Avago Technologies 3ware 9550SXU-4LP - Manual (Page 32)

Chapter 2. Installing the Battery Backup Unit
28 3ware 9550SX Serial ATA RAID Controller Quick Install Guide
5 If you have a 4-port or 8-port 9550SX:
a Hook the clips on the top of the battery module over the
slots on the top edge of the controller.
Figure 25. Clips on the battery module hook over slots on the
top edge of the half-height controller
Figure 26. Attaching the battery module to the half-height
controller
b Press down gently on the top of the battery unit so that the
battery holder flexes slightly and the clip on the bottom
slips over the slot on the bottom edge of the controller.