Cisco CS-MARS-X10

RAID Controller Back-Up Battery Unit The RAID Backup Battery Unit (RAID BBU) prevents RAID data loss by preserving data held in the RAID cache module during a power outage. The RAID BBU can provide up to 72 hours of battery power until the system power is restored.

The RAID BBU requires 24 hours to fully charge from when the appliance is first powered on, and is continually charged thereafter from the system power. The total charge capacity of the battery degrades over time. The show healthinfo CLI command reports the relative charge state of the RAID BBU.

There is a direct relationship between the relative charge and the battery backup time
(100%charge = 72hours). A 100 percent charge provides 72 hours RAID cache protection. Similarly, a 75 percent charge provides 54 hours of protection (100%charge * .75 = 72hours * .75).

Make sure there is sufficient charge to provide RAID cache protection for the total probable hours the MARS Appliance could be without system power. For example, a 90.3% charge (65 hours) would allow 2 hours to manually restore system power if a total power outage occurred in an unattended facility between 17h00 Friday to 8h00 Monday (63 hours).