Can a car battery have 12 volts and still be bad?

Yes it can be bad if it’s output is 12 volts with no load and the engine not running… Load it down and watch the voltage drop… The starter is a good load to use for measuring the output under load.. Even a new battery voltage will drop with the starter running, but the battery should easily crank the car….

Can a battery have 12.4 volts and still be bad?

If your battery is: … Cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell. Fully charged (according to the battery charger) but the voltage is 12.4 or less, the battery is sulfated.

Can car batteries test good but 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.

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Can a battery reads 12.5 volts but won’t start?

A: Because it doesn’t have any “capacity”, if you measured the “voltage” while attempting to start the engine you will see the voltage drops significantly and can’t provide the needed amperage AND voltage to start the car.

At what voltage is a car battery no good?

If you don’t have a voltage of around 12.6 volts, you may have a bad battery. Now start the car, and look for a revised voltage over 10. If your voltage drops below 5 when the car is running, it is bad and should be replaced right away.

Is 12.1 volts car battery bad?

12.6V volts or above – Your battery is healthy and fully charged. … 12.1 – 12.4 volts – Your battery is partially discharged and should be recharged as soon as possible, using a suitable battery charger.

What are the symptoms of a dead cell in a car battery?

But for many, when a car battery dies — as they certainly will at some point — one or more of the following symptoms are usually present.

  • Old battery. …
  • Slow to start. …
  • Cranks or clicks, but won’t start. …
  • Dash lights work, but car won’t start. …
  • More frequent jump starts. …
  • Heavy corrosion or film.

How do I know when my car battery needs replacing?

How to Know When it is Time to Replace Your Car Battery

  1. 1) Your Battery Struggles to Combat Seasonal Challenges. …
  2. 2) Your Car Has Been Sitting For Too Long. …
  3. 3) Your Vehicle Struggles When Starting. …
  4. 4) Your Battery Is Older and Triggers a Dashboard Light. …
  5. Alternative Starting and Battery Problems.
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Why does my battery voltage go up and down?

When the battery’s state of charge is low, the voltage is raised slightly to quickly put the charge back in. When the state of charge is high, the voltage is lowered slightly to prevent overcharging. If the vehicle has a voltmeter gauge, you may see the voltage move up or down. This is normal.

Why does my car keep dying with a new battery and alternator?

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.

Can a bad battery read 13 volts?

Without the engine running and the key off a fully charged car battery should sit at about 12.6 volts. Lower indicates a discharged battery or possibly a gauge that doesn’t read correctly. Higher voltage usually means the gauge is off.

What are the signs of a bad alternator?

4 Symptoms of a Faulty Alternator

  • Car Won’t Start. A dead battery almost always lies behind a car that won’t start. …
  • Engine Stalling. A dead alternator almost always leads to a car that won’t start. …
  • Electrical Issues. A dying alternator can lead to a wide range of other electrical issues. …
  • Unusual Sounds.

How can you tell if you have a bad alternator?

7 Signs of a Failing Alternator

  1. Dim or Overly Bright Lights. …
  2. Dead Battery. …
  3. Slow or Malfunctioning Accessories. …
  4. Trouble Starting or Frequent Stalling. …
  5. Growling or Whining Noises. …
  6. Smell of Burning Rubber or Wires. …
  7. Battery Warning Light on Dash.
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How much voltage should a 12 volt car battery have?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts. If you don’t have a multimeter to tell you the voltage of your battery, you can do a test of your electrical system by starting the car and turning on the headlights.

Is 11.9 volts enough to start a car?

When the voltage of the starting power supply is lower than 11.8V, it will be difficult to start the car. … When the battery voltage is lower than 10.8V, it is generally impossible to start the car. You need to replace the battery or use Jump Starter to start the car in an emergency.