Quick Answer: What can cause a car battery to not hold a charge?

How do you fix a battery that doesn’t hold a charge?

How to Fix a Car Battery That Won’t Hold a Charge

  1. Prepare the battery. Put on the safety glasses. …
  2. Perform a load test. Connect the load tester to the positive battery terminal first and then to the negative post. …
  3. Remove the cell covers. …
  4. Perform a hydrometer test. …
  5. Test the cells. …
  6. Add the treatment chemicals (optional).

What would cause a car battery to not hold a charge?

One significant reason why a car battery won’t hold a charge is age. Obvious signs that your battery is too old and worn out include corrosion and cracking. If it’s at least four years old, then it should probably be replaced. For younger batteries, a car that isn’t started for days or weeks can also lose its charge.

How do I know if my alternator is bad?

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.
INTERESTING:  You asked: How would I know if I need transmission fluid?

How long will a bad car battery hold a charge?

Most car batteries which are in good condition will last at least two weeks without needing you to start the car and drive to recharge it, according to the AA.

Why does my car battery keep dying overnight?

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 should a battery hold a charge?

If you’re dealing with a fully charged battery that’s relatively new and in perfect condition, it will take 2-3 months for it to lose its power completely. However, you’re probably pushing your luck if you let it sit idle for more than two months.

How long should a battery hold its charge?

If the battery is new, it should hold a charge for a month or two. Older batteries will go flat much more quickly. We recommend that you remove the battery from your car when left for long periods. Charging a battery that while connected to your vehicle can sometimes affect the car’s electronic systems.

Can a bad ground cause battery drain?

A bad ground might not cause a battery to drain, but it will prevent it from properly recharging.

Can a bad alternator drain a battery when the car is off?

Even while your car is off, your battery provides power to things like the clock, the radio, and the alarm system. … But when the engine is off, the alternator can’t recharge the battery, allowing little electrical mishaps to drain your battery entirely.

INTERESTING:  Why do people hang shirts on broken down cars?

Can you jump start a car with a bad alternator?

You actually can jumpstart a car with a bad alternator, and the car will keep running for some time, no matter how bad the alternator is, well, considering you have a good battery. This is because if the alternator is bad and not producing the voltage required, the car will be running purely off the battery.

Can AutoZone test your alternator?

Every AutoZone in the USA will check your alternator, starter, or battery at no charge.

How do you test an alternator to unplug the battery?

If you’re tempted to test an alternator by disconnecting the negative battery cable, don’t do it. A good alternator may indeed keep the engine running without the negative cable, but this was never a good test. In the pre-computer days, you could pull it off without damaging anything.