CarTireSize
ENFrançaisEspañol

Car Tire Size / Car battery size / Battery life

How long does a car battery last?

About 3 to 5 years for a typical car battery, and closer to 3 where summers are hot. Here is what wears one out, how to read its voltage and its age, and when to have it tested.

How long does a car battery last?
Typical life
3 to 5 years
In hot climates
closer to 3 years
Full charge, engine off
about 12.6 volts
Test it every year
from about year 3

How long it lasts

  • A typical car battery lasts about 3 to 5 years.1,2,3,4,5
  • Heat wears a battery out faster than cold does: in hot climates a battery often lasts closer to 3 years.1,4,6,7

What wears a battery out

  • Mostly short trips shorten battery life, because the alternator never gets the time to fully recharge the battery.1,2,3
  • A parasitic drain is power something keeps drawing while the car is off (a light left on, a faulty part, an added accessory). It can flatten a battery overnight and shortens its life.2,8,9
  • A car parked for weeks slowly runs its battery down on its own, even with nothing switched on.1,3

Read the voltage

  • A fully charged 12-volt battery reads about 12.6 volts or a little more with the engine off; less than that means it needs charging.10,11,12,13
  • At rest, about 12.4 volts means the battery is roughly 75 percent charged, and about 12.2 volts roughly 50 percent.12,13,14
Battery voltage at rest, a rough guide
Reading, engine offWhat it means
12.6 V or a little moreFully charged
about 12.4 VAbout 75 percent charged
about 12.2 VAbout 50 percent charged: charge it

Battery makers' charts do not all agree, so read this table as a rough guide.

Signs, age and testing

  • Signs of a weak battery: the engine cranks slowly when you start it, or the battery or charging warning light comes on.1,4,5
  • The battery's age is on a date sticker or stamp on the case, often a letter for the month (A for January) and a number for the year. Formats vary by brand.7,15,16
  • Once a battery is about 3 years old, have it tested every year.1,5,7,17
  • Battery stores and auto parts stores can test the battery and the charging system for free.2,3
  • Cars with automatic start-stop usually need an AGM or EFB battery, and some cars cannot take a different type than the one they came with.18,19

Questions people ask

Can a car battery die from sitting too long?

Yes. A car parked for weeks slowly runs its battery down on its own, even with nothing switched on.

Why does my car battery keep dying?

Often a parasitic drain, something that keeps drawing power while the car is off, or mostly short trips that never let it fully recharge. A store can test the battery and the charging system for free.

How many volts is a car battery?

About 12.6 volts or a little more when it is fully charged, with the engine off.

Where is the date code on a car battery?

On a sticker or a stamp on the case, often a letter for the month and a number for the year. Formats vary by brand.

Does heat drain car batteries?

Heat wears a battery out faster than cold does. In hot climates a battery often lasts closer to 3 years.

How many years do AGM batteries last?

The sources we read do not agree, from the same 3 to 5 years up to two or three times longer, so we give no number. Cars with start-stop usually need an AGM or EFB battery.

Find the battery your car takes: Car battery size.

How we checked this page

Checked on October 27, 2026. We kept a fact only when two independent sources agree, and each one is numbered to its sources below. We never write a price. This page was written with an AI assistant and checked against the sources below.

Sources

  1. How Long Do Car Batteries Last, AAA
  2. Why Your Car Battery Died, Interstate Batteries
  3. How Long do Car Batteries Last? A Car Battery Life Guide, AutoZone
  4. The Average Car Battery Life: When Is It Time for a Change?, NAPA Know How
  5. When to Replace Your Car Battery, Pep Boys
  6. How To Protect Your Car Battery From The Heat, Les Schwab
  7. Car Battery Buying Guide, Consumer Reports
  8. What Causes Parasitic Drain on Your Car Battery?, AutoZone
  9. Parasitic Draw: Why Does My Battery Keep Dying?, NAPA Know How
  10. What You Need to Know About Car Battery Voltage, AutoZone
  11. Car Battery Voltage, OPTIMA Batteries (Clarios)
  12. How Many Volts Is a Car Battery?, Advance Auto Parts
  13. Basic Rules for Battery Care and Maintenance (E.P.M. Form No. 0004), Deka / East Penn Manufacturing
  14. How Many Volts Is a Car Battery?, NAPA Know How
  15. Where Is the Expiration Date Located on a Car Battery? It's NOT There, CarParts.com
  16. 6 Signs You Need To Have Your Car Battery Replaced, AAA Oregon/Idaho
  17. How Can the Summer Heat Affect Your Car Battery?, Batteries Plus
  18. What's an AGM Battery?, Interstate Batteries
  19. Can I Replace an EFB Battery with an AGM Battery?, Batteries Plus
Share: