At our office, most of our machines have a similar UPS to the one you are looking.. The APC 500VA 0r 550VA models put out about 330 watts for a limited amount of time and will allow the user to shut down normally if a power outage occurs. Fifteen minutes or less is all you get depending on your wattage.. Still, the UPS models generally provided by large retailers are NOT the most powerful, longest lasting, and most expensive. Check out the APC website and look at the variety of products they have.
On the other hand, we have a few devices, such as servers and ethernet switches in our office which we want to stay on a little longer should the power go out.. For those, 750, 1000, or 1500 commercial versions work for us..
For most homewowners, the model you're looking at will probably do fine. Still, it's your choice as to how much money you want to throw at the device.
Hope this helps.
I am trying to figure out what I need for a battery backup. I just have a normal desktop computer running Windows XP. I am looking at one backup that says it will work for about three minutes at maximum load of 330 Watt's or six minutes at a load of 165 Watt's. How do I know how many watts my computer draws? I see that they are making them with the ability to shut down your computer automatically when the power goes out. That being the case it seems like you wouldn't be something that would last very long. I would think the software would have the computer shut down within two or three minutes. Anyway any advice you could offer me would be greatly appreciated. There are so many different backups out there I don't really know where to start.