barry,
sorry for not replying to your pm.... been mega busy.
if your charger has adjustable delta peak settings (sometimes referred to as cutoff voltage or similar) you need to dial that into your charger.
from memory, it's normally a drop-off of 0.2 of a volt or so. nicad voltage under charge drops when the cells reach full capacity.
google is your friend
generally, use high currents (four amps or so) for punch, lower currents for duration.
have you run the mini yet?