How to Test Car Battery Voltage

Meters measure battery voltage.

The state of your car battery determines your vehicle's ability to start and its electrical system's performance. When the battery begins to cause problems for your vehicle, you should to test its storage and starting capacity. A simple test with the proper electrical metering equipment will determine the current state of your battery and its potential for replacement.

Things You'll Need

• Voltmeter

Instructions

1. Apply the parking brake of the vehicle.

2. Open the vehicle's hood.

3. Turn on the voltmeter. Set the negative lead of the voltmeter to the ground terminal post of the battery. Press the voltmeter's positive lead to the positive battery post. Read the display to determine the voltage stored in the battery. A normal battery level will remain between 12.5 and 12.8 volts.

4. Start the vehicle. Check the draw on the battery while the vehicle is starting. Hold the leads to the battery as the vehicle is running to determine the functionality of the vehicle charging system. Turn off the vehicle.

5. Watch the voltmeter display as the vehicle sits. Replace the battery if the voltage drops steadily after the engine is turned off.

References

• 2 Car Pros: How Do I Check My Car Battery?
• AA1Car.com: Diagnosing A Car Battery That Runs Down