## Can a car battery show 12 volts and still be bad?

Rather it is voltage under a load that is important.

If the battery is bad, then you would notice the lights going REALLY dim when you try to start the car..

## Is 11.9 volts enough to start a car?

However, in practice, the normal voltage for most of the passenger cars can be in the range of 12.2-12.49V, which indicates an incomplete charge. A decrease in performance and the quality of the device begins in the case of reduction to 11.9V or less.

## How low should battery voltage drop starting?

0.5 VoltsYour voltage drop reading should be no more than 0.5 Volts. But some manufacturers will take a voltage drop reading between 0.2 and 0.6 as acceptable for the positive side of the starter circuit. If you get a higher reading, conduct a voltage drop on the terminals in that side of the circuit.

## What causes a car battery to die quickly?

Some of the most common reasons for a car battery to die repeatedly include loose or corroded battery connections, persistent electrical drains, charging problems, constantly demanding more power than the alternator can provide, and even extreme weather.

## How long can a car battery sit unused?

two monthsAnswer: Car batteries can keep their charge for two months or longer without running.

## Can you fix a dead cell in a car battery?

Now, you can replace the battery covers. In case of sealed batteries, you need to replace the plastic plugs and the cover. You can connect the battery terminals to the battery charger and allow the charging slowly for 24 hours. … You have saved lot of money by simply reconditioning your old car battery.

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

When the battery is not being charged and not delivering charge to a load, this is the rule of thumb. For a 12 volt, leadacid battery, the voltage measured between these two points should be between 11 and 13 volts. The closer the voltage is to 13 volts, the closer the battery is to being fully charged.

## Can a battery test good but still be bad?

As long as battery voltage remains above 9.6 volts, the battery is considered “good.” But if it drops below 9.6 volts by the end of the test, the battery may be “bad,” or the battery may have to be recharged and retested if it was not fully charged prior to the test.

## How can you tell if a battery cell is bad?

Once a cell goes dead, the battery is bad and must be replaced. The best method to test a car battery for a dead cell is to check the specific gravity of the electrolyte fluid. Specific gravity is the density of the electrolyte fluid compared to water. The specific gravity for the electrolyte is ideally 1.265.

## How do I know if my starter or ignition switch is bad?

If you turn on the ignition switch and hear a whining sound and the engine is not cranking, then it’s possible that the starter gear is not engaging the flywheel. If this is occurring, then your starter may have to be replaced.

## How do I know if my alternator is bad?

If you have a bad battery, here are some of the symptoms you may encounter:Engine Doesn’t Crank or Start. … Engine Barely Turns Over. … Dim Lighting. … Engine Starts and Stays Running When Jumped. … Dim or Overly Bright Lights. … Discharged Battery. … Alternator Noise. … Electrical Issues.More items…•

## How can I test if my car battery is bad?

The most common symptoms that come with a bad battery include:Battery light illuminated on the dashboard.Engine cranks slowly when starting.Vehicle requires frequent jump starts.Clicking when you turn the engine.Lights are dim.Car won’t start.

## How can you tell if car battery needs replacing?

It’s Time for a New Battery When You NoticeSlow Engine Crank. When you attempt to start the vehicle, the cranking of the engine is sluggish and takes longer than normal to start.Check Engine Light. … Low Battery Fluid Level. … Swelling, Bloating Battery Case. … Battery Leak. … Old Age.

## What can drain a car battery when the car is off?

What may drain a car battery when it’s off, however, are things such as interior lights, door lights, or even bad fuses. While your engine runs, the alternator recharges the battery — which is why you typically don’t have to worry about the battery dying while you’re blasting the radio on your drive to work!

## How can I test my battery?

Use a third-party app to test an Android battery. Download an app meant to test the health of your battery, such as AccuBattery. Open the app and follow the instructions on the screen to set it up. Then use your phone as you normally would for at least a day.