How to Prevent Premature UPS Battery Degradation

How to Prevent Premature UPS Battery Degradation

1. Importance of Maintenance, Inspection, and Testing

• Preventive maintenance is essential for any UPS system, especially the batteries
• Regular monitoring helps detect early warning signs, allowing timely replacement to avoid system failure
• Batteries should be inspected at the cell level at least once a year

2. Physical Inspection Guidelines

• Check terminals and inter-cell links for corrosion
  
• Look for cracks, swelling, or electrolyte leakage on the battery casing
  
• Tighten all cell connectors and clean battery surfaces
  
• Remove any dust, dirt, or foreign materials

3. Advanced Monitoring Practices

Use a Battery Monitoring System (BMS) to track critical battery health parameters:

• String and cell float voltages
• Charge and discharge current
  
• Ripple current and ripple voltage
  
• Cell temperature and ambient temperature
  
• Internal resistance of each cell
  
• Total number of charge/discharge cycles

4. Battery Testing Methods

4.1 Impedance Testing

• A non-intrusive method used to monitor battery health trends over time
• Conducted by injecting AC current and measuring resistance in milliohms

4.2 Discharge Testing

• Involves discharging batteries under both normal and peak loads
• Identifies which cells can still retain charge and which are near failure

4.3 Partial Discharge Testing

• Discharges the battery to about 80% of its capacity
  
• Temporarily reduces system availability, but the battery becomes usable again within 8 hours