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Home / Car Auto / How to Guide / Boost Charging A Battery

Boost Charging A Dead Car Battery

dead car battery

If your car's battery is relatively new, but has been left discharged state for too long, it would be considered dead by all accounts. It won't measure at the proper voltage and it won't be able to start your car. In the video below we will show you a unique method to boost charge your dead car battery and bringing it back to life.

Video: How to Boost Charge

Video Transcript:

Here we have a relatively brand new car battery, less than 1 year old. It should still be capable of starting a car but it was unfortunately left in a discharged state for too long.

When we test the dead car battery with a multimeter, we get a reading of 6.8 Volts. Since this is a car battery it should have a reading within the 12 volt range. Because the voltage has dropped so low, a normal car battery charger will not recognize it as a 12 volt battery. In some cases you may be able to slow charge it over a period of a few days with a 12v charger if the charger allows you to force the charge mode to 12v. Typically when a 12v battery drops below 9v the normal method of using a car charger doesn’t work.

The method we use in this video is what we call parallel charging. We use a fully charged 12v SLA (sealed lead acid) battery that has at least double the capacity of the car battery. Note it is important the batteries have the same voltage. In our case they are both 12v batteries.

We then cable them together in parallel, connecting one end of the red cable to the positive (+) terminal of our fully charged SLA (sealed lead acid) battery and the other end to the positive (+) terminal of our bad battery.

Then we connect one end of the black cable to the negative (-) terminal of our fully charged SLA battery and the other end to the negative (-) terminal of the bad battery.

You will need to let the batteries sit for 2-3 days to bring the dead battery back to or closer to 12 volts. Be sure to do this in a covered and cool well ventilated area. In our case we left the batteries cabled together for 3 full days to insure the dead battery becomes equalized. We then test the original dead car battery with a multimeter and we get a reading of 12.23v.

We now use the Genius 26000 Wicked Smart car battery charger and it is able to recognize the battery which was once nothing more than a dead car battery that needed to be replaced. The charger immediately begins pulse charging to desulfate the car battery. Since the Noco Genius 26000 is a sophisticated car battery charger, it has a built in microprocessor, enabling it to detect signals that indicate the battery has become sulfated. It then automatically begins pulse charging our car battery.

In pulse charging mode, the charger is sending out high currents of electricity for a short duration in a pulsing fashion which helps blast off any sulfur buildup on the lead plates which make up the 6 battery cells in this battery. After the charger is done with pulse mode charging it will default back to a regular charge mode. The great thing about this car battery charger is it won’t overcharge your battery. Once the battery is fully charged, the Noco Genius 26000 will go into a storage mode where it will float charge the car battery to maintain optimimum charge without overcharging and damaging the car battery.

We leave the charger overnight to complete the process of fully pulse charging and recharging the car battery.

Once the charger indicates the battery is charged to 100%, we are ready to install the battery in our car for reuse.

This process has given a dead car battery a second life.

We hope you have learned something from this video. Be sure to visit www.Atbatt.com to save money on your next car battery.