It usually means that the alternator isn't charging properly.
The alternator has a serious failure.
Can be loose or corroded battery connections, loose drive belt, or the alternator is failing.
alternator is probably not charging. you need to fix this NOW. new alternator is likely the only repair.
A dead alternator is most likely. Maybe the ECM but not likely.
Engine overheat, low oil pressure, or alternator voltage.
I have a 76' Malibu and almost the whole time I have had it the gen light is on except when I just put a new alternator in it. Then the light would go out for a while, but always came back on after a while. What I found out was there is a Diode that goes bad in the alternator and causes the light to come on. Soon you have to get a new alternator.
Alternator is defective and needs replacing.
A few causes that will make the Battery Light come on are: 1. Faulty Battery 2. Loose Battery Connection 3. Battery is not Charging, ie. Faulty Alternator
There is no problem...the problem was the alternator. You have fixed the problem.
Your alternator is on its way out.
The generator/alternator is over or under charging.
more than likely a loose belt. it's usually a serpentine belt but whichever one is turning your alternator. the alternator itself could also be faulty or not properly charging.