What is the starting current of a 12V car?
2 Answers
The maximum current output by the battery when starting the engine of a car using a 12V battery is 550A. The battery is a crucial component of a car. Without it, the car cannot operate normally. When the engine is not started, the battery supplies power to all the electronic devices in the car, and it is also responsible for starting the engine. A battery refers to a type of battery that can be recharged and reused after discharge. There are lead-acid batteries, nickel-iron batteries, and nickel-cadmium batteries, among others. The positive electrode of a lead-acid battery is lead dioxide, the negative electrode is lead, and the electrolyte is a dilute sulfuric acid solution. During discharge (use), the positive and negative electrodes react with sulfuric acid to form lead sulfate. When the concentration of the sulfuric acid solution drops to a certain level, the battery must be recharged. Using an external power source to recharge the battery can restore the electrodes and solution to their original state, allowing the battery to be used again after charging. Battery usage precautions: Be sure not to use the electronic devices in the car for extended periods when the engine is not started, and avoid turning on power-consuming devices simultaneously when starting the engine.
To be honest, in all my years working in the automotive industry, the cranking current for 12V vehicles actually spans quite a wide range, typically fluctuating between 150 to 600 amps. If you drive a compact car, the cranking current might only be around 150-250 amps; but for large SUVs or pickup trucks, it can easily reach 400-600 amps. Temperature has a huge impact on it: in cold weather, when engine oil thickens, the current may spike to over 500 amps just to start. Battery health also plays a major role—a new battery can handle the current steadily, whereas an old battery might see a sudden surge in current during cranking accompanied by a voltage drop, leading to failed starts. Every time I service vehicles, I advise owners to regularly clean battery terminals because corrosion increases resistance, indirectly raising current demands. Proper maintenance can help avoid these headaches.
