What is the average voltage reading of a fully charged automotive battery?

A fully charged automotive battery typically has a voltage reading of about 12.6 volts to 12.8 volts. When checking the voltage with a multimeter, a reading of 12.6 volts indicates that the battery is in good condition and fully charged, as this voltage reflects the typical state of charge for a lead-acid battery at rest and without load.

When the battery is discharged, the voltage drops; for example, a reading of 12.4 volts suggests that the battery is moderately charged but not fully. A reading of 12.0 volts generally indicates that the battery is about 50% charged, and a reading around 11.6 volts indicates a deep discharge, which can lead to battery damage if sustained. This understanding of voltage readings is crucial for maintaining battery health, ensuring that it performs optimally within a vehicle's electrical system. Therefore, recognizing that 12.6 volts is the mark for a fully charged battery makes it clear why this is the correct choice.