Here's why:
* Battery's Role: The car battery provides the initial power to start the engine.
* Alternator's Role: Once the engine is running, the alternator takes over the role of powering the electrical system. The alternator generates a higher voltage than the battery, typically between 13.5 and 14.5 volts.
* Charging: This higher voltage from the alternator charges the battery, keeping it topped up.
* Voltage Fluctuations: The exact voltage can fluctuate slightly depending on factors like engine load, temperature, and battery condition.
Important Note: A reading below 12 volts while the engine is running indicates a potential problem with the charging system, likely the alternator.
