How To Check Car Battery With Voltmeter. Touch the negative black battery terminal with the negative black meter probe. Set voltmeter reading to auto-detect or 20 volts.
For your battery to pass a load test the multimeter must read between 95 to 105 volts straight for 30 seconds when the battery is tested. Set the dial to 20 which will allow you to accurately measure between 0-20 Volts. As acid and dirt accumulates across and over the terminal the charge starts to leak.
Switch on the headlights for 2 minutes.
The resting voltage should ideally be no lower than 126V. Connect the multimeter probes to the car battery. Connect the multimeter to the positive and negative battery terminals. This means a more accurate reading.
