If the car is running when the battery is tested with a multimeter, the charge from the powered alternator will skew proper readings. 2 Place the red multimeter lead on the red positive battery terminal and the black multimeter lead on the black negative battery terminal. read more
To check whether your battery has reached the leaking point, use a multimeter. Set your voltmeter to a low setting on the voltage scale. Turn on the voltmeter. Then touch the battery negative terminal (-) with the black probe from your meter, and touch the dirty battery cover with the red probe. read more
To test a car battery with a multimeter, set the multimeter to measure DC voltage, and set the dial to 20 volts; with the car off, disconnect the battery cables and attach the multimeter leads to the positive and negative posts on the battery. read more