Originally Posted by CaptNKILL
I really don't know too much about these things but I think it'd be a good thing to get some day.
A few questions...
Does a UPS battery still need replaced every 3-5 years if you very rarely lose power?
How much do the replacement batteries normally cost?
Are there any other benefits (or problems) related to using a UPS other than getting a couple minutes to shut your computer down properly?
You can stretch the batteries sometimes more than 5 years, but generally they aren't going to last that long. Even if you don't lose power often the batteries are still trickle charged so there is some wear and tear on them.
For my 1200va model the battery costed $70 + shipping, which is a little less than half the total cost of the unit. It is a little bit more than you might be able to find other batteries for, but it comes with free recycling of the old battery so you don't have to hunt down a place to return the old one at.
There are several advantages of a UPS. It will prevent surges / spikes, electrical noise, and under / over voltage situations if it has AVR. My units will kick on at least once a month for electrical noise. AVR (Auto Voltage Regulation) allows the UPS to keep a steady 120VAC in occurrences where you have sags or spikes. So if you only have 100V coming into the house the unit can input that and continue to input out 120VAC. Same goes for high voltage although technically if you have an Active PFC PSU it should be able to handle these load changes on its own. (Your monitor on the other hand won't)
One little catch I've noticed with APC though is they have 2 AVR models, an XS, and the RS. The XS only does "boost" for brownouts, where the RS does both directions. The XS is slightly cheaper and is what you find in every store, where the RS you see at most online retailers. Just look at the pictures on the box or on the site. It's funny because APC doesn't sell the XS models directly, so they probably only make them to compete in retail stores.
I have my router and modem also backed up so if the power just flashes you don't have everything reboot on you. They don't draw much so you can easily put them on with your pc.