What is the normal voltage for a car battery?
2 Answers
Car batteries generally have a voltage of 12V or 24V. The following are common fault manifestations of car batteries: 1. Battery discharge: Difficulty in starting the car, weak lighting; the detected CCA of the battery is below the standard value. 2. Battery failure: Difficulty or inability to start the vehicle; the tester's result indicates the need to replace the battery. 3. Battery short circuit: The tester's result shows a bad cell battery; the open-circuit voltage of the battery is usually 10V or decreases by 2V, with the CCA value close to 0. 4. Battery fluid deficiency: A hollow sound when tapping the battery case; the battery weight is significantly reduced.
I've been driving for thirty years, and the normal voltage of a regular car battery when parked is around 12.6 volts. A range of 12.6 to 12.8 volts is the ideal full-charge value, indicating good battery condition. When you start the engine, if it rises to 13.5 to 14.7 volts, it means the alternator is charging and the system is functioning properly. Don’t underestimate this voltage—it’s crucial: below 12.4 volts, you might experience slow starts, especially on cold mornings when the battery tends to weaken. I learned this the hard way—once after a business trip, the voltage dropped to 11 volts, and the car wouldn’t start at all. I had to rely on a neighbor to push-start it. Since then, I’ve made it a habit to use a simple voltmeter to check the positive and negative terminals every month. Maintenance is straightforward: avoid leaving lights on, and if the car sits unused for more than two days after a long trip, charge the battery. This can save you the cost of a replacement and ensure you don’t get stranded unexpectedly on the road.
