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The scientific principle of a lead acid battery
If you want to gain insight into the entire process of recondition a lead-acid battery, then it is important to know how exactly a lead acid battery works.
The operation of a lead-acid battery
A lead acid battery consists of a number of plates with a layer of lead oxide. These plates are in a solution of water and sulfuric acid. This solution is called the electrolyte fluid.

When the battery releases energy, a layer of lead sulphate forms on the lead plates and the sulfuric acid is extracted from the electrolyte liquid, so that only the distilled water remains. When the battery is recharged, the entire process is reversed: the lead sulphate is broken down so that only lead oxide remains on the lead plates and the sulfuric acid mixes with the water again.
What can go wrong in a lead-acid battery?
With a lead-acid battery that has not been charged for a long time or that remains in a discharged state for a long time, the lead sulfate crystallizes on the lead plates. This is called sulfation and it is this process that causes the battery to stop functioning. The crystal lead sulfate is so hard on the lead plates that no chemical reaction can occur. As a result, the battery can no longer be charged and the car will therefore no longer start.
Many drivers therefore immediately assume that their batteries have completely given up and decide to purchase a new battery. However, a battery can still be recovered in this case. If the crystallized lead sulphate that has formed on the lead plates can be broken down, then your battery will work as new again.
Is it difficult to overhaul a lead-acid battery?
Not at all! Overhauling a lead-acid battery is not at all as difficult as it seems at first glance and if you are a little handy, you can easily do this yourself.
Safety precautions
Make sure that you are always very careful. After all, the electrolyte fluid in a lead-acid battery contains the corrosive substance sulfuric acid.
- Always wear gloves, an apron to protect your clothing and safety glasses.
- Always work in a well-ventilated area.
- Also protect the floor because the strong sulfuric acid can even affect it.
- Also be careful that you do not spill electrolyte liquid outside, as this can seriously contaminate the soil.
Practical approach
Once you have taken the necessary safety measures, you can practically get started.
Step 1: Heat 475 ml of distilled water to almost boiling point. Add 250 grams of Epsom salt and stir this mixture until the Epsom salt is completely dissolved.
Step 2: Remove the terminal covers from the battery. With a closed battery you will have to drill 6 holes exactly where the cells are located.
Step 3: Divide the Epsom solution in 6 identical quantities, add it to each cell and make sure that lead battery plates are covered with this liquid. You can easily do this with a plastic funnel.
Step 4: Replace the closing covers or close the holes and shake the battery a few times. This gives the Epsom solution the chance to mix with the electrolyte fluid of the battery.
Step 5: Discharge the battery up to 50% and fully recharge it in the normal way. Your battery should now do well again!
Tip: if you fully charge your battery again, keep an eye on this entire process. Check every hour if everything is still going well and if your battery is charging properly.
Do you want to extend the life of your lead-acid batteries?
You can do much more to extend the life of your lead-acid batteries. We cover this and many other ways to guarantee the life of your batteries in our Battery Recondition Review article .
In this program you will also learn how you can overhaul your lead-acid batteries yourself. It goes without saying that you can save a lot with this.
