NCR 7458 - Manual (Page 59)

Chapter 3: Hardware Service 3-35
Replacing the Lithium Battery
Caution: Danger of explosion if battery is incorrectly replaced.
Replace only with the same or equivalent type as recommended by the
manufacturer. Discard used batteries according to the manufacturer's
instructions.
1. Slide the Electronics Tray out of the terminal cabinet.
2. Locate the Battery (see the board illustrations earlier in this section).
3. Pry the Battery out of the socket.
19664
Pry Out Battery
Positive Side of Battery
4. Insert the new battery.
5. Replace the Electronics Tray.
6. Run Setup and set defaults. Set the Date/Time and make any
desired special settings.