The motor is where it starts. A motor mfgr. gives guidelines as to how much currant it will accept before damage from excess heat occours. A motor designed to run 30 amps constant with burst of 40 amps for 10 seconds should be propped to not excede those guidelines. The prop makes the load for the motor. So you get a SC designed for 30+ amps, the correct size prop, the battery that gives you a proper run time. Doesn't matter at all how many amps the battery can produce if the motors load is correct. Too large of a prop will make the same setup go way past safe specs.