User's Manual

RAID Controller Batteries 181
10
RAID Controller Batteries
Some RAID controllers have batteries. If the controller has a battery, Storage
Management displays the battery under the controller object in the tree view.
In the event of a power outage, the controller battery preserves data that is in
the nonvolatile cache memory (NVRAM) but not yet written to disk. The
battery is designed to provide a minimum of 72 hours protection for DIMMs
up to 64 MB and 48 hours protection for 128-MB DIMMs. The actual period
of protection (or holdover time) depends on the battery’s charge level.
When a RAID controller is first installed in a server, the battery is fully
discharged. When the server is powered, the battery begins a full charge cycle.
On most controllers, it takes three hours to fully charge the battery. The
controller can be used during this time; however, the battery is unable to
meet the specified holdover time until it is fully charged. The battery is still
able to handle brief power losses during the initial charge cycle.
There are two types of controller batteries:
• NiMHi batteries
• Li-Ion batteries
The NiMHi batteries need to be reconditioned approximately every six
months to maintain reliability. (See Recondition Battery) A battery
recondition fully discharges and then recharges the battery. When the battery
needs reconditioning, the controller reports its state as Degraded. In addition,
the controller may generate event 2145 to indicate that the battery needs
reconditioning.
For information on Alert Messages, see the Dell OpenManage Server
Administrator Messages Reference Guide at support.dell.com/manuals.
The Li-Ion or lithium ion batteries are automatically reconditioned by the
controller. These batteries do not require that you run the battery recondition
task. To see which type of battery the RAID controller has, refer to the
documentation that came with the controller.