IBM Storwize V7000 Unified Series Problem Determination Manual page 247

Attention: If your system is powered on and performing I/O operations, go to
the management GUI and follow the fix procedures. Performing the replacement
actions without the assistance of the fix procedures can result in loss of data or
access to data.
Even though many of these procedures are hot-swappable, these procedures are
intended to be used only when your system is not up and running and performing
I/O operations. Unless your system is offline, go to the management GUI and
follow the fix procedures.
Be careful when you are replacing the hardware components that are located in the
back of the system that you do not inadvertently disturb or remove any cables that
you are not instructed to remove.
Each power supply unit in a control enclosure contains an integrated battery that
is used during temporary short-term power outages. You must replace the battery
with the exact same model.
To replace the battery in the power supply unit of the control enclosure, perform
the following steps:
1. Read the safety information to which "Preparing to remove and replace parts"
on page 209 refers.
2. Follow the removing steps of the replacing a power-supply unit procedure. Go
to "Replacing a power supply unit for a control enclosure" on page 214.
3. Remove the battery, as shown in Figure 59 on page 224.
Chapter 5. Control enclosure
223