Informational Guide

How Many Volts Is A Car Battery?

Learn exactly how many volts are in a car battery. We look at this and all the surrounding factors that influence car batteries and their ability to function.

The car battery is one of the most important components of your vehicle. It provides the electrical current needed to start the engine and run the accessories.

When the car battery suffers from low voltage, you will struggle with performance and might face a car that requires a best car battery for warmer weather. To make sure your car battery is running as it should, you need answers to top questions, such as how many volts is a car battery?

The automotive battery is rechargeable and supplies electrical current to your motor vehicle. The main purpose of this battery is to feed the starter, which in turn starts the engine.

What is the voltage of a car battery? A fully charged automotive battery measures 12.6 volts, but a battery that isn’t working right could read differently.


Ideal Car Battery Voltage: Ranges Discussed

Fully Charged Voltage

How many volts is a fully charged car battery? A fully charged automotive battery should measure 12.6 volts if it is still in good condition. Using the jump start can tell you what the voltage is on your equipment.

Voltage when the car is starting

How many volts is a bad car battery? Once it gets more than 0.2 volts below the normal, it could be considered dead or bad. You won’t be able to start your car with much less than normal. If you are able to, it’s possible to damage the starter in the process. Some manufacturers agree that the voltage could drop 0.2 and 0.6 volts during starting.

Voltage when the car is running

How many volts is a car battery supposed to have while it is running? The voltage goes up in a good car battery while the vehicle runs. You should receive readings of 13.7 to 14.7 volts. Of course, for this to happen, the car must have a properly working alternator.

Factors That Can Affect Car Battery Voltage

Battery voltage is affected by several things. For one, the automotive battery lasts longer in colder climates, unless you choose the best car battery for warmer weather.

You might also face a poor charging system, such as a failed alternator. If the battery withstands dirt or corrosion, it could also have trouble charging properly. Finally, the older the battery gets, the harder it becomes to hold the charge.

car battery

How To Measure Car Battery Voltage – Load Testing & More

Now that you know how many volts are in a car battery, it’s time to perform a load test to see where your battery stands.

  1. 1
    Put on safety equipment, including eye protection.
  2. 2
    Attach the load tester and apply a load for thirty seconds to the battery to get an accurate reading.
  3. 3
    If you have a healthy battery, it will read more than 9.6v during the entire test.

If it isn’t healthy, you need to replace the battery before you are left stranded.  You might also consider battery reconditioning. Ideally, you should load test your battery if you notice any issues or every six months.

Here is a YouTube video showing the process of load testing a battery.

Indications That You Need To Replace Your Car Battery

Aside from load testing, there are other signs that indicate when you might need a new battery.

  • Slow crank: If it takes longer than normal to start your vehicle.
  • Bloated or swollen battery case: Excessive heat could cause this to happen.
  • Low battery fluid levels: If the fluid dips below the lead plates, you could face trouble with performance.
  • Accessories and lights don’t work at full blast: If the lights begin to dim, the battery might be dying.

If you use a load tester or multimeter, you can also tell when it’s time to replace the battery. How many volts is a good car battery? When the vehicle isn’t running, you want it to read 12.6 volts.

Car Battery Maintenance

  • Avoid taking the car on short trips, as this doesn’t provide enough recharging time.
  • Ensure the battery is adequately fastened under the hood.
  • Make sure the lights are off when the car isn’t running.
  • Clean the car battery regularly.
  • Test the battery every six months.
  • Avoid using electronics while the car is idling.

Ideally, you want to educate yourself about the car battery. You should know how many amps and volts is in a car battery, so you know when something is wrong. Also, keep a note of your voltage readings, so that you can compare them over time.

People Also Ask (FAQs)

At what voltage is a 12 volt battery considered dead?

If the battery can’t reach above 10.5 volts when charged, it likely has a dead cell.

What is a car battery voltage when turned off?

A fully charged battery will read between 12.6 and 12.8 volts.

How long does it take to recharge the battery after starting the engine?

It depends on the automotive battery and the charging system. Many modern vehicles require ten minutes or less of continuous driving to recharge.

At what voltage will a car not start?

Once it reaches 11.5 volts, it may no longer start your car.

How many volts is a hybrid car battery?

The hybrid car battery ranges between three types: the lithium-ion, nickel-metal hydride, and the traditional lead-acid, each with its own voltage requirements.

How do you test voltage without a multimeter?

Start by looking for signs of wear to the battery. Then, start the headlights and run them for 15 minutes without starting the engine. Next, crank the engine on and watch the bulb brightness. They should only dim for a second and not by much.


Now that you know how many volts is a charged car battery, it’s time to take care of your vehicle. Inspect the battery often and make sure you have a working car battery that ensures you always have the starting power you need.