Did You Know:
UPS battery related failure is responsible for 37% of UPS system failures. What can you do to mitigate UPS Failure?


The high discharge rate batteries typically use in large UPS systems have a design life of 20 years, but an average service life of 15 years.


Factors that can cause premature battery failure include:

  • High or low charge voltage
  • Excessive charge current
  • Strained battery terminals
  • Manufacturing defects
  • Improper room temperature
  • Overcharging and over cycling
  • Loose connections
  • Manufacturing defects
  • Poor and improper maintenance

The best way to determine a battery’s health without discharging it is to use a monitoring system that measures the internal resistance of all of the cells in the battery.

Recommended Task Flooded IEEE 450 VRLA IEEE 1188
Monthly Quarterly Annually Monthly Quarterly Annually
Battery System Voltage x x
Charger Current and Voltage x x
Ambient Temperature x x
Visual Inspection x x
Electrolyte Levels x
Pilot Cell Voltage and Specific Gravity x
Specific Gravity All Cells 10% x
All Cell Voltages x x
All Cell Temperatures 10% x
Detail Internal Visual Inspection x
AC Ripple Current and Voltage x
Capacity Test 5 Years x

Organizations should use trending data to optimize battery life instead of replacement based solely from age and to mitigate risk by being proactive in performing corrective actions and/or replacement.


Here are a few helpful tips for keeping your UPS unit in good health:

  • Give it space. Make sure that your UPS unit has enough room to breathe and be serviced comfortably and safely.
  • Location, location, location. The UPS unit should be nowhere near water or any area where the temperature fluctuates tremendously. Avoid heaters, AC units, and anything else that can cause the battery temperature to change rapidly.
  • Clean environment. Make sure your UPS is breathing in only the finest quality air. Keep the UPS in an area that is clean, dry, and dust free so it can last much longer.
  • The magic numbers. To gain optimal performance from the UPS, keep the ambient temperature in the battery cabinet around 78° F.
  • Regular checkups. Regularly perform a simulated power mains failure and battery discharge tests so you know how your UPS is doing.
  • Monitor your investment. Consider investing in battery monitoring solutions to protect yourself against downtime.

* Never attempt to service the equipment yourself as dangerous voltages exist within the system even when switched off. Refer all service and repair work to a professional service provider.