How do I know if a UPS is still under warranty



 The date of manufacture is contained in all APC serial numbers.  The serial number will be a number like
AS0636310220.  The first 4 digits indicate the year and week of manufacture, so in this instance 
the unit was manufactured in the 36th week of 2006.  Most APC UPS come with a 2 year warranty as standard.
The exception to this are the SUVT and Symmetra ranges which come with a 1-year warranty.