What you need to know before buying a replacement battery
A replacement car battery is a new battery you buy to replace the one that no longer holds a charge or won't start your car. Before you buy one, you need to know three things: what size and type your car needs, whether you want a standard or premium battery, and where you'll have it installed. The wrong battery won't fit in your car's battery compartment, and the wrong type won't work with your car's electrical system.
Your car's manual or the battery currently in your car tells you what you need. Look for the battery group size (a code like 24F or 35), the voltage (almost always 12 volts for cars made after 1950), and the cold cranking amps or CCA (a number that tells you how much power the battery delivers in cold weather). Write these down before you shop.
Key Takeaways
- Find your battery's group size, voltage, and cold cranking amps in your car's manual or by looking at the label on your current battery.
- Standard batteries cost less but last three to five years; premium batteries cost more but often last longer and work better in cold weather.
- You can buy a replacement battery at auto parts stores, big-box retailers, dealerships, or online, and have it installed at most of those places.
- Installation usually takes 15 to 30 minutes and costs nothing to $50 depending on where you buy; many stores include installation in the price.
- Bring your old battery with you when you buy the new one, because most retailers will recycle it and some offer a core charge credit toward your purchase.
Standard batteries versus premium batteries
A standard battery is the basic option. It typically lasts three to five years and costs less upfront. Standard batteries work fine in moderate climates and for drivers who don't need extra power for aftermarket electronics or frequent cold starts.
A premium battery (sometimes called an AGM or absorbed glass mat battery) lasts longer — often five to eight years — and delivers more cold cranking amps. Premium batteries handle cold weather better and work well if your car has a lot of electrical features or if you live somewhere with very cold winters. They cost more, sometimes $50 to $100 more than a standard battery, but the longer lifespan can make up for the higher price over time.
If you're not sure which to choose, match what was in your car before. If your old battery lasted a long time and you were happy with it, buy the same type again. If it died quickly or struggled in winter, try the next step up.
Where to buy a replacement battery
You have several places to shop. Auto parts chains like AutoZone, O'Reilly Auto Parts, Advance Auto Parts, and NAPA carry batteries in stock and usually install them free or for a small fee. Big-box retailers like Walmart, Costco, and Sam's Club sell batteries at competitive prices and often include installation. Your car's dealership has batteries made for your exact model and will install them, though the price is usually higher. Online retailers like Amazon ship batteries, but you'll need to arrange installation separately.
Call ahead or check the website to confirm the battery you want is in stock. Some stores let you order online and pick up the same day. If you order online for delivery, ask whether the seller will install it or whether you need to take it to a mechanic or auto shop afterward.
What installation involves and how long it takes
Installation means removing your old battery from the engine compartment and putting the new one in its place. The technician disconnects the negative cable first (usually marked with a minus sign or black), then the positive cable (marked with a plus sign or red), unbolts the battery hold-down bracket, lifts out the old battery, sets the new battery in place, rebolts the bracket, and reconnects the cables in reverse order — positive first, then negative.
The whole process takes 15 to 30 minutes for most cars. Some vehicles have the battery in a harder-to-reach spot (under the back seat, in the trunk, or under a plastic cover), which can add time. After installation, the technician may need to reset your car's computer or radio settings, depending on your car's model.
Most auto parts stores and big-box retailers include installation free when you buy the battery from them. Dealerships and independent mechanics may charge $20 to $50 for installation. If you're handy and have the right tools, you can install a battery yourself, though many people prefer to have a professional do it to avoid damaging the electrical system.
Understanding battery specifications and why they matter
The group size is a standardized code that tells you the battery's physical dimensions and terminal location. Common sizes include 24F, 35, 51R, and 65. A battery that's the wrong group size won't fit in your battery tray or won't let the cables reach the terminals. Always match the group size exactly.
Cold cranking amps (CCA) measures how much power the battery delivers when your engine is cold. A higher CCA number means the battery can start your car more reliably in freezing weather. If you live in a cold climate, choose a battery with a CCA rating at least as high as your original battery, or higher. If you live somewhere warm, CCA matters less.
Reserve capacity (RC) is how long the battery can power your car if the alternator fails. It's measured in minutes. Most people don't need to compare this number, but if you drive long distances or want extra peace of mind, a higher RC is better.
What to do with your old battery
Car batteries contain lead and sulfuric acid, so they can't go in the trash. Most retailers that sell batteries will take your old one for free when you buy a new one. Some offer a core charge — a credit of $5 to $15 that reduces the price of your new battery if you turn in the old one. Ask whether the store offers a core charge before you buy.
If you're not buying a new battery at a store, you can take your old battery to a recycling center. Search online for "battery recycling near me" or call your city or county waste management office to find a location. Some scrap metal dealers also accept car batteries. Never leave a battery on the curb or in a landfill.
Signs your battery needs replacing soon
Your battery may be failing if your car is slow to start, the engine cranks but won't turn over, the dashboard lights dim when you turn on the headlights, or you hear a clicking sound when you turn the key. These are signs the battery isn't holding a full charge or isn't delivering enough power.
If your battery is more than three to five years old and you're seeing these signs, a replacement is probably the next step. You can have a mechanic or auto parts store test your battery for free to confirm it's the problem. If the battery tests fine but your car still won't start, the issue might be the alternator, starter, or electrical connections instead.
Frequently Asked Questions
How do I know what battery size my car needs?
Check your car's owner's manual in the section on maintenance or specifications. You can also look at the label on your current battery — it shows the group size, voltage, and CCA. If you don't have the manual, write down your car's year, make, and model and take it to an auto parts store; they can look up the right battery for you.
Can I install a battery with a higher CCA rating than my original?
Yes. A higher CCA rating means more starting power, which is safe and can help in cold weather. You must keep the same group size and voltage, but you can go up in CCA. Going higher in CCA won't hurt your car's electrical system.
What happens if I disconnect the battery cables in the wrong order?
If you disconnect the positive cable first, you risk a spark or electrical shock. Always disconnect the negative (black) cable first, then the positive (red) cable. When reconnecting, reverse the order: positive first, then negative. If you're not comfortable doing this, have a professional install the battery.
How much does a replacement battery usually cost?
Standard batteries typically range from $50 to $150, depending on the size and brand. Premium or AGM batteries usually cost $100 to $250. Prices vary by retailer and your location. Installation is often free or costs $20 to $50 if charged separately.
Will replacing my battery erase my car's settings?
Disconnecting the battery may reset your radio, clock, and seat position on some cars. Modern cars may also need a computer reset after battery replacement. Ask the technician whether your car will need a reset, and they can do it while the battery is being installed.