Using A Multimeter To Check My Car Battery

Using a multimeter to check your auto battery

One of the most important components of a vehicle is the automotive battery. This is the component responsible for starting the engine and supplying power to the entire electrical system of the vehicle. Taking care of your car battery will allow it to withstand the extreme conditions and to keep it in top shape.

One way of taking good care of your car battery is by having simple battery checks. It will help you determine your battery needs to be reconditioned or be replaced. It will also reduce the risk of experiencing car battery failure.

This is a guide that will help you test your car battery. Later below, this guide will teach you how to test a car battery with a multimeter. It will also provide you some useful information on how to check the voltage of a car battery.

This useful guide will also walk you through the step by step process of battery testing with a voltmeter. Teaching you how to check the charge percentage of your battery and how to do it efficiently and properly.

2 Ways Of Testing A Car Battery To Check For The Voltage

testing the voltage Before we proceed to the step by step guide on how to check the voltage of a car battery by using a multimeter. You first have to understand that the process of checking a battery is done in two ways. It can be done by conducting a voltage test with a multimeter or voltmeter or by performing an Electrolyte Gravity test.

This guide is centered on the first one, but to give you an idea about the other method. The second method is a test that uses a hydrometer to check it the battery is charged and if to see how much voltage it has.

Both of these tests use different instruments, but they will provide you accurate and reliable results. So if you are planning to test your car battery by yourself, you can either choose the method that is much convenient for you.

Simple Vehicle Electrical Test to Know If The Battery Is Charged

If you don’t have both instruments to conduct your battery test, there is a quick and simple way of knowing if your car battery is charged. This electrical system test is simply done by starting your car’s engine and turning on the headlights. Once the engine is running and the lights are turned on, observe the brightness of your lights.

Then you can compare your observation below:

● Dim Headlights – This means that your vehicle’s electrical system is NOT running on your car battery and the alternator producing a little amount or no charge at all.
● Brighter Lights as Engine Revs Up – It means that the alternator is producing a certain amount of charge but not enough to keep the car’s battery to be charged.
● Normal Lights and No Change as Engine Revs Up – This simply means that the electrical system of the vehicle is powered by the battery. The alternator is functioning normally, and it produces enough power to keep the battery charged.

With this simple electrical system test, you will know if your car battery is charged and is probably in good shape. However, if the battery system is showing some problems but the lights test is ok. This means that something on your vehicle discharges your battery or the battery is not holding any charge.

How To Use A Multimeter

Now that you already know the two tests that can be conducted to check for a car’s battery voltage and determine if it is charged. We can now focus on the first method and learn how to do it.

To conduct this test, you will use a multimeter to get the actual reading. If you are going to use a multimeter, keep in mind that you have to configure the device to read up to 20 DC volts.

To make sure that you are doing the right steps, you refer to the step by step guide below:

Step 1 – First you have to do before conducting the test is to turn your ignition off and make sure that your multimeter is set to read up to 20 volts.

Step 2 – Then you have to remove the cover of the battery terminals to allow you to connect the probes of your device.

Step 3 – Once the battery terminals are exposed, connect the negative probe of the multimeter to the battery’s negative terminal.

Step 4 – Carefully connect the other probe (positive) of the multimeter to the positive terminal of the car battery.

Step 5 – Then ask someone to turn on the lights of the vehicle, just to provide the battery with a light load and allow the device to get some reading.

Step 6 – Finally, check your multimeter for its reading at a temperature of approximately 80°F or 26.6°C. Then compare the reading below.

● Reading is 12.5V and above – Battery is well charged (76% – 100%)
● Reading is 12.3V or roughly 12.5V – Battery has good charge (75%)
● Reading is 11.8V and below – Battery has low charge (25%)

NOTE: In case you get a lower reading, try to slow charge your car battery just to improve the chemical reaction. Then redo the test to see if there is a significant improvement (reading gets higher). If the reading stays low or without any improvement, this means the battery is dead, and you need to replace it.


There’s your step by step guide to how you should use a multimeter to test your automotive battery. It’s pretty simple, right? This comprehensive guide also provided some vital information about battery testing. The two methods on how to determine the charge of an automotive battery and the simple electrical system test to check if the battery is charged.

With this quick and useful guide, you can now conduct battery tests on your own to allow you to keep your car batteries in good condition. You can use this test as regular preventive maintenance for your car to reduce the risk of being stranded due to a dead battery.