Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alt belt.
A light in your car might be on, running down the battery!!
This could be the voltage regulator. Both the positive from the battery and the starter would be connected to it.
Keep the car light on
The the alternator is defective.
Dead/disconnected battery or bad starter if it starts intermittently. Probably the battery though.
the battery light means that your battery is being charged properly. so let it light.
The car light? YES! Leaving your car light on WILL make your battery run out. Things like leaving your car door open if the light is on because it is open will cause the lgiht to Mae your car battery run out. There is a big difference between shorted out a car battery and running the battery down. Lighting in itself won't short a battery out but will run it down.
its the alternator if the car is running with a battery light on. but check fuses first
No, a car battery does not have mercury in it. It would be very dangerous to have mercury in a car battery.
there are lots more amps in a car battery eg there about 1.5 in a flash light and in a car battery there about 300 A car battery is a wet cell battery and a flashlight battery is a dry cell battery.
A dead cell in the battery will cause this. Also, any light that is on pulling power from the battery. Another possibility is a stuck relay.