What is the lifespan of an typical UPS battery?
Solution 1:
Your UPS vendor should have guidelines. Our APC UPSes tell us when they think the batteries need to be replaced - from memory, it's about 2 years. How heavily the UPS is loaded has a big impact on battery life. APC recommends that you never load them more than 1/2 way.
Solution 2:
I find UPS batteries fail after 2 to 3 years of continual use. If it's an APC UPS they have a battery test function and I use this about once a month to make sure the battery is OK.
JR
Solution 3:
My main APC UPS is on year 3 with it's current batteries and it's still doing fine. However, I will be bringing in a technician to run some tests to ensure that this is the case. The city I am in recently had a major power outage in it's downtown core. My UPS kept our systems up and running for 25 minutes until it was restored. I was quite impressed.
Keep up regular maintenance and have a technician look over your solution. It's a small price to pay to avoid being left in the dark.
Solution 4:
Battery life also depends on the power quality the UPS is plugged in to. If that UPS is plugged into an outlet with really crappy power, where it moves load to battery for partial seconds quite often, that kind of short-cycling can kill a battery a lot faster than it can in a location with really good power. I can remember one case at my old job where they were replacing the battery in one of the wiring closets every 12 months due to crap power, yet the rack UPSes I was using got to 36 months old without any issues at all.
Also, cost of the UPS does factor in to this. The more expensive ones do a better job of conditioning power internally to the UPS itself which can extend battery life. Also, some are engineered to handle transient power blips or under-volts (under 200ms or there abouts) without going to battery at all.
Solution 5:
APC says 3-5 years: http://www.apc.com/solutions/display.cfm?id=1371A38E-2B31-B5C1-CADC3E466F676960&ISOCountryCode=us
Also here: http://www.schneider-electric.us/en/faqs/FA158934/
The above is consistent with my experience of nearly 30 years in IT.