in this case, it is more likely either the alternator or

regulator is out. In old cars, the regulator is a standing alone parts while in newer cars, the regulator are built in with the alternator. I would check the Hynes manual for your car available from most auto shops to see if you can find out which one is bad by using a multimeter (萬用表). It is unlikely both gone bad at the same time.

By the way, if your brake light is still on when the hand brake is released, you need to check you brake system as well. That means your brake system has an uneven pressure.