Telephone battery rooms at 48 volts is similar but not the same as large battery systems used for 120 to 240 volt DC systems for electrical control rooms.
Yes, most use buss bars to tie main runs of batteries together, then to go to next bank or level of batteries paralleled runs of fine strand copper cables are used. These battery rooms are to carry a substantial load while the genset starts and comes on line.
When a battery is taken out of the system a temporary jumper is used around that battery. It is either one or two cables with the same circular mil area as the designed buss bar.