These electronically controlled units can have about a hundred things kill the battery including improperly installed or faulty stereo amps installed by others.
First:
Have both the battery and charging system checked again, I have seen bad out of the box alternators and batteries
Second:
Disconnect the battery and see if it goes dead anyway, the above test may not reveal this type failure
Third
you need a way to detect a "significant draw". All cars draw between .01 amps and .1 amps. Significant is thought to be .5 or larger. There are meters available to do this and I bet you have a Friend that has one.
Once you have proven and measured the draw start pulling fuses.
If you have removed all the fuses and the draw continues you have missed something.
get alternator that works properly check ur alternator and ur battery one ofem is outta wack or bad wireing
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.
Battery light usually means alternator not charging. Most common solutions would be be a bad alternator, bad connection, or loose alternator belt. If the battery and alt test ok than check the connections to the alternator and battery. You may also have a battery drain (something that is staying on and killing the battery)
An alternator keeps the battery charged in a vehicle. In a 2006 Chevrolet Impala when the alternator fails the battery will keep dying and no power will be available when attempting to start the car.
Either the battery has a dead cell and needs replacing, or alternator is defective, loose or corroded battery cables, or something is draining the battery. Look for a courtesy, trunk, under hood, glove box light that is on. Also can be a defective brake light switch which causes the brake lights to stay on.
If you have no power to anything, and your battery isn't dead, then you more likely have a bad ground. If the battery is dead/keeps dying, there's a good likelihood that the alternator isn't charging it adequately.
Is it new? if it is it's not the battery. If it's really old your battery most likely is leaking.
battery hooked up backward, wires crossed somewhere or it could be the solenoid.
Alternator is more than likely overcharging the battery. The voltage regulator is bad. It may be built into the alternator.
have the battery tested, average life of a battery is 2 to 3 years. if battery is good check voltage regulator and starter motor. there is a short somewhere if the battery is good
Sounds like the alternator is not charging the battery up / WORKING check charging system. Charge battery to 12.8 volts and then start engine and hook volt meter to battery and it should read 13.8 to 14.3 volts. If it don't then replace alternator. Also need to make sure the alternator belt is tight.
The battery may have a dead cell and need replacing. You may also have some light that is on or a relay that is stuck.