One large data centre that would rather remain anonymous, was able to identify from their battery monitoring that the charger on the UPS had been incorrectly set and was overcharging the batteries.
Telecom NZ
In addition to the obvious advantages of battery monitoring, they also require battery monitoring on their UPS system for health and safety reasons. They do not want their staff or contractors manually reading battery voltages and impedance, with the risk of high voltage and high current. As batteries are often in battery cabinets access to battery terminals has become more difficult.
Telecom NZ also use the data from the discharge test at commissioning as the bench mark for future tests. A discharge test is undertaken shortly before the battery warranty is due to expire and if a claim is to be made they have documentation to back up the claim.