IBM ServeRAID M5025, User Manual

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ServeRAID M5025 SAS/SATA Controller User’s Guide 5-1
Chapter 5
Installing the Intelligent
Battery Backup Unit
This chapter explains how to install the intelligent Battery Backup Unit
(iBBU) on the ServeRAID M5025 SAS/SATA Controller.
Attention: Electrostatic discharge can damage the iBBU and the
controller on which it is installed. Always ground yourself
and/or use a ground strap before you touch the controller
or the iBBU. Perform all installation work at an ESD safe
workstation that meets the requirements of EIA-625—
“Requirements for Handling Electrostatic Discharge
Sensitive Devices.” Follow the ESD recommended
practices in the latest revision of IPC-A-610.
The battery in the iBBU must charge for at least six hours during fast
charge under normal operating conditions. To protect your data, the
firmware changes the Write Policy to
write-through until the battery unit
is sufficiently charged. When the battery unit is charged, the RAID
controller firmware changes the Write Policy to
write-back to take
advantage of the performance benefits of data caching.
The maximum ambient temperature for battery packs is 0 °C to 45 °C.
Note: The temperature of the battery pack during fast charge is
typically 15–20 degrees higher than the ambient
temperature. Therefore, for the fast charge circuit to
complete a fast charge cycle, ambient temperature should
be less than 40 °C. If the ambient temperature is greater
than 40 °C, the fast charge cycle could terminate
prematurely.