How to Buy a Battery for Your Car

car batteries on shelves

Your car battery is a storage device for the electrical power you need to start your car and operate your car’s options. If your car battery isn’t working as it should, you may not be able to start your car when you turn the key or it may not charge while you are driving. There are several problems you can experience with a car battery that require replacement:

  • A cracked battery case
  • A frozen battery, visible by bulging sides
  • A battery that won’t accept a charge
  • Loose battery terminals
  • Missing battery filler caps

If you have one or more of these symptoms, you will most likely need to buy a replacement battery for your car.

How do you choose the right battery for your vehicle? What should you look for in a new battery? Follow these steps to get the best battery for your needs.

Part 1 of 4: Find your battery group size

Car batteries are all sorted by a group size. It indicates the measurements of the battery case as well as the orientation of the battery terminals or posts. In order to find the right battery for your car, you’ll need to know the group size.

car battery with arrow pointed to 65S

Step 1: Check for the group size on your old battery. If the battery that originally came with your car is still in it, look for the group size on a label on the battery.

The label may be on the top or on the side of the case.

Group sizes are typically a two-digit number and may be followed with a letter.

group size chart

Typical side-post battery group size numbers are 70, 74, 75, and 78.

Typical top-post battery group size numbers are 41, 42, 48, 24, 24F, 51, 58R, and 65.

Step 2: Check your owner’s manual for a group size. Look under the specifications section in your owner’s manual.

The battery group size as well as other pertinent battery information will be in the specs.

Step 3: Search online for the group size. Use an online resource to determine a battery group size for your car.

picture of autobatteries site

Find an online resource such as AutoBatteries.com to find the group size.

Input your vehicle details including year, make, model, and engine size.

You’ll be presented with the group size and CCA result when you submit the information.

Part 2 of 4: Find your batteries minimum cold cranking amps

Your vehicle requires a certain amount of amperage to start, especially in cold weather. If your battery doesn’t have sufficient amperage to turn over in cold weather, it won’t start and you’ll be stranded.

close up of car battery pointing at CCA

Step 1: Look on your battery’s label. On a label on the top or the side of the battery case, look for a number followed by “CCA.”

If the battery isn’t original to the car, you’ll need to verify that this number is accurate.

The label may be faded or illegible. You may have to find the CCA through another method.

Step 2: Check your manual. Check your owner’s manual specifications for a minimum CCA rating.

Step 3: Check online. Check your online resource for a minimum CCA rating.

  • Tip: The minimum CCA rating can be exceeded without any negative effects, but don’t install a battery with a rating below the minimum CCA rating.

Step 4: Find a battery with a high rating. If you live in a cold climate with several months well below the freezing point, you may want to look for a battery with a higher CCA rating for easier cold-weather starts.

Part 3 of 4: Determine the battery cell type

Most car batteries in use are known as a conventional lead-acid battery. They have cells inside the battery made of positive and negative lead plates in battery acid in a case. They are reliable and have been around a very long time, and are the least expensive type of battery. Most cars will operate without a problem with a conventional lead-acid battery.

Enhanced flooded batteries, or EFB batteries, are a step up from a standard conventional lead-acid design. They are built more sturdy inside and provide double the cyclical stability of the standard battery. They can withstand severe discharges better and can even be used for one of the most demanding technologies now available, stop-start technology. EFB batteries are more expensive than a conventional car battery but you should expect it to last longer on average.

Absorbent glass mat batteries, or AGM batteries, are among the highest quality batteries on the market. They can withstand the most aggressive on and off-road use you can throw at them without skipping a beat including stop-start technology. They can withstand the rigors of high-demand electrical components like DVD players and custom audio systems, and can recover the best from severe battery discharges. AGM batteries are among the most expensive batteries and are used in high-performance, luxury, and exotic cars primarily.

Part 4 of 4: Select the brand and warranty you want

battery comparison chart

Step 1: Pick a recognized brand of battery manufacturer. While the quality of the battery may or may not be any better, a recognized name brand will have better customer support in the event you have battery problems while you are under warranty.

  • Tip: Popular battery brands are Interstate, Bosch, ACDelco, DieHard, and Optima.

Step 2: Pick the grade that is right for you. If you plan on keeping your vehicle for 5 to 10 years, select the higher grade battery that is designed to last longer.

If you are going to be selling or trading in your vehicle soon, select the minimum battery grade that will get you by in the meantime.

battery usage in months

Step 3: Select the battery with the best warranty coverage. Batteries have varying coverage terms even among the same manufacturer.

Pick a warranty with the longest full replacement term followed by a pro-rated term.

Some warranties are 12 months free replacement while others can be 48 months or possibly even longer.

If you aren’t comfortable handling or choosing your car battery, you can enlist the help of a seasoned professional. Ask a certified mechanic to remove or replace your battery for you if you want to make certain that you get the right one for your car.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Car trouble?

Our mechanics make house calls.

  • Get a quote & book a service online
  • Save up to 30% compared to shops
  • Repairs, maintenance & diagnostics
  • 12-month, 12,000-mile warranty
GET A QUOTE

Excellent rating

Rating@3x

Need a mechanic?

Our certified mobile mechanics make house calls in over 700 U.S. cities. Fast, free online quotes for your car repair.

Get a quote

Post a question and get free advice from our certified mechanics.


Ask a question