Choosing a Car Battery: How to Find the Right Size, Brand, and Rating
Your Guide to Choosing a Replacement Car Battery
Your car battery is located under your vehicle's hood. Not only does it provide the electricity needed for your door locks, sliding windows, lights, and other car accessories, but it also allows you to start your vehicle. The moment your battery dies, your car is no longer functional.
Like other motor-vehicle components, batteries wear out over time and need to be replaced. Do-it-yourself car-battery replacement can be a real money saver, but how do you make sure you're choosing the right battery? There are five important factors that must be considered when searching for an appropriate replacement battery.
5 Important Factors in Choosing a Car Battery
- Reserve Capacity
- Cold-Cranking Amps
1. Determine Your Car's Battery Group Size
It is important that your car battery fits snugly and securely in its battery tray. A car's battery tray will vary in size depending on the manufacturer, but most are designed to accommodate batteries of a specific group size.
Your car's battery group size can be found in the battery section of the owner's manual. If you no longer have access to your original owner's manual, you may also consult the reference guides provided by battery retailers to determine the appropriate battery group size for your car.
Common Battery Group Sizes
- Size 75: Most General Motors cars
- Size 65: Large-bodied Ford, Lincoln, and Mercury cars
- Size 35: Recent Honda, Nissan, and Toyota cars
- Size 34: Most Chrysler cars
- Size 34/78: Some Chrysler and General Motors cars
Buying and installing an incorrectly-sized battery will be a waste of money and may cause damage to your car.
2. Choose a Battery Brand
While there are many car-battery brands on the market, most are fabricated by just a few manufacturers. Some brands share a name with their manufacturer (e.g. the manufacturer Exide produces batteries with same name).
Battery Brands by Manufacturer
Johnson Controls Industries
Ideally, you should buy whichever battery brand is specified in your vehicle owner's manual. If you find that the recommended brand is too expensive and you want to do some cost-cutting, be sure to choose only batteries whose specifications meet the requirements outlined in your owner's manual.
You may be tempted to buy the cheapest brand available, but this is usually not advisable. Cheap batteries are often rife with defects and tend to perform poorly in the long term. Purchasing a cheap battery may save you money now, but in the long run, maintenance and replacement will likely cost you more than you saved in the first place.
Battery-Service Centers That Sell and Install Reasonably Priced Car Batteries:
- Pep Boys
Battery Retailers That Sell Reasonably Priced Car Batteries but May Not Offer Installation:
- Trak Auto
- Sam's Club
You can also buy car batteries from local service stations and tune-up shops, but selection may be limited and the batteries they stock may not be as fresh as those offered by larger retailers.
3. Check the Battery's Age
Newer batteries tend to perform better and last longer than older batteries. Be sure to check the manufacturing date on any replacement batteries you are considering purchasing for your vehicle. Generally, a battery is considered "fresh" if it is less than 6 months old.
Unfortunately, manufacturing dates are rarely listed in conventional notation. Instead, 2-character alphanumeric codes are used to express the age of a car battery. The first character will be a letter from A to L, representing the month of manufacture; the second character will be a number from 0 to 9, representing the year of manufacture.
How to Interpret Battery Age Codes
- The letter indicates the month: A is January, B is February, C is March, and so on.
- The number indicates the year: 0 is 2010, 1 is 2011, 2 is 2012, and so on.
An age code of L8 would indicate that a battery was manufactured in December of 2018.
Each decade, the numerical characters used in battery manufacture date codes complete a cycle and reset at zero (e.g. 2020 is 0, 2021 is 1, 2022 is 2, and so on).
4. Check the Battery's Reserve Capacity
A battery's reserve capacity rating (RC) refers to its "standing power." This is the amount of time the battery can continuously supply the minimum voltage necessary to run your car should the alternator or fan belt fail. With an excellent reserve capacity rating, your car can run on its battery alone if the alternator stops working.
Do not simply select the battery with the longest reserve capacity you can find. Consult your owner's manual to learn the recommended reserve capacity rating for your particular car model. Only choose batteries whose RC ratings fall within the recommended range listed in your vehicle owner's manual.
Battery RC ratings are generally listed in minutes. If you can't find the RC rating on a battery's label (some labels do not list this information), check the product literature or ask a store assistant.
Think of your battery's RC rating as your car's emergency kit. The longer the operating time of a battery's reserve capacity, the less likely you are to become stranded in the event of unexpected trouble.
5. Check the Battery's Cold-Cranking Amp Rating
Cold-cranking amps (CCA) measure your battery's ability to start your car during extremely cold weather. During freezing conditions, many vehicles are difficult to start (ignite) due to the thickening of engine oil.
The cold-cranking amp rating listed on a battery refers to the number of amps a battery will be able to support for 30 seconds at 0 degrees Fahrenheit. Choosing a battery with a high CCA rating is a good idea if you plan to use your vehicle in a cold climate.
If you live in an area that has a relatively warm climate year-round, cold-cranking amps need not be as important a consideration in your battery selection process.
Don't Confuse CCA With CA
CCA (cold-cranking amps): This indicates how much electrical power the car battery can deliver to the car's starter motor at 0 degrees Fahrenheit.
CA (cranking amps): This is another measure of electric current in the battery, taken at 32 degrees Fahrenheit. Generally, a battery's CA rating is higher than its CCA rating.
How to Choose the Right Cold-Cranking Amp Rating for Your Car
- Check your owner's manual, and stick to the CCA rating specified for your car battery.
- Do not choose a battery with a CCA rating significantly lower or higher than what is recommended by your car's manufacturer.
- If a battery with your car's exact CCA rating recommendation is not available, you may choose a battery with a slightly higher rating than is specified in your owner's manual.
How to Change a Car Battery Part 1
How to Change a Car Battery Part 2
Additional Car Battery Tips
- Your car's battery may be covered by your vehicle's warranty; Check on this before purchasing a new battery from a retailer other than your car dealer.
- If your car is no longer under warranty, dealerships will likely charge more than other battery retailers for products and labor.
- Installing used car batteries can be dangerous. Buy new batteries whenever possible.
- If your battery begins to fail, start searching for a replacement immediately. You are more likely to find a good deal if you shop around than if you become stranded and need to buy a battery at the first retailer you come across.
- A new car will normally need a battery change after 3 to 4 years.
- Car batteries are not maintenance-free. You must check your battery regularly to keep it in good shape. Keep the terminals, cables, and connectors clean and free of corrosion. Use a wire brush and a baking soda/water mixture to scrub away any accumulated whitish, greenish, or bluish material on the battery terminals.
- Check your battery connections frequently. Make sure that the cables and posts are securely connected.
- Consider keeping a portable battery charger inside your car for emergency use.
- Jump-starting a dying battery can be helpful if you are stranded, but do not attempt this without first researching the correct procedure. Incorrect wiring connections could cause damage to your engine.
How to Jump-Start a Car: Connecting Jumper Cables to the Dead Car Battery
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.