# What Voltage Is A 12v Battery Considered Dead?

## What happens if you charge a battery with the wrong voltage?

If you charge the battery to a voltage that is higher than its current voltage at its discharged state, but less than the voltage at its fully charged state, then it will charge to that voltage – it will be partially charged.

Yes, the voltage will flow through the supplied voltage source like a resister..

## Can you charge a battery with a higher voltage?

A higher voltage will cause too much current to flow during charging and reduce the battery life. Over charging a battery (too much current due to too high voltage) causes heat and loss of electrolyte in wet cells.

## Can a bad battery still show 12 volts?

At 12 volts your battery is not healthy. If you fully recharge the battery & it doesn’t hold an open circuit voltage of 12.4+ volts then it can be considered faulty ! Read the voltage as you try to start the vehicle. The voltage will drop considerably if it’s defective but it may read 12 volts at no load.

## Is 11.9 volts enough to start a car?

The Minimum Voltage Range To Start a Car In general, while both the engine and the generator are in the working state, the voltage of the battery should be within 13.7 – 14.2V. If more, then it is harmful to the battery, if less, then it is not fully recharged.

## How do you know if it’s your battery or alternator?

Some of the things to look for are no-starting and trouble starting, dimming lights and problems with stereo system output. If your car starts but stalls when you’re underway, your battery is probably not being recharged due to a faulty alternator.

## Can you fix a shorted battery?

Applying momentary high-current bursts in an attempt to repair shorted cells offers limited success. … Replacing a shorted cell in an aging pack is not recommended unless the new cell is matched with the others in terms of voltage and capacity.

## What voltage is a dead battery?

If the battery cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell. If the battery is fully charged (according to the battery charger) but the voltage is 12.5 or less, the battery is sulfated. Sulfation is the natural byproduct when the battery discharged.

## Is it better to charge a battery at 2 amps or 10 amps?

It is best to slow charge the battery. Slow charging rates vary depending on the battery’s type and capacity. However, when charging an automotive battery, 10 amps or less is considered a slow charge, while 20 amps or above is generally considered a fast charge.

## Is 12.2 volts enough to start a car?

12.2v is enough to start the car. It’s a 12v battery after all, it’s just voltage settling after being at ~14v when driving.

## How many volts do you need to jumpstart a car?

For cars with large engines, a jump start cable with a cross section of 25 mm is recommended. The vehicle which has suffered a breakdown must be supplied by a battery with the same voltage. Normally, the voltage of most vehicles is 12 Volts. Only a few vintage cars are operated with a voltage of 6 Volts.

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

No 12-volt battery will remain at over 14 volts for more than seconds unless it’s being charged. The lowest limit is 10.5 volts (used in testing) and obviously unsatisfactory in practical use.

## How do you tell if it’s your starter or battery?

When you attempt to start the car, there is a low whining sound. If jump starting gets your engine started and running, but the car will not start again once you turn it off, the battery is probably the problem.

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

That’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.

## Why does a dead battery still have voltage?

In general, the more surface area the chemicals have to deposit charge onto, and take charge away from, the higher the current the battery can produce. … A nearly dead battery still provides 1.5 volts, but has a very high internal resistance so that drawing even a trickle of current zeros out the voltage gain.

## What is the maximum voltage to charge a 12v battery?

A typical 12-volt lead-acid battery must be taken to approximately 14.2-14.4 VDC before it is fully charged. (For 24 volt systems, double these figures.) If taken to a lesser voltage level, some of the sulfate deposits that form during discharge will remain on the plates.

## How do I know if my Optima battery is bad?

12.0-12.4 volts – LOW with 25-75% charge If your Optima is in this range and you think it should be charged, it’s not taking or not holding a charge. This usually means that your battery is sulfated, which happens when it sits for a long time (not charging) or is deeply discharged when it shouldn’t be.

## What is the minimum voltage needed to start a car?

Therefore, you should always keep your batteries properly charged. With a working generator and engine, they should normally operate at 13,7-14,2 volts. The higher level can overload the equipment, while significantly lower voltage is not enough for a full charge.