What is Sulfation in Battery; Why It Is Bad and How to Prevent It?

Battery Maintenance Tips - November 11, 2021

What is Sulfation in Battery; Why It Is Bad and How to Prevent It?

Lead acid battery is an electro-chemical equipment. Lead acid battery converts the chemical energy in to an electrical energy which then is used to power the electrical system of a car or a bike or even your house or for that matter any building when connected to the inverter.

Maintaining the battery of your car and bike is very important. As much as you care for the external damages and the expiry of the battery you must also keep an eye on the problem arising due to the internal chemical reactions in the battery which can potential reduce the performance and ultimately the life of the battery. One such process is Sulfation.

Lead acid battery consists of Sulphuric Acid and the positive and negative plates made out of alloy consisting of either lead, antimony or copper. These chemicals react with each other and the loose electrons from these reactions are used for electrical supply. In these reactions as the electrolyte which is mixture of Sulphuric Acid breaks down, Sulfur ions are get loose and forms crystals. The Sulphur ions accumulate on the plates this process is called Sulfation.


Lead acid battery due to its nature is bound to experience sulfation. Let us look at common causes that lead to sulfation in a battery.

  1. Leaving the battery idle for long time is the biggest reason behind sulfation. It is recommended to start the car battery or a two wheeler for at least 15 to 20 minute every week or two. The longer the battery sits idle faster will it sulfate.
  2. Electrolyte level – When the electrolyte levels go down and remain low for a long time it expose the plates. When exposed to air the plates sulfate faster.
  3. Improper charging. The must be charged to 100% at all times to get maximum results. Not charging battery to its level gives room for sulfation since the inactive area of plates starts to sulfate.


Reversible Sulfation and Irreversible Sulfation are the two types in a Lead Acid Battery. Reversible, as the name suggest is the mild sulfation which can be reversed or treated and get the battery working to its normal potential. In Irreversible Sulfation battery is badly damaged, loses its capacity rapidly and dies down quickly.

Irreversible Sulfation or the Permanent Sulfation occurs when the user does not start the battery for months or the battery is left in a low state of charge for long period of time because of incomplete charging.


If your car battery is showing signs of low performance then it is probably sulfating. If you face problem starting the vehicle engine or slow start or if it takes longer than usual to start the car the battery is possibly going under sulfation. Other signs to watch for are the reduction in the performance of the AC, dimming head lamps, Horn not working or delay in response, low cabin lights etc.

The visual sign of sulfation can also be seen on the battery terminals. Sulphation leaves a white dust that accumulates on the battery terminal which cause corrosion on the terminal. If you see it it’s time to check the battery immediately.


Taking proper care of your battery and periodic checks is the simplest way to prevent sulfation. Here are few things you should keep in mind

  1. Never leave the battery idle for more than a week. Even if you are not taking out your vehicle for months make sure you start the engine for 15 minutes every week
  2. Make sure the battery is not exposed to extreme temperature conditions. Read user manual for maintaining battery in your region
  3. The more the battery used the healthier it is. It all depends on the charge cycles of the battery meaning battery must be discharged and charged every now and then in order for it maintain chemical reactions
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