How to Check Car Battery Voltage With a DMM


Turn on the multimeter. Set the meter scale to "DC Voltage."


Place the negative (black) meter probe on the negative battery post. Place the positive (red) meter probe on the positive battery post.


Read the multimeter display; the battery voltage differential should be approximately 12.6 volts DC.

Tips and Warnings

  • If the multimeter leads are inadvertently reversed, the voltage reading on the multimeter will be a negative number.
  • An automotive battery provides electrical energy for vehicle starting, and serves as the electrical return (also known as "ground") for the entire electrical system. Since the battery plays such an important role in the operation of an automobile, it is necessary to test the battery periodically. One important test is a voltage check.