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RAID Controller Batteries

Dell OpenManage™ Server Administrator Storage Management User's Guide

  Battery Properties and Tasks

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:

The NiMHi batteries need to be reconditioned approximately every six months to maintain reliability. (See "Recondition Battery" for more information.) 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.

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.

All RAID controller batteries should be replaced every three years. You should also monitor the Recharge Count and Max Recharge Count properties for the battery. (See "Battery Properties" for more information.) These properties indicate when the battery is approaching the maximum number of times that it can be recharged. When the battery approaches this limit, it should be replaced.

NOTE: Some controllers do not have batteries. Other controllers have lithium ion batteries which are automatically reconditioned and therefore do not have a Recondition task in Storage Management.

Related Information:

Battery Properties and Tasks

Use this window to view information about the battery and execute battery tasks.

Battery Properties

The battery tree-view object has the following properties.

Property

Definition

These icons represent the severity or health of the storage component. See "Storage Component Severity" for more information.

Name

This property displays the name of the battery.

State

This property displays the current status of the battery. Possible values are:

Ready — The battery is functioning normally.

Degraded — The battery needs to be reconditioned.

Reconditioning — The battery is being reconditioned. See "Recondition Battery" for more information.

Charging — The battery is undergoing the recharge phase of the battery Learn cycle. See "Start Learn Cycle" for more information.

Learning — The battery is undergoing the discharge phase of the battery Learn cycle. See "Start Learn Cycle" for more information.

Missing — The controller is missing a battery.

Power Low — The battery charge is low and the battery needs to be reconditioned.

Failed — The battery has failed and needs to be replaced.

Unknown — The battery state is not available.

Predicted Capacity Status

This property displays the charge capacity of the battery. Possible values are:

Ready — The battery can be charged to full capacity.

Failed — The battery cannot be charged and needs to be replaced.

Unknown — The battery is completing a Learn cycle. The charge capacity of the battery cannot be determined until the Learn cycle is complete.

Learn State

This property displays the current status of the battery Learn cycle. Possible values are:

Active — The Learn cycle is currently in progress.

Failed — The Learn cycle initiated but then terminated without completing successfully.

Timed out — The Learn cycle is timed out.

Requested — The Learn State displays Requested when either the controller firmware or a user attempts to initiate a Learn cycle while the battery is charging. The battery must be fully charged before the Learn cycle begins. The Learn State displays Requested until the battery is fully charged. When the battery is fully charged, the Learn cycle will begin.

Idle — The Learn cycle is currently not active.

Next Learn Time

This property displays the number of days and hours left before the controller firmware initiates the next Learn cycle.

Maximum Learn Delay

This property displays the maximum number of days and hours that you can delay the battery Learn cycle. The controller firmware automatically initiates the battery Learn cycle. You cannot stop or pause the Learn cycle, but you can delay it. See "Battery Delay Learn Cycle" and "Start Learn Cycle" for more information.

Recharge Count

This property displays the number of times the controller's battery has been recharged.

Max Recharge Count

This property displays the maximum number of times the controller's battery can be recharged.

Battery Tasks

Do the following to execute a drop-down menu battery task:

  1. Expand the Storage tree object to display the controller objects.

  2. Expand a controller object.

  3. Select the Battery object.

  4. Select a task from the Available Tasks drop-down menu.

  5. Click Execute.

Drop-down Menu Battery Tasks:

Recondition Battery

Does my controller support this feature? See "Appendix: Supported Features."

Some controllers have NiMHi batteries which need to be reconditioned approximately every six months to maintain reliability. This reconditioning cycle requires a full discharge and recharge of the battery. It ensures that the battery's capacity is being measured correctly and that the battery's full holdover time is maintained. See "RAID Controller Batteries" for more information.

The controller battery should be reconditioned when either of the following occurs:

The battery recondition takes approximately 8 to 10 hours. During this time, the battery is fully discharged and recharged. The battery holdover time is reduced to zero (during discharge) and then restored as the battery is fully charged. The write cache is disabled during the battery recondition resulting in performance degradation.

Do the following to recondition the controller battery:

  1. Expand the Storage tree object to display the controller objects.

  2. Expand the controller object.

  3. Select the Battery object.

  4. Select Recondition Battery from the Available Tasks drop-down menu.

  5. Click Execute.

NOTE: The Recondition Battery task is only available on controllers with NiMHi batteries that are in Degraded state or that have generated alert "2145". Some controllers do not have batteries. Other controllers have lithium ion batteries which are automatically reconditioned and therefore do not have a recondition task in Storage Management.

Related information:

Start Learn Cycle

Does my controller support this feature? See "Appendix: Supported Features."

Use the Start Learn Cycle task to initiate the battery Learn cycle.

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.

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.

The controller firmware automatically initiates the Learn cycle. You cannot stop the firmware from running the Learn cycle, although you can delay the start time of the Learn cycle. For more information, see "Battery Delay Learn Cycle".

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.

Battery Delay Learn Cycle

Does my controller support this feature? See "Appendix: Supported Features."

The controller firmware automatically initiates the battery Learn cycle. 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:


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