How & When to Water Forklift Batteries

Forklift battery maintenance – it’s a chore but a necessity. In today’s age, more than ever, proper battery watering methods are vital to reaching the full life expectancy of a forklift battery. Since the battery usually costs roughly 30% of the entire forklift sale, proper battery watering procedures are essential.

Why Water a Battery?

A forklift battery is expected to last for five years. To achieve this, strictly follow the proper watering and charging guidelines. Not properly watering a forklift battery risks lowering the life expectancy of a lift truck battery by up to 50%, or two and a half years. The cost is too high to ignore these guidelines.


How to Water a Battery

  • Gravity Feed System – This system features a large water drum or tank hoisted in the air and has a hose attached to it that the operator takes from cell to cell until they are properly filled. This method may require a flashlight to see the level of water in each cell.
  • Battery Watering System – These systems hook your batteries up to a “hose-like device” that attaches to each cell and properly fills each cell. After this, it automatically shuts off when each cell is filled properly. These systems offer the most convenience and fill accuracy.
  • Hose / Watering Gun Method – This method involves hooking a battery watering gun attachment to a hose and going cell-by-cell and manually filling each cell to the proper level discussed above. As with the Gravity Feed System, this method may require a flashlight to see the level of water in each cell.
  • Overwatering & Underwatering
  •  You should fill the battery to the level discussed above and not anymore or any less. Doing the contrary can lead to leaks or downtime. 

When to Water a Battery

In a perfect world, batteries are run for 8 hours, charged for 8 hours, and cool for 8 hours. Some lift trucks offer an indicator, but the best time to water your batteries is always right before each shift, after batteries have had time to cool, and the worst time is right before or during charging.

Even though it may be tempting to charge during lunch breaks, this is not ideal. If watering occurs before or during charging, it can lead to the water boiling over and acid leaking from the battery. Also, let the battery charge completely and avoid keeping it stored in extreme conditions.  

How to Water a Battery

  • Gravity Feed System –  This system features a large water drum or tank hoisted in the air and has a hose attached to it that the operator takes from cell to cell until they are properly filled. This method may require a flashlight to see the level of water in each cell.
  • Battery Watering System – These systems hook your batteries up to a “hose-like device” that attaches to each cell and properly fills each cell. After this, it automatically shuts off when each cell is properly filled. These systems offer the most convenience and fill accuracy.
  • Hose / Watering Gun Method – This method involves hooking a battery watering gun attachment to a hose and going cell-by-cell and manually filling each cell to the proper level discussed above. As with the Gravity Feed System, this method may require a flashlight to see the level of water in each cell.
  • Over watering & Under watering
    Batteries should be filled to the level discussed above and not anymore or any less. Doing the contrary can lead to leaks or downtime. 
Benefits of lithium forklift battery
Forklift Battery Over-watered


This picture shows an overwatered battery. 


When the water was filled above the lead acid plates, acid leaked, forming “cauliflower.” Under-watering causes the battery to run dry and increases downtime and maintenance.

How to Stay Safe When Watering Your Battery

Wearing proper gear and removing metallic jewelry can prevent serious injuries. Here are some items to wear:

  • Protective gloves
  • Protective apron
  • Eye protection

    How Do You Put Water in a Forklift Battery?

    There are different methods for this, but no matter which you use, it’s vital to only water each cell in each battery until the top of the lead-acid plates is reached. These plates are visible in each cell and usually 2.5 inches below the cell cap.

    Watch how easy watering a battery can be. The video shows the process it takes to water a Crown H2GO battery properly. 

    Do you have questions about your forklift battery?

    Feel free to ask our experts any questions!