A typical car battery lasts three to five years. Heat shortens that life, and cold reveals weaknesses.
In this article
- Warning signs
- Testing
- Replacement
Warning signs
Slow cranking, dim headlights and a dashboard battery light are common. A battery older than four years deserves a test.
| Reading (at rest) | Meaning |
|---|---|
| 12.6 V or more | Fully charged |
| 12.4 V | About 75 percent |
| 12.0 V | About 25 percent |
| Below 11.8 V | Discharged, may be failing |
Intervals and costs are typical ranges. Your owner’s manual comes first.
Testing
Most auto parts stores will test a battery for free. A healthy 12-volt battery reads about 12.6 volts at rest.
Cars start fine until the one cold morning they do not.
Replacement
Match the size, terminal layout and cold cranking amps in the manual. Cars with start-stop need an AGM or EFB battery.
Do it in this order
- Test after year three
- Clean the terminals
- Check the date code
- Dispose of the old battery properly
Practical tip
Some cars need the new battery registered with the computer. Skipping this can shorten its life.
Bottom line
Test annually after year three and replace before it strands you.
Specifications, prices and rules change. Confirm current details with the manufacturer or the relevant authority before you buy or repair.
