Will a car alternator charge a dead battery?

For starters, an alternator can charge a battery with a low charge, but it cannot charge a dead battery. As we said above, the battery's job is to start the engine and then work as an electrical load balancer.
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How long does it take for an alternator to charge a dead battery?

Generally, if you can keep your engine RPM up, your alternator will charge your battery at a faster rate. If you are driving on a motorway, you should be able to charge your car battery in 30 minutes. If you are driving in the city, it may take an hour or more.
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Can an alternator charge a battery directly?

Regulating the current to the battery

The current from an alternator is rectified into direct current by a set of diodes that allow current to flow through them in one direction only. To charge the battery the voltage supplied to it must not be too low or too high.
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How do I know if it's the battery or the alternator?

If the engine starts but dies immediately, your alternator probably isn't keeping your battery charged. If a jump starts and keeps your car running, but the car can't start again off of its own power, a dead battery is probably your answer.
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What are the symptoms of a bad alternator?

7 Signs of a Failing Alternator
  • Dim or Overly Bright Lights. ...
  • Dead Battery. ...
  • Slow or Malfunctioning Accessories. ...
  • Trouble Starting or Frequent Stalling. ...
  • Growling or Whining Noises. ...
  • Smell of Burning Rubber or Wires. ...
  • Battery Warning Light on Dash.
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Charging a dead car battery using the cars alternator



When your car won't start but all the lights come on?

If your headlights can turn on, but your car won't crank, that means that your battery is charged, but either the starter or ignition is the problem. If the starter or ignition is the problem, a starter engine can be jumped by using a charged battery.
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Can a completely dead battery be recharged?

Simply put, no car battery, whether healthy or dead, can charge itself. It always requires an external power source to get charged. Can Dead Batteries be Charged? Once a car battery is dead, the alternator will fail to recharge it completely.
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Will alternator charge battery while idling?

Assuming the alternator, engine, belt, and battery are all in working order, then yes, a car battery will charge when idling. The only caveat is that it doesn't really “charge” that fast. This is solely due to the fact that the engine doesn't have a load on it when your car is simply idling.
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How do you make a dead battery work again?

Prepare a mixture of baking soda mixed in distilled water and by use of a funnel pour the solution into the cells of the battery. Once they are full, close the lids and shake the battery for a minute or two. The solution will cleanse the inside of the batteries. Once done empty the solution into another clean bucket.
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Can a battery be too dead to jump?

No, the battery cannot be too dead that it cannot be jump started. First of all, this is a chemical element. So, naturally, it can't just “stop working” without a single symptom. There is not a chemical reaction that could immediately interrupt itself under these conditions.
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What can drain a car battery when the car is off?

What may drain a car battery when it's off are things such as interior lights, door lights, or even bad relays. While your engine runs, the alternator recharges the battery — which is why you typically don't have to worry about the battery dying while you're blasting the radio on your drive to work!
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Can a car battery go dead from sitting?

Typically, your car can sit about four weeks to two months without driving before the battery dies. The reason your car can sit only for so long before it dies is the fact that your car battery is in use even when you're not behind the wheel.
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Will a dead battery ruin an alternator?

A weak battery cannot have any effect on alternator, but a poor or weak alternator can deteriorate the battery very quickly. A broken battery also has an effect on an alternator as it puts more pressure and stress on the alternator while working and sometimes destroy the alternator as well.
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How long should I leave my car running to charge the battery?

Remember: After you've done a jump start, you'll need to keep the vehicle's engine running for around 30 minutes to allow the alternator time to charge the battery sufficiently.
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Does revving the engine charge the battery?

Yes, revving the engine will still charge the battery faster.
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Will a car battery recharge itself overnight?

A car can't recharge its battery overnight. The car isn't on overnight (and definitely shouldn't be on!), so, therefore, the alternator isn't on either. When the car is off, there's nothing to provide the battery with any additional power.
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How long should you run a car after a flat battery?

Be sure to drive your car for about 30 minutes before stopping again so the battery can continue to charge. Otherwise, you might need another jump start.
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How long does it take to charge a dead car battery while idling?

While idling older vehicles for 15-20 minutes may give them enough of a charge to restart, this approach is generally not recommended. Many modern cars are equipped with sophisticated battery management systems that are designed to help extend battery life.
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Can a car battery be dead even if lights work?

Even if your lights, radio or accessories turn on, your battery may still be dead or undercharged. These components require a lot less power than the starter. Therefore, your battery may have enough ability to turn the radio/lights on, but not enough to turn on the starter.
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Why won't my car start but the radio and lights work?

So, your lights come on, the radio works, but your car won't start, and you hear nothing. This means neither the starter motor is receiving power and thus represents a problem with the starting ignition system. Specifically, this could be either the battery, the starter solenoid, or the ignition switch.
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What does it mean when your car won't start but it clicks?

It might be a battery or alternator problem.

Perhaps your battery's dead, or your alternator, which charges the battery, isn't working correctly. If the source of the clicking is electrical, the starter (a small motor energized by the battery that gets the engine running) doesn't have enough juice to stay powered.
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Can you jumpstart a car with a bad alternator?

You actually can jumpstart a car with a bad alternator, and the car will keep running for some time, no matter how bad the alternator is, well, considering you have a good battery. This is because if the alternator is bad and not producing the voltage required, the car will be running purely off the battery.
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How do you check if an alternator is working?

A simple test to check the working of the alternator is by running your car; and then unplugging the positive connection of the battery. If the car stops, then you most likely have a problem with the alternator. Another simple test is to check your interior lights.
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What is the sound of a bad alternator?

If you're hearing a grinding sound in your car, this could indicate that the alternator is going bad. The grinding sound may be caused by a worn-out bearing. Your car can also make a whining sound when the voltage regulator is sending signals to the alternator to charge more than is necessary.
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