I've been reviewing our server/networking UPS's out at our branches and have found a vast majority of them are 7-8 years old (some 10 or more, but not many) with about half of them having a battery replaced between 1-4 years ago.
In your opinion, when do you start replacing these devices with new models? Do you wait until they fail or do you preemptively replace them? Do you have a life cycle plan for them?