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How Many Volts Is A Car Battery? Here’s The Answer

How Many Volts Is A Car Battery? Here’s The Answer

A wise man rightly said that the battery is the nerve center of your car. Your car battery serves several purposes in the car.

It ignites the car to running several components like the radio, infotainment system, lights, air conditioner, and much more.

But do you know how a single battery can achieve so much? It’s due to the alternator that sends more than sufficient power to the battery and makes it work above its rated voltage ratings.

However, the battery can go wrong or even dead due to unknown or unavoidable reasons.

To avoid looking up to a dead or unhealthy battery, you should often gauge its volts.

As a thumb rule, the higher the volts, the better the battery ought to perform and vice-versa. To know more about this topic, continue reading further.

How many volts is a car battery?

As a quick roundup, voltage (or volts) is how the electrons travel from one point to another in an electrical circuit.

Talking about car batteries, the higher the voltage, the better the performance. However, not all batteries carry the same voltage.

Many factors like the car’s size, power needs, the strength of the interior components, and much more have a significant say in how much voltage is sufficient for that car.

A standard car battery has around 12 volts. However, as said earlier, even a 12V rated battery can hold 15V for its better working due to the alternator.

But remember that even if the battery has 12 volts rated voltage and can hold 15 volts at max, it doesn’t mean the voltage will remain constant/

In fact, as the battery ages, its voltage starts to fluctuate. For example, after a certain number of miles, the voltage may hardly read 15 volts.

Due to this reason, while you’re driving, the battery can read anything between 12.4V to 14.7V. This range indicates a healthy battery, and the battery is working at approximately 100% capacity.

However, as the voltage falls below 12.4V, you can assume that the battery is getting discharged faster than recharged.

As a result, it’s only operating at its 75% capacity. Similarly, the lower the voltage levels, the lower its performance. Like,

  • At 12.2V, the battery is working at its 50% capacity.
  • At 12V, the battery is operating at its 25% capacity.
  • Lastly, at 11.9V, the battery is fully discharged and will require quick charging. It happens that either the alternator is not charging the battery or the battery is near its age.

Hence, it would help if you always kept an eye on the battery voltage levels and the above levels, and the battery’s corresponding health.

Also read:

  1. How many amps is a car battery??

How to test your car battery’s voltage?

So you have decided to check your car battery’s voltage by yourself? No issues, follow the following step-by-step guide on how to test a car’s battery voltage.

There are multiple methods to test the voltage, but the easiest one is through a voltmeter.

A voltmeter is a device that measures the potential difference between two points on a circuit. It’s available in both analog and digital forms. For quick and accurate results, you’d use a digital voltmeter.

Note: To test the car battery voltage, experts suggest performing this test after at least 12-hours of turning off the engine.

  • Once the car’s engine is cool enough for you to start the test, proceed with the positive terminal.
  • That is, remove the battery’s positive terminal cover, connect the voltmeter’s positive lead to the battery’s positive terminal. Similarly, connect the voltmeter’s negative lead to the battery’s negative terminal. Once the connections are made, proceed to the next step.
  • Now, carefully take the voltmeter readings. If the readings are between 12.6V and 12.8V, the battery has a full charge. If the voltmeter displays voltage below 12.4V, it indicates your battery needs a quick charge. Again, if the charge is below 12.2V, you should trickle or slow charge the battery.
  • It’s important to note here is that even too much charge in the battery is a point of concern. If the voltmeter reading shows a voltage of over 12.9V, it means the battery is holding a charge over its capacity and directly means that the alternator is in bad shape as it’s sending a charge faster rate. To drain out this excessive charge, either turn on the high beams of your car or any other power-consuming component of the car for a few minutes.
  • Check again if the voltage has come down or not.
  • If yes, disconnect the connections and close the hood.

How many volts does a car battery need to start?

As said in the beginning, even if the battery has 12V as a rating, it can still hold 15V of charge. Hence, the minimum volts required to start a car is 12.4V-14.7V.

Anything less than may require more effort in starting the car, and if the voltage exceeds 14.7V, it’s again an area of concern as too much charge can lead to explosions (in rare cases). However, if you have a small-medium car with a standard engine, even 12V can start the car.

Also read:

  1. How Long Does It Take To Charge A Car Battery

How Often Should You Test Your Battery?

Though a battery can deliver a maximum of 3-5 years or 30,000-50,000 miles, you can’t achieve these figures unless you test your battery at regular intervals.

While the mechanic will test the battery for its volts and health every time you’ll visit him for service; you should also try to test your car battery at least twice a year at home.

Or if you are going for a long road trip or have just arrived from the same, you’d test the battery either before leaving or after returning.

Are 12.2 volts enough to start a car?

No, a voltage of 12.2V is not enough to start a battery as this voltage reading indicates a discharged battery. You would need at least 12.4V to start a car with a standard engine capacity and standard car fittings.

Are 10 volts enough to start a car?

No, even a small car has a battery of 12V. If the voltage reading is 10V, it indicates that the battery has bad cells and is either dead or fully discharged.

Hence, you can’t start the car with such a low voltage. You’ll have to charge the battery to at least 12.4V to start the car in one go.

How many volts are in a 12-volt car battery?

The battery’s internal composition is tough to understand. It is because a typical battery can easily hold more volts than its marked capacity.

A 12-volt battery consists of 12.9 volts when fully charged by the alternator and 11.4V when fully discharged.

Can a bad battery still show 12 volts?

Here, you have to keep an essential thing in mind. If the battery is not in use by any car component, i.e., it’s without any load, even a bad battery can display 12-volts.

It occurs due to a battery’s internal mechanism, allowing it to start the car. However, a bad battery won’t run any component of the car.

Hence, don’t assume your battery is healthy even if it shows 12V. Test the battery by turning on the headlights, and if they appear dim, the battery is in bad shape.

Or you can test the battery with a voltmeter. If the voltmeter reading is less than 12 volts against the battery, the battery is in bad shape.

Also read:

  1. Here are some ways to recondition a car battery?

Are 13 volts good for a car battery?

A standard car battery can hold a maximum of 15V even if it has a rating of 12V. 13V is suitable for the battery as when the car is running, and the engine is in a fine state, the voltage level will fluctuate between 12.4V-14.7V. So, you don’t need to worry about the battery displaying 13 volts.

Are 11.8 volts enough to start a car?

No, 11.8 volts is not enough to start a car even if the battery has a voltage rating of 12V as 12V is the minimum volts the particular battery should maintain to remain in a working condition.

So, 11.8 volts will do nothing, and you’d immediately charge the battery and up the volts to at least 12.4 volts.


Your car battery has a life of a maximum of 3-5 years, after which it’s dangerous for both you and the car to continue with the same battery.

Else, you will find yourself stranded in the middle of the road, or the different car components won’t extract power from the battery to operate. In other cases, the bad or worn battery may even cause excessive heating of the engine.

Hence, you’d always keep an eye on your battery’s health. And the best way to determine its health is by testing the battery for its volts.

For example, if the battery has a rating of 12 volts, the alternator can provide it a maximum of 15 volts. And a healthy battery ought to have at least 12.4-14.7 volts to keep working.

Anything below 12.4 volts can cause starting problems and issues in using the various car components.

Hence, it’s advisable to test the car battery at least twice a year at home through a voltmeter. Plus, the mechanic will also test the battery at the car service time.