There are a wide variety of different power sources for forklift equipment. That is why it can be challenging to narrow down the options and find the power source solution that works best for your operations. While internal combustion (IC) and lead acid power sources have traditionally been some of the most common options, there are new developments in power technology for fleet solutions.
While lithium-ion, thin plate pure lead (TPPL) and hydrogen fuel cells have been used in different industries for years now, they are newer to material handling. Some worry that new technology means that we do not truly understand whether they will be capable. But there is good evidence that they are just as (if not more) capable than IC and lead acid.
Lithium-ion battery packs were first developed in the 1980s, but they were not always energy or cost effective. As technology has improved, so have lithium-ion battery packs. Because the technology was new and still improving the favored and reliable battery of choice was internal combustion (i.e., propane or diesel) or lead acid batteries. Within the last decade, the push for clean energy by local government leaders have been driving significant improvements in lithium-ion technology.
Lithium iron phosphate (LFP) are a relatively new technology, but they are quickly emerging as the power source of choice for industrial forklift applications. One of the primary benefits of LFP batteries is that there is a significantly reduced risk of thermal runaway compared to other types of lithium-ion battery packs. Plus, they contain no cobalt, which can eliminate the ethical and environmental conflicts that come with nickel manganese cobalt oxide (NMC) batteries. As the cobalt material becomes more sparce, you will not have to worry about lithium iron phosphate materials running low. At the rate production is going, NMC will not have enough known cobalt reserves to keep up with lithium production.
Lithium iron phosphate batteries can be considered one of the safest, nontoxic battery chemistries available. Even though LFP battery packs might have slightly lower cycle life, the benefits outweigh the concerns associated with NMC batteries.
You will still get far more life out of an LFP battery than a lead acid or TPPL battery. Many LFP batteries can last up to 3,500 cycles at 80% depth of discharge without seeing a loss in performance. This is extremely helpful for companies that work multiple shifts in a day and need a power source that does not lose power even if the state of charge is diminishing.
LFP batteries can also withstand extreme temperatures thanks to their improved thermal stability. LFP battery packs have one of the highest thermal runaway temperatures than other lithium-ion chemistries. They can withstand temperature up to 518 degrees Fahrenheit. The higher the thermal runaway temperature the safer the battery pack is.
Plus, LFP batteries can be much more compact than other forklift power sources due to their energy density. The more energy dense a power source is the more compact it can be. This is ideal for some of the smaller equipment that some warehouses and operations use to get the most out of the space they have - i.e., reach trucks, narrow aisle forklifts, etc.
LFP battery: A lithium-ion battery that incorporates lithium iron phosphate as the electrode material and uses graphite carbon electrodes with a metallic backed anode.
Depth of discharge (DOD): The depth of discharge is the capacity that has been discharged from a battery when fully charged, example 80% DOD.
Battery management system (BMS): The brain of the battery pack. It manages the operation of a battery pack. The BMS also allows users to monitor cells within a battery pack. It can provide the status and health of a battery.
Forklift telematics: A combination of telecommunications and informatics provides data on battery performance to improve efficiency, reduce operating costs, monitor forklift driving behaviors & remain on top of maintenance schedules.
Cold storage equipment: Material handling equipment that is intended to be operated in refrigerated environments generally between 0 – 50 degrees Fahrenheit.
Automated guided vehicles (AGVs): Automated guided vehicles (AGV) are vehicles designed to perform material handling or load carrying without the use of an operator or driver. AGVs are guided by sensors, markers, tape, or wires in the facility and have a fixed navigational route.
Supply chain resilience: The magnitude to which a supply chain can adapt, tolerate disruption, and transform during change.
Just in time (JIT) manufacturing: A workflow method to increase efficiencies by receiving goods as needed for the production process. The increased efficiencies help reduce associated inventory costs.
Industry 4.0: The fourth industrial revolution. It is the automation of conventional manufacturing and industrial applications. Industry 4.0 will use modern smart technologies including artificial intelligence (AI), robotics, Internet of Things (IoT), genetic engineering, quantum computing, and others.
Industrial Internet of things (IIoT): The interconnected sensors, instruments, and other devices connected with computers' industrial applications, including manufacturing and energy management. In use cases, smart devices may be deployed in vehicles, robotics, power systems, and more.
