What Is Car Battery Acid Stratification And How Does It Cause Premature Battery Failure?

car battery acid stratification
All motorists with lead-acid automotive batteries should be wary of the possibilities of stratification, which is a phenomenon that can cause cells to fail. But what is car battery acid stratification? We will go through the basics of it to hopefully help you be better equipped to prevent it.

While there have been regular advancements in the performance of vehicle batteries, their general components have been the same since the 1880s. A standard lead-acid battery contains a liquid mix of sulfuric acid and water. This mixture is called the electrolyte.

The electrolyte should be evenly distributed between the top and bottom of a battery. An even concentration within the liquid is vital for the optimum performance of cells. If the acid concentration settles on the bottom of the battery, this is called car battery acid stratification. It causes sulfation in the plates located in the bottom half, which will significantly reduce a battery’s lifespan due to accelerated corrosion.

Which drivers are more prone to experience this battery condition?

Anyone that does short distance driving every day, irregular car usage or has a faulty under-charging alternator. It is a common problem with city dwellers who live in proximity to their amenities, with the result being, the alternator is not allowed to give sufficient daily charge to the battery.

How Do You Prevent Car Battery Acid Stratification From Forming?

Equalization charge

Stratification can occur if a battery is undercharged. You must make sure that the charger voltage is high enough to charge the battery properly and to spread the electrolyte solution evenly. To prevent stratification, you can perform an equalization charge, which balances the voltage and specific gravity of the electrolyte in your vehicle’s battery. Specific gravity refers to the ratio of the weight of the liquid solution to the weight of water at a specific temperature. Equalization also prevents the build-up of sulfate crystals.


If you are a driver who makes short trips frequently, or doesn’t use their car often enough, get your battery checked regularly. Keeping your battery at optimum charge at all times, to get its maximum starting and auxiliary life-cycles.

Next Page: How A Lead Battery Is Made