Before you start, make sure you have the necessary tools. To test your car battery at home, you’ll need a digital multimeter or voltmeter, safety gloves and goggles, and a clean cloth or brush ...

Note that a fully charged battery should read around 12.6 volts. If it's below 12.4 volts or so, it may need to be charged. For reference, it should hold roughly 13.5 to 14.5 volts when the ...