How long does a UPS typically last during a power outage?

A UPS system is designed to bridge breaks in the incoming mains power supply for a set duration. This can be for a brief period, to power through momentary outages lasting milliseconds to a few minutes, or for longer durations, sometimes up to several hours. Most UPS systems provide 5-30 minutes of runtime. Available runtime depends on the load (kVA/kW) the UPS is powering, the battery charge percentage, and even the battery’s age. The most commonly used battery is a valve-regulated lead-acid (VRLA) type, but some UPS can also be installed with lithium batteries. For long-duration runtimes, a UPS system is installed with one or more battery extension packs, providing runtimes lasting hours, supported by a smaller battery and a local standby power generator.