The Computer Revolution/Uninterruptible Power Supply

An uninterruptible power supply is a device that contains a built in battery that provides power. A UPS will allow devices to remain powered up in the event of a power outage. The time that the UPS can stay powered depends on the type of devices connected to it. Most UPS devices protect against power fluctuations. Most UPS batteries last 3 to 5 years before they need to be replaced. UPSes are helpful if a user experiences a power outage while in the middle of typing a document, allowing the user to quickly save open documents and shut down the computer properly.

A UPS made by the company APC