Nvram Backup Battery Pack - Hitachi NAS Platform 4000 Series Hardware Reference Manual

NVRAM backup battery pack

Each server contains a battery pack. The battery pack maintains the NVRAM contents
when the server is not receiving power (due to a power failure or a short-term shut
down). The battery pack is located behind the front bezel cover of the server, on the left-
hand side. The battery pack is hot-swappable and can only be accessed after the front
bezel has been removed.
Figure 8 Model 4040 NVRAM backup battery pack (front view)
Figure 9 Model 4060, 4080, and 4100 NVRAM backup battery pack (front view)
Battery pack characteristics:
Each server contains a single battery module. The module contains dual redundancy
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inside.
The battery pack uses NiMH technology.
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A battery pack has a two year operational life. A timer starts when a server is booted
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for the first time, and the timer is manually restarted when a replacement batter pack
is installed. After two years of operation, a log warning event is issued to warn the
user that the battery pack should be replaced.
The battery pack is periodically tested to ensure it is operational.
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A fully charged battery pack maintains the NVRAM contents for approximately 72
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hours.
When a new server is installed and powered on, the battery pack is not fully charged
■
(it will not be at 100% capacity). After being powered on, the server performs tests
and starts a conditioning cycle, which may take up to 24 hours to complete. During
the conditioning cycle, the full NVRAM content backup protection time of 72 hours
cannot be guaranteed.
Hitachi NAS Platform and Hitachi Unified Storage Series 4000 Hardware Reference
Chapter 4: Hitachi NAS Platform server components
NVRAM backup battery pack
38