Very interesting – it implies drivers.
While it is conceivable that battery locomotives could be used on construction, I suspect that the requirement might be for operating a small remote-controlled unit for moving the new stock around at the Rouse Hill maintenance depot.
There seems to be a proliferation of such units occurring and little is known about them. For example, Bombardier have one at their Wulkuraka maintenance depot near Ipswich for the new Queensland electric trains. It met with a slight accident last year as the attachment shows.
Variations on the theme are also being supplied for use at light rail depots, wheel lathe facilities and possibly freight terminals.