How To Fix a Dead Cell In A Car Battery?

Giving you tips on how you can revive your car battery.

Have you been in the middle of your trip and your car suddenly stops – right in the middle of nowhere – and you have no clue what happened? Yes, it happens mostly to new drivers or new car owners.

You’re clueless, you have no idea what occurred to you, and then you found out that it’s the car battery that is having the problem. You will ask yourself, how to fix a dead cell in a car battery? Especially if you don’t know anything?

It is an annoying moment and who would like that to happen while you are enjoying a road trip? Of course, no one.

Now, the question is, how can we revive a dead cell from a car battery? It is so easy to answer, no, don’t restore it, instead – buy a new one. But no again, you can fix a dead cell by reconditioning the car battery. Reconditioning your battery ordinarily add few more years to your car battery’s life timeline. To know more about how we can recondition car batteries, watch out for the detailed step by step process.

How Do You Know That There’s A Dead Cell in a Car Battery?

Before we can recondition a car battery, we need to know first the signs on how to spot the dead cell in a car battery.

A 12-V car battery has six cells, and each cell is all giving voltage and amperage. So since each cell provides equal energy on to start the car, if one cell fails, the car battery won’t be able to afford the energy needed to start your vehicle.

You can check them and think if you are currently experiencing any of these signs so you can prevent the car battery to die in the next two weeks.

1. Your vehicle is too slow to start the engine at all.
2. Your car starts fine and runs good, but after turning off the engine for a few hours to eat your lunch, you can’t start it again the same way you started it in the morning.

If this happens to you most often than not, then it is time for you to check your car batteries and revive that dead cell.

To identify if the car battery’s cell is dying, you need to test it using a voltmeter. If the voltmeter reads a 12.4V and higher, then you are still good to go with the battery – the problem could be on any part of the car’s engine and not the battery itself.

However, if it is lower than 12.4V, then it is time for you to get serious and start reconditioning your car battery.

Reconditioning A Car Battery’s Dead Cell

If you were thinking that it’s a waste of time instead of buying a new battery, then, by all means, close the tab and stop reading. But if you want to save $300 or use it for other essential things, then read on.

Reconditioning a dead cell of a car battery is entirely a thrifty way to save the car battery and prolong its life for another few years. Most of the car shops who buy supposedly “dead car batteries” take them at a lower price then refurbish them and sell them at a higher price.

Now, who earn more? It’s not you. It’s them. But if you try to refurbish them by carefully following the steps, then you will save a ton of bucks, and you will be able to extend the battery’s life instead of putting it on the car shop’s garage for them to sell it like crazy.

To start reconditioning your dead cell, you need to have the following tools first:

1. A drill
2. A mighty screwdriver
3. Protective Goggles
4. A half gallon of distilled water
5. A pair of neoprene rubber gloves
6. Your trusted battery charger (Any brand that you are comfortable using and the one that is compatible with your battery type)
7. Plastic funnel
8. A turkey blaster
9. And yes, an Epsom salt!

Reconditioning Car Battery Process

Please make sure that when you perform this, the car battery is in a well-ventilated area and it also needs to be fireproof.

1. Heat a half quart of distilled water to its boiling point (150 degrees). Add eight oZs of magnesium sulfate or Epsom salt to the boiling water and stir it well until the salt is entirely dissolved.

2. Before doing anything on the battery, make sure that it is clean. You can clean the outside of the battery using a baking soda and clean water. Make sure to eliminate any form of corrosion especially on the wire connections and terminals.

3. Using the screwdriver, cautiously uncover the battery cells. Remove the top cover of the sealed battery first then next the plastic caps and puncture holes at patterns. You can use a damp towel to reduce the ruins that are surrounding the battery slots.

4. Use the plastic funnel to fill the batteries with the solution that you have prepared on the first step of this procedure. Once they are all filled in, reinstate the battery covers.

5. You can now charge the car battery gradually for 24 hours. You can repeat this process three times, which will eventually improve the lifespan of the battery.

And voila, you can use your recharged and refurbished battery again! You saved a few bucks, and you lengthen the life of your car battery – and yes, you can drive long roads again!

Isn’t that a hack? Yes! And only a few who are reading this until this line knows this. You’re fortunate. You chose to save and use your skill than to buy and waste money.

Safety Tips

Even if it’s so simple to read, or also to perform, we still need to be cautious while doing the whole process. Please take a look at this list and keep these things in mind before and during the procedure.

1. You need to have a compatible charger.

There are many battery chargers in the market, but like phone and laptop batteries, car batteries have their compatible charger. You cannot use a charger that is not suited for the battery type that you have. A compatible charger should function well with 12-volt batteries.

2. Make sure that you are using a protective gear.

Aside from rubber gloves, you also need to wear protective glasses, protective clothing that will dodge acid burns. Acid burns can be treated, but it is better safe than going into the hospital or taking in first aid.

But yes, first aid kit needs to be always ready, in case of emergency.

3. You need to check the voltage.

Like what I have mentioned in the beginning, if you want to recondition the battery, you need to make sure that it is below 12.4V as it indicates that two or more cells are already dead. 10.1V to 12.3V is still good to go for reconditioning, but anything lower than 10V is technically obsolete. (Here is the helpful article).

4. Your storage area should be observed.

While you are reconditioning your battery, it is essential to store it in a safe place where it is not exposed to direct sunlight. Also, after the reconditioning process, it should not be stored in a hot location or even an area that is receiving direct rays of sunshine.

5. Even if the battery is maintenance-free, it needs a regular checkup.

Don’t be too fooled by the tag line, “maintenance-free” – it only means that you don’t need to get it checked by the mechanic as frequent as lead-acid batteries that require a constant tune-up.

If you are not going to use the car battery for months, it is recommended to charge it frequently using a trickle charger. Using a trickle charger in charging the car battery can improve its lifespan as well.


Before we ask ourselves on how to fix a dead cell in a car battery, we also need to ask ourselves if the battery is the real problem why your car is not starting. We need to check that first by monitoring the voltage of the car battery. If it drops around 10V below, then you need not to think twice.

Check your car battery’s user manual, see the battery type, check the specifications – and buy a new battery because any battery that is below 10V has obsolete cells already. You cannot revive it.

However, if the voltmeter reads 10.1 to 12.3 volts, then you can still refurbish your car battery and give a chance to its dying cells to get back to work. You can save $300 and buy anything that you want or keep it for the future.

As you can see, the process still depends on what the voltmeter will show as results that’s why it is critical to pay attention to the voltage test before performing any procedure.

And if it requires you to recondition the car battery, be sure that you have read the safety tips before you proceed. It is always better to prevent bad things from happening than trying to mend them.