From the entry on Regeneration:
\"Characters with no Stamina do not heal (see Absent Abilities in
Abilities). One or more ranks of Regeneration overcome this. An absent
Stamina character with Regeneration 1 recovers at a normal rate;
additional Regeneration ranks speed up that rate.\"
Currently, a construct with no Stamina and Regeneration 2 shows 1
condition healed every 5 rounds. It should show 1 condition every 10
rounds.