Car Battery Dead – Will a Battery Desulfator Revive it?

A good quality car battery can set you back several hundred dollars and once dead, you’ll probably not help but consider if it can be revived even if only you buy you some time.

You may be familiar with the desulfate function – some car battery chargers have the feature inbuilt.

Check your charger’s owner manual if this is the case. Or, if not available, you have the option of using a separate desulfator unit that you connect to the battery.

Whichever it is, is it worth the extra dollars to buy a battery charger with this feature?

Does it really work and what kind of results can you expect?

If you’re in this position then read on to find out whether it’s worth purchasing one and what benefits you can expect.

Does the Desulfate function Revive a Dead Battery?

Honest answer – there’re no guarantees. In some cases, car batteries that are not able to accept charge beyond a certain point or hold charge have been revived.

Note though that the battery will most probably not be restored to as good as new condition!

Some batteries cannot be revived!

To increase the chances of success:

  • Make sure it is a lead-acid battery. The feature does not work with LiFePo4 batteries
  • The battery should be charged for the unit to work
  • Be ready to leave it connected for several days or longer. But even then, there’re no guarantees!

When to Desulfate?

Car battery chargers with an inbuilt desulfate feature may be able to detect and automatically start with desulfation with no intervention on your part.

You may also manually start it (check if the charger supports it) or hook an external unit to the car battery if:

  • You notice a drop in the 12V battery’s ability to hold the charger, or
  • Battery voltage fails to rise considerably even after the battery has been charged for the expected time

How Often to Use it?

Some desulfators can be connected continuously to a lead acid battery without any problem.

Some battery chargers with a desulfation feature may be able to detect whether a battery is desulfated and then automatically start desulfating without any intervention required on your part.

Consult your user manual for your specific desulfator or battery charger.

How to Desulfate a Battery

The connections

If it is a separate unit, connect the desulfator red or positive connector to the battery positive terminal and the black/negative terminal to the battery negative terminal.

How to Select the Battery Voltage

You may have to select the battery voltage either 12V, 24V, or other. When properly connected and working, the led indicator light should show.

How Long to Leave the Desulfator Running

You may have to leave the unit running for a day or more before you see a noticeable increase in battery capacity and voltage.

What to Expect?

If it works, the desulfator will increase the battery’s capacity to hold charge. The voltage to which it can be charged to can increase noticeably.

Do not expect it to restore the battery to its original brand-new condition.

In some cases, you’ll not be lucky. There may not be a noticeable difference in the performance of the battery even after leaving it connected to the battery.

Unfortunately, that is the way it is, there’re no guarantees!

You may also be interested in this post: Does a car battery have a dead cell? Signs and tests to do

Closing Thoughts

If a lead acid battery cannot be charged or has lost its capacity to hold charge you may be able to revive it by leaving it connected to desulfator for several days.

Note, there’re no guarantees!

Recommended Posts

Can you charge a dead battery

Leave a Comment