Why does my car battery keep dying?

Some of the most common reasons for a car battery to die repeatedly include loose or corroded battery connections, persistent electrical drains, charging problems, constantly demanding more power than the alternator can provide, and even extreme weather.
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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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Is it my battery or 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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Why is my car battery suddenly draining so fast?

Electric cars can suffer battery drain because of extreme temperatures, damaged batteries and parasitic drain, just like conventional cars. Another reason why your electric car's battery might be draining is due to faulty charging. If your electric car's battery isn't charged, the problem could be a damaged charger.
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How do I know if my alternator is bad?

7 Signs of a Failing Alternator
  1. Dim or Overly Bright Lights. ...
  2. Dead Battery. ...
  3. Slow or Malfunctioning Accessories. ...
  4. Trouble Starting or Frequent Stalling. ...
  5. Growling or Whining Noises. ...
  6. Smell of Burning Rubber or Wires. ...
  7. Battery Warning Light on Dash.
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Here's Why Your Car Battery Keeps Draining



Why won't my car battery hold a charge?

One significant reason why a car battery won't hold a charge is age. Obvious signs that your battery is too old and worn out include corrosion and cracking. If it's at least four years old, then it should probably be replaced. For younger batteries, a car that isn't started for days or weeks can also lose its charge.
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How much do alternators cost?

Alternators can average anywhere from $100 to $350 depending on make and model. Most vehicles will have an average cost between $350-400 for the total job of an alternator replacement if no other parts need to be replaced. If the serpentine belt is included in the process, add another $20 to $50 to your bill.
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How do you check alternator by disconnecting battery?

If you're tempted to test an alternator by disconnecting the negative battery cable, don't do it. A good alternator may indeed keep the engine running without the negative cable, but this was never a good test. In the pre-computer days, you could pull it off without damaging anything.
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Can AutoZone test your alternator?

Every AutoZone in the USA will check your alternator, starter, or battery at no charge.
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Can a alternator drain your battery?

Contrary to its purpose, an alternator can drain a battery. It's rare, but it's possible. A draw on the battery only occurs if there's a problem with either a component in the alternator itself or connections to it.
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How can I test my alternator myself?

More videos on YouTube
  1. Get a multimeter.
  2. Set your multimeter to DCV (DC Volts) above 15.
  3. Make sure your alternator's positive and negative terminals are clean.
  4. Put the multimeter's black cable to the negative terminal and the red cable to the positive terminal.
  5. Look for an ideal alternator reading of around 12.6.
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How do you know if you need a new battery or new alternator?

If your car's battery isn't holding a charge, you have a problem with your alternator or battery. If your battery can start your vehicle but dies as the car runs, you have a faulty alternator. If your battery has been charged and can't start your vehicle, it's a battery issue.
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How can I test if my alternator is bad at home?

A battery test is easy to perform and can be done at home. First, open the hood and start the car. While the engine is running, remove the negative cable from the battery. If the vehicle stalls or dies, the alternator is likely bad.
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What does a broken alternator sound like?

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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What causes an alternator to fail?

Alternators have a number of moving parts, so as they get dirty and are subjected to extreme temperatures, those internal components can wear out, causing the alternator to go bad. One of the most common problems you're likely to experience with an alternator is a failure in the bearings.
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Can AutoZone replace alternator?

You can bring the vehicle to AutoZone and have the alternator tested on the vehicle to ensure the charging system is performing correctly. Some of these steps may vary slightly depending on your exact year, make, model, and engine.
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How long should a car battery hold a full charge?

If you're dealing with a fully charged battery that's relatively new and in perfect condition, it will take 2-3 months for it to lose its power completely.
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How long will a car run with a bad alternator?

However, for most vehicles, expect as much as two hours of run time and as little as five minutes. Based on the speed at which you are traveling, this could be as little as a few miles or up to 100 miles away, if you are lucky!
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Is it my battery or starter?

Low pitched whining noises and the noise of a cranking engine without it starting are both signs of a dead battery. No noises at all are also a sign of a flat battery. Check for any visible signs as well, such as the battery warning light illuminating. The latter could also be a sign of an alternator problem.
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How often do you need a new alternator?

Numerous factors work with and against alternators, so it's tough to pinpoint an exact lifespan of an alternator. However, we can say with near certainty that an alternator will not last for the average life of a vehicle. In general, you can expect alternators to last about 6-10 years, or about 80,000-150,000 miles.
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What are signs of bad battery?

Watch for these five telltale signs of a bad battery so you aren't caught out in the cold!
  • Dim headlights. ...
  • Clicking sound when you turn the key. ...
  • Slow crank. ...
  • Needing to press on the gas pedal to start. ...
  • Backfiring.
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Which fuse is for alternator?

But when someone mentions the “alternator fuse”, they're generally referring to the primary, high-amperage fuse (or fusible link) between the alternator and the battery. Like any fuse, the primary alternator fuse acts as a circuit protection device.
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What can damage an alternator?

Driving a vehicle through water that is deep enough to splash or flood the alternator can damage the alternator shaft bearings and possibly the brushes and electronics inside the unit as well. Water can also cause corrosion that over time will damage the wiring and bearings inside the alternator.
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