I've replaced a handful of car batteries over the years and want to share what I've learned about the process with others.
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
|Delphi||Exide||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.
Jonas on July 28, 2020:
Help me which battery i suppose to use in my toyota rav4 2003 model ?
Allan George on June 15, 2019:
The stock ALT. size was 35 Amp. Was changed to 60 Amps
pegD on November 26, 2016:
This is one outstanding article...Wish they would do it for ALL major issues like brakes, tires, belts to educate those of us NOT "in the know" !!!! Wonderful help!!!
Anna on November 21, 2016:
If there ar no more 36R batteries in my area, what other battery would work.
msnny on August 27, 2016:
Great info to have and use .... Thxs
Kristen Howe from Northeast Ohio on June 12, 2015:
Great tips on how to choose the right car battery. Voted up for useful!
koustubh from Mangalore, India on October 05, 2012:
Minorkle on July 18, 2012:
I know nothing
Dyan on February 06, 2012:
I am using a 12Vdc motor on a mini truck. Connected to it is a pick and carry hydraulic power unit. The DC motor of the hydraulic power unit is 12VDC, 1.5Kw, 210A (nominal) and can be run on a maximum - 2Kw, 310Amps.
after about 10-12 cycles (each cycle is 80 sec) the new battery drains. we are using a 70AH 12V battery.
Please suggest suitable battery with the correct AH value?
Ajay on July 29, 2011:
Hi, i have a car battery with the following specifications:
12V 65RC 390A 43Ah. Can you explain them??
μεταχειρισμενα αυτοκινητα on July 11, 2011:
I don't know how to change the battery of my ?????????????? ?????????? but thank to your hub.It gives me ideas and tips on how to choose a better replacement for my old ones.
jump program on March 03, 2011:
Nice post here. I was looking also for the right battery for my car. Thanks for posting this info. I'll consider this.
Dustcarts on February 08, 2011:
Choosing a car battery does not have to be a difficult task. You can ask for help, or find out the information for yourself. You can also replace the dead battery yourself as it is a pretty simple process. Batteries come in all sizes and are designed especially for certain cars. You can find batteries at Auto Zone, Wal-Mart and other retailers that sell car parts and accessories.
Art Jewelry on January 03, 2011:
My battery was dead today.
It was only two years old. I thought that it should last longer, but after reading your article I realize that it is normal for a cheap battery like the one that I bought.
Thanks for the great info.
Jump Manual on December 30, 2010:
Very informative blog nd it really help me in selecting my Car battery.
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farid999 on October 30, 2010:
Besides a low starting price repossessed cars on sale auctions offer quality cars in a lot of ways, most of the cars are in top condition and will look quite new with the warrant still on. There are no pieces of junk in fact, you will be amazed at how unbelievably good and well maintained these cars are being sold at a price that even teenagers can afford.
Diana on August 11, 2010:
My ex husband left a new auto battery sitting in the storage barn. How long will a new battery hold it's charge?
snow2010 from New York on August 03, 2010:
great hubpages car battery, if you want to change your auto batteries, here is a video tips for you to learn.
Bruce on June 26, 2010:
It sounds to me like your choice of the primary "value" rating (amp-hours) is based on the assumption that the value comes from how many amp-hours the battery can put out before it runs out of sufficient voltage. However, your typical vehicle user depends on the alternator to put out ALL of the amps used (except during starting, but even those amp-hours get recharged by the alternator). Battery amp-hours are only important if you plan on running your battery for extended periods, right? That is something that perhaps an RV'er might be interested in, but other vehicle owners only need enough amp-hours to get their engine cranked, plus a safety margin.
John Best on May 28, 2010:
What about the most fundamental measure of battery capacity, the AMP-HOUR rating? Years ago anyone who knew the most basic things knew that to make a truly informed comparison, you looked at the AMP-HOURS compared to the prices. Just a few years ago, it used to be stamped on the battery. A high AMP-HOUR rating for the dollar is precisely the fundamental measure of battery value. Other so-called 'parameters' are at best secondary in importance. Seriously, what am I missing here?
