Know how long for an alternator to charge the car battery

A car alternator is a reliable tool to recharge the car battery. When your car engine’s RPM is up, it takes a relatively significantly faster time to charge the battery by this tool.

When your car runs on a Motorway, your alternator may need approximately half an hour to charge the battery. Again when you will run on the messy road with your car, you will need one or more hours to recharge your car’s battery.

However, let’s dive in the deep to know how long for the alternator to charge the car battery.

How fast does a car alternator charge the battery?

I already described it in the intro section of this article. However, how long does an alternator need to charge the car battery it depends on the car engine stage. If your car engine is at the idle state, it takes a considerable time for the car alternator to charge the battery. When your car engine runs, your car alternator may take more or less half-hour to recharge the battery fully. Again on a messy road, it takes relatively one hour. (In a crowdie road, your car will run slowly) And if the engine is in idle stage, your car alternator will take more than one hour to charge the car battery.

Does your alternator need a running engine to recharge the car battery? Or it can recharge the car battery even the engine is at an idle stage?
A car alternator can recharge your car battery even when your car engine is in the idle stage. The car used in the 60’s century was featuring a too weak DC Generator, which could not successfully recharge the battery when the engine is at an idle stage.

However, today’s car engines are powerful enough to recharge the battery even in an idle stage. Alternators (mainly from the 70 century) feature a considerable power when they remain even at the inactive phase. Car alternators are more reliable and efficient to recharge the car battery if your car engine is at an idle stage.

Lastly, it is associated with the electrical load of your car. If your vehicle has to take a low electrical load (light, radio, AC, other gadgets), your car alternator can charge the battery when the engine is idle.

The fact is, an alternator charge the battery in a very low voltage if the engine is idle. But when you drive the car, when the engine is running, your car alternator can quickly charge the battery.

How will you know your alternator is charging your car battery?

Some new car models have a specialized computerized system to describe the details state of the car alternator. However, still, several methods are practicing to taste whether the alternator is in full shape or not. We are suggesting picking the voltage method. This method is most comfortable and healthier also.

  1. Collect a voltmeter at first.
  2. Check your battery is there enough juice to taste the alternators or not. (you can do with by connecting the voltmeter with the battery)
  3. If you observe, your voltmeter gives you a 12 voltage reading of the battery, which means you can go for the next step.
  4. If your battery has less than 12 voltages, recharge the battery at first. Either you have to recharge your battery or utilize some other methods to taste the alternators.
  5. Start your engine (up to 2000 RPM). Again taste the battery by running the engine in such away. If your battery is showing a reading in between 13 and 14 voltage that means your car alternator is fine. If you get a battery voltage less than this range, your alternator has some issues.
  6. Repeat the same process by putting on the car’s light, AC, and radio. If the battery voltage is more than 13 volt, if the engine RPM is 2000 and if all the function is running smoothly, that means your alternator is pleasingly charging your car battery.

Safety tips and warning while handling an alternator:

  1. Never make your car alternator culprit all time. If you find your car alternator is not working correctly, there may also be some other issues for why it is happening. So check well to see the main culprit—for example, a cold engine, a blown -fuse, bad wiring, and so on.
  2. Never try to taste the car alternator by starting the car. It could damage your car alternator and other engine parts as well.
  3. While checking the alternator, keep away all your jewelry, loose fabric even your hands from any moving parts of your car engine.


Why alternator cannot charge the car battery quickly, if the engine is in the idle stage?

A car alternator cannot rapidly charge the car battery faster if the engine is not running. It happens due to the presence of voltage control in all modern car alternators. This voltage control never allows the alternator to cross the 14volts range to charge the battery.

Which RPM is the best for a perfect alternator output?

5000 RPM is the best alternator shaft speed for extreme output. The exciting thing is you will never be able to force your alternator to start working until it reaches 100 RPM Alternator Shaft Speed. Using the pulley ratio, you can also pick the alternator speed.

Final verdict:

Once you have read the entire article; how long for an alternator to charge the car battery, now you know the charging ability and pattern of your car alternator.

Now you can say whether your car alternator is charging the battery fully or not. And if the alternator is charging your car battery, so how long it will take!

That’s all for today; please share my article.
Thank you.

Read also: Car Battery Overcharging

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