The battery on a forklift truck contributes to over 30% of the total cost of the truck. Maintaining and ensuring to top up the battery water is essential to get the most out of your investment.
Failure to correctly maintain the battery will result in unexpected purchase costs of replacement batteries. In addition, your sites productivity will be affected through reduced truck run times and increased energy usage.
The “water” in the forklift battery is called electrolyte and is a mixture of sulfuric acid and water. During charging the battery heats up and some of the water will leave the battery cell through evaporation. In addition, though a process called electrolysis the water breaks down into hydrogen and oxygen gases, which float out of the cell. Overtime this reduces the electrolyte level in the battery, and the water will need replacing.
If the electrolyte level in the cells of the battery get too low, then the plates in the cells can become exposed which causes damage. In addition, the sulphuric acid becomes more concentrated.
Thus, replacing and maintaining electrolyte levels in forklift batteries is necessary for improved performance and increased lifespan.
Quality of Maintenance Water
It is important to use the correct type and quality of water for forklift truck batteries. Mains water from your tap contains impurities that can cause damage to the battery. During discharge of the battery the impurities attach themselves to the plates inside the battery cells. Over time this builds up into a crust type of layer, this reduces the active surface area of the cell plates. This build-up of impurities can have a detrimental impact on the capacity of the forklift battery and therefore the amount of operational time between chargers and its life expectancy.
To avoid this from happening it is important to use water where the impurities have been removed. There are 2 primary types of pure water used for topping forklift batteries, distilled water and deionized water.
Distilled Water for Forklift Batteries
Distilled water is used in many industrial applications and is one of the purest water types. Its energy intensive process leaves behind purified water free of all forms of impurities and minerals.
Distilled water is produced by heating a vessel containing water until the water forms steam, the steam is then cooled and condensed back to water in a second container. Any impurities in the first vessel, where their boiling point is below 100 degrees centigrade, will remain there.
Pros
- High levels of purity
Cons
- An expensive and time-consuming process. Suitable for industrial applications that require large volumes of pure water.
Deionized Water for Forklift Batteries
Deionized, also known as demineralized water, is produced by passing water through an ion-exchange resin made up of cationic and anionic beads. Impurities in water cling to these resin beads electrostatically leaving only pure water to pass through.
Deionization does not remove organic compounds, but these are not harmful to lead acid batteries.
Pros
- Cheap method
- Quick process
- Ideal for forklift batteries
- Can be produced on-site
Cons
- Not as pure as distilled water, but the quality is more than suitable for forklift batteries
Where to get suitable water for your forklift battery
You can purchase a complete deionized water system. Having a deionized pure water system on site can help ensure that pure water is always available on hand should the need arise. These are usually inexpensive and avoid the issues around purchasing and storing water. Most come with replacement cartridges, making it simple to maintain.
You can also purchase deionized pure water but keep in mind that these containers have a shelf life and are expensive to ship because of the weight. But should your requirements be small then purchasing deionized water is a viable option
Forklift Battery Maintenance Procedure
It is important to have the correct procedure to maintain the electrolyte levels in your forklift battery as indicated and instructed by the manufacturer. Under or overtopping the battery can adversely affect the batteries performance, giving reduced truck run times and reduced battery life. Maintaining the correct battery water level with pure water ensures optimal battery efficiency and performance.
When to Top a Forklift Battery?
When determining when a battery should be topped the important factor is whether the plates in the cell are covered, or likely to become uncovered during the next discharge cycle. The electrolyte level should always be higher than the cell plates.
If the plates in the cell become uncovered irreversible damage will happen to them. High electrolyte levels are equally damaging as it reduces battery performance and causes spills and leaks that corrode the cell tops, battery tray and are a risk to health and the environment.
When topping up a forklift battery it is always important to wait until the battery is fully charged. Adding water prior to a battery being at the top of its charge can lead to increased risks of electrolyte spilling out of the cells. This is because the electrolyte levels change in battery cells through a process of tidal flow. When a battery is at the top of charge and in the gassing phase then electrolyte levels are at their peak, this is due to an increase in the volume of the water through heating and the electrolyte being “forced” out of the cells during charge.
The electrolyte level should be checked shortly after the battery has finished a full charge. If the battery is fully charged, and the battery water levels are low then the forklift battery requires a top-up of pure water.
Frequency to Top a Forklift Battery
The frequency at which a forklift battery needs to be topped depends on several factors including age, quality, technology, temperature and usage.
The best thing to do is to check periodically to make sure that electrolyte levels are well-maintained or set a schedule whereby all forklifts must be checked on a day of the week or if used less often then monthly checks.
Modern batteries come equipped with battery electrolyte indicators that alert you when battery water needs topping off. Basic monitors have a green LED light that turns off when the battery requires topping up, while more advanced indicators have countdowns to let you know precisely when a battery needs topping.
How to top up a forklift battery with water?
The cheapest, but least accurate way, to top a forklift battery with water is to use a bottle and funnel. With this method, it is difficult to gauge the level of water in the cells. It is also slow and unnecessarily exposes the person to health risks from the acid in the cells.
The use of forklift battery watering guns is a relatively cheap and safe alternative of topping up batteries which prevents spillages and inaccurate pouring when filling by hand. The watering gun is connected to a suitable water supply and the cells filled on at a time.
You can also consider a single point battery filling system. With a battery filling system each cell is fitted with a topping valve, and the valves are connected in series with piping. You simply connect a water supply to the system and each cell is then filled, with the valve shutting off automatically when the water gets to the correct level in the cell.
Single point battery filling systems have the highest upfront cost but are the quickest and safest systems to use.
Safety First!
Always make sure that you are wearing goggles and gloves when inspecting electrolyte levels and topping off battery water. Using protective equipment doesn’t only ensure your safety but also the safety of those around you.
To learn more about lead-acid forklift batteries repair and maintenance visit Tontio.com
