What voltage is required to start a car?
2 Answers
A car requires 12V voltage to start, which is provided by the battery. Here is detailed information about car batteries: 1. Overview: The battery is an essential part of a car and can be divided into traditional lead-acid batteries and maintenance-free batteries. 2. Structure: The lead-acid battery in a car mainly consists of positive (negative) plates, separators, electrolyte, case, connecting strips, and terminals. 3. Advantages: Compared to traditional batteries, modern batteries have advantages such as not requiring any liquid addition, easy terminal connection, and long power storage time. Since the battery uses a lead-calcium alloy as the grid frame, the amount of water decomposition during charging is minimal, and water evaporation is also low. Additionally, the sealed structure of the case means very little sulfuric acid gas is released.
I've encountered many car starting issues during repairs, with 12 volts being the critical voltage. Most cars use a 12-volt electrical system, and a fully charged battery should maintain around 12.6 volts. During startup, the voltage briefly drops to 10 or 11 volts, but if it falls below 10 volts, the starter motor may not be able to turn the engine, causing the car to fail to start. Ambient temperature has a significant impact; in sub-zero winter conditions, the voltage can easily drop below 9 volts, while it's better in summer. I remember one car that started as slow as a snail, and when I measured the voltage, it was only 8.5 volts—replacing the battery solved the problem immediately. Preventive measures include regularly checking the voltage, which takes just a few minutes with a multimeter; if the voltage is consistently below 12.4 volts, it's time to recharge or replace the battery. Ignoring it can shorten the battery's lifespan or damage the starting system, doubling repair costs, while proper maintenance can save a lot of money.