Car Battery Keeps Dying but Alternator is Good? 

Car batteries are designed to power your vehicle for your years. Ironically, car batteries die at the most inconvenient times. Although the car batteries usually do not drain or die too fast under normal circumstances, …

Car Battery Keeps Dying

Car batteries are designed to power your vehicle for your years. Ironically, car batteries die at the most inconvenient times. Although the car batteries usually do not drain or die too fast under normal circumstances, some common issues in car battery charge or usage can lead to premature car battery drainage. A flat out car battery can create a lot of trouble for you.

However, this article will tell you the car battery dying basics and how to take the necessary steps in the event of a dead car battery. 

Reasons for car battery dying 

A number of factors contribute to draining a car battery. Some common reasons for car battery dying include: 

  1. Interior Lights Left On: The headlights, dome lights, door lights or cabin lights that are left on for a long time drain car battery in a matter of hours. When your car is sitting idle, always turn on excessive lights to save battery. 
  2. Weak and Poorly Maintained Battery: A weak battery fails to hold the necessary battery charge. Even the smallest of battery drains like radio use can kill weak and poorly maintained batteries quickly. 
  3. Corroded or Loose Battery Terminals: Corrosion on battery terminals disperses electric input and impedes the battery charging process. Lose battery terminal connections contribute to charge wastage and drain the battery. 
  4. Extreme Temperatures: Extremely hot or cold weather can kill an old or weakened battery. 
  5. Big Battery Drains: Battery drains like glove box and trunk lights typically drain battery charge faster than any other component. 
  6. Charge System Issues (bad Alternator): A bad alternator will stall your engine and stop your car while driving since it fails to draw the voltage needed for battery charge. Similarly, stretched belts, worn terminals and loose connections also hamper the proper function of an alternator. 
  7. Parking for Too Long: Parking the car for a prolonged time eventually drains the battery.

What to do if your car battery is drained?

The best solution is to call an expert for a car battery inspection and repair. You can try to jumpstart your vehicle to get it working temporarily. You may also want to look into the cause of draining car batteries and remediate these issues as best as you can. You can:

  1. Turn off excessive car lights/electric components 
  2. Repair and maintain the car battery on time 
  3. Clean the battery terminals and tighten the connections 
  4. Spot and eliminate the parasitic battery drains 
  5. Replace the car battery with a new one

Frequently Asked Questions

What drains a car battery?

Typically, the most common factor that drains a car battery is a bad alternator. An alternator is a component in your car battery’s charging system that pushes out the voltage necessary for charging the battery. In other cases, things like interior lights, door lights, bad relays and excessive use of electrical equipment while the car is turned on/sitting idle are among the causes of car battery draining. You can connect a digital multimeter to your car battery’s negative terminal to view the changes in reading and see whether your car battery is dying or not.

Why is my battery dying so fast

Car batteries die due to prolonged use, lack of care and due maintenance. However, some factors can accelerate the battery dying. A bad alternator that is not charging properly or a weak battery is among the top reasons for a car battery dying too fast. An open circuit that sucks out power from a vehicle that is off is also another reason for dying car battery.

How to tell if alternator is draining battery? 

A bad alternator is among the top reasons for battery draining in cars. Some signs of a bad alternator that is draining the battery include a dead battery, car not starting upon ignition, engine stalling, frequent electrical issues and unusual sounds. A bad alternator on a running engine can fully drain out the car battery between 30 minutes to two hours. If you notice your car engine dying or stalling, it is best to inspect the alternator.

To check this problem, keep the car engine running. Remove the cable from the negative terminal of the car battery carefully. Once you do this and the engine vehicle stalls or dies, then it is a sure sign that the alternator is bad. You will need to replace the alternator to correct the problem. 

Does leaving your car on drain the battery? 

Yes, it does. Leaving your car on for too long not only leads to excessive fuel consumption but also the car continues to drain the battery charge. As long as the car is powered on, the different electrical parts will continue to suck out battery power. Even when the car is sitting idle while on, the engine and alternator will continue to consume car battery and thereby, drain it with time.  

Will corrosion drain car battery?

Corrosion impedes the performance of your battery. Corroded battery terminals have reduced current drawing capacity, which means more work and lesser charging for the battery. Although corrosion is not a direct cause of draining a car battery, it can drain out battery power and significantly reduce its lifespan. Inspect your battery’s terminals to spot signs of corrosion. If the terminals are corroded, you will need to carefully clean the battery terminals to restore the battery’s charging capacity close to normal.

How long does it usually take to drain a car battery?

Most car batteries die anywhere between 4 to 7 hours. After 8 hours, the car battery is completely drained. Speaking in terms of Amp-hours, it takes anywhere between 60 and 100 amp-hours to fully drain a car battery. However, the amp0hour capacity is dependent on the amount of draw amperage receives. 

Final Thoughts! 

Excessive use of interior lights, a bad alternator, loose connections, corrosion around terminals, extreme weather and parasitic drains are among the top reasons for car battery drain. If your car stops or the engine stalls while you are driving, there is an issue with your battery. Check for potential causes and ask an expert to fix the battery for you.