When to Replace Your Car’s Battery

March 20, 2025

5 min read

March 20, 2025

5 min read

Your vehicle depends on its electrical system to operate everything from the starter to the turn signals. A car’s battery is the heart of the electrical system.

If your battery isn’t in good condition, you might encounter a loss of power, hard engine starting, and electronic features that don’t work. If your battery shows signs of failing, replace it right away.

See our detailed, step-by-step visual guide and video about how to change a car battery - opens in new window or tab.. Also check out our car battery buying guide - opens in new window or tab..

Why Battery Maintenance Is Important

Using a handheld battery tester to test a car battery's voltage. — We recommend performing a regular voltage test on your car battery.

Car batteries have a finite lifespan. They are heavily affected by weather conditions and the way you drive. Proper battery maintenance ensures you won’t have to replace your battery prematurely.

We recommend performing a regular voltage test. A voltage test tells you about the battery’s overall health and its total capacity. Most batteries should output around 12.6 to 12.8 volts. If your battery’s voltage falls below this level, it’s time to consider a replacement. Car battery testers are affordable handheld devices with cables that clamp onto the battery terminals. Most importantly, they give you ample warning before a faulty battery conks out.

Battery maintenance is also essential for safety. Many of your car’s safety systems, like the anti-lock braking system (ABS), airbags, and traction control, are powered by the battery. If the battery’s output is inconsistent, those safety systems might not function properly.

How Long Car Batteries Last

A stack of used vehicle batteries. — Car batteries don’t last forever. Be prepared to replace your battery every three to five years.

The average car battery lasts between three and five years. However, several factors can affect your car’s battery life. For example, if you take a lot of shorter trips, your engine might not have a chance to fully recharge your battery while driving. Modern vehicles have numerous electronic systems that put a heavy load on the battery. When coupled with poor battery care, this can cause the battery to fail prematurely. A failing battery can cause the stereo system, lights, door locks, and car alarm to function erratically.

Climate is another major factor:

Extremely hot temperatures can make the fluid inside the car battery evaporate, which is damaging to the internal components.
Frigid temperatures can vastly reduce the charging capacity by slowing down the chemical reactions that take place during the charging and discharging - opens in new window or tab. process.
Major fluctuations in temperature can wear out a battery that isn’t rated for harsh environments.

We recommend keeping your vehicle in a garage or other controlled climate during the hottest and coldest months of the year.

How can you extend your car battery life?

Proper car battery maintenance is essential for extending its life. Clean the terminals - opens in new window or tab. regularly to prevent corrosion and keep a proper flow of electricity for good charging and discharging - opens in new window or tab..

Limiting short trips as much as possible is another incredibly effective way to keep your battery in good condition. Longer drives help keep the battery fully charged and in turn, prevent reduced capacity. Whenever possible, you should also keep your vehicle safe from extreme temperatures by storing it in a garage or other temperature-controlled area when the weather is very hot or cold.

What are the signs that your car battery is dying?

One tell-tale sign of a worn battery is slow engine starting. If you turn the key and it takes longer for the engine to start up, this is a sure sign that you need a battery replacement soon.

If you notice that your car’s interior lights and headlights are dimmer than usual, this means the battery is not putting out the right amount of voltage to operate the electrical system. While you could resolve this with basic car battery care such as cleaning the terminals, it could also mean that the battery is failing and needs to be replaced before it dies.

Replacing Your Car Battery

A Honda 31500-TZ7-A01 12V AGM car battery. — It’s easy to replace your car battery at home.

Replacing your car battery is a relatively simple process for most vehicles. See our detailed step-by-step guide and video - opens in new window or tab..

Here's a quick summary. First, locate the battery under the hood or in the trunk, and remove any access panels covering the battery. Remove the negative terminal, which is always black, and move the clamp and cable out of the way. Then, remove the red positive terminal and move that clamp and cable away from the battery.

A clamp holds the battery down to prevent vibration and keep it secure. Loosen this clamp and remove it or move it aside. Now, you should be able to carefully lift the battery out, taking care not to scrape against painted bodywork.

After you remove the old battery, put the new one on the battery tray. Reinstall the battery hold-down clamp, tightening it securely so it doesn’t vibrate loose with the movement of the vehicle. Remove the plastic terminal protectors, then attach the positive terminal first, followed by the negative terminal, tightening the cable clamps securely.

Finally, dispose of the old battery at a recycling center or hazardous material facility.

Car Battery Replacement Cost

Removing a used car battery as part of a DIY battery replacement. — DIY battery replacement is easy and saves money.

The cost of replacing your car’s battery depends on the kind of vehicle you drive and the replacement battery. You can commonly buy a standard lead-acid car battery for between $50 and $150, while a high-end absorbent glass mat battery costs between $150 and $250.

Installing a battery yourself is a simple job. However, some people prefer to have a professional do the job in cars where the battery is located in an awkward spot or requires the removal of interior panels. The labor for this process costs as much as $100.

About the author

Michael O'Connor

Michael O’Connor, a Bay Area writer and marketer, grew up restoring classic cars and learning to drive on the cross-country Americruise car show tour with his father. His interest in writing was inspired by car magazines and the rodding novels of Henry Gregor Felson. Michael is an alum of Sonoma State’s Creative Writing program and has been penning for the automotive industry since 2015.

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This article is meant to provide general guidance only. Automotive maintenance, repair, upgrade, and installation may depend on vehicle-specifics such as make and model. Always consult your owner's manual, repair guide for specific information for your particular vehicle and consider a licensed auto-care professional's help as well, particularly for advance repairs.