Charging voltages over 14.7 volts can prematurely dry the battery by boiling out electrolyte, and increase risk of a battery hydrogen gas explosion. Less than 14.3 would be a weak alternator or regulator. Much less than 14.2 at a fast idle is bad wiring, bad alternator or regulator, or a bad connection or fuse link.

Is 14.8 volts too high?

Low maintenance batteries 13.2-14.7V is normal. 14.8V is considered overcharging. A bad regulator over charging would most like shoot upwards of 16.0V. State of charge, temperature, age of batteries all have an effect on the charging rate.

Is 14.9 volts too high?

That voltage is nothing to worry about. When you charge a 12v battery on a battery charger its voltage will reach a max of 15.3V while taking current. Ideally your alternator will run at 14.2v.

Is 14.7 volts a good battery?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts. If they are dim, that indicates the lights are running off the battery and that little or no charge is being produced by the alternator.

Is 14 volts too high for a battery?

In order to push energy into the battery, a higher voltage of about 14 volts is created. Higher than 15 volts indicates a fault in the charging systems voltage regulator or related circuits. If its substantially excessive, this can cause electrical system and/or battery damage.

Is 14.6 volts too much?

The battery terminal charging voltage must be less than 14.7 volts to prevent excessive gassing. 14.8 would start to be a worry (there might be liquid or corrosion on the battery) and 15 volts would be a real concern, but 14.6 is fine. Less than 14.3 would be a weak alternator or regulator.

What should voltage be at idle?

Most alternators that are charging properly should produce a voltage of about 13.8 to 14.2 volts at idle with the lights and accessories off. Always refer to the vehicle manufacturers specifications. Many Asian vehicles, for example, have higher charging voltages of around 15 volts.

Is 17 volts too high for alternator?

17V is too high for any 12 V battery. 17 volts is just about max unregulated output on a 12 volt alternator so I would suspect that the voltage regulator is defective or somehow not working correctly. To put things in less dramatic terms.

How do I know if my alternator is bad?

7 Signs of a Failing AlternatorDim 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.24 Aug 2020

Do alternators charge at idle?

The answer is YES, yes the car battery does charge while the engine is idling. Then the alternator is producing AC current, thereby charging the battery while your car is idling.

Is 18 volts too high for alternator?

Premium Member. 18 volts is a bit high. It is possible that your rebuilt alternator has a faulty regulator.

Why is my alternator putting out 17 volts?

17 volts is just about max unregulated output on a 12 volt alternator so I would suspect that the voltage regulator is defective or somehow not working correctly. To put things in less dramatic terms.

How do I check for a bad alternator?

An illuminated dashboard light can indicate a problem with an automobile charging system. However, a very simple way to check if the alternator is working is to run the car and disconnect the positive terminal of the battery. If the vehicle stops running, then you probably have a bad alternator.

How do you tell if an alternator is overcharging?

Symptoms of Your Car Alternator Overcharging:Car Battery Voltage Gauge Reading is High. You notice a high voltage reading on your cars vehicles dashboard. Car Battery Gets Hot When Charging. Your Headlights Burn Out Quickly. Your Car Battery is Bulging on Sides.

What are the signs of a bad alternator belt?

Symptoms of a Bad or Failing Alternator BeltBattery light is on. When the battery light on your instrument cluster comes on, you will need to pay attention. Dimming or flickering interior lights. The lights on the inside of your car are used primarily during the nighttime hours. Engine stalls.5 Jan 2016