What is the normal voltage and ampere rating for a car battery?
2 Answers
Gasoline-powered cars typically use a 65AH battery, while trucks use a 100AH battery. Diesel engines usually require 150-200AH batteries. Most vehicles use a 12V battery (single battery), whereas large trucks may use a 24V system (two batteries connected in series). The function of a car battery is to convert chemical energy into electrical energy, serving as a DC power source. Here are the specific functions: 1. Starting the engine: It provides a strong starting current to the starter (usually as high as 200-600A). 2. When the generator is overloaded: It can assist the generator in supplying power to electrical devices. 3. When the engine is idling: It supplies power to electrical devices. 4. Protecting vehicle electronics: The battery also acts as a large-capacity capacitor to safeguard vehicle electronics. 5. When the generator's voltage exceeds the battery's electromotive force: It converts part of the electrical energy into chemical energy for storage, effectively charging the battery.
I've been driving sedans for decades. The normal battery voltage is 12 volts, and the ampere-hour rating typically ranges between 40 to 60. For my old Buick, a 45Ah battery works perfectly fine. Beginners might not understand why 12 volts is used, but actually, automotive systems are all designed based on this standard. Ampere-hours represent the power supply capacity - for example, a 60Ah battery can deliver high current for one hour. Common issues like failure to start in winter often occur when voltage drops below 11 volts with insufficient ampere-hours, requiring immediate charging or replacement. I make it a habit to check battery status monthly using a simple voltmeter - above 12.4 volts is considered healthy, while lower readings mean it needs charging. Car batteries typically last 3-5 years. When replacing, always choose the same model specification - don't opt for cheaper lower Ah versions, especially since modern vehicles have more electronic devices consuming more power. Avoid using radio or lights with engine off when parked, as power depletion shortens battery life. If you do get stranded, you'll need jump-start assistance, which can be quite troublesome.
