Forklift Battery Charger: Tips to charge your forklift battery to its full potential

About forklift battery charger, Forklift batteries are the same as those in any other vehicle but are larger.

While the function is similar to others, they require special precautions for handling and charging for better performance with a proper forklift battery charger.

Forklift Battery Types

There are three types of batteries that most forklifts use.

Each has its distinct features along with advantages and disadvantages. 

Lead Acid

Lead-acid batteries are the common ones that operators use since they are easy to install and repair.

These batteries are liquid-filled with removable tops and produce electricity when lead plates and sulfuric acid electrolytes react.

However, it needs maintenance to regulate the voltage by keeping the electrolyte levels in check.


People prefer Lithium-Ion batteries over other options, although it is expensive.

It is because they have many benefits, including using Lithium Iron Phosphate (LFP), an energy-dense substance.

Moreover, these batteries have sealed shut tops and can work longer without a proper maintenance schedule.

AGM (Absorbed Glass Mat) 

AGM or Absorbed Glass Mat batteries may not be as common as Lead acid or Lithium-Ion; they are still much better in quality than others.

These batteries have a fiberglass mesh between the plates responsible for containing the electrolyte. 

This fine mesh doesn’t absorb any acid electrolyte and lessens the chance of spills through battery cracks.

Moreover, the maintenance requirement minimizes in such construction since no direct chemical reaction happens.  

On the contrary, they cannot perform well if you haven’t charged them properly; hence, recharging them before they reach 50% is recommended.

Lead Acid vs. Lithium-Ion

  • Charging Time: Consider that different batteries have varying charge times. For instance, a lead-acid battery will take 8 hours to charge 100%, while the lithium-ion will charge fully in 1 to 2 hours.
  • Cool-down Time: Besides charging, the lead-acid batteries require an 8-hour cool-down time before use. However, lithium-ion batteries do not need it and can be used without being fully charged.
  • Charging Method: For different batteries, the charging method varies. The lead battery will need a separate charging place where you will keep them until they are full. You can charge lithium-ion batteries while keeping them intact to the vehicle and connecting the wire directly.

Forklift Battery’s Charging Problem

Forklift batteries are larger as compared to regular vehicle batteries.

So, it involves greater risks than the other, and if the battery is lead-acid, the chance of an issue occurring increases. 

Dangerous Gases

Overcharging a lead-acid battery can emit dangerous gases like hydrogen sulfide, sulfur dioxide, and pure hydrogen gas.

To avoid it, you can keep these batteries in a separate charging room with proper ventilation and sensors to avoid any mishap.


Sulfation is another common problem that rises due to the reaction of lead plates and sulphuric acid electrolytes.

The only solution to this problem is to replace the battery or follow the proper battery reconditioning protocols before further use. 


Due to overcharging, the temperature of a lead-acid battery can also increase exponentially.

Hence it is important to maintain the temperature of the charging room, the charger, and the battery itself so that it doesn’t overheats and explodes.


Lead-acid batteries need proper maintenance, as we mentioned above. For that, you need to water the battery to function.

This watering can cause acid spills that can be very dangerous for anything that comes in contact with it, be it your clothes or skin. 

Thus, making a separate washing station to deal with accidental battery spills is better.

Also, remember to water the battery once it’s fully charged, and do not overfill. 

Leaving extra space in the battery will let the fluids expand and maintain their pH levels.

Moreover, you must water the battery once after every 8 to 9 charge cycles so the lead plates do not explode. 

Sulfated forklift battery

Sulfated forklift battery

Tips for Charging Your Forklift Battery 

Any battery, if properly charged, has a good performance all over its life.

Hence, consider the following tips whether you use a lead-acid or lithium-ion battery. 

Look for the Charging Cycle number.

For every automobile battery, there is a specific number of charge cycles that it can endure.

Here, charge cycles mean charging and discharging a rechargeable battery.

It starts when you plug the battery into a charger and ends when you charge it again. 

As the battery reaches its charge cycle limit, the performance declines, and it may damage other systems connected to it.

Hence, replacing the battery before its charge cycle ends is better.

As a rule of thumb, most manufacturers offer 1500 charge cycles on their battery which end after 5 years of constant use.

So, be vigilant about replacing the batteries once you hit the 5-year threshold.

Avoid Opportunity Charging

A new charge cycle starts when you plug the charger into the battery.

It doesn’t matter whether you have charged it at 80%, 100%, or 5%; it counts it as a charge cycle and reduces the total count. 

For example, if you charge the battery daily, your battery has 1500 cycles lasting for 5 years.

Now if you are charging it twice a day without any need, it will only last for half of the time, i.e. two and a half years approx.

Thus, it’s better to avoid charging the batteries whenever you feel like it and only do it once the battery is drained to 20%. 

Recharge once the battery reaches 20-30%

It is best to plug the charging cord in before the battery runs out completely.

It is because if you let the battery drain till 0%, the battery performance will strongly get affected by it. 

On the other hand, it is also unsafe to start recharging the battery after a little use.

Hence, the best time to charge the battery is when it reaches 20-30%, providing an ideal battery performance while balancing the charging.

Also, once the charging reaches 100%, immediately remove the charger.

Do not leave batteries uncharged for too long.

Since the battery is in use, the lead and sulfuric acid react, forming the lead sulfate on the lead plates.

As you do not energize the battery and leave it like that for too long, these crystals get hard, depleting the system’s performance.

Hence, it is advised to charge the batteries every then and now and not leave them uncharged for longer.

Also, inspect the electrolyte levels routinely to make sure they are enough.

Forklift battery with connectors.

Forklift battery with connectors.

Choosing the Right Forklift Battery Charger

Look at the following parameters to choose the right charger for your forklift battery.

Compare the Battery’s amp hours to Charger’s amp hours

Amp hour is the current level a device can produce in one hour. 

For the battery on your device, you can look for the amp hours on the tag or data plate with the “Ah” abbreviation.

If not, you can find it on the intercell connector or calculate it from the battery model. 

Then, see the Ah rating on the charger. The charger will work fine if the charger capacity is 10% more or less than the battery’s capacity. Otherwise, it will damage the battery.

 Choose the correct Output Voltage.

Again, the output voltage of both the battery and the charger should match each other.

Some chargers can work on multiple voltages, depending on the connected device, while others only have a single voltage capacity.

To check the battery voltage, see the data plate and derive the value from its model number by multiplying the first figure by 2.

Then see the charger’s plate to check if both values are identical.

If the value of the battery is the same as the charger or comes within the supporting range mentioned on it, you are good to buy.

Select the Correct Input Voltage

Output voltage refers to the voltage between the battery and the charger, while the input voltage is the voltage between the charger and the power source. 

Most charging docks offer voltage of 208V, 240V, or 480V.

If your charger supports the same input voltage, it’s good to buy, and if not, choose something else that can conform to the voltage.

You can also check with an electrician for proper inspection of the power outlet. 

Check the Correct Input Phase

On chargers, you can see that it supports two types of phases, two-phase or Three-phase AC supply.

Hence, determine your charging facility and see whether the charger supports the same.

For that, you can look at the data tag or ask the salesperson in the charger shop.

Select a Charger with an “Equalize” setting.

Most of the time, you have to recondition your batteries to avoid sulfation or acid stratification.

You will need a separate reconditioner to use with the batteries.

However, if your charger has “Equalize” mode, it will automatically overpower the battery to reverse the sulfation and maintain battery health. 

Checking the water levels of the battery

Checking the water levels of the battery


Forklift batteries need chargers that can conform to their voltage requirement. If you do not consider it on time, it will harm the battery and the overall system.

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