The 128MB BBWC Enabler is a transportable 128MB battery module increasing the total memory of the controller to 192MB for RAID, read cache, & BBWC. The transportability of the battery memory module protects the write cache data from unexpected power loss, system board failure, or controller board failure. Data retained in the write cache will be protected for up to 72 hours, allowing time to restore power, or transport the module to a functioning system board or array controller. The modular design of the battery memory module is transportable between the Smart Array 641 & Smart Array 642 controllers. 128MB BBWC (Battery Backed Write Cache) Enabler allows the 641/642 controllers an option to add transportable BBWC for enhanced controller performance & increases the total controller memory to 192MB.