HP 3PAR T-Class Installation and Deinstallation Guide

Figure 59 Redundant Power Configuration (T800)
Checking Battery Backup Unit Cable Connections
Battery cables connect the storage system Battery Backup Units (BBU) to the controller nodes.
The BBUs are housed in one or more battery trays sitting above and below the controller nodes.
A battery tray can hold a maximum of four BBUs (Figure 60 (page 69)).
68 Checks and Setup before Powering On the Storage System