Narrow aisle forklift: Found in operations that want to maximize their storage space with racks. This lift truck typically has a tighter turning radius and is usually in areas with aisles no wider than 10.5'.
Reach truck forklift: Found in operations with warehouse spaces that require tighter turning radius and operate with higher racking systems. These types of equipment offer a more effective solution when moving material horizontally.
Narrow aisle picker: Found in operations that use lifts to take the operator up in the racking to pick and deliver materials for filling orders.
Warehouse automation: The process of automating warehouse activities with minimum human assistance. Warehouse Automation solutions include automated storage retrieval systems (AS/RS), automated guided vehicles, Autonomous mobile robots, automated sortation systems, picking systems, and more.
Autonomous mobile robots (AMRs): Autonomous mobile robots (AMR) are more technologically advanced than AGVs. They move around the facility based on the most efficient path using sensors and cameras. AMRs can navigate around obstacles, adapt to their surroundings, and avoid anything in their way.
Risk reduction: Practices used to reduce the frequency and severity of damages and losses in the workplace. This includes fire inspections, safety plans, and programs to address potential operational incidents.
Warehouse ergonomics: Having a functional warehouse environment that can mitigate safety risks, optimize operations, and lower costs.
Inventory management: A systematic approach of ordering, storing, handling, and selling a company's inventory of raw materials, components, and finished goods. This accounts for control over quantity, location, timing, and costs.
Multi-shift operations: The practice of changing out employees throughout a day's operation enables continuous workflows and increases production capabilities.
Warehouse safety: Rules & behaviors to protect warehouse employees from injury.
Energy costs: The total cost of electricity, oil, fuel, natural gas, and other energy inputs used through operations.
Voltage balancing: A technique to improve the capacity and lifetime of a battery pack by equalizing the voltage throughout all the cells
Lithium nickel manganese cobalt oxide (NMC) batteries are one of the most common lithium-ion battery chemistry variations that is used. Developed in 2008, it is a relatively new technological development, but it is already being used a variety of applications.
It has a high energy density and lower cost to produce, which is why it is one of the most popular lithium-ion battery chemistry choices. While nickel tends to have a poor chemical stability, the addition of the manganese helps form a spinel structure that helps achieve low internal resistance. As a result, you will get better stability and energy efficiency.
NMC batteries deliver a longer life cycle than some of its more traditional counterparts. Some NMC batteries get more than 6,000 cycles at 90% discharge rates. Like all lithium-ion batteries, you can opportunity charge NMC batteries. Which can significantly improve uptimes and efficiencies.
New developments in NMC have helped the chemistry safety progress with different formulas of nickel to manganese to cobalt. These different formulas you can see being used for NMC are:
While NMC can refer to a variety of different blends the most popular and traditional option in electric vehicles and energy storage is 1-1-1. This ratio is 33% nickel, 33% manganese, and 33% cobalt. The NMC811 powder blend is recently discovered formula that uses three times less cobalt in the newer version of these batteries. This makes the ratio 80% nickel, 10% manganese, and 10% cobalt. As the technology expands, manufacturers are starting to replace some of the cobalt content with more nickel due to cobalt costs and safety concerns.
NMC cathode contain the most energy (by weight & volume). However, it has its drawbacks. The addition of silicon to the graphite can result in the anode growing and shrinking through the discharging/charging process. This can lead to mechanical instability. It also has slightly lower voltage than cobalt systems. This can make it subject to thermal runaway when it is compacted into smaller sizes because of the ratio of energy density to size.
There has also been some controversy around the practices of cobalt mining in developing countries. There are ethical conflicts when it comes to the labor practices of cobalt mining companies in the Democratic Republic of the Congo, which are one of the cons to this chemistry type.
Lithium-ion battery chemistry: The variations of lithium-ion battery types are most differentiated by the electrode material used by the battery manufacturer.
Thermal runaway: When the heat generated in a battery exceeds the amount of heat that is dissipated to its surroundings. In batteries, this occurs when a cell exceeds a specific high temperature which varies by chemical composition, because of thermal failure, mechanical failure, short-circuiting, and electrochemical abuse.
Industrial lithium-ion battery packs: A type of battery used to power electric material handling equipment in commercial operations. These batteries often are designed to withstand heavy use extreme conditions and are lighter than traditional lead acid solutions.
