EV Battery Cleanliness Testing

Technical Cleanliness · ISO 16232 · EV Battery Thermal Management · Particle Extraction · Cleanliness Classification ISO/IEC 17025 Accredited Testing Where Applicable | ISO 16232 and VDA 19 Capability | EV Component Testing Support Background [PLACEHOLDER: Insert 2-3 sentences describing the client. Example structure below — to be replaced with real data] A [Tier-1 supplier / OEM / component manufacturer] producing [component type, e.g. battery cooling manifolds / thermal management plates / coolant distribution components] for [EV platform / programme type] required cleanliness testing of [component description] before delivery to [customer / assembly plant]. The cleanliness requirement was defined by [OEM specification / internal quality requirement / customer purchase specification], specifying [cleanliness class or particle limits] for components destined for [application, e.g. battery thermal management circuits / high-voltage cooling systems]. Why Cleanliness Matters for EV Battery Components Electric vehicle battery systems introduce cleanliness requirements that go beyond those applied to conventional powertrain components. The reasons are specific to the thermal management architecture of lithium-ion battery packs. Battery thermal management systems circulate a cooling fluid through a network of channels machined or formed into battery modules, cell holders, and cooling plates. These channels are often narrow, the fluid flow rates are precisely controlled, and the thermal performance of the system depends on consistent, unrestricted flow. A particle that would cause no functional problem in a large-bore hydraulic circuit can restrict flow, create a hotspot, or damage a pump seal in a battery cooling circuit. Beyond thermal management, cleanliness is increasingly relevant to high-voltage battery assemblies where conductive particles, particularly metallic particles, can bridge insulation gaps and create safety-critical short circuit risks. This is why some EV OEMs are extending cleanliness requirements from hydraulic and fuel system components to battery assembly components, applying ISO 16232 or VDA 19 particle limits to components that had no cleanliness specification requirement in conventional powertrain programmes.   The Testing Requirement [PLACEHOLDER: Insert specific requirement details] The applicable standard was [ISO 16232 / VDA 19 / both]. The specified cleanliness requirement was [insert cleanliness class or particle count limits, e.g. maximum X particles above Y µm per 1,000 cm²]. The components submitted for testing were [insert component description, e.g. aluminium coolant manifolds / extruded cooling plates / injection-moulded coolant distribution components], with a functional surface area of approximately [X cm²] per component. [Number] components were submitted from [production lot / qualification batch / process validation run]. Approach Extraction Method Selection [PLACEHOLDER: Insert actual extraction method used and rationale] The geometry of the component determined the extraction method. [Insert one of: Pressure rinsing was selected because the component contained internal channels with defined inlet and outlet ports, allowing a controlled solvent flow path. / Ultrasonic extraction was selected because the component had complex surface geometry and recesses that pressure rinsing could not reach effectively. / Agitation was selected based on component size and the accessible nature of the relevant surfaces.] A blank test was performed before component extraction to confirm that the extraction equipment, solvent, and filtration setup contributed particle counts below the defined blank acceptance level. Analysis After extraction, the solvent was filtered through a [5 µm] nylon membrane. The membrane was dried and weighed for gravimetric analysis. The extracted particles were re-suspended and run through the LPC instrument for size distribution counting. The membrane was then examined under the calibrated microscope for particle classification by type: metallic shiny, metallic non-shiny, fibre, and other non-metallic.   [PLACEHOLDER: Add SEM-EDX step if applicable] [SEM-EDX analysis was applied to [X] particles above [Y µm] as required by the specification, to provide elemental identification of the largest metallic shiny particles found.] Results [PLACEHOLDER: Insert actual test results — requires real data] Gravimetric result: [X mg / 1,000 cm²] LPC size distribution   Size class Particles per 1,000 cm² Specification limit [B: 5–15 µm] [result] [limit or N/A] [C: 15–25 µm] [result] [limit or N/A] [D: 25–50 µm] [result] [limit or N/A] [E: 50–100 µm] [result] [limit or N/A] [F: 100–150 µm] [result] [limit or N/A] [G: 150–200 µm] [result] [limit or N/A] [H: 200–400 µm] [result] [limit or N/A]   Largest metallic shiny particle: [X µm] Largest non-metallic particle: [X µm] Longest fibre: [X µm]   Component Cleanliness Code: [CCC result]   Overall result: [Pass / Fail / Conditional pass with comment]   [PLACEHOLDER: Add 2-3 sentences on what the results showed, e.g. whether the components passed, whether any size class was close to the limit, and any notable finding from particle classification] What the Results Showed [PLACEHOLDER: Insert 2-3 sentences summarising findings and outcome]   [Example structure: The results confirmed that all [X] components met the specified cleanliness class in all size ranges above [Y µm]. The largest metallic shiny particle measured [X µm], below the [Y µm] critical particle threshold defined in the specification. The components were released for [delivery / assembly / customer submission].]   [OR if there was a finding: The initial results identified [describe finding]. This was traced to [source — e.g. a specific machining step / packaging material / handling practice], and the supplier implemented [corrective action]. Retesting after corrective action confirmed that the component met the specified cleanliness class.] Relevance to EV Cleanliness Testing This type of investigation reflects a broader trend in EV component qualification. As battery thermal management system designs become more complex and cleanliness requirements extend from conventional powertrain components to EV-specific parts, the analytical workflow developed for ISO 16232 and VDA 19 testing is being applied to component geometries and material types that were not part of traditional cleanliness testing programmes. ALS has been providing technical cleanliness testing to ISO 16232 and VDA 19 since 2014, with ISO/IEC 17025 accreditation since 2019. As EV production scales across Malaysia and Southeast Asia, the cleanliness testing capability developed for conventional automotive components is directly applicable to EV battery system components, providing Tier-1 suppliers and OEM assembly programmes with the accredited cleanliness data they need for qualification and process validation. Frequently Asked Questions Does ISO 16232 apply to EV battery components or only to conventional powertrain parts?  ISO 16232 is applicable to any automotive component where particulate contamination poses a functional risk. The standard does not restrict application to conventional powertrain components. As EV OEMs define cleanliness specifications for battery thermal management and high-voltage assembly components, ISO 16232 provides the established test framework for demonstrating compliance. In practice, the specific cleanliness limits for EV components are defined by the OEM or customer specification, not by ISO 16232 itself.   What extraction method is typically used for EV battery cooling components?  The extraction method depends on the geometry of the specific component. Cooling manifolds and plates with internal channels and defined flow paths are typically tested by pressure rinsing, which forces solvent through the internal channels under controlled pressure. Components with more complex external geometry or recessed features may be tested by ultrasonic extraction. The extraction method is validated for each component type before production testing begins.   Can ALS test EV battery components for cleanliness under ISO/IEC 17025 accreditation?  Yes. ALS Testing provides technical cleanliness testing to ISO 16232 and VDA 19 under ISO/IEC 17025 accreditation. For testing where accredited results are specifically required, confirm the exact method and scope with the laboratory at the enquiry stage. Next Steps See our full Automotive Testing services including EV component testing See our Technical Cleanliness Testing services for ISO 16232 and VDA 19 Contact our team to discuss EV component cleanliness testing requirements   ISO/IEC 17025 Accredited Testing Where Applicable | ISO 16232 and VDA 19 Capability | EV Component Cleanliness Testing Support