HP-71B battery drain with no extra RAM or ROM

[hpcalcuser83]

I have checked for the missing terminal inside the caculator and did not hear or find anything inside. Maybe it was attached to the older battery. I have attached a photo showing the missing terminal. I am not sure I understand where the mentioned foam should be. I do not have any foam in the battery compartment area. So I just need to add some conductive material (battery terminal from another device) at the location of the missing terminal? It seems that this terminal should be connected to a GND connection.
   
-Gil