Without further ado, then, here is the 12V lead-acid battery voltage chart. Very Important: The following table shows the resting voltages of the battery. That means they show the voltage measured when the battery is not in use ie. the car is not being charged, or started or driven. A true resting voltage also requires you. Let's now check out what various battery voltages mean when the battery is in use ie. when you are starting or running the car, or when you're charging the battery using car battery charger. We gave you the definitive Car Battery Voltage Chart for cars in the UK, in 2023. We talked about what these voltages actually mean, and how.