* 14 Volts (While Running): When the car is running, the alternator is providing power to the battery and all the electrical components. The alternator's output voltage is typically around 14 volts, which is enough to charge the battery and keep the car running.
* 13.5 Volts (Not Running): When the car is off, the battery is simply providing power to the car's electronics (like the clock and memory in the radio). This is a lower voltage, typically around 13.5 volts, because the battery is not being actively charged.
Why the Difference?
The alternator acts like a power source while the car is running. It needs to generate a higher voltage (14 volts) to:
* Charge the Battery: This replaces the energy the battery uses to start the car and power electrical components.
* Power the Car: The alternator provides the electricity for all the electrical components in the car while it's running.
Important Note: If your battery's voltage fluctuates significantly outside these ranges, it could be a sign of a problem with the battery, alternator, or charging system.
Here are some additional factors that could impact the voltage:
* Battery Age: Older batteries may have a lower capacity and may not reach the full 14 volts while charging.
* Ambient Temperature: Extreme temperatures can affect battery performance.
* Load: Heavy electrical loads, such as headlights or air conditioning, can draw more power and temporarily lower the voltage.
In summary: The voltage difference you're seeing is normal and expected. It's a sign that your charging system is working properly. However, if you notice any significant deviations or other issues, it's best to have your car checked by a mechanic.
