www.3ware.com 99Appendix A. Installingthe Battery Backup UnitThe Battery Backup Unit (BBU) is an add-on that can be attachedto a 3ware 9000 RAID controller to supply power to the memorymodule from an attached battery pack in the event of a systempower loss. This allows the controller to use write-caching foroptimal performance and not be exposed to data loss in the event ofa system power failure. When fully charged, the battery preservesthe contents of the controller cache memory for a limited period oftime (up to 72 hours). When power is restored, cached data isflushed to disks.Caution: Both the 3ware RAID controller and theBattery Backup Unit are sensitive electronic equipmentand can be damaged through electrostatic discharge.When installing the BBU on the controller, be sure youare grounded. Use a grounding strap, or work on anESD-protective mat. Do not remove the 3ware controller or BBU from theirprotective bags until you are properly grounded. Handle the 3ware RAID controller by its edges or bythe black rail and metal bracket at its two ends. Do not touch any pin, contact, lead, or component onthe 3ware RAID controller.Important: The battery is a heat-sensitive component.The cooler the battery, the longer the battery lasts. Ifpossible, place the controller with the BBU in a slot withgood airflow, away from components that generate themost heat in the system, such as video cards.
