Trusty UPS's...
At a previous employer, we replaced the 2U APC Smart UPS devices in about 11 server racks with 3 free-standing APC Smart-UPS VTs - providing about 45 mins run time for all the servers. A diesel generator was also on-site.
The site was susceptible to brown-outs/power-loss and the idea being if it happened, the backup batteries kicked-in and the generator fired up after about 1 minute of detecting no mains power to site, relieving the batteries of their duty.
We had our first power issue within a month of the new UPS's being installed...
The worst sound ever in a server room is complete silence, and that's what met me when I returned to the site after getting an out-of-hours call.
Power-loss, batteries *didn't* kick in, all servers died.
Needless to say, the UPS installers were notified straight away - I believe some software path/fix hadn't been applied, or a setting hadn't been configured correctly.
Biting the hand that feeds IT
