If trigger motion becomes rough take controller apart. Use emery cloth between button and resistor to polish button and resistor wire surface. Four lane tracks come with 15 amp and 6 lane 25 amp. Make sure wires connecting to power supply are secured well. Keep power supply away from water and out of reach of small children.
Power supply is relatively maintenance free.
Maximum power is 15 volts. Novice racers should keep voltage between 11-13 volts, depending on the motors that are in cars.