Fujitsu PRIMERGY BX620 S5 Options Manual page 44

Storage module variants
To install a BBU card in the storage module, proceed as follows:
Figure 28: Installing the RoMB activation key
Ê Place the RoMB activation key in the round socket (see arrow).
V
CAUTION!
Make sure the writing on the RoMB activation key is facing upward.
44 Options Guide
Storage modules
BX620 S5