Most (all?) decent datacenters also have generators on site, and the intent is that the UPS will never run out of charge. So the fully-discharged case is an error and it might be intentional to require intervention to recover.
Yeah, some people treat UPSes as "backup power" but that's not really what they're intended for. Their intended purpose is to bridge the gap during interruptions... either to an alternative power source, or to a powered-off state.
Yeah, some people treat UPSes as "backup power" but that's not really what they're intended for. Their intended purpose is to bridge the gap during interruptions... either to an alternative power source, or to a powered-off state.