Leak Testing for EV Thermal Management and Battery Enclosures

Liquid-cooled battery packs require zero-defect sealing integrity. A single leak in a cooling channel risks electrolyte contamination, thermal runaway, and warranty liability. At production volumes, the test cycle must fit within the assembly line takt — typically 20–30 seconds — without generating false rejects that inflate scrap costs.

Figurtech instruments are deployed on EV battery tray, liquid cooling tube, and die-cast housing production lines across China's leading EV supply chain.

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Case: EV Liquid Cooling Tube — 23-Second Production Cycle

Instrument: LY Series Direct Pressure Airtightness Tester
Connector: LT-G01 Bend-Clamp Inner-Expansion Quick Connector

Test Parameter	Value
Test Pressure	325 kPa (acceptance window: 298–350 kPa)
Leak Threshold	±1.0 kPa pressure decay
Cycle Time	23 s (Charge 6 s / Stabilize 8 s / Measure 8 s / Exhaust 1 s)
Detection Method	Direct pressure decay

Challenge

Aluminum cooling tubes for EV battery packs are routed through tight packaging spaces, resulting in complex bent geometries. Conventional fixtures apply axial clamping force to tube ends — deforming thin-wall aluminum and generating false rejects. Temperature fluctuations on the production floor introduce pressure variance that further destabilizes test results across a shift.

Solution

The LY Series executes a four-phase automated cycle with on-board temperature drift compensation, eliminating pressure variance from shop-floor temperature changes. The LT-G01 inner-expansion connector seals from inside the tube bore — zero axial or lateral force on the tube wall, zero deformation, zero geometry-induced false rejects. Compatible with tube ODs from 6 mm to 52 mm without tooling changeover.

Result

• 23-second takt time maintained across full production volume
• ±1.0 kPa acceptance window held across complete production shift without recalibration
• False-reject rate reduced to near-zero after eliminating axial-force fixture deformation

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Case: Die-Cast EV Housing — 4-Channel Simultaneous Testing

Instrument: LM Series 4-Channel Airtightness Tester
Fixture: Custom 4-channel pneumatic clamping fixture with glass enclosure

Challenge

Die-cast aluminum EV component housings require leak testing on all sealed chambers simultaneously. Testing one chamber at a time would require a cycle time four times longer than the assembly line takt allows.

Solution

The LM 4-channel system tests four independent sealing chambers in a single cycle. Each channel has its own sensor and pressure regulation — one start command, four simultaneous pass/fail decisions displayed on the touchscreen. Per-channel data is logged with timestamps for production traceability.

Result

• 4× the effective throughput of a single-channel instrument
• Per-channel leak data stored and exportable for SPC analysis
• Deployed in volume production for EV drivetrain component subassemblies

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Recommended Configuration — EV Applications

Application	Instrument	Connector
Battery tray (400 kPa)	LY Series V1000	LT-KZ02 (stainless, 50 bar)
Liquid cooling tube (300–350 kPa)	LY Series V500	LT-G01 (inner expansion, no axial force)
Die-cast housing (multi-chamber)	LM 4-Channel	Custom pneumatic fixture
Large sensor (10–1000 kPa)	LG Auto-Regulating	LT-LW01 (threaded port)