I have advocated having network management cards in UPS units for years. Well it sure paid off recently at work. We use APC UPS units with the AP9616.
A week back we started getting odd email alerts
Severe – UPS: Invalid internal diagnostic self-test.
Since this was odd and we could see in Cacti graphs that the batteries had capacity we went and checked it out. The UPS was hot to the touch. We yanked it and knew we had avoided a problem. It was not till today we realized how close it was to exploding into a fire incident. Check out the photo. The batteries will not even come out they are so deformed. Had we not used monitoring cards it could have been very bad.