I cycle my batteries down to .8 volts/cell.

4 Cell 4.8V pack down to 3.2V
5 Cell 6.0V pack down to 4.0V
8 Cell 9.6V pack down to 6.4V

I use to cycle down to .9V/cell, but my triton is defaulted on cycle mode to discharge down to .8V/cell. This is setup at the factory to discharge down to this value and can not be changed on the cycling mode, so I figured .8 must not be too bad if the Triton takes it down to that value. I would hesitate to go any lower. I have heard of some discharging down to .5V/cell, but that is too low for my taste.

Remember, if you discharge at a slower rate you will get a more accurate reading from the battery.