Subsystem Cache Battery; Cache Active Leds - IBM DS4800 User, Installation And Maintenance Manual

Figure 80. Cache Active LEDs

Subsystem cache battery

The DS4800 interconnect-battery unit contains two battery packs that provide
backup power to maintain any cached data not written to disks in the event of a
power loss. The battery packs can provide power to the data caches in the RAID
controllers for up to three days.
Statement 2:
CAUTION:
When replacing the lithium battery, use only an equivalent type battery
recommended by the manufacturer. If your system has a module containing a
lithium battery, replace it only with the same module type made by the same
manufacturer. The battery contains lithium and can explode if not properly
used, handled, or disposed of.
Do not:
v Throw or immerse into water
v Heat to more than 100° C (212° F)
v Repair or disassemble
Dispose of the battery as required by local ordinances or regulations.
Replace the battery packs in the DS4800 interconnect-battery unit when they are
identified as failing by the DS4000 Storage Manager Subsystem Management
window, or when the Battery LEDs or Battery Needs Attention LEDs light (these
LEDs are located on the power supply-fan units and on the interconnect-battery unit
respectively, as shown in Figure 81 on page 131).
130
IBM System Storage DS4800 Storage Subsystem: Installation, User's, and Maintenance Guide
Controller A
Cache active LED
Controller B
Cache active LED