car battery

7 Dead Car Battery FAQs

Here are the answers to some usual car battery FAQs: 

1. What Causes A Dead Car Battery?

A dead car battery can come about for a lot of different reasons, such as:

  • An electrical component (like the headlights) stayed on when the engine was off
  • The car hasn’t been used or driven for a long time (a fully charged battery will slowly self-discharge)
  • The vehicle’s alternator isn’t charging the battery 
  • Corroded terminals reduce the charge the battery can receive
  • Low temperatures during cold weather might have frozen the battery
  • Very high temperatures in hot weather might have weakened the battery

2. Why Does The Starter Motor Grind Or Click?

Ignition clicks combined with a no-start can indicate a bad starter motor or a problem with the starter solenoid. If there are grinding sounds with a no-start, it could be the sound of the starter motor teeth misaligning with the flywheel (or flexplate) teeth. 

Continuous cranking in this condition can result in more severe, costly damage.

3. Why Does The Battery Die Again After A Jump Start?

Here are some reasons why your car battery won’t hold a charge after a successful jump-start:

  • The car wasn’t driven long enough for the battery to recharge fully
  • The vehicle charging system has a problem, like a bad alternator or voltage regulator
  • An electrical system was left on, draining the battery
  • The battery is too old and can’t hold a charge

4. Can I Recharge A Dead Car Battery?

Often, a “dead car battery” means that it’s fully discharged and the voltage is below functional 12V. You can jump-start the dead vehicle and drive it to let the alternator replenish the battery charge.

Alternatively, you can attach the dead battery to a battery charger

If the car battery voltage is under 12.2V, you may want to use a trickle charger to avoid battery overcharging or overheating.

5. When Is A Dead Car Battery Truly Dead?

A car battery is considered fully discharged at 11.9V. However, if the voltage drops to around 10.5V, the lead plates are likely almost entirely covered with lead sulfate. 

Discharging below 10.5V can permanently damage the battery. 

Additionally, if the battery is left dead, the lead sulfate eventually forms into hardened crystals that can’t be broken up by alternator current or a regular car battery charger. 

At this point, you may have to get a new battery.

6. What Are The Signs Of A Bad Alternator?

You could have a faulty alternator if your vehicle:

  • Headlights are dim or overbright due to inconsistent alternator current to the battery
  • It has trouble starting or frequently stalls
  • It has a malfunctioning electrical component as the alternator isn’t supplying enough current to the battery
  • It has whining or growling sounds from a misaligned alternator belt

7. What’s An Easy Solution To A Dead Car Battery?

Finding a dead car battery under your hood can be pretty stressful, but don’t let it get to you.

An easy solution is to call a mechanic to troubleshoot issues or attach a new battery.


Leave a Comment

Your email address will not be published. Required fields are marked *