What is the starting current of a sedan?
3 Answers
When starting, the maximum instantaneous current of a car battery can exceed 300A, and the car requires 300 to 500 amperes of current at the moment of starting. Below is an introduction to the principle of starting current: 1. Motor starting: At the instant the motor is powered on, when the motor is in a stationary state, the rotor is motionless, and the rotor speed is 0. The synchronous rotating magnetic field cuts the rotor winding at the maximum speed, inducing the highest electromotive force in the rotor winding and generating a large current in the rotor winding. This current will counteract the magnetic flux of the stator field. To maintain the original magnetic flux compatible with the power supply voltage, the stator winding will automatically increase the current. Because the rotor current is very large at this time, the stator current of the motor will also increase significantly, up to 5 to 7 times the rated current. This is the reason why the motor has a large starting current. 2. Starting current: The starting current (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.
Regarding the starting current of cars, based on my years of driving experience, it generally ranges between 150 to 300 amperes, depending on the vehicle model and temperature. For example, a typical 1.6L family sedan draws about 200A during startup, while larger SUVs can reach up to 300A. This is especially noticeable in winter when cold engine oil thickens, potentially causing the current to surge to 400A, which may drain the battery and prevent the car from starting. Last winter, my car failed to start, and after checking, it turned out the battery was old and had insufficient capacity. High currents can also accelerate wear on the starter motor, so I recommend checking the battery voltage and connections every two years. Additionally, avoid cranking the engine multiple times in succession during startup, as this increases wear. Simple maintenance can significantly extend the lifespan of these components.
I often encounter starting issues when repairing cars, and current fluctuations between 150-350A are normal. Small cars may have around 180A, while luxury cars or diesel engines could exceed 350A. Last time, a car owner complained about not being able to start in the morning. We measured a current of 280A and found that the battery terminals were loose and overheating. Cleaning the connections promptly resolved the issue. It's worth noting that excessively high current can accelerate wire aging and even cause arc hazards, so it's essential to regularly check insulation with a multimeter. It's advisable not to modify electrical systems arbitrarily to avoid increasing the load. Additionally, it's recommended to replace the battery every three years, and testing cold-start performance is a more reliable precaution.
