Infographic: 5 Reasons a Vehicle’s Battery Keeps Draining

If you’re enrolled in an auto mechanic college, you likely understand the importance of a well functioning car battery. If a vehicle’s battery is constantly dying, there’s usually another factor at play than just an unfortunate mistake such as leaving the headlights on all night. Car batteries are responsible for supplying the power a vehicle needs to start, in addition to providing the electricity necessary for systems such as the radio, air conditioning, and lights to function while a vehicle is in motion. However, a battery only charges while a vehicle is running, so if there’s a problem that’s preventing it from getting enough power, it’s likely to drain frequently. Persistent battery drainage is not only a nuisance, it could also be an indicator that there’s a serious problem with the battery or a related component.

If you are taking a mechanic program, familiarizing yourself with the common causes of frequent battery drainage will help you to get to the root of the problem faster and perform successful repairs during your career. Below, discover five possible causes behind persistent battery drainage.

5 Reasons a Vehicle’s Battery Keeps Draining

5 Reasons a Vehicle’s Battery Keeps Draining

Meta Description: Attending auto mechanic college? Your ability to diagnose car battery drainage accurately will be enhanced when you know the common causes. Discover them here.

1. Parasitic Drain

When a vehicle is off, the battery still provides power to:

  • Radio presets
  • Security alarms
  • Clocks and more

Parasitic drain can occur due to:

  • Electrical problems (bad fuses, faulty wiring)

This causes some components to take too much power from the battery, leading to:

  • Excessive battery drainage

2. A Faulty Charging System

The alternator supplies charge to the battery. When it’s not working:

  • The battery won’t charge while the vehicle is in use
  • The battery will drain prematurely

Check to see if the alternator belt is:

  • Worn out
  • Loose
  • Cracked

If so, it may need replacing.

3. Too Many Short Drives

Driving short distances can affect the battery by:

  • Not giving it enough time to charge
  • Using excessive power to start the vehicle

4. Worn Out Battery Connections

Battery cables transfer energy from the battery to the starter motor. Check to see if:

  • The connections are loose
  • The terminals are corroded or dirty
  • The cables are cracked or worn

5. Extreme Weather Conditions

Extreme hot or cold temperatures can lead to:

  • A build-up of sulphate crystals
  • Depletion of battery life due to sulphate
  • Excessive strain on the battery 


8 Things That Will Drain Your Car Battery | Car Bibles

7 Things That Can Drain Your Car Battery | Firestone Complete Auto Care

The Top 8 Things That Will Drain Your Car Battery | YourMechanic Advice

6 Reasons Your Car Battery Keeps Dying (

Form is submitting