Uninterruptible Power Supply (UPS)

What is a UPS?

Protects your computer�s valuable data and components from power disturbances (by providing clean, secure power).
Contains a replaceable �spill-free� battery and circuitry that converts 12 volts DC to 240V AC (Mains Voltage).
Runs your computer for up to 10 minutes during a blackout. (Note: Backup time depends on computer load and capacity of the UPS).
Most blackouts are less than a minute so you can �ride through� power outages.
Allows you to finish your work and shutdown your computer safely if it is a prolonged blackout.
Protects your computer, printer, scanner, modem, etc from low level voltage surges and spikes. (Note: A surge power board in conjunction with a UPS is recommended for medium to high exposure voltage surge level areas).

Make a list of all the equipment that is required to keep running in the event of a blackout. e.g. PC, monitor, hubs, routers, external hard drives and other critical equipment.
As a guide, approximate VA of your equipment is as follows: PC = 200VA; monitors = 50VA (15"), 100VA (17"), 150VA (19"), 200VA (21"); hubs and routers = 50VA each; external hard drives = 100VA.
Add up the equipment to be connected to battery backup outlets. e.g. PC + 17" monitor + hub: 200 + 100 + 50 = 350VA.
Work out how much battery runtime you want in the event of a blackout. Usually you select enough time to allow you to shutdown your computer properly. e.g. 5 minutes.
Select the model you need. Be sure to allow some extra capacity for adding more equipment in the future (in the meantime, you will benefit from the extra backup time).