How many volts is a car battery

Posted by

A typical car battery has a standard voltage rating of 12 volts. The actual voltage measured is 12.4 to 12.6 volts with the engine off. This voltage reading reach 13.5 to 14.5 volts with the engine running.

A car battery is the electrical powerhouse of a car. It is responsible for providing electrical power to the entire car’s electronics. A battery in good condition is crucial for your car’s performance. 

You may face difficulty in starting your car. Your vehicle’s electrical components may malfunction if the battery is dead. 

Car battery performance is measured by how many volts it provides. It is also measured with for how long it can provide that typical voltage. 

In this article, we will answer all your questions about the volts, amps, and watts of a car battery.

How many volts is a car battery

A standard car battery is classified as a rechargeable 12-volt lead acid battery. This 12 voltage is their nominated volts. When measured this voltage is different from 12 volts. 

How much voltage a car battery differs from 12 volts depends on factors like the age of the battery, condition of the battery, and condition of the engine (running or off).

How many volts is a car battery before starting? 

With the engine off, the car battery voltage can be anything from 12.4 to 12.6 volts. 

A new fully charged battery can easily give you a voltage rating of 12.6 volts. A battery with over a year or more of usage will always give below 12.6 volts and like 12.4 volts. 

An old battery showing 11.6 to 11.9 volts indicated that the battery is fully discharged and needs recharging. 

Anything below 11.6 volts will indicate a problem with the car battery and you may need to replace your car battery. 

Charging of a car battery using a charger is needed when you drive for short intervals or in high-traffic areas. In these conditions, the car alternator does not get enough time to charge car battery

Using different highly electrically powered items like speakers, lights or heaters can increase your battery consumption. So car batteries need recharging more often and this can make your battery weak.

How many volts is a car battery after starting? 

With the engine running, the car battery voltage can be anything from 13.5 to 14.5 volts. 

This increase in volts is due to the fact the car alternator is providing power to the battery for charging. Due to this voltage rating is always measured a bit higher than standard voltage. 

If this voltage is measured above 14.5 volts, then your car alternator is faulty and is providing more than the required voltage to the battery. 

This can seriously damage the car battery. Remember that there is a separate hazard class for automotive batteries assign by USA DOT and they can cause serious damage to the driver or car.

To measure the volts of a car battery, you can use a voltmeter or a multimeter. Take the voltmeter and connect it in parallel to the battery circuit. 

The most common way is to directly attach a black probe or meter to the negative or black terminal of the battery and a red probe to the red or positive terminal of the battery.

How many amps is a car battery

A car battery supplies about 300 to 500 amps of current for the car’s electrical systems. It depends on the size, capacity, make, and model of the battery. The amp rating is usually mentioned clearly on the front side of the battery. 

Amps is the short form of an ampere, a unit used to measure the flow of current in an electric circuit. So a battery providing 500 amps means that it can provide 500 amperes of current in the electric circuit of the vehicle. 

You need an ampere meter or a multimeter to measure the car battery amperes. To measure the ampere, take the meter and connect it in series with the battery. It will show you the flow of current in the ampere.

How many amp-hours is a car battery

Car batteries have an amp hour rating of 45 to 65 amps hours. Like amp rating it also depends on the size, capacity, make, and model of the car battery. 

An amp hour means the battery’s ability to deliver specific amps of current for an hour without the need to recharge.

A battery with 50 amps hours means it will provide 50 amps of current to the electric circuit of a car for an hour without the need to recharge. If your car battery has a 50 amps hour rating and your car electric circuit draws 5 amps. 

Then your car battery will supply 5 amps to the electric circuit for 10 hours without a need to recharge. 

How many watts are in a car battery

Car batteries have a power rating of 3.6 KW to 6 KW. The power rating of the car battery depends on the volts and amps rating of the battery. 

Volts rating when multiplied by the amps rating gives the power rating of the car battery. 12 V x 300 amps is equal to 3600 Watts or 3.6 KW. 


What is a car battery CCA?

Cold Cranking Ampere CCA is referred to as the battery’s ability to start a car in a cold environment (low temperature). The higher the value the better it is. 150 to 500 CCA is considered to be a good CCA value.

Is 11.9 volts enough to start a car?

Yes, 11.9 volts is just good enough to start a car but it’s a clear indication that your battery is in bad condition. If it remains in the same range after charging then It may need maintenance or need to change.

What voltage is too low for a car battery?

Anything that gets below 12 volts is not good but a battery with a voltage rating of anything below 11.6 is a clear indication that you need to replace the battery.

Is 14.7 volts good for a car battery?

Yes, with the engine running you can get a 14.7 volts rating at your car battery terminals but that is the maximum volts that are considered safe. 

Leave a Reply

Your email address will not be published. Required fields are marked *