Subsystem cache battery
The battery unit in each controller provides backup power to maintain any cached data not written to disks in the event of a power loss. The battery units 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:
vThrow or immerse into water
vHeat to more than 100° C (212° F)
vRepair or disassemble
Dispose of the battery as required by local ordinances or regulations.
Replace the battery units in the DS4700 Express 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 and fan units and on the battery unit respectively, as shown in Figure 104 on page 143.
Replace only the battery unit that is indicated as failed by the LEDs or in the DS4000 Storage Manager Subsystem Management window. You do not need to replace both battery units when the Battery LEDs indicate that only one battery unit has failed.
If the battery age expires, do not call IBM technical support to replace the battery. Instead, reset the battery age using the procedure described in the Storage Manager online help. You should only replace the battery when it is in a failed state, as indicated by the Storage Manager Recovery Guru.
Each power supply and fan unit has green Battery LEDs on the back that indicates the battery status of each battery unit, as follows:
vThe LED is on and remains steady when the battery is fully charged.
vThe LED flashes when the battery is charging or performing a
vThe LED is off if the battery or the battery charger has failed.
The battery unit also has a battery failure indicator LED that is located on the battery unit. This LED will light if the battery fails to hold a charge.
The battery performs a
142IBM System Storage DS4700 Express Storage Subsystem: Installation, User’s and Maintenance Guide
