Battery Unit; Removing Cables - Hitachi VSP N400 Hardware Reference Manual

If the storage system is connected to a PDU, you can stop the power supply by turning
off the PDU breaker.

Battery unit

Battery lifetime
The battery life time is affected by the battery temperature. The battery temperature changes
depending on the intake temperature and height of the storage system, the configuration,
operation of the controller boards and drives, charge-discharge count and others. The battery
lifetime will be three to five years.
Treatment
Use the storage system in a place where the ambient temperature is 86°F (30°C) or less on
average.
Periodic parts replacement is required. If you have a maintenance service contract, parts are
replaced periodically according to the terms of the contract.
Note: The battery protects the data in the cache memory in an emergency, such
as a sudden power failure. In these cases, follow the normal power down
procedure. If not, the battery might reach its lifespan earlier than expected and
become unusable within three years. When replacing the battery, follow the given
procedure for disposing a used battery.
Replacement period
The battery lifetime (intake temperature is 30 degrees C or less.) in the standard environment
is as shown below.

Removing cables

Observe the following instructions when removing cables form the storage system.
To remove a SAS cable, pull the tab of the SAS cable (1) to release the latch and remove the
SAS cable (2).
Note: If the storage system does not receive power for more than six
months, the battery can become discharged and possibly damaged. To
avoid this situation, charge the battery for more than three hours at least
once every six months.
Chapter 6: Maintaining the storage system
VSP N400, N600 Hardware Reference Guide
Battery unit
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