Patent ID: 7659697
Filing Date: 2010-02-09
Classification: G06F

Abstract:
1. A method to supply power to one or more battery-backup assemblies disposed in an information storage and retrieval system, comprising the steps of: supplying a first controller having a first controller load, and a second controller having a second controller load; supplying a first battery-backup assembly comprising one or more first batteries, one or more first battery charging elements, a first BBU load, wherein said first battery-backup assembly is interconnected with said first controller; supplying a second battery-backup assembly comprising one or more second batteries, one or more second battery charging elements, a second BBU load, wherein said second battery-backup assembly is interconnected with said second controller; supplying a power bus interconnected to said first controller, said second controller, said first battery-backup assembly, and said second battery-backup assembly; supplying a first power supply interconnected with said power bus; supplying a second power supply interconnected with said power bus; drawing power from said power bus by said first controller, and said second controller, and said first battery-backup assembly, over a first period of time; drawing power from said power bus power by said first controller, and said second controller, and said second battery-backup assembly, over a second period of time, wherein said first period of time interval differs from said second period of time; establishing a first low threshold voltage; establishing a second low threshold voltage; during said first period of time, determining a first actual voltage for the batteries disposed in the first BBU; during said first period of time, determining a second actual voltage for the batteries disposed in the first BBU; during said first period of time, determining if said first actual voltage is greater than or equal to said first nominal voltage; operative if during said first period of time said first actual voltage is greater than or equal to said first nominal voltage, ending said first period of time; operative if during said first period of time said first actual voltage is not greater than or equal to said first nominal voltage, determining if said second actual voltage is greater than said second low threshold voltage; operative if, during said first period of time, said first actual voltage is not greater than or equal to said first nominal voltage, and if said second actual voltage is greater than or equal to said second nominal voltage, continuing said first period of time; operative if, during said first period of time, said first actual voltage is not greater than or equal to said first nominal voltage, and if said second actual voltage is not greater than or equal to said second nominal voltage, ending said first period of time; during said second period of time, determining a second actual voltage for the batteries disposed in the second BBU; during said second period of time, determining a first actual voltage for the batteries disposed in the first BBU; during said first period of time, determining if said second actual voltage is greater than or equal to said second nominal voltage; operative if during said second period of time said second actual voltage is greater than or equal to said second nominal voltage, ending said second period of time; operative if during said second period of time said second actual voltage is not greater than or equal to said second nominal voltage, determining if said first actual voltage is greater than said first low threshold voltage; operative if, during said second period of time, said second actual voltage is not greater than or equal to said second nominal voltage, and if said first actual voltage is greater than or equal to said first nominal voltage, continuing said second period of time; operative if, during said second period of time, said second actual voltage is not greater than or equal to said second nominal voltage, and if said first actual voltage is not greater than or equal to said first nominal voltage, ending said first period of time.