An Electronic Speed Controller, or “ESC” controls the speed of the motor. ESCs will have a power limit. The more power an ESC can handle, the larger, heavier and more expensive the ESC will be. When choosing an ESC, it needs to match or exceed the motor’s peak amperage. If the peak amperage of the motor is 13 amps, then an ESC rated at 15 amps will be sufficient. An ESC with a lower rated amperage will overheat and possibly fail.
Some common features of an ESC are a low voltage cutoff. The low voltage cutoff will cut the power to the motors when the voltage drops to a specific level. This is a protection feature for LiPo batteries. If a LiPo battery’s voltage drops below its minimal voltage, it can permanently damage the battery. The low voltage cutoff protects the battery from dropping below its minimal voltage.
Some ESCs can be programmed to have different throttle responses, adjust the low voltage cutoff limit, reverse the motor’s direction and change the switch rate.