Inside Your Car 22 May 2026

How long does a car battery last?

Key Takeaways:

Car batteries usually last 3–4 years
Short trips and extreme temperatures shorten battery life
After 3 years, test your battery regularly

The battery is the silent workhorse of your car. It’ll continue to get you from place to place before giving out, seemingly without warning, stranding you with a car that just won’t start. While the signs of a dying battery can be hard to spot there are a few things that can indicate when it’s time for a replacement. So how long do car batteries last? Let’s take a look.

What is the average car battery lifespan?

The average lifespan of a car battery is between three to four years. Most last this long, but usage, weather, and maintenance can affect it.

Once your battery hits the three-year mark, it’s a good idea to have it checked regularly, even if it seems to be working fine. That way, you’re less likely to get caught out with a flat battery at the worst possible time.

Not sure how old your battery is? Most have a date stamp on the case or label that tells you when they were made.

What shortens car battery life?

In reality, a range of factors will impact how long your battery will last.

You’re only driving short trips: The alternator recharges your car battery as you drive. Short trips don’t offer a lot of time for the alternator to get to work and won’t charge your battery as much as longer trips.
Leaving your lights on: We’ve all been there. As easy as it is to do, forgetting to turn off your car headlights or leaving an interior light on is a sure way to drain your battery.
Weather extremes: Your car battery doesn’t like extreme temperatures. While newer batteries tend to be more resistant, both hot and cold extremes can weaken the batteries performance.
Faulty parts: Faulty parts can cause a real headache for your battery. Issues like corroded or loose battery cables, a faulty charging system and even electrical problems like defective fuses and wiring can all contribute to a shortened car battery life.

After ruling out those factors, the best way to get to the bottom of your battery problems is to take your car to a trusted mechanic.

How long should a car battery last without driving?

A parked car battery can last two to four weeks without driving before losing charge. To keep it healthy, drive weekly or use a trickle charger.

What voltage should a car battery have?

A healthy car battery voltage sits at 12.6 volts. When your engine is running, your voltage will be higher and range somewhere between 13.7 volts and 14.7 volts. An easy way to test your charge and the health of the battery is with a car battery voltage test.

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How to test your car battery

When considering how to test your car battery health, it’s important you choose the right timing. Testing the battery voltage directly after you drive your car is likely to give you a higher reading. To get an accurate reading, it’s best to test your battery after the car has rested - preferably overnight.

You can test your battery voltage at home using a handy device called a multimeter. Used correctly, this instrument will give you an accurate battery reading.

How to use a multimeter

1. Set the device to read DC volts and set the dial to 20.

2. Touch the red probe to the positive terminal and the black probe to the negative terminal.

3. A reading will appear on the screen.

4. If you get a negative reading you’ve got the probes around the wrong way. Switch them around to get an accurate reading.

If you do not have a multimeter to check your car battery at home, there are two ways you can approach checking your battery health.

1. There are a few signs that you will probably notice when your battery is on the way out:

a. The battery light is on
b. It’s taking longer than normal to turn over, or feels like it’s struggling
c. The headlight test - your headlights are more dim than expected
d. It’s more than 3 years old
e. There’s buildup or corrosion on the terminals

2. You can book your car in for an obligation-free car battery assessment with mycar - full details here.

Can a totally dead car battery be recharged?

Yes, a totally dead car battery can often be recharged, but it depends on the extent of the damage. If the battery is only discharged, a charger may bring it back to life. But, if the battery has been dead for an extended period or has internal damage, it may need to be replaced.

How to charge a car battery

If you think your battery still has some life in it, there’s a way to charge it up without having to jumpstart it.

Gather your tools:

A battery charger (make sure it’s designed for car batteries).
Protective gloves and goggles (safety first!).
A clean, dry workspace.

Turn off the car: Ensure the vehicle is off before you begin. Disconnecting the charger while the car is running can cause damage.
Check the battery: Inspect the battery for any visible damage, leaks, or corrosion around the terminals. If you see any, clean the terminals with a mixture of baking soda and water.
Connect the charger:

Positive first: Attach the red (positive) cable to the positive terminal of the battery.
Negative second: Attach the black (negative) cable to the negative terminal of the battery or a grounded metal part of the car frame.
Make sure the charger is connected to a power source before turning it on.

Set the charger: Choose the appropriate charging mode based on your battery’s needs (slow or fast charge). Many chargers have automatic settings that adjust based on the battery’s charge level.
Turn on the charger: Switch on the charger and allow the battery to charge. This can take anywhere from 30 minutes to a few hours, depending on the charger and battery condition.
Check the battery’s charge: Many chargers have a built-in indicator to show when the battery is fully charged. If your charger doesn’t have an indicator, check the battery’s voltage with a multimeter after 2–4 hours of charging to see if it’s reached a full charge.
Disconnect and test: Once fully charged, turn off the charger. Carefully remove the cables (negative first, then positive). Start the vehicle to check if it starts up smoothly.

Tip: If your car battery is often running low, it might be time for a replacement or checkup. Call the experts at mycar on 13 13 28 to book an appointment today.

How long does it take to charge a car battery?

Charging a 12V car battery typically takes 30 minutes to a few hours, depending on the charger type and battery condition. Using a standard automatic charger, most moderately discharged batteries will take 2 to 4 hours to reach a full charge. If the battery is deeply discharged or old, it may take longer to charge, and might not hold its charge at all.

When should a car battery be replaced?

While it may seem like your battery’s gone flat for no reason, there are a few warning signs you need a new battery that you might have missed:

Your car will take longer to start up when your battery is low on charge. The engine may sound sluggish and take a few more seconds to get going when you first start the ignition.
Your headlights and interior lights are dim - another indicator that your battery is losing charge. A battery that’s on its way out will struggle with things like your dashboard lights.
Does your car smell like a rotten egg? You may have a battery leak. You’ll need a professional to take a look at the battery rods for corrosion.
Sometimes the easiest way to spot a dodgy battery is by simply looking at it. Batteries can swell and crack, normally due to extreme weather conditions and can cause a misshaped battery case.

While it’s possible to increase the life of your car battery, it will stop working eventually. Get ahead of the unexpected breakdown blues and get in touch with your local mycar. Our experienced specialists are ready to perform a range of battery tests, and if required, replace your car battery on the spot.

If you have an EV, a car battery state of health check is the best route if you think your EV’s battery is on the way out. Contact mycar here to book in a check.

Need a car battery check or replacement? Chat to the experts at mycar

Your car’s battery won’t last forever, so if you do need a battery replacement it’s easy with mycar. With over 275 stores across the country, and a workmanship guarantee that leads the industry, it’s easy to see why we’re a trusted choice for thousands of Aussie drivers. Whether it’s a quick battery check or a full replacement, our expert technicians are here to help keep you moving.

Want to know more about what’s under the hood? Learn more about car batteries, your battery cable, and more in our car advice blog.