IBM System Storage Subsystem DS5020 - Manual (Page 45)

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.
Each controller also contains a rechargeable battery unit that is used in the event of
a power failure.
Figure 7 shows how the battery unit slides into the battery backup slot in controller
A.
The backup battery unit provides power to back up the cache memory of each
controller onto flash drives in the event of a power failure. Each battery unit
contains a sealed, rechargeable SMART lithium ion battery. The battery unit
contains enough charge to back up the cached data in each controller to a flash
drive in the event of a power failure.
When the unit is powered on the first time or whenever the battery is replaced, the
battery chargers will charge the battery to the programmed level. Then, the
Pull handle
Latch
Controller A
backup battery unit
Controller B
backup battery unit
Figure 7. Backup battery unit
Chapter 1. Introduction 15