> Even so, 3 year warranty isn't necessarily enough, if
>someone doesn't have frequent power outtages or if they
>don't need extended runtime, only a graceful immediate
>shutdown when power goes out, a set of batteries for an UPS
>can last longer than 3 years. The hardest thing for the
>batteries to to run them down, keep running the system as
>long as the UPS can manage it.
One (somewhat) amusing situation I found myself in several years ago
involved Exide's recommendations for testing their UPS products. (In
my case I was using three UPS boxes, rated at a total of 190 KVA and
with a six-figure price tag.)
Some Exide sources were horrified at the idea of testing system endurance;
other equally-official sources recommended testing. I wound up running
annual testing by tripping the mains and measuring the time until
the 5-minute warning sounded; in at least one case this saved the
mainframe center I was managing since the batteries had failed on one
of the boxes, giving me only 45 seconds of running time for the load
being supported by that box. That test saved me over $5000 (in 1985
dollars) since Exide paid for the replacement batteries (the warranty
on the box expired four weeks later).
And before someone points out the risks of failure while testing a UPS
box, the tests were run (a) with the bypass feeds live, so if the
UPS itself trips it will automatically transfer the load to the bypass,
and (b) I scheduled the tests at a time when no critical jobs
were running.
Re: No power on my APC UPS 
Linear Mode
