Meaning
Non-destructive liquid pressure test that measures volumetric fluid loss, pressure drop, or fluid passage through battery pack enclosures and cooling plates verifies ingress and egress sealing integrity. In battery manufacturing quality control, hydrostatic leak testing pressurizes liquid cooling circuits with water or glycol mixtures to confirm that internal thermal management channels contain fluid without leakage into cell compartments. Boundary limits isolate fluid containment boundaries without evaluating gaseous hermetic sealing.
Leak-free cooling circuits prevent catastrophic electrical shorting.
Pressure Monitoring
Pressurizing cooling circuits to specific test pressures allows precise measurement of pressure decay rates over defined holding times. Automated stations executing hydrostatic leak testing flag microscopic cracks, incomplete seals, or fitting leaks before module integration. Stable test pressure confirms mechanical joint integrity.
Cooling Circuit Validation
Cold plates integrated into module structures must maintain liquid tightness under thermal stress and mechanical vibration. Quality procedures using hydrostatic leak testing verify that brazed aluminum cooling tubes withstand maximum operating system pressure spikes. Fluid containment prevents corrosive cooling fluid contact with live busbars.
Rejection Thresholds
Quantified maximum allowable leak rates establish clear pass or fail criteria during end-of-line manufacturing inspection. Calibration records for hydrostatic leak testing define explicit pressure drop limits measured over multi-second test intervals. Failed units trigger immediate seal rework or cooling plate scrapping.
