How long does a UPS last?

[JoeH]

The sealed lead-acid gel batterie used in UPS's generally last about 3-4 years in use. Main killer for them is they run at an elevated tempurature inside the UPS enclosure, for instance the reported temperature in my UPS is about 130. The heat lessens their life, just like it would for an auto battery used in the desert compared to use in a cold climate. The batteries are also optimised for high capacity in a small size, not deep discharge use.