Thanks for your quick reply. The numbers you state are what I have understood are the numbers to use.

Now my question is why do some speed controls use a lower voltage?

For instance the great planes silver series spec says:
"Low Voltage Cutoff: Battery voltage x .67"
I interpret this to mean that it will operate to cut off the power to the motor when the battery voltage is 2/3 of the voltage measured/sensed by the speed control when the battery is connected to the speed control. If I assume the voltage is say 12,3 volts for a 3s battery, the speed control would then cut off the motor when the voltage drops to 8.2 volts right?

From what I have checked so far the park zone seed controls also use this cutoff (.67) but they add 9v next to this. So what does that mean?

Ed