Battery backup come in handy when there is no power supply from the wall. Power supply sometimes may get lost due to various reasons. This can cause immediate disruption to your work especially if one had to deliver some important documents within a specific timeline. Worse enough is when one loses the documents due to sudden power outage.The power from the UPS might not last for long but imagine what it might end up saving you. It will give you the amble time you need to save all the important documents. One can also send an important email before the UPS shuts down. You can do all this and shut your computer down before as you wait for the power to come back.