One of our older blog posts on5 Factors that will Shorten the Life of Your UPS Batterygot me thinking about this topic. While each of those factors is important, I thought it would be useful to discuss a few of the variables users have some control over (dictating when power goes out can be tough after all).
Generally, despite some growing lithium popularity (here's a quick Lithium Iron Phosphate vs. Lead-Acid Batteries for UPSes breakdown for anyone interested), the internal batteries in most single phase, and even many 3 phase UPSes, are Sealed Lead Acid (SLA) batteries (a.k.a. Valve-Regulated Sealed Lead Acid or VRLA). More specifically, they are usually Absorbed Glass Mat Sealed Lead Acid Batteries (AGM SLA).
The specifics of a given battery may vary a bit, so I'll give the standard "defer to the manufacturer's documentation &...