How do I know if my car battery is dead?

[ManBearPig]

When I turn the key it sounds like a rrrrrrrr reving kind of noise (it's jarring), but it wont start. The lights on the dashboard light up and the headlights work which I thought doesnt happen if the battery is dead.

P.S. This is a different car from the car I have questions about in another thread. :|

 

[KIAman]

Do the lights go off when you start the car? Does the starter turn but slower than usual? Those are symptoms of a dead battery.

 

[ManBearPig]

Car won't start at all. It's like a grinding noise. Fml

 

[Zivic]

Car won't start at all. It's like a grinding noise. Fml

hard to say over the net, but it could be the starter.... thinking something might be messed up between the starter and the ring gear. it sounds like there is motion? like something is turning? vs just struggling to turn or clicking?

easy way to test would be to jump the car and see if it makes a difference. if it sounds the same, you likely have an issue with the starter

 

[zoiks]

When I turn the key it sounds like a rrrrrrrr reving kind of noise (it's jarring), but it wont start. The lights on the dashboard light up and the headlights work which I thought doesnt happen if the battery is dead.

P.S. This is a different car from the car I have questions about in another thread. :|

The headlights might still work with a battery that isn't providing the amps needed to start the car.
See if you can get a jump from some elses car to make sure. Once it's started, check the voltage to see if the alternator is providing enough juice (13.5v - 15v).

 

[JoeyP]

The headlights might still work with a battery that isn't providing the amps needed to start the car.
See if you can get a jump from some elses car to make sure. Once it's started, check the voltage to see if the alternator is providing enough juice (13.5v - 15v).

I'd suggest a run down to your local Autozone. They'll hook up a device and run tests that will tell you wazzup.

 

[ManBearPig]

But i can't start it to get anywhere. It definitely isnt just a click. Tbh, i dont even want to keep trying to turn the key because its so jarring and doesnt sound good lol...

I'll try jumping it.

 

[Zargon]

hit the starter with a hammer


seriously.....

 

[Vdubchaos]

I'd suggest a run down to your local Autozone. They'll hook up a device and run tests that will tell you wazzup.

All they do is check the voltage, what he said.

 

[jagec]

Stick shift, or auto? If you have enough juice to turn on the lights and it's a stick, you can push-start it, even if you don't have enough juice to crank OR you have a problem with the ring gear/pinion engagement.

I knew someone whose car had a couple of broken teeth on the ring gear. The car ran fine, and it started right up most of the time, but if the missing teeth happened to be lined up with the pinion when the engine stopped, it wouldn't start again.

All they do is check the voltage, what he said.

They don't do load tests? Resting voltage and voltage under load are two very different things.

 

[JoeyP]

All they do is check the voltage, what he said.

The one down the street from me used a device to check cranking amps, reserve amps from running high wattage accessories, voltage, etc. I even got a thermal printout report. The whole process took about 10 minutes. Did it twice.

 

[Zargon]

All they do is check the voltage, what he said.

not at my local autozone, they load test them like joeyp said

 

[phucheneh]

Bad overrunning clutch in the starter. Hammer won't help it.

If you want to be sure, make a recording and share it with us.

But generally, a dead battery either makes the starter solenoid 'click,' which is the sound of it repeatedly trying to throw out the gear that turns the engine over (but failing), or it does nothing.

 

[LTC8K6]

The description does sound like the starter is running but not engaging the flywheel.

It's also barely possible that the solenoid is buzzing from low voltage.

 

[disappoint]

The headlights might still work with a battery that isn't providing the amps needed to start the car...

Right but you can check the battery voltage under load. When you turn on the headlights or crank the engine starter your voltage shouldn't drop too much.