Try start the car.
Check the voltage.
Remove the battery and check it with a volt meter.
If the battery is dead the alarm will not go off
Your car won't turn on.
If the battery will not hold a charge it more than likely has a dead cell. If the battery is over 4 years old, replace it.
Remove the battery and take it to an Auto Parts store. They will check it and tell you if it is defective.
The battery keeps going dead.
the computer will shut off entirely
It wouldnt work
turn the key, and if the interior lights don't come on or flicker, then its dead.
If your car battery is dead, you will not be able to start your vehicle without a jump using jumper cables. When the car won't start and the lights on the dash aren't working, it is most likely your battery.
No start? No turnover? No horn? No lights? Check with a voltmeter
You need to charge the battery with a battery charger.