How To Test a Car Battery With a Multimeter

how to test car battery with a multimeter

A car battery is an essential component of a car without which your car cannot function. It is used to start the engine of the car and is rechargeable. It also provides an electric current to the motor, which starts the engine.

All the car’s electrical systems are powered by this battery after the car’s engine is powered on. The battery of your car is charged by the alternator, which is an electric generator.

Check your Battery voltage: Batteries are placed in the engine bay or if you do not find yours there, consult the manual to locate it. A healthy battery of a car typically has 12.6 volts, but it is advisable to check the resting voltage, which means checking the voltage in the morning when the car rests overnight.

In this way, you will get an accurate gauge of the battery. However, after a long drive, you will get a higher reading which can be misleading; therefore, you must check for the resting voltage for accuracy.

How do you know if your Battery went Bad: You may notice that your car’s battery has gone bad until it is too late and it has completely failed. There are simple signs that will tell you that your car’s battery has gone bad;

  • At first glance, you will see when your car does not start or the engine cranks when you are powering it on.
  • On the dashboard, the light of the battery can be illuminated and the vehicle would require more jump-starts than usual.
  • The car’s lights would be dim than normal, or it would be clicking when you power on the engine.

Is it natural if your car battery wears off: Although car batteries wear off after a span of 3 to 5 years, it would depend on multiple other factors. For example;

  • Cars used for short trips do not let the battery charge entirely, and vehicles parked for a longer time face self-discharge of the battery.
  • The area where you reside will also affect the life of your battery like in cooler regions, car batteries tend to last longer, whereas in hotter areas, they last no more than 3 years.

It is recommended that once your car’s battery has aged 3 years, you need to start getting it tested annually. These tests will help you in knowing the exact level of deterioration of the battery.

What happens if you don’t care: Since the battery and alternator hold such vital importance in running the operations of the car smoothly, you must keep them healthy. If they go bad, it will directly affect the air conditioner, radio system, door locks, or if it completely fails, you will not be able to power on the engine.

To test your car’s battery you can use a multimeter which would help you determine several things. A multimeter is an electronic instrument that measures voltage, indicating the power stored in the battery. Moreover, it can also measure current and resistance. Even bad batteries could show full voltage, but when under load, it is revealed that the battery has gone bad. This is why we mentioned earlier that the battery must be tested after it has rested overnight.

4 Simple Steps To Test Your Car Battery Using Multimeter

We will now be providing a step-by-step guide as to how to test a car battery with a multimeter, which would help determine multiple factors about the car’s battery.

1). Prepare the BatteryNational Safety Apparel Class 0 Black Rubber Voltage Insulating Glove Kit with Leather Protectors, Max. Use Voltage 1,000V AC/ 1,500V DC (KITGC009)

First, you need to locate the battery and check for any dirt and corrosion at the terminal, both positive and negative. If you find any dirt or scrub it away with sandpaper, you will not get an accurate reading.

To prevent your skin from getting damaged from the harmful chemicals, you must wear gloves while scrubbing off the dirt. Clean terminals will be used for the connection points for probes.

2). Multimeter SettingKlein Tools Digital Multimeter, Auto-Ranging, 600V MM400 , Orange , Auto Ranging/Temperature, Capacitance, frequency

Although the multimeter may look complex in the beginning but is fairly easy to use, to begin with, you need to turn the dial to 20 Volts. Then, the surface charge must be removed, and the lights must be turned on for a while and then turned off to get an accurate reading.

3). Touch the Probes to the Battery TerminalDARKBEAM Multimeter Test meter Leads with Banana Plug Digital Clamp Tester voltmeter Probe Test Probes Leads for Multimeter Electronic Test Leads Multimeter Accessories 20A Especially Sharp Model

Multimeter comes with 2 probes of red and black colour. It is designed to ease the user so that they do not get confused while connecting the probe to the respective terminal. The multimeter’s red probe needs to be touched with the positive terminal, whereas the black probe needs to be contacted with the battery’s negative terminal.

4). Measure and Analyze

Once the probes and terminals are connected, you need to check the reading and see if the battery has enough volts to be a healthy battery. Read More: Car battery Rating and Specification

  • A reading for resting voltage of 12.6 would mean that the battery is healthy
  • A reading below 12.6, then you need to get the battery replaced or it needs to be charged.

You now need to do another test, and for that, you will need to turn on the engine. You will notice that at the beginning;

  • The reading of voltage will show a dip but it should not go below 10 volts and if it does then the battery is not healthy and is prone to go bad or complete failure.

Conclusion

We hope you find this article helpful and now know how to test a car battery with a multimeter and can check your car’s battery condition. By following these simple steps, you can quickly test a car battery with a multimeter.

Read Also: How to Test TV Power Supply

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