How To Use A Battery Load Tester

Has your car been misbehaving lately? You go turn on the headlights at night, but the moment you turn on the entertainment system, the lights dim? It could also be that you attempt to start the vehicle, but then it takes several tries before dropping its stubborn attitude and cranks over.

The battery is an important component of your car. The moment it starts experiencing failure, many other components of the vehicle will start malfunctioning. They also do last several years, but that doesn’t mean they won’t fail one day.

If your battery is currently not operating as it should, you should definitely take a look and find out if indeed it is the one misbehaving. For that, you will need a load tester:

But, how to use a battery load tester? There are two ways you can accomplish this; the first is by using a multimeter. This method is used greatly with people who don’t have access to greater tools. The second is through the use of a dedicated battery load testing device.

Testing a battery is quite an easy task for those who are technically inclined. For those who don’t know, there are several things to note before you begin the process of testing.

5 Things You Should Know About Before Using a Battery Load Tester

Step one: To test the battery, you will have to do it without any distractions or hindrances. That means you should park at a place where you are not likely to be interrupted as you work. You will need to let your car sit idle, with the engine off and the handbrake engaged. You can do let the engine be of for 15 to 30 minutes before you begin the test.

Step Two: If you had any electronics drawing power from the battery, you will need to switch them off. This gives the electronics and the battery enough time to remove any charge was still left in the power cables. If you don’t want to lose your vehicle’s programming, you should connect an auxiliary power source into the cigarette lighter port. This power will keep your electronics from losing their saved settings.

Step Three: To ensure that you get a good reading, makes you don’t use anything that may require battery power. That means also the lights that come when a door opens is not supposed to be used. If you need anything out of the car, get it before you begin any testing.

Step four: You will need to gather some tools that will help you in this process. If you have an unsealed battery, you can rely on a hydrometer. This tool is used to test the density of the fluids inside the battery. If yours is sealed, then you will have to rely on a multimeter. This is a tool that has many applications when it comes to electronics, but you’ll only need two for this test. Some batteries do come with inbuilt hydrometers, so before you make a purchase, inspect your battery for one.

Step five: Your safety is paramount. As such, it would be prudent to put on some protective clothing such as gloves, preferably latex. Batteries contain Sulphuric acid which is very corrosive and can damage flesh when it comes into contact with it. You will also need to be away from open flames. Batteries are known to produce hydrogen, which is a flammable gas. No need to tell you how dangerous that is.

2 Tools You Can Use to Do a Battery Load Test

1. Using a Battery Load Tester

This is a specific tool that you can use to test how much power your battery is giving out. If you don’t have one, there are a variety of online stores selling them, so get one for yourself. Ensure it can test up to 1000 cold cranking amps, otherwise you will have bought a tool that can’t accurately match the power of your battery.

For this to work, your battery has to hold at least 75 percent of its total charge capacity. If it is below this point, you need to charge it before conducting the test. Testing it below that percentage will result in false readings.

Once it is properly charged, you need to connect the terminals to the battery posts. You have to start with the negative terminal first, of which the associated cable is usually covered in black sheathing. You then need to connect the positive terminal. The cable is covered in red insulation. The battery post is also denoted by the red color, or a positive sign.

You will then need to read the labels on the battery to find out how much cold cranking amps it can give. To test the battery, you will need to input half of the CCA into the load tester. If the battery is rated at 1000 CCA, you will input 500 CCA.

Next, hold down the load switch button down for at most, 15 seconds. Anything more than this and you risk severely damaging your load meter. A battery in good shape should be giving out power in the range of between 10 to 12.4 volts. If the reading is between 6 to 10 volts, then the battery is on its last legs. A readout of below 6 volts means you need to replace the battery immediately.

2. Using a Digital Voltmeter

A multimeter is capable of testing for various electrical requirements such as how much resistance a material has to the flow of electricity among other things. What you will need here is the dial set to voltmeter.

Once ready, you need to attach the black sensor to the negative post of the battery. Then do the same for the positive, which is red, but connect it to the positive post of the battery. These are usually notated with a plus and minus sign.

The screen on the multimeter will give a read out. If your battery is rated at 12 volts and the reading is 10 percent less, meaning less that 10.8 volts, then you need to recharge your battery and try again. If after charging the voltage remains the same or is lower, then your battery is facing failure and you need to do something about it.