Forklift Battery Maintenance

So you need to charge your forklift battery? When should you clean the battery and how often should you check the fluid levels?

In any business, before attempting electric forklift battery maintenance it is critical that all employees are properly trained on how to charge, store, clean, and maintain forklift batteries. Not only can handling batteries incorrectly can result in very serious injury, but it can also reduce the longevity of the battery and cost you money.

Continue to read in order to learn more about safe practices and tips when it comes to forklift battery charging and maintenance.

Forklift Battery Safety Issues

There are a wide array of safety considerations when it comes to dealing with forklift batteries. Improper transport, charging, electrolyte handling, and incorrect wearing of protective gear can all lead to terrible industrial injuries and in the worst case, death.

Here are the main safety considerations when it comes to the maintenance of forklift batteries.

Moving a Forklift Battery

Lead-acid batteries are extremely heavy, weighing up to 3000 lbs, so they cannot be lifted into the charging station without mechanical help.

The lifting equipment used to assist with this process should ensure that no manual lifting is required. It is also critical that the lifting equipment has a guard in place to stop the battery from sliding or falling off whilst it is being moved as this could lead to serious crush injuries. 

Moving a Forklift Battery

A pallet jack with a transfer carriage would be a good choice of equipment for transporting and lifting a forklift battery.

Charging a Forklift Battery

Charging a Forklift Battery

A highly flammable gas called hydrogen is produced when a battery is being charged. It is critical that the battery charging station is in a well-ventilated area. If not, then hydrogen can accumulate and there is the potential for an explosion.

It is very important to keep the battery charging area free from anything that could ignite the hydrogen such as naked flames, lit cigarettes, and anything that could cause a spark such as breaking a live circuit at the battery terminals.

A hydrogen monitor can help to make sure that levels do not become hazardous.

If you wear metallic jewelry, it should be removed before charging batteries. Metals conduct electricity so there is the potential for the battery to arc, sparks being produced, and risk of explosion, as well as contact with terminal posts and electrocution.

Corrosive Electrolytes

The electrolyte, which is also known as the battery acid, contained within lead-acid batteries is actually sulfuric acid. When carrying out maintenance on batteries, it is vital that only trained personnel handle this chemical. It is highly corrosive and causes chemical burns.

When handling sulfuric acid protective gear should be worn such as gloves and eye protection. There should be an eyewash station and shower close to the battery charging area so if any acid is splashed onto a person, it can be washed off as quickly as possible.

When pouring concentrated sulfuric acid it is vital to slowly add the acid to the water and not do this the other way around, i.e. do not add the water to the concentrated acid. Make sure non-metallic equipment is used as acids react with metals resulting in corrosion.

Forklift Battery Maintenance Checklist

Regular maintenance and service are vital to ensure a good lifespan for forklift batteries. The lifespan of a battery if charged correctly is around five years, but with proper maintenance, this can potentially be increased to as much as ten years. Improper care, however, can reduce the capacity and power of the battery and more than half its life.

Here are some battery maintenance tips to help ensure you carry out the best practices when it comes to looking after forklift batteries.

1) When to recharge the battery

Making sure to charge the battery at the correct time, is really important in order to maximize the battery's lifespan. A battery should only be connected to the charger to be recharged when it gets to about 20% to 30% charge remaining. Continued use and discharge of the battery below 20% can have a negative impact on its lifespan and can also lead to overheating and potential damage to your lift truck.

2) Frequency of charging

Forklift batteries have a limited amount of charges, they only have about 1500 charge cycles. Charging a battery too early, when the charge is still well above 20%to 30% means one of these charges is used up as it cannot tell the difference between a partial or a complete charge. A battery usually lasts about 5 years if it is charged once a day but its lifespan is halved if it is charged a couple of times a day.

Frequency of charging

Another way to maximize the longevity of the lift truck battery is once a battery is being charged, don't interrupt the charge, make sure it completes the charging cycle before you disconnect it from the charger.

