Users Guide

The battery Learn cycle discharges and then fully charges the controller battery.

The Learn cycle recalibrates the battery integrated circuit so that the controller can determine whether the battery can maintain the controller cache for the
prescribed period of time in the event of a power loss. For example, some controller batteries are required to maintain the controller cache for 72 hours.

While the Learn cycle is in progress, the battery may not be able to maintain the cache during a power loss. If the controller is using write-back cache policy,
then the controller changes to write-through cache policy until the Learn cycle completes. The write-through cache policy writes the data directly to the disk
and reduces the risk that data can be lost in the cache if there is a power loss.


The controller firmware automatically initiates the Learn cycle every 90 days. You can, however, delay the start time of the Learn cycle for a further seven
days, after which the firmware automatically initiates the Learn cycle. For more information, see "Battery Delay Learn Cycle."


Battery Delay Learn Cycle

Does my controller support this feature? See "Supported Features."

The controller firmware automatically initiates the battery Learn cycle every 90 days. Although you cannot stop the firmware from running the Learn cycle, you
can delay the start time of the Learn cycle for up to seven days. See "Start Learn Cycle" for more information on the battery Learn cycle.

To delay the battery Learn cycle:
1. Type a numerical value in the Days text box. The value must be within the 0 – 7 range. The value you enter indicates the number of days for which you
want to delay the battery Learn cycle. The Learn cycle can be delayed for a maximum of seven days.
2. Type a numerical value in the Hours text box. The value must be within the 0 – 23 range. The value you enter indicates the number of hours for which
you want to delay the battery Learn cycle.
3. Click Apply Changes. If you want to exit and cancel your changes, click Go Back To Battery Information Page.

To locate this task in Storage Management:
1. Expand the Storage tree object to display the controller objects.
2. Expand the controller object.
3. Select the Battery object.
4. Select Delay Learn Cycle from the Available Tasks drop-down menu.
5. Click Execute.

Related Information:
l "Battery Properties and Tasks"
l "Start Learn Cycle"
Back to Contents Page

NOTE: If you have set the controller to write-back force cache policy, then the cache policy is not changed during the Learn cycle. When using write-
back force cache policy, it is possible for data loss to occur if there is a power loss while the Learn cycle is in progress.
NOTE: The Learn cycle cannot be performed while the battery is charging. If either a user or the controller firmware initiate the Learn cycle while the
battery is charging, then the battery Learn State displays Requested. When the battery is fully charged, the Learn cycle will begin.