What is the cross-sectional area of car battery cables?
2 Answers
For small passenger vehicles, the national standard recommends pure copper cables with a cross-sectional area of 16 square millimeters. However, for large engineering vehicles, the recommended national standard is 25 square millimeters of pure copper. If the cable size falls below the recommended value, it may be difficult to jump-start the engine. With constant power and voltage, thicker cables have lower resistance, ultimately delivering greater current to the starter motor. Additional information: Precautions for using car batteries: Ensure the auxiliary battery is 12V and the negative terminal is properly grounded. Of course, all unnecessary lights and accessories should be turned off to prevent electrical accidents. Never reverse the polarity of the cables, as this may cause sparks during connection. Additionally, make sure the cables are tightly secured to both battery terminals (for full contact) to avoid sparking during the jump-start process.
I used to drive a Volkswagen and had to replace the battery cable. The original factory cable was about 20 to 25 square millimeters. For regular family cars like sedans, cables between 16 to 25 square millimeters are sufficient. However, SUVs or trucks with larger engines require 30 to 35 square millimeters because they need to handle high currents during startup. I had a terrible experience with using undersized cables—once I cheaped out and installed an 18 square millimeter cable, which overheated and smoked during startup, nearly burning out. If the cable is too thin, it can overheat when the current is too high, affecting the battery and even the entire electrical system. Now, I always choose high-quality copper-core cables and leave some margin for safety. Regularly checking for loose or corroded cable ends and tightening them with a wrench can extend their lifespan. The car runs much smoother now, without worrying about stalling halfway.
