I am really happy with my CyperPower UPS and I believe they are one of the top brands to get, right up their with the more commonly known APC brand.
You never mentioned what brand your 600va unit is by the way and I didnt see it in the rig builder.
I have a
CP1350PFCLCD which is a pure sine wave unit at 1350va or 810w.
If my power goes out and the PC was just sitting at idle, I get something like 23 minutes of run time (maybe a bit more) and settings let you control when it auto shuts down if on battery power.
If gaming or doing something with a higher load and the power goes out I think I can still get 12+ minutes to finish up and shut down.
These times are based on memory, but should be pretty accurate.
Also I like both the unit's LCD screen as well as the widget or whatever they are called that I put in the corner of my monitor to see its status.
I did go with a model higher than needed because I wanted the longer battery run time and maybe a few other features were added too.
At the time, the price wasn't that much more either.
That Newegg link I have above shows it at $180 today.
I believe I paid just under $150 near the end of 2014 so you can likely shop around or wait for a sale, maybe memorial day.
I'm not sure if your PSU requires or prefers the pure sine wave, but I think most modern PSUs do.
If not, or you are trying to save some money, you can try the simulated sine wave units.
As far as battery replacement goes, I am still on the original batteries and have had my PC on 24/7 although it idles while I am at work or asleep.
I want to say they last 3 years or more, but I cant remember for sure.
Typically you just pull off the front cover, unplug the connector, maybe unscrew a holder, and then pull out the battery and swap a new one in.
Some units will have 2 batteries so the replacement cost is more. I think mine might actually be a 2 battery unit when I bumped up to the 1350va one.
You can easily check the replacement cost, I don't think they were too crazy, maybe $20 each?
Other things to keep in mind when searching for an UPS:
- The number of plug-ins that are available for On-Battery and just Surge protection. (I run the PC, main monitor, modem, and router all on the battery side)
- Being sure it has things you want like voltage regulation or conditioning.
- Size or shape depending where you want to store it.