Industrial battery charger: A system used to charge large battery packs that power industrial equipment. These systems provide high power output offering a quicker and more efficient charge.
Lithium-ion battery heat dissipation: The capability of a battery to lower the operating temperatures of its cells, allowing the battery to run at a tolerable temperature. Heat dissipation is achieved through fans, battery ventilation, and liquid-cooled components.
Flashpoint: The lowest temperature at which vapors created by a battery can ignite if combined with an ignition source. This temperature helps determine how a volatile material is characterized for fire hazards.
Battery stability: The stability of a battery is determined by its ability to chemically react as intended, physically hold up to daily use and any damages, as well as its ability to handle temperature changes.
Integrated battery: A battery embedded into a design versus a battery that can be removed easily from a unit.
Acquisition cost: The total cost for all expenses related to acquiring assets, services, or a new client. This is after adjustments but before taxes have been accounted for.
Grid power supply: A network that delivers electricity by connecting the power generation sites to the consumers through high-voltage wires that extend through entire countries and continents. These networks start at power generation sites that operate on coal, nuclear, hydroelectric, wind, and solar.
Ingress protection (IP): An international standard that classifies the protection provided from castings and electrical enclosures protecting against dust, water, and accidental touching. These protections are expressed through an IP rating code associated with ranging levels of protection.
Decentralized charging stations: An open charging platform for electric vehicles where every vehicle and charging station is assigned a digital identity allowing for secure identification and communication between charging stations and vehicles.
Internal combustion engines were one of the first power sources that were used to power industrial forklifts. IC forklifts are defined by their internal combustion engines that drive them. Built like an auto engine, they can be powered by a variety of fossil fuels.
Because of this, they are known for their particulate & CO2 emissions. This also means that they require special ventilation when they are used in indoor applications. They have typically been used for outdoor or extreme environments, but many still use them indoors. The most widely used fuel in material handling has been propane. Propane is a clean-burning fuel that is the safest for indoor use.
When other forms of forklift power sources were developed, internal combustion were preferred because of their ability to handle heavy loads. In the past, IC has boasted higher load capacity but that is just not the case anymore, due to newer battery technology.
They have typically been cheaper to initially purchase, but do not let that fool you that their total cost of maintenance over the span of their lifetime is less expensive than its alternatives.
What those do not consider when purchasing an internal combustion forklift are all of the costs that add up over its lifespan. You also have to consider the higher cost of maintenance and repairs. IC engines are known to need more frequent repair and maintenance than other power sources (like batteries). That is because they have got a significant amount of internal moving parts, which means more can wear down and break over time.
You also have to consider the cost of refueling over the lifetime of the forklift. As we all know, fossil fuel costs can fluctuate widely and make it difficult to stick to budget. This is especially true if you have production needs or the cost of fuel increases.
Propane forklift: A Propane operated forklift is a type of equipment that can be run on full power throughout its operation and boasts a longer lifespan than its internal combustion counterparts. This is partly due to the lower operating temperature propane equipment runs on.
Diesel forklift: A diesel forklift is most useful in outdoor environments with rugged terrain, offering the largest lifting capabilities for the heaviest of jobs.
Internal combustion engine forklift: A forklift with an engine that uses fuel to run. The fuel is burned within the engine which produces power directly to the forklift. Fuel is typically gasoline, diesel, liquified petroleum gas, or compressed natural gas.
Combustion engine emissions: The emissions created from running combustion engines create pollutants and negatively impact the environment. The impact of emissions is a concern for many businesses, as government and global regulations push for more accountability and higher sustainability standards.
Workplace noise exposure limits: OSHA has established a workplace noise limitation for workers to protect their hearing against potentially damaging exposure. These regulated limits are weighted based on the duration of the worker's shift.
Forklift total cost of ownership (TCO): Total Cost of Ownership is a common method used to evaluate the entire cost over the lifecycle for a piece of equipment. In the case of forklift batteries, the Total Cost of Ownership includes the cost of maintenance and energy usage, in addition to the purchase price. It can also include the opportunity cost of something like a battery charging room, which might otherwise be used for production in a factory.
Forklift load capacity: The forklift load capacity is measured by how much a forklift can lift and is located on the forklift's data plate. Load Capacity often ranges from 2,000 to up to over 70,000 lbs.
