UniEnergy Technologies Battery » How Many Volts Does A car Battery Need To Start? (Tips For Testing Battery Voltage)

How Many Volts Does A car Battery Need To Start? (Tips For Testing Battery Voltage)

While the car battery’s primary function is to start the engine, it also operates other electronic systems in your vehicle. When the car is powered, the battery supplies the current that supports it. It also powers GPS, security devices, headlights, and audio equipment. As vital as your car battery is, its voltage is crucial for supplying the required energy throughout the car.

Dealing with a dead battery is frustrating, and that’s why routine battery maintenance is important, as it keeps your battery healthy. One of the questions you might ask is, how many volts does a car battery need to start? This is one of the critical figures you must understand to ensure your car battery won’t disappoint you.

This post highlights everything you need to know about car battery voltage. Read through!

How many volts does it take to start your car?

A typical car battery is 12 volts. The volts needed to start your car should be around 12.6V when the battery is fully charged. Nevertheless, the volts needed to start a car will depend on factors such as temperature. Low temperatures make it harder to start the engine since the battery’s chemical reaction is slower in cold weather, requiring more current (not voltage) to turn over the engine.

Standard volts

The standard voltage of a fully charged car battery is 12.6 volts. This figure typically rises to between 13.7v-14.7v when the engine is running and the alternator is charging the battery. The minimum voltage you need to start your car is typically around 12.2V. Below this voltage, you may have difficulty starting your vehicle.

When the battery voltage is less than 12V, you might have issues cranking up your engine. While you might start at this voltage range, your vehicle will be exposed to repeated stress and potential damage. It would help if you got a new battery or jump-start your car.

Furthermore, with such a low voltage range, you must turn off all other electrical units and may need to repeat the starting process several times.

Ideal volts after starting the car

After you start the car, the ideal voltage should be 13.7v-14.4 volts. If it’s consistently above 14.4v, you risk overcharging your battery. It’s important to check your car’s voltage regulator to make sure your charging system is functioning properly.

You can verify these figures using your car’s internal overhead light units. When the headlights have enough brightness, you don’t have to worry since the battery has enough capacity.

In this case, measuring your car battery voltage is important. You’ll be able to see where the battery voltages register and compare them to the ideal voltage rating.

Steps for testing your car battery voltage

How to measure your battery voltage

Since you know the voltage required to start your car, you might wonder how to check the battery’s voltage. When testing the battery voltage, you perform a procedure called a car battery voltage test.

You can test the voltage in various ways. Testing with a voltmeter or multimeter is the standard method. This is a device that you connect to the terminals of the battery to display the voltage of the battery.

Important things to remember when measuring voltage with a voltmeter:

Use the device even when you think you are a battery expert Switch off the engine and wait at least 30 minutes before connecting the voltmeter to allow any surface charge to dissipate Make sure all electrical loads are off when testing

Here are the steps involved:

Connect the voltmeter to the car battery’s terminals Check the device reading with the engine off Start the car engine Check the voltage reading again

During this time, the battery voltage should be above 12.2V with the engine off, and between 13.7-14.4V with the engine running.

What if the voltmeter reading is below 12.2V?

Battery professionals always refer to these figures as an ideal rating and a sign that your car battery is in good condition. 12.6V is the ideal rating for a healthy car battery at rest. However, what if the voltmeter reading is below the minimum voltage required to start your car?

If the voltmeter records a rating of below 12.2V, there are several possible causes:

Cold weather Damaged or old battery Faulty alternator Loose connection or corrosion

Steps for testing your car battery voltage

If you want to test the voltage of your car battery, follow these steps:

Step1: Configure the multimeter

A multimeter can help you get a read on your battery’s voltage quickly. This device is affordable and can offer you accurate figures. Let the car sit for at least 30 minutes before testing it. It’s good to test when the vehicle has been resting and ensure the engine is off. Set your multimeter to DC Volts at 20V range.

Step2: Test the battery

Hold the multimeter’s black lead and place it on the negative terminal. Don’t touch the multimeter leads together.

Put the red lead on the battery’s positive terminal using your other free hand. After reading the measurement, start the engine and note down the voltage again.

Step3: Read the measurement

Based on the type of multimeter you use, you’ll have a unique way of reading the figures. It can be displayed in the dial range, or you may have an advanced multimeter that displays the measurements on the screen.

When the engine is off, the voltage on the device should be 12.4-12.6v on a good battery. The measurements will increase after the car engine starts and the alternator starts charging the battery.

If you get a negative readout, you connected the leads on the wrong side, and the current flows in the wrong direction.

How to test the battery without a multimeter

You can test the battery even when you can’t find a multimeter. While the outcome might not be as accurate, you’ll get an idea of the battery’s condition. You’ll know if the battery might leave you stuck on the road.

Park your car in front of the garage wall or door, where you can see the headlights well Switch on the headlights for at least 15 minutes with the car engine off Switch on the ignition to start the car The lights may dim briefly as the starter cranks the car engine. However, they should regain brightness after a short while If they remain dim or the car engine struggles to run, you might have a weak or dying battery. If the lights fail to come back on while the engine is on, you might have a charging system issue, possibly due to a damaged alternator. The car’s electrical system and lights must regain the power required while the engine is running since the alternator charging unit supplies power.

What it means when the battery has low voltage

You should assess the components to be sure that a battery replacement is the only solution. Besides low voltage, there are other warning signs for a dead battery. They include:

Swollen battery casing: In a lead-acid car battery, electrical power is extracted from the chemical reactions in the enclosed casing. Sometimes things might go wrong with this chemical reaction, hence the swelling. A swollen battery case is a clear indication that you need a replacement. Slow engine cranks or the engine fails to start: Slow engine cranks are a common sign of a damaged car battery. The primary function of a battery is to start the engine. So, a slow crank is a sign that your battery is dying. Dim lights: The car battery powers the headlights. Dim headlights mean that your battery isn’t supplying enough power to the lights. If you notice dim headlights, consider a battery replacement.

How to solve low-voltage issues?

There are various ways to fix low-voltage car battery issues. They include:

  1. Replace the battery

A damaged or old battery is one of the leading causes of low voltage. In that case, you should test the voltage to determine if the battery is faulty. The quickest method to test the battery voltage is using a multimeter.

  1. Have a portable jump starter as a backup

Sometimes, the battery voltage might not be enough to start the car. Get a portable jump starter to act as a backup based on your car size. With a jumper, you won’t have to seek any road assistance when your battery depletes its charge. You can crank the car engine when an emergency strikes and change the battery once you finish your trip.

  1. Check and maintain your charging system

Ensure your alternator and voltage regulator are functioning properly. These components are crucial for maintaining proper battery voltage while the engine is running.


How many volts does your car battery require to run an engine? Using a voltmeter is the easiest way to measure your battery voltage. Typically, the perfect voltage range is 12.4-12.6V when the engine is off. After starting your car, the voltage should increase to 13.7-14.4V. Make sure you properly turn off the engine and wait before doing the test. We have highlighted the information you need. Comment below if you have any questions about car battery voltage.

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