takes a few days; together with EMC and environmental tests, several weeks.

OBC Procedure

1Unit description and rated values are recorded.
2Insulation and dielectric strength are measured.
3Mains voltage and output load are swept to measure efficiency.
4Power factor and current harmonics are measured.
5Behaviour is monitored throughout the charging profile.
6Protective functions (overvoltage, loss of mains, over-temperature) are verified.
7EMC emission and immunity tests are applied.

OBC Acceptance Criteria

The harmonics and power-factor acceptance criteria are the IEC 61000-3-2 / -3-12 limits. Efficiency and power targets are evaluated per the customer's specification; the UNECE R10 and CISPR 25 limits apply on the EMC side.

Evaluation of Results

Efficiency, power factor and harmonic distortion are evaluated together. Power-factor degradation at low load is a common finding and affects mains compatibility.

OBC Report

Unit description and rated values
Efficiency and power-factor measurements
Harmonics-analysis results and limit comparison
Insulation measurements
EMC and protective-function results

Accreditation

EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.

Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.

Scope and authorisations

Related Regulations

UNECE R10
IEC 61000 series power-quality requirements

Otomotiv Testleri — What Does This Testing Field Cover?

The section below describes the field that the OBC test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.

Automotive testing shows that a component keeps working under conditions representing the loads it will meet over the life of the vehicle. A vehicle is not a single product but an ENVIRONMENT: vibration, temperature cycling, salt water, stone impact, electrical transients and electromagnetic noise are all present at the same time and for years.

What distinguishes this family is that VEHICLE MANUFACTURER SPECIFICATIONS sit on top of the standards. ISO and SAE publications establish the common ground; but Volkswagen, BMW, Ford, Stellantis, Toyota and Renault define different severity levels, additional tests and different acceptance criteria in their own specifications. For a component, the phrase "complies with automotive standards" is not sufficient on its own; which manufacturer's specification, and which revision of it, must be answered.

The family carries three separate processes together and they are often confused. Homologation covers the type approvals a vehicle needs to enter traffic and runs under state authority. Supplier approval means passing the vehicle manufacturer's own quality and testing requirements and is a commercial relationship. The third is design verification: the engineering team demonstrating that its own design meets its targets.

At component level the test plan is built around the LOCATION OF USE. A module in the engine bay and a module in the boot do not go through the same temperature and vibration profile; a component inside a door and one in the roof console do not see the same water and dust exposure. The ISO 16750 series is the common framework for this location-based approach.

The shift to electric vehicles has reshaped the field. High-voltage safety, insulation coordination, battery safety, charging interface conformity and the electromagnetic behaviour of high-voltage components have been added to the classical automotive test set. In a quiet vehicle, acoustic and vibration expectations have changed too; sounds once masked by the combustion engine are now audible.

The quality system side cannot be separated from testing in this field. A manufacturer under IATF 16949 presents test results in the PPAP file; measurement system analysis, process capability study and the control plan stand around the test report. A single good result is not enough — the process must be shown to be able to repeat it.

Method groups in this field

Environmental and climatic
Temperature cycling, thermal shock, damp heat, salt spray, dust and water ingress (IP), solar radiation. Severity levels vary with the mounting location.
Mechanical
Sine and random vibration, shock, mechanical loads, fastener torque and durability cycles.
Electrical
Supply voltage variations, transients (ISO 7637), reverse polarity, overvoltage, short circuit and sleep current measurements.
EMC
Component emissions (CISPR 25), radiated and conducted immunity (ISO 11452 series), electrostatic discharge (ISO 10605).
Materials and emissions
Odour, fogging and VOC emissions from interior materials; flammability; UV ageing; coating durability and stone impact.
Functional safety and cyber security
Functional safety evidence under ISO 26262 and cyber security engineering under ISO/SAE 21434; these are tied to regulation through UNECE R155 and R156.

Commonly confused in this field

An automotive report without a specification reference is not accepted in the supply chain; which OEM specification and revision was applied must be stated.
Type approval and supplier approval are different processes. A component with E-Mark approval is not thereby considered to have passed the OEM's own acceptance tests.
A result obtained on a prototype does not carry over to series production; PPAP is done with series production parts.
On the EMC side, measuring emissions alone is incomplete; immunity is a separate body of work and is more critical in a vehicle.
On electric vehicle components, high-voltage safety is a distinct competence; classical 12 V test infrastructure is not sufficient.

Which decisions these results support

Supplier component approval and the PPAP file
UNECE type approval and E-Mark marking
Design verification and durability evidence
Root cause analysis of field complaints and warranty returns
Assessing the impact of a design or supplier change

Related Tests

Frequently Asked Questions About OBC

Is additional testing required for a bidirectional (V2G) OBC?

Yes. Operating in the direction of feeding energy into the mains brings additional tests for grid-connection requirements, islanding detection and power quality; these requirements are determined by the relevant grid-connection standards.