There are several tools that you can use to monitor and configure and LSI SAS controller, however as I have found, some are easier than others to use and some do not always display the correct information.
In my case my controller is a SAS 9260-8i, and when building a server I always make sure that I install the MegaRaid Storage Manager gui for configuring disks and setting up email alerts. However I have often found that this tool is sometimes confusing to use for other tasks so I also make sure that I install the MegaCLI (command line interface). Both utilities can be downloaded directly from LSI here.
MegaRaid Storage Manager installs to /usr/local/MegaRAID Storage Manager, while the cli installs via rpm to /opt/MegaRAID/MegaCli.
Anyway to check the battery status run the following (note i am running 64 bit os)
#>./MegaCli64 -AdpBbuCmd -aAll
Your output will be lengthy – but look for the line below to know if you need to replace your BBU.
Battery Replacement required : Yes
Two additional usefully commands are:
megacli -AdpAllInfo -aALL
lists all the adapters in the machine
megacli -PDList -aALL
lists all disks and enclosures
Note that there is an open source CLI called Megactl, and while its quick and easy to use to see a quick list of your disks and their statuses, its not shown itself to be accurate when it comes to detecting whether or not a battery has failed. You can get it here