How to Test a Car Battery with a Multimeter

Test a Car Battery

Test a Car Battery with a Multimeter.

You may not realize, but checking your car battery voltage is important in ensuring that the car is running at its optimal state. While many mechanics may adopt other unique ways of checking whether the car battery is at its normal 12.6 volts, the use of a multimeter takes precedence.

A bad battery may not allow your vehicle to operate as it can be the cause of the check engine light being on the dash, the battery seems to be weak, and the engine is clinking slowly or at times may not clink at all.

When the car battery is going bad, inserting the key and turning it on the wrong leads to the battery light coming on the dash. When the car is turned on, the battery light on the dash needs to shut off.

What is a multimeter?

A multimeter is one of the dedicated tools in the automotive industry with the capacity of measuring up to 20 volts of current. It is made into something which resembles an OBD scanner with the gauged scales taking most of its screen.

A multimeter has two detachable cables jutting from it, with tips labeled negative and positive respectively.

Additionally, on a multimeter, you are going to see an on and off adjustment knob for ease of switching on and off and also setting the diverse readings on the voltage scale and resetting it.

Multimeters being technical tools need to be carefully used to get the correct measurements on the voltage and resistance. However, using it has always proven to be the biggest headache to most motorists.

When you want to test a car battery using a multimeter, certain things are important.

Testing a car battery for voltage

using multimeter to test car battery

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We have taken a time to look at the how part of these two processes to assist you with the ordeal you may be going through. This is how to test a car battery for either voltage or resistance with a multimeter;

Get your millimeter – there are several brands of multimeters made with the desire of the user in mind. That is why you are likely to see diverse designs and colors in the market.

Switch off the car engine to avoid cases of electrical shock as this is usually likely if the vehicle is still running.

Fix the cables of the multimeter with the negative, which is black on the COM marked slot and the positive, the red cable on the VΩmA area.

Check for continuity of the circuit by taking the positive to the negative terminal, let the tips touch. When there is continuity, you are likely to experience a beep with the signal of continuity and a reading of zero on the screen. It is worth noting that when the readings remain at 1 and do not fall to zero or a sign of OL is indicated, and the beep of continuity doesn’t come, the cables or the multimeter may have some problem. Some multimeters may have dedicated continuity test modes, which will display.

These are usually easy to use in spite of the fact that battery testing using the gadget does not rely so much on the setting.

Switch the multimeter on and set the dials, because the battery is a direct current, adjust the multimeter to DC.
Configure the range of reading if voltage or resistance you may wish to have if your multimeter is not set up for the auto range.

In our case, set it at 12.6V or lower to get the right reading of voltage.

Attach the positive terminal to the positive end of the car battery and the negative terminal of the multimeter to the negative end of the car battery.

You will have the desired car battery readings displayed on the multimeter screen in volts, for this case, 12.6 volts.

Getting the right reading does not mean your battery is good, go to the ignition and switch the car on, if it picks, and doesn’t drop below 10, it means that the alternator is charging the battery.

If the core cranking drops below 10 or the standard 7.5 volts, the battery is bad and needs to be replaced.

If the testing doesn’t solve the issue, you may need to look at the terminals to check for any sign of corrosion. If corroded, rub with sandpaper to remove the corroded cover to see if the battery will pick now.


Other issues may be a foot with your car battery which may necessitate your visiting of the nearest car parts shop for a new battery if you find it to be bad.

Make the right choice as the car battery and even other appliances we may have on the automotive are not usually made them work on the alternating current, which is accompanied by a lot of risks.

It is, however, advisable that while conducting the testing process, the user still wears protective clothing’s to avert any cases of accidents, arising from shock, which is imminent where the electric current is concerned, it’s that simple.

Guest post by Tim Miller.

About the Author Tim Miller

My name is Tim Miller who have a deep love with automotive and my beautiful wife. I often discover and get knowledge from others as well as share my experience and knowledge about car with other people who have the same love . Visit my site here

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