55
Chapter 4: Power Supplies and Fans
4.4 Power Management
The Chassis Management Module assumes the maximum power case for each blade prior to
applying power. If the system power is not sufficient, the CMM will not allow that unit to power
up. After a blade is powered up, the blade BIOS calculates the actual power load required by
that blade based upon the installed devices and informs the CMM of its requirements. The
CMM then recalculates the remaining power for additional blades.
Backup Battery Power
Backup battery power (BBP) modules, like all rechargeable batteries, eventually their capacity
and performance decline as they age. Regular maintenance of charge and discharge cycles
is recommended to maintain the effectiveness of the BBP batteries. At least one charge and
discharge cycle for every 30 days is recommended. The BBP maintenance scheduler can be
enabled and configured through the CMM.
When the BBP function is disabled through the CMM, the battery will discharge until the
minimum energy state is reached. While the battery function is disabled, regular BBP
maintenance cannot be performed since the battery energy remains at the lowest state and
will not re-charge. As a result, the battery capacity and performance will decline at a faster
pace, and/or cause the battery to no longer operate. The battery will remain the minimum
charge until the BBP function is again re-enabled through CMM. The user should use the
disabling BBP function with caution knowing that the possible outcome of degraded battery
performance or not operational battery.
The discharge duration can be extended by adding additional BPP modules.
