Do You Know How Many Watts Does a Car Battery Have?

A watt is a power unit. Power is defined as the pace at which energy is created or consumed. A battery is used to power any type of electrical device. Especially a car battery which is used to power the whole car.

Now, how many watts does a car battery have?

To get watt, multiply the ampere by the nominal voltage. A car battery can have 7200 watts per hour. In that case, there will be 60 amps every 10 hours and 12 volts. The amps per hour/Ah value might be mentioned on the battery. So, applying the formula will tell you the watts. 

This information is written down below to answer your question broadly. This will enlighten you on everything about watt in car batteries. 

So, let’s get started then-

How Can You Check Car Battery Watt?

Batteries are devices that turn chemicals into energy. The quantity of energy stored in a battery is referred to as its power capacity. Watt-hours are a common unit of measurement for this power.

Now, before we understand what is watt in a car battery. We have to understand two more things- the voltage and ampere. 


An electric circuit uses electrons that carry the electricity. These electrons need something to push them along the circuit. This electric pressure is known as voltage.

So, in a battery, these electrons flow from positive to where it needs to charge then to positive. 


Ampere is basically how much electric charge is flowing in a point in one second. You can measure this by using an ampere measurement device.


Now, you will easily understand what is watt in a battery. Basically, when you multiple volt and ampere together you will get Watt. The formula for this-

W (joules per second) = A (coulombs per second) x V (joules per coulomb)

W= Watt

V= Voltage 

A= Ampere 

After applying this formula. Then you’ll be able to tell how much current is flowing and at what rate.

Now that you know the important stuff, how do you check the battery?

Well, oftentimes a multimeter is used to check the car battery. It is electronic measuring equipment. This device is used to determine the voltage, Ampere, and resistance of an electrical source.

To help you more, we have recommended you top two multimeters-

These are not so expensive and easily available. You can easily check voltage and ampere with it, which is quite important. Because these are needed to measure the watts.

How Many Watts Does a Car Battery Have?


An automobile or car battery is a six-cell plastic box filled with an electrolyte. Which is a sulfuric acid solution that is electrically conductive.

This chemical reacts with the electrodes of the battery. There are metal plates containing lead and lead oxide, to produce 12 volts of energy. When completely charged, a “regular” battery produces 12.6 volts.

Here is how to calculate the watt of a car battery-


A car battery is normally measured in voltage. And watts are calculated using battery amps and voltage. 

The following formula is used to compute battery watts: 

  • Amps x Voltage

Suppose, a car has 60 amps per 10 hours and 12 volts. Then if you multiply them, you will get 7200 watts-hour.

This formula can be used to calculate the wattage of a car battery.

How Many Watts can a Car Consume?

When it comes to automobile battery wattage, this is the correct question to ask. You can also ask how much power the battery can really hold.

That depends on the type of battery you are using. Things may get tricky with lead-acid batteries. Because the more amps you draw out, the less power you receive.

A car battery can typically maintain 5 amps for 10 hours. As a result, such a battery has a capacity of 50 amp-hours. This equates to approximately 600-watt hours.

if you use the 20-hour rate, the battery should provide roughly 2.7 amps. This is also a 54-amp-hour (648-watt-hour) battery.

We are recommending you the top three car batteries-

These are the top 3 batteries for your car. But before buying them do check the size that fits your car.

To fit the battery in your car’s battery tray, make sure one thing. And that’s- you’re buying the correct sized battery with the correct specifications.

Some sizes are mentioned here. These will give you an idea of the most popular battery sizes-

  • Size 34/78 – Typically has two ports and can fit various Chrysler and General Motors vehicles.
  • Size 34 – The majority of these batteries will fit Chrysler vehicles.
  • Size 35 – These batteries are often used in Honda, Nissan, and Toyota vehicles. 
  • Size 65 – These batteries are commonly used in Ford, Lincoln, and Mercury vehicles. 
  • Size 75 – These batteries are commonly used in General Motors vehicles.

By the way, after you have your battery, regularly check its state. For that, you can use battery testers. We are recommending you some best battery testers here-

Any of them will help you know the condition of your battery. 

We hope this article helps you grasp what you’re searching for.

Frequently Asked Questions

Question: How many volts should a fully charged car battery have?

Answer: A fully charged car battery should have a voltage of 12.6 volts or greater. This value should be between 13.7 and 14.7 volts when the engine is running.

Question: How long can a 50 Watt automobile battery run?

Answer: If the battery has a total energy capacity of 480 watt-hours, which is 12 volts x 40 amp-hours. If you divide this by 50 watts, you get 9.6 hours.

Question: Are 11.9 volts sufficient to start a car?

Answer: The normal voltage required to start the car is 12.6 volts. This parameter is between 13.7 and 14.7 volts at the moment of exploitation.


By now we hope you know how many watts does a car battery have. This article also included instructions on how to calculate the watts of any automotive battery. 

Thank you for staying with us for so long. And you can always reach us through social media and email. 

Rob Dahm

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