That typically means that the alternator is not functioning.
the battery light means that your battery is being charged properly. so let it light.
If the battery light comes on when you try to start your car, either your battery is low or your alternator is going bad. These can be checked by going to an Advance Auto or Auto Zone, they will test it for you for free.
alternator faulty
Most cases the battery light comes on because the alternator isn't charging. The alternator may need replaced as well as the battery. It may be something more simple as a poor connection.
Alternator isn't charging enough soon batt will die from undercharging
have your alternator check. It is like that for most car. It is not the battery's fault. But you could have a lose connection to your battery.
Your alternator is not keeping the battery charged.
You can put in a new battery in the car. Then press down on the maintenance button so that the battery light comes on. You will then have it reset and ready to go.
have the alternator circuit checked
Not a good sign, This could mean that your charging system (alternator) isn't doing its job. If you have problems starting the car due to not enough battery power, then check your battery to see if it is holding the charge. If after a while that you had to boost or jumpstart your battery your car gradually dies then check your alternator to see if it is putting out charge to the battery.
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.
your car is over heating