Preserve critical controller memory and write-cache continuity with a rechargeable CMOS battery designed for supported HP storage and server platforms. The 56Q78AA package pairs a proprietary battery form factor with 500 mAh capacity and 3.6 V DC output, giving compatible Smart Array controllers the backup power they need to retain configuration data and cache state. Built for specific HP controllers and ProLiant systems, this battery is intended for environments where downtime, cache loss, or configuration resets are not acceptable. Its NiMH chemistry supports rechargeability, reducing replacement frequency compared with disposable cells while fitting the maintenance model of enterprise hardware. For infrastructure teams managing legacy HP arrays and servers, this part helps extend the service life of installed platforms without changing the underlying architecture. It is a practical fit for spare-parts inventories, field replacements, and planned maintenance on systems that still carry business-critical workloads. When the goal is to keep supported hardware stable and predictable, this battery delivers the right form factor, the right chemistry, and the right compatibility profile.