What is the normal operating voltage of an auto electrical sytem with engine running?

The normal operating voltage of an automotive electrical system with the engine running typically ranges between 13.5 to 14.5 volts. This voltage is generated by the alternator and is necessary to power the vehicle's electrical components and recharge the battery. If the voltage falls significantly below this range, it may indicate a problem with the charging system or battery. Conversely, excessively high voltage can indicate a malfunctioning voltage regulator.