Quick Answer: Can A Battery Read 12 Volts And Still Be Bad?

What do I do if my car wont start but the battery works?

Here are some things to try if your car won’t turn over.What To Do If Your Car Won’t Start: …

Try: Cycling the Key.

Try: Tapping on the battery Terminals.

Try: Smacking the starter.

Try: Shifting the Shifter.

Try: Swapping Relays.

Try: Smacking the Fuel Tank.

Try: Un-flooding a flooded engine.More items….

How do I know if my battery is bad or my alternator?

If the engine starts but dies immediately, your alternator probably isn’t keeping your battery charged. If a jump starts and keeps your car running, but the car can’t start again off of its own power, a dead battery is likely your answer.

What are the signs of a bad alternator?

6 Symptoms of a Failing AlternatorThe indicator light. … Headlights are dim or flickering. … Other electrical failures. … Strange noises. … Car stalls or has difficulty starting. … Battery dies.

Can a bad alternator destroy a new battery?

Can a bad alternator kill a new battery? Yes, very easily. A failing alternator can overcharge, which will damage the battery. An undercharging alternator will leave the battery flat, which speeds up its failure.

Can a battery read good but still be bad?

Yes, it could test out okay and still have problems. That is what my batteries did before I replaced them. … Someone finally told me that while batteries can test out okay – they can lose some of their capacity for “cold cranking amps”. I replaced them and all was fine again.

How long does it take to Desulfate a battery?

48 hoursDepending on the size of the battery, the desulfation process can take from 48 hours to weeks to complete. During this period the battery is also trickle charged to continue reducing the amount of lead sulfur in solution.

Is 11.9 volts enough to start a car?

A flat battery can show 12 volts , but not be good enough to start a car . … 11.9v indicates the battery is completely discharged. Anything under 12.2v means the battery is in a state of discharge, and a healthy battery should show 12.6v in a static state.

How do you know if you have a bad battery?

How to Tell if Your Battery Has Gone (Or is Going) BadDashboard Lights. One of the most obvious bad battery signs is a warning light on the car’s dashboard. … Old Battery. Another pretty simple sign that the car may be having a battery problem is the age of the battery. … Slow Start. … Bulging Battery Case. … Odd Smell. … Electrical Issues.

What voltage is a dead battery?

A reading of 12.65-12.77 volts means your battery has a full charge. 12.45-12.54 volts means you have a 75% charge, 12.24-12.29 is 50% charged, and 11.99-12.06 volts is 25% charged. 11.75-11.89 volts means your battery is dead.

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 can you tell if a 12 volt battery is still good?

To test the voltage, make sure to connect the battery cables. Start the ignition while holding the leads on the positive and negative terminals. You will notice that the voltage will drop, but it should not drop below 9.5 volts. It needs to be replaced if it drops below this voltage.

How do you tell if its your starter or your battery?

The battery sends a burst of energy to the start which uses this energy to turn the engine over and get it car started. If you put the key in the ignition, but only hear a click when you turn the key, you’ve got a problem with your starter.

What should a 12 volt battery read when fully charged?

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 does it mean when my car wont start but all the lights come on?

This is usually due to battery failure, which is due to something being left on and causing the battery to drain. It could also be due to poor connections, damaged battery terminals, or a bad or dead battery. Sometimes, this could even be due to the starter, with the control terminal becoming corroded.

At what voltage is a 12 volt battery considered dead?

12.0 voltsResting fully charged 12-volt batteries are around 12.8-12.9 volts, and flat dead ones are at 12.0 volts, so 12.4 volts on a resting battery means it’s about 50% charged.

How many volts should a good battery read?

12.4-12.9 voltsCheck the voltage. A good car battery should read 12.4-12.9 volts when the car is off. Anything lower doesn’t necessarily mean the battery is bad. Your car’s electrical system may have drained it, or there may be an issue with your alternator.

Why won’t my car start but I have power?

If your vehicle won’t start, it’s usually caused by a dying or dead battery, loose or corroded connection cables, a bad alternator or an issue with the starter. It can be hard to determine if you’re dealing with a battery or an alternator problem.