Signs of a bad or failing car battery are slow cranking, starter clicking, lights dim in your car, having to jump start the car after you shut it off.
If your car is hard to crank, the starter is clicking or your lights are dim then your car battery could be bad and need replaced.
If the car battery is 5 years old or older then it can be time to replace the car battery because if the battery is not bad yet it will soon be.
Also check for corroded or loose battery connections as that can prevent the car from starting properly or at all and corroded connections can prevent the battery from charging properly as well.
The most common reason a car battery goes bad is due to age.
Car batteries have a lifespan of around 5 to 7 years before they go bad and lose the ability to hold a charge and start a car.
If your car battery is older than 5 years then it's likely time to replace the car battery with a new one before it goes bad and leaves you stranded.
Also leaving the lights on in a car can cause the battery to go bad if you drain the battery fully too often or if you have a bad alternator then the car battery can also go bad.
A dragging starter motor can also draw too many amps from your cars battery and then lead to the car battery going bad.
If your car is having a hard time cranking over, the starter is just clicking or the car is hard to crank over and slow to start then your car battery could be bad.
Or you could have corroded battery cable connections or a loose battery cable connection as well.