Avago Technologies 3ware 9650SE-12ML (Channel) - Manual (Page 304)

Troubleshooting
292 3ware SAS/SATA RAID Software User Guide, Version 9.5.1
2 Remove the BBU control module from the 3ware RAID controller and
the battery module from the remote card.
3 Unplug the battery from the control module.
4 Return the BBU control module and battery module to 3ware.
For more details on removing the BBU, see the installation guide that came
with your 3ware RAID controller.
0049 Battery temperature is normal
Event Type
Information
Cause
The battery pack temperature being monitored by the Battery Backup Unit
fell outside of the acceptable range and then came back within the acceptable
range.
Action
None required
004A Battery temperature is low
Event Type
Warning
Cause
The battery pack temperature being monitored by the Battery Backup Unit
has fallen below the acceptable range. The most likely cause is ambient
temperature.
Action
The Battery backup Unit is presently still able to backup the 3ware RAID
controller, but you should replace the battery pack if the temperature warning
persists and is not due to environmental reasons.