Ambient Temperature and UPS Batteries
Q: Why does the operational ambient temperature affect my UPS batteries?
A: UPS sealed valve-regulated lead-acid (VRLA) batteries — including the Elite VRLA family — use a “starved electrolyte” design: minimal liquid inside, held in suspension by an absorbed glass mat (AGM) so the battery is not spillable. The battery is designed to operate at an ambient temperature of 20–25 °C over its service life.
When operated above 25 °C the electrolyte evaporates at an accelerated rate. The pressure builds up inside the battery, forcing the emergency valve to open and purge the gas. Loss of gas means loss of liquid inside the cell, and the battery dries out faster than it should — leading to premature failure.
Practical rule: UPS batteries operated at over 30 °C achieve less than half their expected service life. Battery rooms and UPS cabinets in hot environments need active cooling to preserve battery economics.
Connections
- VRLA Batteries — referenced, source: https://standbysystems.co.za/ups-batteries-questions-and-answers/