Technician watering a lead-acid battery.

As an experienced provider of material handling equipment and service, we receive inquiries about proper forklift maintenance daily. Questions span all varieties of lifts and applications, but one topic seems to be most common: how to maximize the life of lead-acid batteries. In this article, we’ll cover the four basic components of lead-acid battery maintenance:

  1. Battery Watering
  2. Planned Scheduled Maintenance Servicing
  3. Charger Compatibility and Configuration
  4. Battery Washing

Lead-acid battery technology is a mature platform, reaching as far back as the mid 19th century. Given this history, lead-acid batteries are generally seen as workhorses, providing reliable forklift power that can stand up to tough industrial environments for years on end when properly maintained.

Importance of Lead-Acid Battery Maintenance

Lead-acid batteries contain pairs of oppositely charged lead plates suspended in an electrolytic fluid made up of sulfuric acid and water, which creates electricity by means of a chemical reaction occurring between these plates and the fluid around them. The chemical reactions and their byproducts require regular monitoring, cleaning, water replacement, and electrolyte balancing to maintain safe, dependable operation. Though this maintenance may be burdensome, when properly maintained, a high-quality lead-acid battery can last well beyond its expected economical useful life.

So, while there is a cost to properly maintaining a lead-acid battery, we should commit to maintaining our lead-acid batteries until the natural end of their lifespan, as the extra maintenance effort will not only lead to a lower overall cost of ownership, but is also preferable in terms of environmental impact caused by discarding these batteries prematurely.

Battery Watering Frequency and Tips

We should maintain our lead-acid batteries out to their maximum lifespan, and what better place to start than to ensure that we’re watering our batteries at the correct cadence. To answer the question: how often should lead-acid batteries be watered? The answer comes in two parts – frequency as well as sequence of maintaining activities, both equally important.

Watering Frequency

Generally speaking, lead-acid fork truck batteries should be watered once a week. Watering frequency is determined by how quickly water evaporates from each battery cell, which in turn is a function of how often the battery is used and recharged. Heavier use will result in faster evaporation, causing a more frequent need to water. To determine your particular frequency, we suggest checking water levels in your batteries weekly, and comparing these levels to your battery’s maintenance manual for minimum safe operation level (usually measured as fluid level height above the battery plate container, but as a general rule never so low that the plate is sticking out of the water).

When to Water

Water should be added to lead-acid batteries right after charging. Charging causes the water level in a battery cell to rise. After charging, the water in the battery reaches its highest temperature, and expands to its largest volume. Adding water right at this time up to the maximum fill line will protect against overfilling and spills.

In a normal operation, lead-acid batteries like to operate for a single 8-10 hour shift per day, then be charged for the next 8 hours, and then sit idle for the remaining 6-8 hours until the next shift. This cadence gives plenty of time for the battery to charge at a slow enough rate that battery water will not “boil over” (or expand so far as to spill from the battery), followed by enough time to cool before the next use.

When water is added before charging up to the fill line, this higher water volume will expand due to the heat of charging into a near-certain boil over condition, exposing operators to hazardous electrolyte fluid that can cause serious harm. For this reason, adding water after charging is just as important as adding water often enough that the cells are not exposed and damaged.

Planned Scheduled Maintenance Servicing

Lead-acid forklift battery planned maintenance servicing encompasses a regular schedule of inspections, cleaning, and performance checks to ensure optimal battery health, extend the battery’s lifespan, and prevent unforeseen downtime due to battery failures. Recommended planned maintenance procedures forklift batteries includes:

  • Regular inspection for physical damage, leaks, loose connections, checking electrolyte level and color, etc. then completing any necessary repairs
  • Thorough washing to remove dirt, grime, and other contaminants that can affect battery performance
  • Equalization charges to balance the cells within the battery pack and maintain optimal performance
  • Battery case cleaning to prevent the accumulation of debris and potential damage to the battery

Planned Maintenance Frequency

The standard interval that planned maintenance should be completed is approximately every 500 hours, or as recommended by the manufacturer. However, the frequency at which you should conduct planned maintenance on your forklift battery can vary depending on several factors, including:

  • Usage: How often and how intensively your forklift is used can impact the maintenance frequency. For example, a forklift that is used daily in a high-volume warehouse will likely require more frequent maintenance compared to one that is used occasionally.
  • Environment: The working environment can also affect maintenance frequency. A dusty or dirty environment may require more frequent cleaning and battery checks.

The average frequency for many warehouse operations to complete planned maintenance is every 3-6 months. Each time planned maintenance is performed, it should be documented to create a maintenance history that can assist in identifying recurring issues or predicting potential future problems.

Charger Compatibility and Configuration

When it comes to forklift batteries, it is crucial to ensure that the charger is compatible and correctly configured. The use of an incompatible charger can lead to undercharging or overcharging, both of which can adversely affect the battery’s health and longevity.

