Compaq Battery-Backed Write Cache Installation Instructions

NiMH Batteries
The NiMH batteries in the battery module are continuously recharged through a trickle-charging process
whenever the system power is on. Under normal operating conditions, the battery module lasts for three
years before replacement is necessary.
IMPORTANT: The battery module may have a low charge when it is first
installed. In this case, a Power-On Self-Test (POST) message 1794 is displayed
when the server is powered up, indicating that the battery module is temporarily
disabled. No action is necessary on your part, since the internal circuitry
automatically recharges the batteries. The recharge process can take up to four
hours. The array controller will function properly during this time, although without
the performance advantage of the battery module. When the batteries are charged
to 79 percent of their capacity, the battery module is automatically enabled.
Battery Module LEDs
The battery module has two LEDs, one green and one amber. When the battery module is connected to the
controller and the server is powered up, the green LED indicates the status of the battery charge. When the
battery is connected to the controller and the server is powered down, the amber LED indicates the status of
data retention. The following table provides an interpretation of the possible LED illumination patterns.
CAUTION: After the server is powered down, wait 15 seconds and then
check the illumination pattern of the LEDs before unplugging the cable
from the battery module.
• If the amber LED blinks after 15 seconds, do not remove the cable
from the battery module. The module is backing up data, and data
will be lost if the cable is detached.
• If neither LED blinks after 15 seconds, it is safe to remove the cable
from the battery module.
When the server is on, review the POST messages before either
unplugging the cable from the battery module or plugging the cable into
the module.