Car Radios take very little energy to run, so it'll take many hours of non-use to kill the battery. It is probably the wiring of the radio that is wrong. The radio should fully go off when car goes off. There needs to be a positive a negative and a wire hooked up under the fuse box to allow radio to come on when car comes on and go off when car goes off. You should be able to figure this out by the color of the wires on your wire hareness (wire adapter for radio to stock connector.) or just bring your car and radio to a car audio shop and they can do it for you.
If so, it would only be a dead battery, and a jump start would get you going again.
Check the battery with a vom meter while the engine is running. It should read about 14.5 volts and if so the alternator is working, than have the battery checked Now if the meter does not read 14.5 volts, have the battery, and the alternator checked. If they both check out okay, the problem is in the battery or the alternator circuit on the vehicle.
Locate the power drain. You either have a switch on the doors or trunk that isn't cutting off...a light stays on. OR you have a badly installed car stereo/amp/or alarm system. Have you checked your alternator output? You can do so for free at Auto Zone. They can check it "on car". If you can, and it's an aftermarket stereo system, (after checking alternator and battery) disconnect stereo from power and wait overnight to see if better. This could also happen if you have a low-wattage alternator and a HUGE sound system that sucks down power. Auntetr
What else is in the system? Was the battery charged and tested when the new alternator was put in? A new alternator can blow out if it is trying to charge a "Bad" battery. Was it a new alternator that was tested by a shop? It is possible it is a factory defect. If it was done by a shop I would take it back to the shop. It is also possible that there is a wire off or grounding that is draining the system. Have you installed a stereo amplifier? Some amplifiers draw more current than the car can provide.
The alternator is part of the electrical system. It is what charges the battery and keeps it charged.
There is several things that can cause your battery light to come on. Go to your nearest Advance Auto Parts and have them hook up the battery and alternator tester because your alternator could be bad, or if you have a lot of electrical products such as a powerfull stereo system, gps, DVD player etc., you could be drawing to many amps for you battery and alternator to keep a charge
The main cause of battery drains is a bad electrical system. The electrical system is normally powered by the alternator and once the alternator goes bad the battery has a hard time holding a charge,
Depending on how long the interval was between alternator changes. Less than a year and I would look for warranty on the alternator. Now there are factors beyond the alternator manufacturers control. A battery that is on it's last legs will take out an alternator really fast. A stereo system with a large Amp(s) will also shorten the life of an alternator drastically. These situations will not be a warranty issue.
Apparently the alternator is bad or the battery is shot, take the car to autozone and get a free charging system check.
Have the charging system checked. Possibly loose or corroded wiring, a loose alternator belt, or a bad alternator.
Could be charging system (battery, alternator) or fuel system (pump, line).
The computer controls the alternator. If the charging system is malfunctioning, that could be the cause of the weak battery.The computer controls the alternator. If the charging system is malfunctioning, that could be the cause of the weak battery.
The charging system on modern cars has 2 parts. The alternator and battery. On older cars there is also the voyage regulator. On modern cars it is built into the alternator. The electrical system however has many more parts.Alternator, voltage regulator, and alternator belt. The batteries themselves are part of the cranking system, not the charging system.
If the battery and alternator are good and the charging system is not working, then you either have loose or corroded wiring or the drive belt is slipping.
Your alternator is probably rebuilt and not really new. I have had this problem several times and I have bought a new battery and alternator. The alternator keeps your battery charged and powers your electrical system, so even when driving you can lose all power in the car from the alternator draining your battery. Take the battery and alternator to an auto store and they will test both for free. Ask them about the difference in a rebuilt alternator and a brand new one. This is a very common problem.
The diode in the alternator is probley going bad, Check charging system. And replace alternator.
The alternator switches off
It helps relieve the stress on your Battery and Alternator.
It may need replacing or it can be the alternator is overcharging the battery. Have the charging system checked out. The alternator should output from 13.5 to 15.5 volts with the engine running at idle.
It means something is wrong with your charging system. Can be a loose of corroded battery cable, defective alternator or a battery with a dead short.
Odds are, Yes, the alternator is not functioning properly. Have the charging system checked.
1. Alternator charging system malfunction.. [not charging enough]
This is not a battery problem. Your charging system, the alternator, is not putting out enough juice to charge the battery until you reach 4000 rpm. Have the alternator and charging system checked.
More than likely no. It's far more dependant on your vehicle's alternator than the battery. Even so, unless you've installed a large, multi-amp, mega-system, you'll probably be OK with your current battery and alternator. If you can see your headlights "dimming to the beat", then you may need a bigger battery, or simply a capacitor inline with the amp. Caps can cost as much (or more) than a battery(or alternator). So if your headlights are dimming, you'll have to weigh the pros/cons of each to determine your best course of action.
When a stereo system drains too much battery power, it is time to add a capacitor. The capacitor will not increase the battery, but instead will modulate it allowing for additional stereo usage.
It is not really a battery light. It is a charging system light. It is on because the system has malfunctioned. Normally this means the alternator is not working properly.