Possible issues that could occur if the charger is not configured correctly include:

  • Battery Life and Performance: Using an incompatible or incorrectly configured charger can significantly impact the lifespan and performance of the forklift battery. Overcharging, undercharging, or missed equalizations can lead to premature battery failure, reduced capacity, and decreased runtime.
  • Safety Concerns: Incompatibility or incorrect configuration of the charger can pose safety risks. For instance, overcharging can generate excessive heat, potentially causing thermal runaway or battery damage. It is important to select a charger that monitors battery temperature to prevent such hazards.
  • Efficiency and Productivity: A properly configured charger ensures efficient and effective charging cycles, maximizing battery life and providing consistent power to the forklift. In contrast, an incompatible or incorrectly configured charger can result in inefficient charging, leading to increased downtime and reduced productivity.

To avoid these issues, it is recommended to:

  • Ensure the charger is compatible with the specific forklift battery model.
  • Follow manufacturer guidelines for charger configuration settings, such as voltage, current, and charging profiles.
  • Implement proper charging practices, including regular equalization charges and monitoring battery temperature during charging.

Battery Washing

Battery washing is a crucial aspect of forklift battery maintenance, as it removes harmful accumulations of acid and dirt that can compromise battery performance, lead to corrosion, and shorten the battery’s lifespan.

Spot cleaning and power washing are two different methods used for cleaning forklift batteries. Here’s an in-depth explanation of their benefits and differences:

Spot Cleaning:

  • Targeted Cleaning: Spot cleaning involves manually cleaning specific areas of the forklift battery, such as the terminals, connectors, or any visible dirt or grime. This method allows you to focus on problem areas and remove contaminants effectively.
  • Minimal Water Usage: Spot cleaning typically requires less water compared to power washing. It’s a more controlled and precise process, where you can apply cleaning solutions directly to the targeted areas without excessive water runoff.
  • Reduced Downtime: Spot cleaning is a quicker method as it focuses only on specific areas, allowing you to clean the battery without removing it from the forklift. This can help reduce downtime and keep the equipment operational.

Power Washing:

  • Thorough Cleaning: Power washing utilizes high-pressure water jets to clean the entire surface of the forklift battery. It can effectively remove dirt, grease, and other contaminants from hard-to-reach areas, ensuring a thorough cleaning.
  • Efficient and Time-Saving: Power washing can cover larger areas quickly, making it an efficient method for cleaning multiple forklift batteries or heavily soiled ones. It can save time and effort compared to spot cleaning, especially when dealing with larger fleets of forklifts.
  • Deep Cleaning Power: The high-pressure water jets used in power washing can dislodge stubborn debris, loose corrosion, and other build-ups. This method is particularly useful for removing accumulated dirt or acid residue that may affect battery performance.

Ultimately, the choice between spot cleaning and power washing depends on factors like the level of contamination, available resources, and time constraints. It’s recommended to consult the forklift battery manufacturer guidelines to determine the most suitable cleaning method for your specific battery type.

Washing Frequency

The frequency of washing forklift batteries may vary depending on factors such as usage, environment, and battery condition. It’s recommended to consult the specific manufacturer’s guidelines for the most accurate and appropriate cleaning schedule for your lead acid forklift batteries. Generally, a thorough washing of the entire forklift battery is suggested 2-4 times a year, depending on usage. This helps remove dirt, grime, and other contaminants that can affect battery performance.

When to Wash

It is generally recommended to wash forklift batteries regularly to prevent acid and residue build-up, improve performance, and increase their lifespan.

This critical element of comprehensive forklift maintenance is generally done every 90 days in a normal warehouse operation. It is generally done alongside routine maintenance and inspections. By including it as part of routine battery maintenance and inspections, it helps with detecting any potential issues that without washing may not be possible to see.

Forklift batteries should also be washed after overflows or spills. Thoroughly washing the battery after overflows or spills occur helps prevent corrosion and maintain optimal performance.

Today, lead-acid batteries are significantly less expensive to purchase than more recent lithium-ion alternatives, albeit with some basic additional maintenance requirements. Many operations turn to an experienced partner like Fairchild Equipment for assistance keeping their batteries and chargers maintained or when considering transitioning to lithium-ion batteries.

The manufacturer of your forklift battery will have specific guidelines for the maintenance frequency based on the type and model of the battery so it’s recommended to consult the forklift battery manufacturer’s documentation or seek assistance from a qualified professional like Fairchild Equipment for specific guidance to ensure proper care and prolong the life of your battery.

We hope that this discussion has been helpful for your commercial material handling needs. Fairchild Equipment is the Upper Midwest’s premier Material Handling Equipment and Service resource, with headquarters in Green Bay, Wisconsin, and numerous locations in 5 states ready 24/7 to serve your needs. For more information or to discuss which Warehouse Optimization solution might be best for you, please send us a message or call us at (844) 432-4724.


2140 Hutson Rd.
Green Bay, Wisconsin 54303
(920) 494-8726