# You asked: What is too much voltage for a car battery?

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## 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.

## Is 15 volts too high for car 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 system’s voltage regulator or related circuits. If it’s substantially excessive, this can cause electrical system and/or battery damage.

## At what voltage is a car battery ruined?

The bottom line is that if you venture below 10 volts, the battery is dead.

## What voltage is too high for a 12 volt battery?

To charge a standard 12-volt battery, you have to bring it up to above 14 volts (amount varies with the type of battery). When checking the batteries, (at rest) use these “Voltage Landmarks”. The typical wet-cell battery (lead plates in a mixture of sulfuric acid and water) needs to be charged up to about 14.

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## Is 14.8 volts too high?

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. If it’s cold out and you ran the batteries down some then it will be higher than normal.

## What should voltage be at idle?

At idle, most charging systems will produce 13.8 to 14.3 volts with no lights or accessories on (although some may charge at a slightly higher voltage depending on temperature, engine RPM, type of battery, and the battery’s state of charge).

## What happens if battery voltage is too high?

Voltage will become dangerously high. The battery can overcharge which will leave it useless. Engine components that aren’t designed to handle the pressure, temperature or power will be damaged. The alternator isn’t designed to handle excessive power and eventually it will burn out.

## 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.

## What happens if an alternator is overcharging?

Alternators that overcharge will typically produce excess voltage to the battery, making the battery case swell up, become very hot and lose its electrolyte through boiling. Improperly jump-starting the vehicle can send a surge through the battery that destroys one or more cells in the battery or shorts it out.

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## Is 11.9 volts enough to start a car?

This voltage range means the battery is in good condition for starting the vehicle. If the measured reading is less than 12.2 volts, the battery’s resting voltage is weak, which means it most likely needs to be charged or replaced.

## How many volts does a car battery lose overnight?

If you measure the voltage immediately after the end of a drive, it should be more like 13.2, and drop to 12.7 within a few minutes as the chemical reactions in the battery slow down and stop when you stop charging it.

## How can I tell if my 12V battery is bad?

There are some sure ways you can tell if your battery is bad by simply taking a good look. There are a few things to inspect, such as: a broken terminal, bulge or bump in the case, crack or rupture of the case, excessive leaking, and discoloration. Broken or loose terminals are dangerous, and can cause a short circuit.

## What voltage is too low for a 12 volt car battery?

12.0 volts or below – At 12.0 volts your battery is considered to be fully discharged or ‘flat’ and should be recharged as soon as possible. The lifespan of your battery will be severely affected if it remains within this voltage range for extended periods of time.