when running the nimh the voltage starts at 6 volts and works its way down to 4.2 volts which is when the failsafe will kick in
when running lipos they start at 7.4 and the regulator keeps them at a constant 6 volts keeping the servos at there best performnce threw the whol race
you just have to pay close attention that you dont run them to flat and charge them with a lipo compatible charger