Scott on April 12, 2010:
Yes, a group 48 will physically fit where a group 91 was. The only possible issue with the group 48 battery, it may have less CCA than your original battery. Try it, it will be fine and will certainly cause no harm. Watch the polarity of the connections.
Jim Brix on March 30, 2010:
Is a group 48 battery compatable with a group 91 battery? I was told I can use either one of these on my car. I have a 2002 Landrover Freelander with a group 91 battery on it now. It, has a bad cell. I have a group 48 battery in my garage that I can use but want to make sure before I install it.
sunilkumar boregowda on March 17, 2010:
Thanks for the Information. Helped me a lot for buying a battery.
Lori Catz on February 04, 2010:
Does every state recycle car batteries?
Novak on January 19, 2010:
I've trusted my batteries to places like Autozone, simply because they can find the right battery for your car and insure it, so if anything goes wrong before a certain period of time, you get a replacement for free.
arshumum on January 17, 2010:
nice one, folk! i use Marathon here and it's quite durable
Shannon Paulk on January 07, 2010:
Since many of us our driving our cars for a longer period of time due to the slow economy, keeping your battery healthy is an issue many are now forced to deal with. Good info.
DIY Grandma on December 29, 2009:
I applaud the effort, but would suggest some improvement. For example what does "Do not choose batteries with CCA rating which is much lower or much higher TO the rating recommended by your car's manufacturer, as well as those CCA rating of 200 amps or more." mean? My car (’91 Deville - luxurious “beast”) requires 770 CCA. I put in a 36/96 850 CCA battery w/ 100 hours of RC & 3 years of free roadside battery service all for just under $55! (Black Friday weekend $10 off sale + Manufacturer’s $20 rebate + $10 core refund at PepBoys) Before that I had unfortunate experience of having an ignorant mechanic put in a battery with only 675 CCA & had nothing but trouble with it. So I decided to do it myself side-terminals & all. My car started right up - better than it had in years!
Take a look at www.aa1car.com/library/2003/us20310.htm (starting with “Replacement Batteries” about half way down) if you need more information. (You can read about the author & website owner here: www.aa1car.com/larrypage/larrycarley_photos.htm). I have no relationship to him or his site whatsoever - don’t even know him. But I have found the info I’ve needed on his site many times in the past several years. I’m a grandmother (of 2 teenagers) trying to keep my car running as long as I can, not a mechanic.
What do you think would happen if you filled the cells to the top as instructed in “Here's how to put water in the battery: twist open the cap and top up with distilled water”? Have you ever seen a battery “boil over”? I have. Spilled battery acid is bad news! Sulfuric acid is nasty stuff & it eats skin for an appetizer & steel for lunch! You only need to keep the lead plates inside the battery covered. Do NOT fill it to the top! Most batteries have a mark or some type of indicator about 1 to 1&1/2 inches below the top. THAT’s the level you fill it to. Most batteries have two rectangular caps on top. Each covers 3 of the 6 cells. These need to be carefully pried off with a flat screwdriver. (Don’t let the metal part of the screwdriver touch any metal part of the battery connections!) Be sure to replace the caps by firmly pushing them down as far as they will go.
Don’t touch the whitish, bluish, greenish stuff with your bare skin either. If you do, you’ll definitely feel it burn. Rinse it off immediately. Think of the horror scenes in movies where someone falls into a vat of acid. Yeah, battery acid IS that stuff for real. If you mix baking soda into the petroleum jelly you put on the terminals, it will deter formation of that whitish bluish greenish stuff which is actually concentrated sulfuric acid with a very low (acid) pH of about 0.1. It only has a pH of about 0.5 diluted in water in the battery. Don’t get it on your clothes either - it will eat right through them. Be especially careful to wear eye protection. Battery acid can cause severe eye damage.
car repair garages on December 11, 2009:
You'd need a car repair garage to install it though, wouldn't you?
Hugo Diaz from Minnesota on November 23, 2009:
Lots of good tips. Thanks
StephaBon on November 16, 2009:
Thanks for all the info. I've needed to jump my car 3 times out of the last 4 times I've turned it on. Time for a new battery!!
