FCOM Systems Description 1 Tome 2.
Chapter 34: On BAT comes on amber when one or more IRs is supplied only by the a/c battery. It also comes on for a few sec at the beginning of the alignment, but not for a fast realignment.
And the AMM says
ADIRS Start Procedure.
(1)
On the overhead panel, on the ADIRS CDU:
(a)
Set the three OFF/NAV/ATT selector switches to NAV.
(b)
Make sure that the ON BAT light comes on for 5 seconds and the ALIGN legend of the IR1, IR2 and IR3 annunciators comes on.
(c)
Make sure that the FAULT and OFF legends of the ADR1, ADR2 and ADR3 pushbutton switches are off.
(2)
On the CAPT and F/O main instrument panels, on the PFDs :
-
make sure that the CAS, ALT and V/S come into view.
-
make sure that the attitude data come into view 40 seconds approximetaly after the three selector switches are at NAV.
(3)
On the ADIRS CDU, set the SYS DISPLAY selector switch to 1 and the DATA DISPLAY selector switch to PPOS, and make sure that dashes are shown on the CDU display