What is the normal voltage of a car battery?
2 Answers
The normal voltage of a car battery is 12V. If measured with a multimeter, a battery voltage between 11.8V and 12.8V is within the normal range, so there is no need for any concern. The vehicle battery provides energy for starting the car and is one of the essential components of an automobile. The maintenance methods for car batteries include: 1. Do not overuse the battery; 2. Regularly clean the positive and negative terminals; 3. Periodically check the vent holes on the cover of non-maintenance-free batteries to avoid blockages; 4. Avoid low battery water levels; 5. When parking for an extended period, start the vehicle once a week to charge the battery.
Every time I check my car's battery, I first look at the voltage. The normal voltage is around 12.6 volts when the engine is off, which is the standard value for a battery at rest. After driving, when the engine is running, the alternator kicks in, and the voltage gradually rises to between 13.5 and 14.5 volts, which indicates the battery is being charged. I make it a habit to use a multimeter to take simple measurements every three months. If the voltage drops below 12 volts, it's a sign to pay attention—it could indicate battery aging or circuit issues, which may lead to starting difficulties or dimming headlights. Once, I encountered a situation where the voltage dropped to 11 volts, and the car wouldn't start halfway. The mechanic said the battery should have been replaced long ago. Regular checks can avoid these troubles and even help extend the battery's lifespan by a year or so.
