HP NetRAID 1 Controller - Manual (Page 71)

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Battery Backup Module
The Battery Backup Module preserves data handled by the HP NetRAID adapter by providing
protection from power supply interruptions to the HP NetRAID cache memory.
The Battery Backup Module can preserve 4 MB of data in DRAM for up to 72 hours.
The HP NetRAID Battery Backup Module monitors the voltage level of the DRAM modules
installed on the HP NetRAID card and supporting circuitry. If the voltage drops below a predefined
level, the Battery Backup Module switches the memory power source from the HP NetRAID card to
the battery pack attached to the HP NetRAID Battery Backup Module. As long as the voltage level
is below the predefined value, the HP NetRAID Battery Backup Module provides the memory
refresh cycles necessary to retain the contents of the HP NetRAID memory modules. If the voltage
level returns to an acceptable level, the Battery Backup Module switches the power source back to
the HP NetRAID adapter card.
Charging the Battery Pack
The battery pack is shipped uncharged. The battery will charge automatically when the system is
turned on.
Description Time to Charge
Battery, NIMH, 4.8V, 650mA onboard battery
pack with mounting brackets 6 hours
Minimum Battery Charging Time
The full data retention time is not available until the battery pack is fully charged. Set the HP
NetRAID cache write policy option to Write-Through while charging the battery pack. After the
battery pack is fully charged, you can change the cache write policy to Write-Back.
Changing the Battery Backup Module
The batteries installed in the Battery Backup Module carry a one-year warranty. The HP NetRAID
software will warn you when the battery needs to be replaced. Do not attempt to install a new battery
pack. You must remove the Battery Backup Module and send it to Hewlett-Packard. We will install
a new battery pack.
To change the battery pack, follow these steps:
1. Bring down the operating system properly. Make sure that cache memory has been flushed.
You must perform a system reset if operating under DOS. When the computer reboots, the
HP NetRAID controller flushes cache memory. Turn the computer power off. Remove the
computer cover. Remove the HP NetRAID controller.
2. Disconnect the battery pack from J2 on the Battery Backup Module.
3. Disconnect the entire Battery Backup Module from the HP NetRAID controller. Unscrew
both the plastic standoff and the metal clip.
4. Do not remove the battery pack. Place the Battery Backup Module in an anti-static bag.
5. Mail the Battery Backup Module to:
Support Materials Organization