Lastly, when a battery has discharged avoid leaving too long before connecting it to the charger and starting another charging cycle. If it is left sitting for more than a couple of hours then sulfation can occur. This will significantly impact the life and performance of the battery, decreasing its run time.

3) Temperature

Keep a close eye on the temperature of the battery whilst it is charging. Too much heat can reduce the battery life significantly. The temperature should stay as close to room temperature as possible, around 77°F (25°C). If the forklift battery gets too hot or electrolyte starts to leak from the vent caps, the charging cycle should be paused and then restarted at a reduced rate once it's cooled down

Conversely, if it is too cold, less than about 59°F (15°C), it takes longer to charge the battery. Also, if the battery has been used in very cold temperatures, before charging, check it has not frozen.

If your business requires electric forklifts and other battery-powered industrial material handling equipment to be operated in extremes of temperature, this will have a detrimental effect on the battery's lifespan. The temperature at which the electric forklift or material handling equipment is being operated should really be kept below 113°F (45°C).

If your lift truck has to be operated in extreme temperatures, then it is critical the battery has proper circulation in the compartment in order to try and keep the battery as cool as possible. The performance of the battery decreases and as a rule, the battery life is reduced by half for every 10°C above 25°C. For example, the lifespan at 40°C is half of that at 30°C. The good news is that there are batteries available that are designed for use in extremes of temperature.

4) Check the Water Levels

Check the Water Levels

To extend the life of forklift batteries, it is important to perform a check of the water levels regularly.

When it comes to best practices, this should be done about once per week or every 5 to 10 charges.

For a battery to work to its maximum power and capacity, it must contain the correct level of fluid. Check a cell or two to see if there is sufficient water in these cells to cover the plastic battery element. 

If the fluid level is not clear then all the cells should be checked.

The water level in the cells should be topped up using distilled water, add water according to the recommendation of the battery manufacturer. Generally, the pH of the water should be greater than 5 but less than 7 and any water impurities must be within the manufacturer's set limits. Tap water must not be used.

The distilled water should only be added after the battery has been fully charged. Care should be taken to not add excess water as there must be a little space left to allow expansion when the battery is being used. If white deposits or crystals are visible on the battery's plate then it should be referred to a specialist for proper service.

Lastly, gravity reading using a hydrometer should be taken each month for all cells in the battery after it has been fully charged. After a complete charge cycle and it is fully charged, a typical forklift battery has an ideal specific gravity of 1.285. This value for ideal specific gravity, of course, may vary according to the model and specification of your lift truck battery.

5) Cleaning the Battery

Another critical step in battery maintenance is making sure the forklift battery is cleaned on a regular basis. Each month the top of the forklift battery should be cleaned using warm water or a battery cleaner fluid. Regular cleaning cycles are often required to maintain the manufacturer's warranty.

Regardless of the warranty, however, it is generally best to clean the battery regularly to avoid a build-up of chemicals that can result in tray corrosion and reduce the life of the battery. The build-up of chemicals can also result in faster than usual discharge of the forklift battery and can even affect the electrics in the lift truck.

When cleaning the battery it is important to follow the safety procedure such as remove metallic jewelry, avoid contact with the terminal posts and wear protective gear as needed to avoid contact with any corrosive chemicals.

6) Equalization

Another important maintenance issue for your batteries is equalization. This is when a battery is overcharged in order to get rid of the build-up of crystals caused by sulfation, as this can reduce the battery life.

Check the specification of your forklifts batteries to see if equalization is required, as this may not be needed for all types of batteries. Those that do require this process may have an equalization setting on the charger. Usually, wet cell batteries require equalization about once a week. It is important to adhere to the recommended frequency of equalization to extend the life of your batteries.

To see the 6 types of forklift batteries and factors to consider when buying, check out our forklift battery page. 

Tim Postlethwaite

Tim Postlethwaite // Staff Writer