I. Fault Inspection Steps

‌Visual Inspection‌: Check the battery casing for damage, swelling, or leakage. Replace immediately if abnormalities are found.

‌Voltage Measurement‌: Measure voltage with a multimeter. Normal range is 3.6V–4.2V. Below 3.6V may indicate zero voltage or high internal resistance failure.

Internal Resistance Test: Measure with an internal resistance tester. Low resistance indicates good performance; high resistance may indicate failure.

Discharge Test: Connect to a constant-current load and measure the discharge curve. Rapid discharge indicates insufficient capacity or failure.

II. Common Faults and Solutions

Unable to Charge:

Causes: Zero voltage, high internal resistance, protection circuit malfunction, or charging equipment issues.

Solution: Test equipment with series-connected batteries of the same model; use stable charging equipment; zero-voltage batteries require professional handling.

Unable to Discharge:

Causes: Zero voltage, high internal resistance, damaged protection circuit, or abnormal equipment circuit.

Solution: Test equipment with fully charged batteries of the same model; inspect protection circuit with multimeter; repair abnormal circuits.

Shortened runtime:

Causes: Incomplete charging, significant voltage/capacity variation within a cell string, micro-short circuits, or high self-discharge.

Solutions: Recharge or replace defective cells; avoid high temperatures and physical damage.

Thermal runaway: Most dangerous! Triggered by internal short circuits, leading to fire or explosion. Prevention relies on strict quality control and avoiding misuse.

III. Critical Safety Guidelines

‌Prohibited Disassembly: Non-professional disassembly may cause accidents.

‌Regular Maintenance: Promptly identify and address issues.

‌Proper Disposal: Dispose at recycling stations; do not discard carelessly.

IV. Professional Testing Methods (Optional Knowledge)

‌Model-Based Diagnosis: Compare measured values with equivalent circuit models to identify faults, suitable for early detection.

‌Data Processing Method: Analyze sensor data to extract fault characteristics.