How to Measure Car Battery Voltage

Knowing your car battery voltage means you’re less likely to become a victim of a dead battery.

Step 1 - Battery Cables

Start by using your wrench to loosen the clamp of the negative battery cable. Ease the cable off the terminal. After doing this, repeat the action with the positive cable. Always do it in this order to avoid a possible short circuit. Set the cables aside, being careful that they don’t touch each other.

Step 2 - Voltmeter

The voltmeter has two wires, one red and the other black. To check the car battery voltage you’ll need to attach the red wire to the positive terminal and the black wire to the negative terminal.

Check the reading on the voltmeter. You want to see a reading of 12 volts. Allow a small variation on either side. If the reading is well below 12 volts you should be aware that the battery is weak and might well need to be replaced, especially before winter applies.

Step 3 - Finishing

To replace the battery cables, first put the positive cable back on the terminal and tighten it. After this, replace and tighten the negative cable. Put post protectors on top of these to stop corrosion.