Common UPS Battery Issues

Common UPS Battery Issues

1. Grid Corrosion

• Occurs in batteries that have exceeded their designed service life
  
• Caused by natural chemical reactions that gradually corrode the internal grid
  
• Lead material flakes off from the battery plates over time
  
• The corrosion process can be slowed but not stopped
  
• In compact battery designs, this can lead to internal short circuits

2. Sulphation

• Common in UPS systems with frequent charge/discharge cycles
  
• Happens when batteries are not fully recharged
  
• Lead sulphate crystals build up on the plates and in the electrolyte
  
• Leads to higher internal resistance and slower charging
  
• Light sulphation may be reversed with a 12-hour high-current charge
  
• Severe sulphation usually requires battery replacement

3. Short Circuits

• Caused by porous positive plate material separating from the grid
  
• During discharge, shed material may create unintended contact
  
• Can result in internal cell short circuits and failure

4. Dry Out (Water Loss)

• Typically caused by overcharging
  
• Overcharging increases acid concentration in the electrolyte
  
• Leads to water evaporation and reduced capacity
  
• Results in separator failure and faster self-discharge
  
• Accelerates sulphation and overall battery degradation

5. Thermal Runaway

• Triggered by a continuous increase in internal battery temperature
  
• Generates excess heat, which further increases temperature
  
• Poor heat dissipation causes external and internal heat buildup
  
• Can result in battery casing deformation or melting

6. Top Mossing

• Caused by poor alignment of plates or separators during manufacturing
  
• Reduces contact area between plates and electrolyte
  
• Leads to crystalline moss formation inside the battery
  
• May cause self-discharge and soft short circuit failures