Many thanks.
I will be using my A123 2200 ma hr cells. The motor is a battery powered chainsaw one. I would like to use a Opto Isolator to drive the MOSFET gate. Should simplify gate turn on / off. Provide isolation to circuits of the receiver & servo board. I will put a load resistor across the servo motor leads to square up the gate signal.

motor specs below. Will not up load.
14 to 20 vdc
15,000 rpm 25 amp 345 watts is maximum efficiency speed.
stall current is 180 amps. in the weeds.