IBM DS3500, Installation, User'S, And Maintenance Manual

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when the Battery fault LEDs indicate that only one battery unit has failed. Each controller has a green
Battery charging LED that indicates the status of the battery unit.
v The LED is on when the battery is fully charged
v
The LED flashes when the battery is charging or performing a self-test
v
The LED is off when the battery or the battery charger has failed or is missing
Cache battery learn cycle
The battery performs a learn cycle the first time the storage subsystem is turned on, and again every
eight weeks thereafter, to assess the charge capacity of the battery. If the battery fails the learn cycle or
takes too much time to reach full charge, the Battery charging LED turns off, the Battery fault LED turns
on and the Storage Manager identifies the battery as failed.
The learn cycle takes up to three hours. During this time, the cache will be active if the battery is in
optimal condition. If the learn cycle is interrupted, the current learn cycle will be terminated and the
battery will perform a new learn cycle at the next scheduled interval (eight weeks from the current learn
cycle). A learn cycle interruption is caused by removing the battery from the controller chassis, resetting
the power to the storage subsystem, or if a storage enclosure or battery overheats.
Data caching starts after the battery is charged to the programmed voltage level, which occurs when the
storage subsystem power is first turned on, when a new battery is installed to replace a failed battery, or
when the subsystem power is turned on after months of inactivity.
Attention: Write caching is suspended while a battery pack is either charging or self-testing.
Chapter 4. Operating the storage subsystem and storage enclosure
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