What does Battery backup mean?

Battery backup meaning in Business Dictionary

See uninterruptible power.

Battery backup meaning in Computer Science Dictionary

Hardware product used to provide power to computer systems and peripherals for a few days if the energy happens to be reasonable or removed. A battery backup permits the computer to shutdown safely or keep consitently the computer running in the event that energy is off for under a couple of minutes. The picture is an example of a battery backup from APC.