How to Make a Car Battery Fail Test | Step-by-Step Guide

How to Make a Car Battery Fail Test

Car batteries are its power source, so if they aren’t functioning properly, you will have problems. Since it is so readily overlooked by those who need help understanding its significance, proper battery care and testing are relatively easy. This article will instruct us on how to make a car battery fail test more effectively.

What exactly is a battery test, and how can I do one?

A battery load test is an example of a battery test that evaluates the amps a charged battery generates. The acronym CCA or cold start amps known as battery power.

How to Make a Car Battery Fail Test

By running a load test, you can determine if your battery can power the starter motor. You need a battery load tester to complete the test.

How to Make a Car Battery Fail Test

Use it as follows:

  • Start by fully charging the battery. To guarantee a precise outcome, you must take this action. If you have a battery charger handy, you can use it. Make sure the voltage of the battery matches the voltage shown on the battery label using a voltmeter.
  • Next, ensure your multimeter is configured to measure voltage and is connected to the battery. Charge the battery before the stress test if the measured voltage exceeds 10% of the label value.
  • The multimeter must now be unplugged from the battery. Once more, check the battery label to see the rated current. You should see “CCA” with a number after it. This quantity represents cold start amps. To acquire the number for your stress test, divide that number in half. If your CCA is 500, for instance, you would need 250.
  • Make careful you connect the positive terminal of the load tester probes to the positive and negative terminal to the negative battery terminal.
  • A minimum of 15 seconds should be given away from the sensors. Then, read the load tester and contrast it with what you saw in other steps to see whether they match.

Your battery will only generate enough power to start your engine if the reading is between 10% and 15% below the level you estimated. 

How to Make a Car Battery Fail Test

How to Make a Car Battery Fail Test

Overcharging a car battery can result in it failing the test. This involves using an excessively high voltage for an extended time.

Shortening the battery life and damaging the cells may occur. It may also result in battery acid leaks, which could harm the vehicle.

Overcharging a car battery might also make it fail the test. It follows that you need to charge it sufficiently or at all. In addition to shortening battery life, this can harm the battery cells.

Discharging a car battery too thoroughly is another technique to guarantee it won’t pass the test. Thus, before recharging, the battery is fully utilized. In addition to shortening battery life, this can harm battery cells. Maintaining a constant charge and avoiding overcharging, undercharging, and over-discharging are the best ways to keep your car battery from failing the test.

How to Make a Car Battery Fail Test

Process of Testing a Car Battery

Configure your multimeter.

To test your car battery, you don’t need any expensive equipment. A basic multimeter can tell you a lot about the condition of your automobile battery.

You must initially confirm that the settings are the right ones. Choose 20V DC if you don’t have an auto-ranging multimeter.

Configure your multimeter

Join your multimeter

Before connecting the multimeter:

  • Turn off the ignition.
  • Make careful to turn off all the lights and accessories as well.
  • Connect the red wire to the positive terminal, typically identified by a “+” or a red cap.
  • Connect the black wire to the battery’s negative terminal.
Configure your multimeter

The battery requires a value greater than 12 volts. If it’s lower, you must charge the battery or it could be damaged.

Test before proceeding

You can test the battery upon startup if you want further details. This test will enable you to decide whether the battery only requires charging or a replacement.

Configure your multimeter

Make careful to turn off all the lights and accessories once more. You can also disable the ignition or fuel system if you don’t want the engine to start. The engine must be just fired up for this test.

Go to an automobile parts store.

There are alternatives if you don’t have a multimeter or must prepare to test your car battery. Many auto parts retailers provide free battery testing.

Configure your multimeter

You can also go to your neighborhood mechanic. However, this battery inspection typically associates with some form of diagnostic cost.

Frequently Asked Questions

Why do batteries lose power?

The acid build-up is a frequent reason for battery failure. The top half of a stratified battery’s cell has low acidity because the battery concentrates the electrolyte at the bottom. This effect is akin to when the waitress forgets to deliver a stirring spoon, and sugar settles to the bottom of a cup of coffee.

Why do automobile batteries lose power so rapidly?

Corrosives include battery acid. Although it may seem obvious, connection corrosion contributes to car batteries’ constant drain. Investigate what’s happening under the hood. The connectors on the top of the battery, designated as the battery terminals, have positive and negative labels.

How can you check if a car battery is failing?

Apply a load equivalent to 50% of the CCA battery’s rated voltage for 15 seconds using the battery load tester. It is the suggested approach. Using a battery tester, apply a load equal to half the CCA requirements for the automobile for 15 seconds.

Why should the test battery be charged?

If your battery has difficulties producing electricity, it may have a chemical issue. Maintain your battery regularly to get the most out of it. 

What is Normal Battery Voltage with Load?

The normal voltage for a car battery under load, such as when the engine is running, should be between 13.7 and 14.7 volts.

Expert Opinion

You can hire a technician to complete this task if you’re uncomfortable using one or want to avoid investing in one. Hiring a mechanic to complete this task alone will cost you far more than purchasing the multimeter. If you own a multimeter, you can at least complete this task as often as necessary.