What Volts Does a Car Battery Need? (Ideal Range)

It can be very difficult to deal with dead batteries in cars. This is why it is important to maintain your battery health. One of the main questions you may wonder is – how many volts is a car battery? It is important to know this figure so that you can maintain a healthy car battery.

This guide will discuss the optimal range for car battery voltage. Also, we will discuss the best way to check car battery voltage. 

How Many Volts is a Car Battery – Ideal Range

When the engine is off, the voltage of your car's battery should range from 12.2 to 12.6 V. The voltage of a fully charged car battery falls to between 13.7 and 14.7V when the engine is running. At 75% battery charge, voltage drops to around 12.4 V. A 25% charge will give you a voltage of around 12 V. 

It is possible to measure the car's battery and see its voltage. You can then compare this voltage to your ideal range. However, even if it says it’s a 12-volt battery, different types of car batteries can measure slightly differently than others. It’s important to see what your particular car battery is rated for before measuring the voltage to know if the readings are good or bad. 

How to test your car's battery voltage

1. Modify Multimeter

With a multimeter, you can quickly get a readout of the car battery’s voltage. You can get accurate readings for a very low price.

Let the car sit on its own overnight before testing it. It’s best to test it after the car has been resting and then again with the engine running. The multimeter should be set to DCV 20. 

RELATED: 10 Best Multimeters – Review & Buyer’s Guide

2. Take a test battery

Touch the negative terminal with the black end of your multimeter. Make sure you don’t touch the leads together.

With your other hand, place the red lead (positive end) on the battery’s positive terminal. After you have read the measurement you will be able to follow the exact same steps while the engine is running. You can also record the figure. 

3. Measurement

You will be able to read the measurement in different ways depending on which multimeter you have. You might display it on a dial or digital multimeter, which displays the number on a screen. 

The voltage reading on the meter, with the engine off should reach 12.4 to 12.6 V for a good battery. After the alternator charges the electric system, the dimension will rise.

Negative readings indicate that the circuit is not flowing correctly. You can switch the positive and negative leads to obtain a positive reading. 

RELATED : Reconditioning a Car Battery at home (5 Simple Steps).

You can test your car battery without a multimeter

If you can’t access a multimeter, you can still test the car battery. While the results won’t be as accurate as if you had the tool, these steps can give you an idea of the car battery’s health. This will allow you to recognize whether your battery is likely to go dead soon.

1. Place the car against a wall or garage door so that you are able to clearly see the lights.
2. After turning off the engine, switch on the headlights and leave them on for fifteen minutes.
3. Start the engine by turning the ignition.
4. Although the light might temporarily dim as the starter starts the engine they should soon regain their brightness. 
5. You could have a dead or dying battery if they get extremely dimmed or struggle to start.
6. If the lights don’t come back around with the engine running, you could also be looking at a discharge due to a failing alternator. Because the alternator charging circuit supplies power, the electrical equipment and lights will gain power while the engine is running.  

The headlights stay bright when everything is functioning as it should. This applies regardless of whether you rev the engine or idle. You should have your battery replaced. 

READ MORE How to check the health of your car's battery at home (8 steps)

Conducting a Car Battery Load test

You can perform a battery test with your multimeter. Once again, set the multimeter at 20 volts. If you don’t have this setting, it must at least be set above 15 volts. 

Be sure to test the battery voltage before moving on. Turn the car off and leave the headlights on. In these two minutes the battery should still be able support the headlights. 

After turning off your headlights, connect the multimeter again to the battery. Even though you have turned the headlights off, your reading should remain normal. If it is less than that, it’s not holding a charge well. 

Better yet, use a battery tester. It will charge the battery and allow you to see its health. You can tell if the voltage drops dramatically when the load tester is activated.

RELATED: 10 Best Car Battery Testers & Analyzers – Review

Is it necessary for a car battery to be charged at 240 volts?

Based on several factors, the car battery requires a different voltage in order to turn on. The starting voltage can be affected by the season (winter or summer). Gas and diesel engines also have differing requirements. It is also important to know if the engine has been heated or cold.

In general, if the engine hasn’t been running, the battery voltage will be around 12.6 volts. A voltage reading below 12 V might allow the battery to still crank the engine. It will not start the engine if it drops to 11.8 volts. A voltage below 11 volts will make it nearly impossible for a car to start. 

What time should a car battery be replaced?

The battery, which provides power for all electric accessories and the engine when it isn't running, should be checked at least every six months. You should also check it if the temperatures drop significantly because colder weather can put a lot of stress on a battery that’s already struggling. 

If the battery isn’t holding a charge the way it should, you should replace it. If not, you could end up stranded with a car engine that won’t start. Of course, this situation never happens when it’s convenient.

READ MORE: What Does it Cost to Change a Car Battery Battery? 

Car batteries should last for at least 4 years before needing to be replaced. How you take care of the battery will determine how long they last. Longer drives can increase the battery’s lifespan. If you can only make short, irregular trips, it’s best to hook the car battery up to a charger when it is at home. It is important to inspect the car battery and prevent corrosion.