# Quick Answer: What Is A Good Charging System Open Circuit Voltage Reading?

## Is 14.7 volts too high?

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..

## Can you test an alternator with a multimeter?

Conduct a Voltmeter Test Get a cheap voltmeter. With the engine off, battery voltage should be between 12.5 and 12.8 volts. … Then start the engine and check for increased voltage readings. If you see higher readings, chances are the alternator is good.

## What is the normal range for charging system voltage?

The “normal” charging voltage on a typical application might be 13.9 to 15.1 volts at 77 degrees F. But at 20 degrees F. below zero, the charging voltage might jump as high as 14.9 to 15.8 volts for a short period of time. On a hot engine on a hot day, the normal charging voltage might drop to 13.5 to 14.3 volts.

## Is 15 volts too high?

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.

## What should a 12 volt battery read when fully charged?

12.9 voltsThat’s only a difference of 0.25 volts on each cell from fully charged to fully discharged. So a 12volt battery will measure at about 12.9 volts when it’s fully charged and about 11.4 volts when it is fully discharged. That’s a total of 1.5 volts that represents the full range of charge on a 12volt battery.

## What should a fully charged AGM battery read?

The sealed AGM and gel cell battery voltage (fully charged) will be slightly higher in the 12.8 to 12.9 range. If you have voltage readings in the 10.5 volt range on a charged battery, that typically indicates a shorted cell. If you have a maintenance-free wet cell, the only ways to test are volt meter and load test.

## How can you tell if a circuit is open?

Maintain the first test probe at the hot wire terminal of the circuit. Remove the second probe from the neutral terminal then place it on the ground terminal for the circuit. Once more the multimeter will read “OL” or infinity if the circuit is open or zero if the circuit is functioning.

## What is meant by open circuit voltage?

The open-circuit voltage, VOC, is the maximum voltage available from a solar cell, and this occurs at zero current. The open-circuit voltage corresponds to the amount of forward bias on the solar cell due to the bias of the solar cell junction with the light-generated current.

## What is open circuit voltage of fully charged battery?

A fully charged battery will put out 12.66 volts exactly. If the battery is not fully charged, the voltage will still be in the 12 volt range, but slightly less than 12.66.

## What voltage should my alternator read?

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.

## How can I tell if my alternator is overcharging?

You can test to see if the alternator is overcharging, using a simple voltmeter.Start your vehicle and open the hood. … Locate the vehicle’s battery. … Turn the digital voltmeter on and adjust it to the proper settings, if necessary. … Connect the clamps or leads of the voltmeter to the battery. … Examine the voltmeter.