Key takeaways
On-board charger testing falls into four lines: EMC (conducted emission and immunity), electrical safety (temperature rise, insulation resistance and dielectric strength), interface durability (mating cycles, salt spray), and environmental protection (IP rating and vibration). EMC problems originate in the switching supply and the layout, so addressing them early is cheaper; connector erosion and temperature rise depend on terminal crimping and plating, and need vehicle-level load conditions to validate.
The on-board charger is the energy entry point of an electric vehicle, and a frequent source of complaints and recalls. Its testing cannot be summed up as "one EMC report" — by failure risk it splits into four lines.
1. EMC: explore it first during development
Inside the OBC is a textbook high-power switching supply, and conducted emission is usually the first limit to be hit: the switching frequency and its harmonics travel out along the power harness and are measured as a disturbance voltage on the LISN. Emission limits for automotive components come from CISPR 25 / GB 18655, immunity from the ISO 11452 series.
Immunity covers two scenarios: conducted disturbance on the vehicle harness (bulk current injection, conducted transients), and radiated fields. At the exploratory stage, validate to the target customer's levels and leave margin in layout and filtering.
2. Electrical safety: temperature rise and insulation
The temperature rise test at rated load maps directly onto complaints such as "the charge port gets hot": measure the temperature distribution at the interface terminals, internal joints and critical devices, and assess heat build-up over long full-load charging. Insulation resistance and dielectric strength validate the clearance design between the high-voltage circuit and the housing; insulation retention after damp heat ageing is a common checkpoint.
3. Interface durability: mating cycles and salt spray
The vehicle-side charging interface is cycled to the mechanical mating count in the interface standard, assessing contact wear and retention force; drift in contact resistance after cycling is the core criterion — continuity does not mean the contact resistance is unchanged. Salt spray addresses corrosion protection of the contact plating, and measuring the change in contact resistance after exposure is more meaningful than judging appearance alone.
4. Environmental protection: IP and vibration
Externally mounted interfaces and charging guns usually require IP67 (dust-tight plus short-term immersion). Vibration and shock at the vehicle mounting position follow ISO 16750-3 or the customer profile, with attention on internal power devices and connector solder joints.
5. How to combine the standards
EMC: CISPR 25 / ISO 11452. Environmental and mechanical: GB/T 28046 and ISO 16750. Interface performance and dimensions: the corresponding interface standard (the national AC and DC interface standards, IEC 62196 and so on), to the version the customer specifies. OEMs often add their own tightened items, which the procurement technical agreement governs.
Turnaround time is arranged according to the actual project. You are welcome to state your target date when submitting samples; we will check it against the current schedule, confirm a feasible plan with you, and update you at each milestone.
