The COMBATT is a NiCad discharger.It is quite simple in its operation, your NiCad pack is simply discharged through a large 50 watt resistor. As the NiCad discharges, your computer ’samples’ the voltage of the battery pack on load, and marks a series of red points on your screen, i.e. it draws a line. At the point when the pack voltage just dips below 1 volt per cell (4 volts for 4 cells, 8 volts for 8 cells and so on) your computer will automatically stop the discharge of the pack.
COMBATT: the NiCad discharger - [Link]
http://www.electronics-lab.com/blog/?p=2479