How Large is the Car Starting Current?

[McElijah]

Generally, the starting current of a sedan ranges between 100 to 300 amperes. If the engine has a larger displacement, the starting current will correspondingly increase. Principle of Starting Current: At the instant when the motor is energized and is in a stationary state, the rotor remains motionless with a speed of 0. The synchronous rotating magnetic field then cuts the rotor windings at the maximum speed, inducing the highest electromotive force in the rotor windings and generating a very large current. This current counteracts the magnetic flux of the stator field. To maintain the original magnetic flux compatible with the power supply voltage, the stator windings automatically increase the current. Since the rotor current is very large at this time, the stator current of the motor also increases significantly, reaching 5-7 times the rated current. This is the reason why the motor has a large starting current. Introduction to Starting Current: The Cold Cranking Amps (CCA) index refers to the minimum current obtainable under specific conditions at -17.8°C and -28.9°C. This index links the starting capability of the battery with important variables such as engine displacement, compression ratio, temperature, starting time, the technical state of the engine and electrical system, and the minimum operating voltage for starting and ignition.