Is It a Dead Battery or a Bad Alternator? Here’s How You Can Tell 

There is that sinking feeling when you turn the ignition key in your car and wait for the engine to respond, but nothing happens. It could be a dead battery or a bad alternator. But how do you tell the difference?

Not being able to get your car moving when you need it the most can drive anyone mad. Fortunately, we have some tips you can try out. Read on to discover the difference between a dead battery and a bad alternator and how you can fix them.

Alternator vs. Battery: How to Tell The Difference

If your car is having trouble starting, it may be due to a dead battery or a bad alternator.

The car will usually start but stall soon after if the problem is with the battery. This is because the battery is not providing enough power to keep the engine running.

The car will not start if the problem is with the alternator. This is because the alternator is not providing any power to the battery. 

You can jump start the car to test whether the battery or the alternator is the problem.

If the vehicle starts and then stalls, it is likely due to a dead battery. If the car does not start, it is likely due to a bad alternator.

How to Test Your Auto Battery

Use a voltmeter. If the voltmeter reads 12.6 or higher, then the battery is good. If it reads 12.5 or lower, then the battery is dead.

Another way to test the battery is to use a load tester. If the battery passes the load test, then it is good. If it fails the load test, then the battery is not working.

How to Tell If Your Alternator is Failing

To test if your alternator is failing, first, check the battery.

If the battery is over three years old, it might be time to replace it. If the battery is less than three years old, try charging it overnight. The alternator might be faulty if the battery still will not hold a charge.

To test the alternator, start the car and let it idle for a few minutes. Then turn on all the lights, the radio, and the heater. If the car’s battery dies while the engine is running, the alternator is bad and requires a replacement.

Prevent a Dead Battery or Alternator 

To prevent a dead battery, regularly check your battery’s water level and keep it clean from corrosion. Also, don’t let your car idle for too long, as this can drain the battery.

If you think your alternator may be going bad, have it checked by a mechanic.

Knowing the Difference: Dead Battery or Bad Alternator

If you’re having trouble starting your car, it might be a dead battery or a bad alternator.

If your car won’t start, it’s likely a dead battery. If your car starts but dies, it’s likely a bad alternator. If you’re not sure, take it to a mechanic to have it checked out.

Check out some of our other blog posts if you found this article helpful.