I bought rs2bl080 RAID controller and AXXRSBBU8 battery. Battery is connected with REB. Booted computer and there was message "If battery is connected and has been allowed to charge for 30min and this message continues to appear, then contact technical support for assistance". My computer has run several hours, but this message wont dissapear. Also I don't see battery detected on controller properties menu.
From event view I saw that battery is detected, battery is charging, Battery temperature is normal and there is this message "bbu disabled changing wb virtual disks to wt" and next one is "battery not detected"
this seems to be an Issue where is not 100% clear how to fix, but in this cases there always some steps to go ;-)
What kind of Server-Mainboard do you use ? (Sometimes an Firmware-issue of the Board could infect the raid-controller ... for shure shoud not infect bbu but i would better check this)
1. Check the cabling of the BBU including connector and wires.( The wires are verry thin and the connector are also. I also have seen that a BBU comes with false marked wires/ connectors)
2. There are a new Firmware Update for your RS2BL080 here: https://downloadcenter.intel.com/download/23601/6GB-SAS-Hardware-RAID-Firmware-Flash-Update-for-DOS-Windows-Linux-and-UEFI Intel® Download Center (Use this even Releasy Notes don´t point exactly to your issue) Update the firmware and after that load the defaults in the RAID Controller firmware.
3. Check Server Mainboard / prepare to update the Firmware
I hope this brings you further to a running BBU ;-)