An Uninterruptible Power Supply (UPS) battery is a critical component of a UPS system, which provides emergency power to connected devices when the main power source fails. The UPS battery ensures that there is no interruption in power supply, allowing for the safe shutdown of equipment or the continuation of operations during short outages. 
UPS systems are commonly used to protect computers, data centers, telecommunications equipment, and other electrical devices where an unexpected power disruption could cause data loss, business disruption, or equipment damage. The battery in a UPS is typically a sealed lead-acid (SLA) battery, although other types like lithium-ion are also used in modern systems.
The UPS battery works by storing electrical energy when the main power is available and releasing it when there is a power failure. It is connected to an inverter within the UPS, which converts the stored DC power from the battery into AC power that can be used by the connected devices. The capacity of a UPS battery is measured in volt-amperes (VA) or kilovolt-amperes (kVA), indicating how much power it can supply and for how long.
UPS batteries are designed to provide power for a limited time, typically ranging from a few minutes to several hours, depending on the system's capacity and the power load of the connected devices. This duration is usually sufficient to either switch to an alternative power source, such as a generator, or to safely shut down the equipment.
Regular maintenance and timely replacement of UPS batteries are essential to ensure their reliability and effectiveness. Over time, batteries can degrade, reducing their ability to hold a charge and deliver power when needed.