High Precision in Situ Structural Deflection Mapping in Commercial Battery Testing Tooling
In situ deflection mapping decouples test tooling flexure from cell swelling to restore true electrochemical capacity and volumetric degradation profiles.
Battery Compression Fixture Calibration
Meaning
Metrological validation of the force and displacement measurement systems within a cell restraint assembly ensures that mechanical test data remains traceable to national standards. This procedure, referred to as battery compression fixture calibration, establishes the accuracy of the load cells and displacement sensors used to compress pouch or prismatic cells during cycle testing. It defines the limits of measurement uncertainty under varying thermal and mechanical conditions.
The process is complete when the fixture is certified to operate within specified tolerance bands across its entire loading range.
Reference Validation
High precision proving rings or master load cells provide the reference standards for adjusting the sensor outputs. During battery compression fixture calibration, the reference cell is placed in series with the fixture’s active load path to verify force accuracy at multiple pre-set intervals. Sourcing contracts often require this procedure to be performed at least once every six months to guarantee the integrity of cell test data.
This validation prevents false pass results during cell qualification trials.
Compliance Correction
Structural deformation of the test fixture itself must be measured and subtracted from the raw displacement data. This stiffness correction accounts for the minute bending of the steel plates and columns under high forces. Without this adjustment, the recorded cell expansion values would include the deflection of the test machine.
Proper calibration maps this compliance curve across the full load range to allow real-time correction during dynamic testing.
Sourcing Metric
Certified measurement uncertainty dictates whether a laboratory can produce legally defensible data for automotive validation. Automotive buyers rely on calibrated fixtures to compare cells from different global suppliers. Discrepancies in test setup stiffness lead to incorrect selections of cell models.
A standardized calibration process eliminates these discrepancies and secures consistent supplier evaluation.