Vans on October 25, 2009:
Costco Kirkland Brand batteries are made by Johnson Controls. I've had very good luck with them. I've tried just about every brand from AC Delco, Exide, etc. I have not had very good luck with their deep cycle boat batteries though which is where Johnson Controls built their reputation. It could have been my fault for letting it get too run down though.
MarkS - Venture17 - Lafayette, etc. on July 21, 2009:
A few corrections-
The two cranking amp numbers displayed on batteries are most often CCA (taken at 30F) and HCA (taken at 80F). HCA is not nearly as important for anyone who actually lives where the temps drop below 60F, but as you note, sounds good.
If the battery is the correct BCI number (e.g. 24F, 35, etc.) then the higher the CCA and RC, the better. There's no "only a little higher" limit, except that it doesn't pay to spend significant change on a battery with higher ratings than specified for your vehicle, unless you have added a lot of power hungry equipment to it. But if prices are comparable, you will generally get more life (barring broken plates) out of a battery with higher CCA and RC ratings.
Do NOT use a common wire brush to wet scrub exposed battery terminals. Accidentally shorting the battery terminals can result in burns, or even an explosion. Specialized terminal cleaners are fine, and use a fiber or plastic bristle brush to scrub the battery case. Make sure none of the baking soda you use ends up going into the cells of the battery (that will partially neutralize the battery acid).
Topping off (only to the full level line) with distilled water IS a good recommendation. Some water is lost over time as hydrogen and oxygen (gas), as well as evaporation, even in "maintenance free" batteries. Under normal conditions, checking the levels by carefully removing the caps once every 12 - 18 months should be sufficient.
In general automotive use, batteries will last 4 to 5 yrs -some may only go 2 1/2 yrs, some may go 7 (the extremes are rare). Greatly discharging a battery, or jostling around a discharged battery is very damaging.
Beyond that, I think you have a great article.
Philip Siddoway on May 17, 2009:
Is there a list of good, better or best batteries, so I know which ones to stay away from. Is there a list of which batteries have the most warranty batteries. Thank you. PMS
vertical jump training on May 08, 2009:
Hi..Some nice writing and good information.I do agree with this.. You keep rocking..Thanks for the excellent Hub!..keep going on with the good process..I was still wondering at your info's ideas.Thanks for sharing the ideas..The videos were very helpful!Great Hub
Live N Learn (author) from Las Vegas on January 19, 2009:
Hello, Rhys! Thank you for reading this hub. I used the phrase 'a little bit more' because I couldn't specify the figure since different cars have different auto manufacturer's manual. Please refer to your manual so that you will be able to determine what is the right capacity of battery that your car needs. I hope this reply helps. :)
Rhys on January 12, 2009:
I am living in the middle east and customer service is a mirage on the horizon. I need a group 48 battery for my Audi and the only one I could find that wasn't at the dealer was 100Ah instead of 80ah. I called a mechanic in the US and he said it doesn't matter but here you say it should only be "a little bit more." So what's a little and what could go wrong if you have too much capacity?
Live N Learn (author) from Las Vegas on November 11, 2008:
Hello, chloesdad! Taking good care of your car is one of the real money savers. A happy car won't leave you stranded :)
Jeff M from Newington NH on November 10, 2008:
A great step-by-step hub for even the most uneducated in car maintainence! Thanks!
Live N Learn (author) from Las Vegas on October 07, 2008:
Thank you for the warm appreciation, sherlynavia! I'm a fan of yours :-)
sherlynavia from United States on September 30, 2008:
This is an incredibly useful resource to everyone.
Live N Learn (author) from Las Vegas on July 28, 2008:
Thanks! I'm happy I helped:)
Babu on July 22, 2008:
When i go for new batteries i will surely use your tips
Free Car Quotes on July 19, 2008:
Great Hub you have here :) please read my new hub about getting free online car quotes...
Live N Learn (author) from Las Vegas on May 05, 2008:
Thank you once again, Angela Harris! Batteries provide power to our cars so we should pay special attention to them as we do to other automotive parts of our vehicles.
Angela Harris from Around the USA on May 04, 2008:
I had no idea there was so much to know about buying a car battery. Thanks for the automotive education.