Most likely cable running from stud on top of alternator to battery terminal is corroded or broken.
That light doesn't mean that your battery needs to be replaced. It means that your battery is not being charged while the car is running. Have your alternator tested.
If your battery is not being charged , the battery light will come on in your dash
Possibly a bad alternator. The Alternator charges the battery when the vehicle is running. If the battery is not being charged this could cause the vehicle not to start.
What else is in the system? Was the battery charged and tested when the new alternator was put in? A new alternator can blow out if it is trying to charge a "Bad" battery. Was it a new alternator that was tested by a shop? It is possible it is a factory defect. If it was done by a shop I would take it back to the shop. It is also possible that there is a wire off or grounding that is draining the system. Have you installed a stereo amplifier? Some amplifiers draw more current than the car can provide.
The battery is most likely being over-charged. Check the alternator diodes or the voltage regulator.
A lot of auto part stores will test them for free. Give them a call. Your alternator can only be tested when the engine is running, therefore you will have to get a boost or use a battery charger for the battery. If you have a voltmeter, test at the battery terminals with engine still running, if you get 13.5 to 14.7 volts, the alternator is charging. In some cars, the voltage could go over 15 volts if the battery is close to dead (right after being boosted), but the voltage should go back to normal as the battery gets closer to fully charged. Turn off the engine, the voltage will go down to 12.5 volts if the battery is now charged, lower if is not. If there is no change, the alternator is not charging. KGP484
The battery is constantly being charged by the alternator as long as the engine is running. The alternator is driven by a fan belt or serpentine belt and provides a consistent steady flow of direct current of around 14 or 15 volts. The amount of voltage is kept steady even at varying engine revolutions by a voltage regulator.
Bad alternator and/or belt. Your battery isn't being re-charged while you run the engine, so the electrical things drain the reserve from the battery.
Yes, a poor or open ground would prevent an alternator or generator from being charged.
If your alternator stops working you are powering the vehicle on your battery and your battery is not being charged by your faulty alternator so eventually as the battery drains down the car will stop running. Avoid using any electrical power...ie...lights, power windows ect and get your alternator repaired immediatley.
When a battery is being charged, hydrogen gas is produced.
When a battery is being charged, hydrogen gas is produced.