Importance of Perform Regular UPS Battery Maintenance
Uninterruptable Power Supply (UPS) systems typically rely on Valve Regulated Lead Acid (VRLA) batteries for their standby energy reserve. Battery systems do however have a finite operating life, and given time will eventually fail.
One of the key reasons for power loss to mission critical IT equipment under mains failure conditions is due to faulty UPS batteries. Undertaking regular battery inspections as part of a UPS service contract is essential. Battery inspections will help with the detection and resolution of any impending or potential problems and will help significantly reduce the risk of unplanned power failures to mission critical IT services.
The following details a range of battery issues that may occur;
Ambient Temperature – Ideally 20°C ambient temperatures should be maintained throughout the UPS battery life. Ambient temperature will vary depending on UPS type and installation characteristics. Higher temperatures can potentially contribute to a shorter battery life and in extreme conditions can lead to battery swelling that will require replacement of the effected cells.
Overcharging – This can occur because UPS charging levels are not set at a fixed level but vary depending on the voltage, current and temperature. A high overcharge current can lead to corrosion reducing battery life.
Extended Discharge Period - Leaving a battery in a discharged state for extended periods can lead to the formation of sulphate crystals that inhibit recharging, preventing normal battery operation. If discharging becomes too deep, battery recharging may become impossible and the battery will require replacement.
AC Ripple - Any AC voltage that is present on the DC charging voltage is known as AC ripple. Where AC ripple is present, this can adversely affect the batteries useful working life.
Planned Maintenance Options
It is recommended that UPS equipment installations are fully supported with a regular planned preventative maintenance contract and ideally remote monitoring services. UPS System Planned Preventative Maintenance procedures should include as a minimum the following activities:
- Measurement of open circuit battery voltages
- Verification of UPS float voltage.
- Inspection of batteries for swelling or leaks, casing cracks
- Tightening the inter-cell terminal connections
- Inspection of battery terminals and cable connections for corrosion.
- Removal of any debris and general battery cleaning.
Battery Impedance Testing
Battery impedance testing helps identify possible battery issues because battery impedance will increases with age, and more significantly as result of fault conditions. Battery or a string of batteries showing an impedance that is significantly higher than others in the installation will be suspect and should be examined more closely and replaced if faulty.
Battery Load Bank Testing
To identify the true UPS battery autonomy, load bank testing can be undertaken. Battery load bank testing does however involve taking the UPS batteries off line and depending on electrical arrangements can be disruptive to services. We do not recommend that batteries are fully discharged when load bank tests are performed.
Workspace Technology offers UPS & battery maintenance plans as part of our full range of mission critical optimised maintenance services for clients across the UK. You can view our UPS planed preventative maintenance service schedule here.
For more information on Workspace Technology’s Mission Critical Maintenance Services please contact firstname.lastname@example.org or call 0121 354 4894.