Forklift refueling procedures: When refueling an internal combustion forklift, OSHA has guidelines for best practices, protective equipment, and ordered steps to minimize potential accidents when refilling the forklifts.
Heavy load forklift: Forklifts capable of handling heavy loads, often used in industrial and construction applications. This type of equipment most often requires an internal combustion engine to handle the heavy loads as intended for this type of forklift.
Liquid petroleum gas (LPG): Liquid petroleum gas, also referred to as propane, is considered a clean-burning alternative fuel. LPG is the safest fuel source when operating internal combustion equipment at indoor facilities.
Hydrocarbon fuels: Hydrocarbon fuels include natural gas, oil, coal, and petroleum and are made from molecules consisting of both hydrogen and carbon.
Forklift fuel types: When a forklift uses fuels, it runs on gasoline, diesel, propane, or compressed natural gas. Electric forklifts have minimal use when operating equipment for outdoor applications compared to fuel-power equipment.
Internal combustion engine maintenance: The maintenance required when operating an internal combustion engine includes changing fluids, repairing, or replacing engine components, and regularly scheduled service appointments.
Internal combustion engine efficiency: The efficiency of an internal combustion engine is estimated to be roughly only 30% of fuel used goes into causing the car to experience movement. The remaining portion is wasted through parts heating, friction, and expelled through the exhaust system.
Industrial emissions: The airborne pollutants and greenhouse gases released into the atmosphere during industrial operations are resulting in damages to the environment and atmosphere globally. Many corporate sustainability efforts are aiming to eliminate practices that produce emissions.
Outdoor forklift: Outdoor forklifts are built to handle uneven terrain and feature larger, more stable inflatable tires. Equipment used outdoors needs to withstand a range of weather conditions, making internal combustion the primary engine used in outdoor operations.
Nonrenewable energy sources: Natural resources that cannot be naturally replaced quickly enough to keep up with the current societal demands. These energy sources include petroleum, oil, coal, and natural gas.
Fossil fuels: These fuels began their creation underground long ago as dead plants and animals have decomposed over time. Humans use heavy-duty drilling equipment to extract these materials that have turned into refined fuels.
The concept of hydrogen fuel cells first emerged in the late 19th century, but started to take on greater long-term viability when the technology was improved for use during the space program in the 50’s. The first hydrogen fuel cell forklift was built in 1960 thanks to, Allis Chalmers, a US manufacturing company for construction equipment. Hydrogen fuel cell forklifts are powered in a similar way that a traditional lead acid or lithium-ion battery pack, except that fuel cells generate electricity with a chemical reaction via a proton exchange membrane.
The primary difference between lead acid and a hydrogen fuel cell battery is that hydrogen fuel cell batteries do not require toxic chemicals to produce the current. Alternatively, they use only hydrogen and oxygen that are naturally found in the air around us.
Instead of CO2 emissions or noxious fumes, the only byproduct is water after the chemical reaction is complete. Because hydrogen fuel cells produce zero emissions, they have become one of the looked at power sources in the material handling industry. They are often used in indoor and outdoor applications, similar to IC forklifts. They can be refueled just as quickly and produce less noise and virtually no emissions.
However, investing in hydrogen fuel cell technology might require more infrastructure investment in your facility. You will need to invest in refueling technology, unlike batteries, which can run off your existing electrical grid. Hydrogen fuel cell refueling process has an advantage. Because the energy density of hydrogen fuel cells is very high, hydrogen-powered equipment can operate for longer times and with less frequent refueling than an internal combustion engine.
Hydrogen fuel cells are not as energy efficient as some of its lithium-ion counterparts. The energy efficiency of hydrogen fuel cell technology is around 60%. In comparison, lithium-ion technology is nearly 99% energy efficient. While hydrogen fuel cell technology is more efficient that IC engine equipment, it’s hard to compete with its counterpart lithium-ion technology.
Proton exchange membrane: This membrane is a material used to facilitate the movement and separation of protons as they pass through the cell. The membranes help the hydrogen ions to separate.
Hydrogen fuel cell: A fuel cell that electrochemically separates hydrogen molecules and then splits the hydrogen electrons and protons, creating a circuit.
