I have a 54831M and not sure of the differences.
Mine has a CMOS battery and believe a battery (with solder terminals) on one of the boards (maybe the video board).
I don't remember seeing a Dallas EEPROM, but, due to it being mentioned in this thread, thinking that maybe I have seen one; or a similar chip.
If your scope is similar to mine, the bottom board is the Acquisition Board and that doesn't contain any batteries. Any batteries would be on the mother board and the boards plugged into the mother board.