This episode of Gear Tips covers two ways theck your car’s battery. We used a Digital multimeter and load tester to test the performance of a car battery. If the battery’s voltage is 12.6 V or above, it is considered healthy. The load tester is a great way of determining whether the battery can deliver the required amount of current. Checking a car battery with a multimeter and load tester is an excellent way of gauging the battery’s health. How to test a car battery with a digital multimeter.