Important points you need to know when purchasing a UPS.
Firstly, there are 3 main types of UPS's:
- Standby, or off-line: switches from the regular power source to an internal battery when there is a power disturbance.
- Line-interactive: uses a transformer to minimize the need of having to use an internal battery with every power fluctuation.
- On-line: supplies power to the connected equipment from an internal battery, with the battery charging on an ongoing basis.
A UPS should have a capacity of at least 25% greater than the total power usage requirements of the connected devices. For example, a computer that runs between 180 VA to 280 VA should be connected with a 300 VA UPS.
You can check the plate on the back of the device to see how much power your device uses.
Manufacturers will state how much time the UPS will last for under full-load or half-load conditions.
The most common time is about 10 minutes.
Lastly, make sure that the UPS you choose comes with Power Management Software. This will allow you to setup the UPS to auto-shutdown on your computer when you are not around.