can you use a multimeter on a car battery

[MacKaylee]

Yes, you can and should use a multimeter to check your car battery. It's a straightforward way to diagnose starting issues and check the battery's health. The key measurement is DC voltage. A fully charged, healthy battery should read 12.6 volts or higher when the car is off. A reading between 12.0 and 12.4 volts indicates a partial charge, and anything below 12.0 volts means the battery is discharged and likely needs recharging or may be failing.

To get an accurate reading, set your multimeter to the DC voltage setting (marked as V⎓ or DCV) with a range that includes 20 volts. Connect the red probe to the battery's positive terminal (+) and the black probe to the negative terminal (-). For a more telling test, check the voltage while a helper cranks the engine; this is the cranking voltage. A healthy battery should maintain a voltage above 9.6 volts during cranking. A significant drop below this suggests the battery can no longer deliver the necessary current and should be replaced.

The table below shows what different voltage readings typically indicate about your battery's state of charge and health.

Battery Voltage (Engine Off)	State of Charge	Battery Health Assessment
12.6V or higher	100%	Fully charged, optimal health.
12.4V	75%	Adequate charge, but monitor.
12.2V	50%	Low charge, needs recharging soon.
12.0V	25%	Very low charge, recharge immediately.
Below 11.9V	0%	Deeply discharged, potentially damaged.
Above 14.0V (Engine Running)	N/A	Alternator is charging correctly.
Below 13.5V (Engine Running)	N/A	Potential alternator charging issue.
Drops below 9.6V during cranking	N/A	Battery is weak and likely needs replacement.

Always prioritize safety. Wear safety glasses and gloves, and be careful not to short-circuit the terminals with the probes. Checking the voltage is a great first step, but if you're having persistent problems, a load test at an auto parts store provides a more definitive diagnosis of the battery's ability to hold a charge under stress.

[OLouis]

Absolutely. I do it every few months just to keep an eye on things. Pop the hood, set the dial to DC voltage—look for the "V" with a straight line and dots—and touch the probes to the correct terminals. If I see a number around 12.6, I know I'm good. If it's dipping toward 12.0, it's time to take the car for a good long drive or hook up a trickle charger. It’s a five-minute job that gives you a heads-up before you ever get stuck with a car that won't start.