How to Test Your Car Battery Like A PRO

How to test a car battery like a pro is one of things you need to know how to do as a car owner or driver.

It can be very scary when you one wakes up in the morning and gets ready to work, only to start the car and it won’t start.

The next thing you discover is the battery light on the dashboard begins to flash. This obviously means that the battery is faulty or something is wrong with the battery. So, in this article, I will be showing the various ways of testing your car battery like a pro.

how to test car battery


Before considering how to test a car battery using the most common means, you have to keep track of some important and most necessary preparation tasks such as follows;
  • Start by turning your car off and turning off all the lights.
  • You will also need to turn off any other electric or electronic device that might use battery power
  • without the ignition on.
  • Then you can continue by turning your ignition off.

However, it’s also a good practice to temporarily disconnect your entire ignition system by removing the fuel pump relay or fuse, or by simply uncoupling the ignition coil (if your car is equipped with a coil, distributor and plug wires).

Primary instrument used for testing the battery is a multimeter, which means, we will also be looking at how to test the car battery using the multimeter. In this vain, let us begin.

Testing Your Car Battery Checking the Battery Terminals

Firstly, you check to be sure that the battery terminals are not dead and are working fine.

To do this, with the ignition system disabled, start by touching your multimeter’s red probe to the battery’s positive terminal, then the black probe to the terminal that connects through the cable to the same battery terminal.

Then, ask someone to assist you by cranking up the engine. In that moment, if the multimeter registers more than 0.5 volts, it means you most likely have to clean the clamps or replace the cable connecting the battery to your car.

Repeat the process with the other battery terminal, but this time, you will need to be switching the probes to in order to connect the black probe to the battery terminal.

If you see fluffy or powdery greenish-white deposits around the terminals, it could well just mean that corrosion has built up to a point where it’s preventing the battery from receiving or delivering a charge.

Testing Your Car Battery with A Multimeter

Testing your car battery with a multimeter isn’t as difficult as it seems. Even if you’re not used to the idea of using a multimeter, you’ll find that the process of checking your battery using the multimeter is, in fact, fairly simple.

Begin by removing the battery’s positive terminal cover, then clean it to remove any corrosion. Set your voltmeter to the lowest voltage setting that’s above 15 volts, then connect the negative lead to the negative battery terminal and the red lead to the positive terminal.

This is essentially the whole process, and now you simply have to know what voltage to expect from your battery.

Testing Your Car Battery Voltage Using the Voltmeter

What is a Voltmeter? It is an instrument used for measuring electric potential in volts. If you are noticing some power issues in the car electric system and before blaming the car fault on your battery, you need to also make sure the alternator is working fine.

But the question just popped out; what is an  Alternator?

An alternator converts energy from the engine into alternating electrical current for the battery, which powers the vehicle’s electrical systems. So, if it seems like your battery isn’t working, this is the first place you should look.

A simple method for checking your battery’s voltage involves using a voltmeter, which measures the electrical potential difference between two points in an electric circuit (in crude layman’s terms: voltage). We recommend you opt for a digital voltmeter as they are much easier to use.

For the most accurate reading, perform this test twelve hours after turning off your vehicle to give any surface charge a chance to dissipate.

  • Make sure your vehicle is turned off.
  • Remove the battery’s positive terminal cover.
  • Check the terminal for any corrosion and clean it off if necessary.

You’ll then want to attach your voltmeter’s positive lead to the positive lead on your battery. After that, connect the negative voltmeter lead to the negative battery terminal following the same steps you did for the positive end. Now, you’re all set to check the voltmeter readings.

  • Check the reading. A fully charged battery will typically display a voltmeter reading of about

12.6 to 12.8 volts. If your voltmeter is showing a voltage anywhere between 12.4 and 12.8, that means your battery is in good shape.

  • Any voltage above 12.9 volts is a good indicator that your battery has excessive voltage. If

that’s the case, turn on the high beams to drain excessive voltage surface charge. (Also, an excessive charge could mean that your alternator is to blame for an over charged battery.)

  • Charge your battery if the voltmeter displays a voltage below 12.4. But if you’re voltmeter is

reading anything below 12.2 volts, you should consider “trickle charging” your battery. This essentially means that you would be charging your battery at a much slower rate, which allows you to avoid the risk of applying excess charge amperage that could cause a lot of excess heat and off-gassing (and in extreme cases, explosions).

That will be all.

In conclusion, if you follow the steps listed above in order to know how to test your car battery,

you will never have difficulties understanding how the car battery works. This is not limited to gender. For as long as you are old enough to drive and maintain a car, knowing how to test your car battery like a pro should be of utmost important to you.

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