1. Let the battery settle
A recent charge or drive can temporarily affect the reading. For a meaningful resting voltage check, follow the battery or vehicle maker's guidance on rest time.
2. Set the meter for DC voltage
Choose a DC voltage range that safely covers a 12 volt automotive battery. Confirm the test leads are in the correct meter ports.
3. Measure across the terminals
Place the red probe on the positive terminal and the black probe on the negative terminal. Read the display without allowing the probes to bridge the terminals.
4. Interpret the result in context
Resting voltage can suggest state of charge, but battery temperature, chemistry, recent charging, and surface charge affect the number. Use manufacturer specifications rather than treating one generic voltage threshold as universal.
5. Use a fuller test when needed
A battery can show reasonable open circuit voltage and still perform poorly under load. If starting performance is weak, a load or conductance test can provide more useful information.
Next, read car battery reconditioning or learn what sulfation means.