The standard voltage for a lead-acid car battery is 12 volts. This 12V battery consists of six cells, each producing around 2.1 volts, totaling approximately 12.6 to 12.8 volts when fully charged.

Key Voltage Information for Lead-Acid Car Batteries:

• Fully Charged Voltage: 12.6 to 12.8 volts
• Normal Operating Voltage (Engine Running): 13.7 to 14.7 volts (due to the alternator charging the battery)
• Discharged Voltage: Around 12.0 volts
• Deeply Discharged Voltage: Below 11.8 volts (indicates the need for recharging)

It's important to maintain the battery within the correct voltage range to ensure optimal performance and lifespan. If the voltage drops too low, it can cause difficulties in starting the car or lead to battery damage over time.