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Final Testing & Inspection

1. Definition

Post-formation quality verification where every single battery is tested before shipment. Chengguang performs 100% testing — no sampling-based release. Defective batteries are identified, segregated, and analyzed for root cause. This is the last quality gate before the battery leaves the factory.

2. Process

1. High-Rate Discharge Test (100%)

CCA simulation: Battery is discharged at the rated CCA current for 30 seconds at ambient temperature. Voltage must remain above the specification threshold (typically >7.2V at -18degC equivalent). This is the most critical pass/fail test.

2. Open Circuit Voltage Check (100%)

OCV must be >12.60V after formation and stabilization. Low OCV indicates: internal short circuit, insufficient formation, or contaminated electrolyte.

3. Visual Inspection (100%)

  • Case: No cracks, no deformation, no acid residue. Color consistent.
  • Terminals: Correct type, position, and post diameter. No damage or corrosion.
  • Label: Correct model, specifications, polarity markings. Aligned properly. No peeling edges.
  • Cover seal: No gaps, no electrolyte leakage. Heat seal uniform around perimeter.
  • Handle (if equipped): Securely attached, correct color.

4. Leak Test (100%)

Battery is pressurized to 2-3 psi and checked for pressure drop over 30 seconds. Or: inverted and observed for electrolyte leakage. Any leakage = immediate rejection.

5. Weight Check (100%)

Weight must be within specification range. Underweight = missing electrolyte or plates. Overweight = potential internal defect.

6. Batch Sampling Tests (1 per 500-2000)

  • C20 Capacity (IEC 60095-1): 20-hour discharge at C20 rate. Must deliver >=95% of rated Ah.
  • Reserve Capacity (SAE J537): 25A discharge to 10.5V. Minutes recorded.
  • Charge Acceptance (EN 50342-1): Current accepted at 14.4V from 80% SoC.
  • Vibration Test (JIS D 5301 or EN 50342-1): 3-5g RMS for 8 hours. No damage, no leakage, CCA retention >90%.

7. Documentation

Every battery's test data (CCA, OCV, weight, production timestamp) is recorded and stored for 5 years. Certificate of Analysis (CoA) is generated per shipment lot. This full traceability is a core IATF 16949 requirement.

3. Quality Control at Chengguang

CCA (> specification), OCV (>12.60V), leak test (no pressure loss), visual (no defects), weight (within range). Chengguang: 100% testing, zero sampling-based release. IATF 16949 full traceability from grid casting to final test.

4. Why Grid Quality Matters for OEM Buyers

Every manufacturing step directly impacts the battery you receive. When sourcing OEM batteries, ask your manufacturer about their grid alloy, paste formulation, curing profile, and formation process — these are the four factors that determine real-world battery life in your market. Chengguang's IATF 16949 certification guarantees documented, audited, and traceable manufacturing at every step.

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Author: Chengguang Power Tech Engineering Team | Reviewed: IATF 16949 Quality Department | Battery Database