How To Recondition A Forklift Battery

method for reviivng the fork lift batteries.The battery of a forklift is almost the same as that of a lead-acid battery of a car. However, forklift batteries are much bigger, heavier, and they are a lot harder to try to recondition. Nonetheless, it is not impossible to do so.

In this article, i will share with you how to recondition a forklift battery so that you will have an idea on how to make your battery work again. Forklift batteries are deep cycle batteries. This means that they can be discharged at a very low level and you won’t have any issues with them getting damaged.

There are several steps that you can do so that you can restore your forklift batteries. However, if the battery is really beaten up and you feel that you won’t be able to do it, it is best to let the experts handle the reconditioning process for you.

The steps i will be sharing with you are how to clean, replace fluids, and remove the sulfation from the forklift battery. You may need some tools for you to successfully perform the steps we will be teaching you. It may require you to shell out some money if you don’t have the tools needed but that is a more cost-efficient option compared to buying a new forklift battery.

Prepare The Battery To Be Revived

A single battery of a forklift is very heavy. It can get as heavy as a few thousand pounds. For you to remove the battery, you are going to need a forklift to help you out. To be sure, read the user’s manual of your forklift so you can see the specific instructions on how to remove as well as maintain the battery of your forklift.

When you have successfully removed the battery from the forklift, put it somewhere where there is good ventilation. Prepare the voltmeter so you can check the voltage of the battery. Compare that with the voltage on the battery’s label. When you have taken note of those number, discharge the forklift battery to 80% of the voltage that you see on the label.

Clean The Forklift Battery

Once you have discharged the forklift battery to the right level, you can proceed to clean the terminals of the battery. To do this, put some baking soda onto the terminals as well as on top of the forklift battery. After that wet the surface with water and then brush it with a soft-bristle brush.

While the baking soda can neutralize any acid that is on the surface of the battery, you should still use protective clothing, gloves, and goggles. The acid of the battery is corrosive so you should be careful not to touch it with your bare skin. If you observe that the baking soda didn’t remove all of the dirt completely, you can put some dishwashing detergent on the battery so you can remove any grime and dirt left.

Measure The Battery Water’s Acidity

To be able to access the water inside the battery, you need to take off the cell caps. Ideally, the battery water should have 30% sulfuric acid and then 70% distilled water.

Here, you need to use a hydrometer so you can measure the acidity of each of the battery’s cells. By measuring the acidity, you will know the amount of acid or water that you are going to have to add to the cells.

Forklift Battery Restoring

To restore the needed acid to water ratio for each of the cells, you should add water or acid to the individual cells of the battery. Remember not to use tap water because it has contaminants and minerals that can lead to your battery getting damaged.

During this particular process, it is important for you to check the concentration of the acid so that you will know the amount of acid or water that you are going to add. Each cell may need a different ratio, so you need to check them individually.

After that, put the cell caps back, and then you can connect the battery charger to the battery. Charge it for about eight hours or until it is charged completely. Check to see if the forklift battery was able to reach the required voltage. Recheck the acid to water ratio of each of the cells and then make the necessary adjustments. You can then try to charge it again.

You have to take note that you should discharge the forklift battery before you try to recharge it for a new cycle. This is to avoid any overcharge as it can damage the forklift battery permanently.

You may have to do this process a few times. If you have checked that the ratio of acid to water is correct, then there must be an issue with the cells themselves. Using a voltmeter, check the voltage of each cell so that you will know which of them is faulty or damaged.

To do this, put one probe of the voltmeter to the terminal and then immerse the other in the liquid. If you find any faulty cell, you may have to have them replaced or reconditioned by professionals.

Remove The Sulfation

One of the leading causes why lead-acid batteries fail is because of sulfation. When you do not use the battery, the sulfate crystals begin to form. These crystals can then deposit on the negative plates of the battery.

What happens next is that this affects the performance of the forklift battery greatly. Even charging is affected because you will need to charge it longer because of a high internal resistance. You may be able to reverse the sulfation.

Here, you will need a desulfation or anti-sulfation device. This device sends out pulses to the terminals of the battery, removing the sulfate crystals that have formed. You can also use a desulfation charger as a preventive measure for healthy or new batteries.


The process of the ways to restore forklift batteries is more complex as compared to a car’s lead-acid battery. But you can do it by yourself as well just like in regular batteries. However, if you feel that you need help, you can always call the professionals to do it for you.