Methods and apparatus are set forth for automatically controlling a battery back-up unit (BBU) associated with a rack mounted device, under rack A.C. power outage, rack Emergency Power Off (EPO) and normal rack power down conditions. The methods and apparatus contemplated by the invention deactivate...http://www.google.com/patents/US5432386?utm_source=gb-gplus-sharePatent US5432386 - Battery back-up control circuit for battery backed up rack mounted devices
