How Large is the Car Starting Current?
2 Answers
Car starting current should be around 10A. More relevant information is as follows: 1. The car battery provides current for car starting, and can assist the generator in supplying power to electrical equipment when the generator is overloaded; when the engine is idling, it supplies power to electrical equipment. 2. The battery is also a large-capacity capacitor that can protect the car's electrical appliances. When the generator's terminal voltage is higher than the electromotive force of the lead-acid battery, it can also charge. 3. The starting current refers to the minimum current that can be obtained under specific conditions from -17.8 degrees to -28.9 degrees, linking the battery's starting capability with the engine's displacement, compression ratio, temperature, the technical state of the engine and electrical system, and the minimum operating voltage for starting and ignition, as well as variables.
The starting current of a car is quite substantial, generally fluctuating between one to two hundred and five hundred amps. It depends on what car you drive—my compact car draws a little over 200 amps when starting, while for large trucks or off-road vehicles, it can even surge to six or seven hundred amps. This is because the starter motor has to crank the entire engine flywheel in an instant, hence the high current. It gets even more extreme in cold winters when thickened engine oil pushes the current to higher values. I recommend choosing a battery with a high Cold Cranking Amps (CCA) rating, such as models with 500 CCA or above. If you frequently take short trips, the battery tends to discharge easily, increasing the starting strain—occasionally take longer drives to recharge it properly. If the engine cranks slowly with a grinding noise, it's time to check the battery or wiring.
