Write Back Cache Batteries

This Field Change Order (FCO) addresses a manufacturing defect in Write Back Cache (WBC) batteries manufactured during 1996, which were installed in HSZ20-based storage array controllers (including RA310, SWXRC-03, and SWXRC-Zx models). These batteries are at risk of an early-life 'open' failure, potentially causing sudden unavailability of customer RAID or mirrorsets. The solution is to replace affected 1996 batteries with units manufactured in 1997 or later. The document provides detailed ESD safety procedures, a required tool list (#10 Torx screwdriver), controller shutdown and battery replacement steps, and post-installation firmware patch and cache error clearing procedures.