Question: What Should An Alternator Charge At Idle?

Does alternator charge at idle?

Yes, the alternator does charge the battery while the car is idling – regardless of the load on the battery.

However, if your electrical use load (radio, lights, fan, etc) exceeds the amount of charge the battery is receiving from the alternator, you will end up with a discharged battery at some point..

Do you have to drive for alternator to charge battery?

You don’t need to drive the car around to charge the battery, you can just start the engine and leave it running for 5-10 minutes. … Generally a few minutes – 5 or 10, of driving time where the RPMs get high enough to raise the alternator output to charge the battery effectively to replace the energy used for starting.

How much voltage is too much from an alternator?

Measure voltage between alternator frame and battery’s negative terminal. More than about 1/10 volt says there’s a “grounding” issue. Otherwise it is likely the alternator’s regulator. Take it to a parts dealer and they can generally check it.

What should my alternator be charging at?

The voltage should read a minimum of 13 volts. A good alternator should put out between **13.5-14.5 volts. Stress test the alternator – Place a load on the alternator by turning on the headlights, the radio and the air conditioning. The voltage should remain high with these circuits on.

What should a 12v alternator charge at?

13-14 voltsA car alternator needs to be putting out at least 13-14 volts (ideally between 13.8 and 14.2 volts) to effectively charge a 12 volt car battery. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery.

What does a bad alternator sound like?

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. If you hear any type of whining or grinding sound that’s a good indication that your alternator needs to be checked.

How do you tell if it’s your 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 likely your answer.

Is 15 volts too high for alternator?

Higher than 15 volts indicates a fault in the charging system’s voltage regulator or related circuits. If it’s substantially excessive, this can cause electrical system and/or battery damage. You mentioned your voltmeter runs at about 15 volts most of the time.

How many amps does an alternator put out at idle?

50 ampsAt idle speeds of about 650 RPM it can only produce 50 amps or so. This is why when you have a loose alternator belt or a defective belt tensioner, you only hear the squeal when you hit the gas initially after you start the engine, not with the engine idling.

Can a bad alternator destroy a new battery?

If an alternator goes bad, it certainly can kill a battery. Car batteries don’t like being run all the way down. … If the alternator was ailing for a while, the battery may have been low for a long time, which also isn’t good for a battery. Fully charge the old battery and have it load-tested.

Can you jumpstart a car with a bad alternator?

Fortunately, it is possible to jumpstart your vehicle with a bad alternator so that you can get it back on the road and drive it to the nearest auto shop. The vehicle only needs enough electricity to power its onboard computer (engine control unit) and fuel injectors.

Can bad alternator cause idle problems?

Modern vehicles require a steady electrical current of specific voltage in order to run properly. … Drops in electrical output from a failing alternator can cause these systems to malfunction, leading to a poorly running engine. Symptoms will be rough idle, misfires, poor acceleration, hesitation and stalling.

How do I know if my alternator is bad?

If you have a bad battery, here are some of the symptoms you may encounter:Engine Doesn’t Crank or Start. … Engine Barely Turns Over. … Dim Lighting. … Engine Starts and Stays Running When Jumped. … Dim or Overly Bright Lights. … Discharged Battery. … Alternator Noise. … Electrical Issues.More items…•

What keeps making my alternator go bad?

Alternators put out alternating current, and the battery needs direct current to charge, so there is a voltage rectifier that converts it, and it can suddenly go bad, too. … Dust and dirt can get into the alternator, and over time cause shorts or wear on the brushes.