Informational Guide

How Many Amps Is A Car Battery?

A properly working automotive battery is important for all cars. Knowing how many amps in a car battery allows you to troubleshoot any problems that arise.

A properly working automotive battery is needed to start the engine and run the vehicle’s accessories. Knowing how the car battery works allows you to troubleshoot any problems that may arise. Ideally, you want to know how many amps is a car battery, which is what we seek to cover.

white car

The car battery is rechargeable and supplies a necessary electrical current to your vehicle. Basically, the battery feeds the car’s starter, which prompts the engine to start. If the car battery doesn’t have enough juice, it won’t start the engine.

Ideal Car Battery Amp Rating

Car Battery Capacity measured in Amp Hours

The car battery capacity is listed in ampere-hours (Ah). This describes the number of amps a battery provides over 20 hours without dropping below the required voltage. 

Reserve Capacity

The reserve capacity indicates the minutes a fully charged battery is able to deliver 25A and maintain the appropriate amount of voltage. This number is most important with deep cycle batteries.


The cranking amps or marine cranking amps show the maximum current from a fully charged 12V over thirty seconds at 32 degrees Fahrenheit. It’s most often used with marine batteries. 


Cold cranking amps shows the maximum current from a fully charged 12V battery over thirty seconds at zero degrees Fahrenheit. It’s used most often for passenger vehicles that need batteries for cold weather.

Hot Cranking Amps

Shows the amount of current that a battery can provide over thirty seconds at eighty degrees Fahrenheit. This number is valuable when evaluating the deep cycle batteries.

Pulse Hot Cranking Amps

This value shows the maximum current over three to five seconds between 77-80 degrees Fahrenheit. Overall, it can measure the strength of an automotive battery.

How Many Amps Does It Take To Start a Car?

Most fully charged automotive batteries are designed to work with a particular engine, but how many amps is a fully charged car battery? The amps you need to start your car engine will depend on what model you drive. The ambient temperature and voltage will also adjust this value. Most times, a car will require between 400 and 1000 amps to start and power up the electronics.

However, in some cases, having 300 amps might be enough to start the car engine, especially if you drive a compact vehicle. Your vehicle’s owner’s manual should tell you what type of battery is needed to run your car correctly.

How to Measure Car Battery Amps

battery measuring

You can use a multimeter to check the car battery amperage. Once you know - how many amp-hours is a car battery – you will be able to tell if your battery is working correctly.

  • Set your multimeter.
  • Connect it to the battery.
  • Test the battery.
  • Record your measurements.

Here’s a helpful video to get you started.

How to Recharge a Car Battery

There are many ways to recharge your car battery, from providing a jump start to using a maintainer. If you plan to use a maintenance charger, connect the equipment to the appropriate sides of the battery. Make sure you have the settings correct on the unit and turn it on. With something that automatically turns itself off, you won’t have to worry about overcharging. If the battery doesn’t hold a charge, you might consider replacing it or try battery reconditioning.

Car Battery Maintenance Tips

Everyone wants to extend the life of the car battery. With these tips, it’s simple to do.

  • Take the car out on longer trips.
  • Secure the battery tightly under the hood.
  • Keep the lights and accessories off when the car isn’t running or is idling.
  • Clean the battery often to remove corrosion.
  • Test your battery twice a year.

Replace your battery at the first sign that it is worn out.

People Also Ask (FAQs)

Does a battery’s amp rating change over time?

If the battery is in proper working condition, you should receive the specified amp rating every time.

How quickly does a car battery charge while you’re driving?

It depends on the electrical system and battery in your vehicle. For the most part, a ten-mile highway drive should be enough to charge most batteries completely.

How many amps does it take to start the engine?

The majority of cars require between 400 and 1000 amps to start, but each vehicle has different specifications. Check the owner’s manual to find out how many amps and volts the car battery is.

How many amps does a 12-volt car battery have?

Most car batteries have a capacity of 48Ah, meaning it will deliver one amp for 48 hours. However, answering the question - how many amps is a normal car battery – will depend on what type of vehicle you drive.

How many amps do you need to charge the car battery?

The basic car charger operates around 2 amps, meaning it would take 24 hours to fully charge a dead 48Ah battery.

Is it possible to use a charger with higher amps?

Once you figure out how many amps is a regular car battery, you want to choose a compatible charger. However, you could use one that supplies more amps than needed without damaging the battery. Just make sure you don’t overcharge the battery.

Can I leave car battery charger on overnight?

If the battery charger features safety precautions that keep your battery from getting overcharged, you could leave it on overnight. Otherwise, you want to remove the charger as soon as the battery is fully charged.


So, how many amp hours is a standard car battery? Now you know that the figures change based on the vehicle you drive. However, you should have a better understanding of how to protect your car battery and keep it working correctly.