What to check before you buy
AGM or EFB for start-stop cars
Fitting a standard flooded battery to a start-stop system shortens its life to a year or two.
Battery registration matters
Most modern European cars need the new battery registered to the energy-management module or it will be undercharged.
Test before you buy
A voltage-drop test on the earth strap or a load test on the battery costs nothing and rules out most 'alternator' faults.
What the related jobs cost
| Job | Parts (US) | Total (US) |
|---|---|---|
| Battery replacement | $90–$400 | $120–$565 |
| Alternator replacement | $150–$650 | $265–$1,310 |
| Starter motor replacement | $130–$600 | $225–$1,260 |
| Air conditioning recharge | $40–$220 | $105–$470 |
When people buy electrical & sensors
- Slow crank or no start
- Battery warning light
- Parasitic drain
- Sensor fault codes
Frequently asked questions
- How long does a car battery last?
- Three to six years in temperate climates, less in very hot regions where heat accelerates plate corrosion.
- Battery or alternator?
- If the battery light is on while driving and charging voltage is under 13.5V at idle, suspect the alternator. If the car cranks slowly but runs fine once started, suspect the battery.