Alternator overcharge is caused by a defective voltage regulator, and the only solution is to have the alternator refurbished or replaced.

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.

Can a bad battery cause overcharging?

Leaving the battery on a charger for too long can overcharge it. Even if the person who is charging your vehicle is knowledgeable and experienced, if you’re dealing with a defective battery charger, this itself could cause your vehicle to overcharge.

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 vehicle’s dashboard. Car Battery Gets Hot When Charging. Your Headlights Burn Out Quickly. Your Car Battery is Bulging on Sides.

Can a bad battery make an alternator overcharge?

Overcharging of the battery by a defective or malfunctioning alternator will result in the battery reaching an overcharged state. When overcharged, the plates inside the battery shed material and lose their capacity to hold electricity.

Is 14 volts too high for alternator?

To fully charge in reasonable times, alternator output must be 14.2 V to 14.5 V as measured right across the battery posts. Above 14.5 volts charging voltage, batteries have a greatly increased tendency to release excessive acidic vapors, hydrogen gas, and to corrode things around the battery.

Why is my alternator putting out 18 volts?

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

Is 15.2 volts too high for alternator?

Every alt warranty now expressly says a firm no to that or voided warranty. If battery light not on now just drive the car, nothing wrong. The setpoint in the regulator itself is 14.5 volt, it’s not supposed to ever go under that. 15 is fine.

Why is my alternator putting out 17 volts?

It may be that the regulator is packing up and the alternator is going to max. unregulated output because of a bad battery output voltage (alternator input) connection between the battery and the alternator.

How much voltage is too much from an alternator?

For some alternators, it’s normal to see as low as 13 volts. For some, a constant 13.6 volts is an indication of a problem. For others, it’s normal to see as high as 16 volts for long stretches. Still, it’s perfectly normal for others to see the alternator not charge at all intermittently.

What happens if voltage is too high?

Voltage that is too high can cause premature failure of electrical and electronic components (e.g. circuit boards) due to overheating. The damage caused by overheating is cumulative and irreversible.

Can a bad ground cause an alternator to overcharge?

Poor ground connections are an often-overlooked cause of low charging output and alternator failure. Check for voltage drops at the positive and negative battery cable connections, the alternator BAT+ power connection and the engine ground strap(s). Voltage drops on the negative side can cause overcharging.

What are the signs of a bad voltage regulator?

Bad Voltage Regulator Symptoms
Too High Voltage in the Battery.Dead Battery.Battery Light or Check Engine Light.Inconsistent Operation of Electrical Components.Vehicle Dies While Lights.

How do I stop my battery from overcharging?

To be on the safer side, and for a healthy battery like, you can try out these tricks as well:
Try to plug in your charger before reaching 10%Unplug your charger around 80-90%Don’t perform heavy tasks (like gaming, or editing) while charging.

What happens if car battery is overcharged?

Overcharging a battery causes excessive gassing — the electrolyte gets hot and both hydrogen and oxygen gas are generated. On older vented batteries, the electrolyte could cook away, leaving the plates exposed and ruining them. On sealed batteries, the buildup of gases could cause the battery to burst.