Electrochemical reaction: A process that causes electrons to travel between electrodes resulting in a flowing energy current. The byproduct of this reaction creates water and a release of heat.
Hydrogen ion: The positively charged electron of a hydrogen molecule is created when a hydrogen atom adds or losses an electron.
Energy density: The measure of how much energy a battery contains in proportion to its weight. This measurement is typically presented in Watt-hours per kilogram (Wh/kg). A watt-hour is a measure of electrical energy that is equivalent to the consumption of one watt for one hour.
Fuel cell electric vehicles (FCEV): An electric vehicle that operates on a fuel cell and sometimes paired with a small battery can power the electronic components on board to provide a cleaner alternative energy solution.
CE rating: A marking is used to indicate a product has met European Economic standards and is compliant with relevant EU laws relating to environmental and health efforts.
Output voltage: The output voltage refers to a measurement of the voltage being distributed from the device supplying the power to another device.
Hydrogen gas storage requirements: Storage of hydrogen in gas form requires specialized high-pressure storage containers and proper spacing of tanks. The use of hazardous materials signs is needed to be displayed identifying the risks associated with hydrogen.
Hydrogen infrastructure for energy applications: Hydrogen fuel cells requires onsite infrastructure to refuel hydrogen-powered equipment. This infrastructure is costly and requires much planning to help operations achieve their energy-neutral goals.
Direct manufacturing costs: Costs directly associated with the production and manufacturing of products. These costs will vary with the scale of production. This cost is primarily related to the cost of materials and labor.
Hydrogen transportation costs: If operations do not opt-in for designing an onsite hydrogen refueling infrastructure, hydrogen transportation is another way operations can receive fuel for their equipment. Unfortunately, transporting hydrogen is one of the inefficiencies operations will have to face due to its low energy density. To transport hydrogen, it must either be pressurized and delivered as gas or liquified. This makes transporting hydrogen costly.
Energy neutral: A operational design that focuses on environmental and low energy-use practices throughout the production process. The aim of utilizing these practices aim to help operations produce net zero-emissions neutralizing any electricity used in production.
Isolating hydrogen: To create hydrogen fuel cells used in energy storage, hydrogen needs to be isolated from oxygen. There are many techniques for isolating hydrogen, electrolysis, partial oxidation, or steam reforming.
Hydrogen electrolysis: Using electricity to isolate hydrogen and oxygen. Electrolysis is done using a unit called an electrolyzer. Electrolyzers are most often used because this technique helps create carbon-free hydrogen production.
Hydrogen reformer process: Producing hydrogen via steam methane reforming. Methane reacts with steam and pressure to produce hydrogen, carbon monoxide, and carbon dioxide during this process. Once products form, hydrogen is separated to produce fuel.
Cryogenic hydrogen storage: The use of specialized vacuum-sealed storage containers allows for the hydrogen to be stored due to its abnormally low boiling point.
Compressed hydrogen storage tanks: The storage of hydrogen in tanks that allow for compression rates that range from 5,000 – 10,000 psi to increase the density of the hydrogen during storage, mainly used with storing hydrogen in gas form.
Hydrogen corrosion: Reaction caused by hydrogen interacting and degrading metal. This process brittle the metal and decreases metal strength.
Energy efficiency of hydrogen fuel cells: Hydrogen fuel cells are overall 60% energy efficient. This technology is more efficient than IC, at 30% efficiency but not as efficient as lithium-ion technology.
Cold combustion: A reaction where chemical energy is converted into electrical energy. The difference between hot combustion and cold combustion is that energy is generated by the reaction and not transferred.
Fuel cell stack technology: Cells connected in series to generate electricity to power equipment. Typically fuel cell stacks can consist of hundreds of fuel cells and can depend on the cell type, size, and temperature it operates in.
Hydrogen forklift: A forklift that runs on an all-electric system using a hydrogen cell to power the electric system. This propulsion system only produces water and heat as byproducts when operating.
Hydrogen fueling system: Like internal combustions, hydrogen-powered material handling equipment needs to be refueled. Hydrogen fueling systems store hydrogen for equipment when it is time to refuel.
Hydrogen generation system: This system helps to produce hydrogen using electrolysis. Another name for this hydrogen generation system is Electrolyzer.
Carbon neutral manufacturing: The practice of ensuring all CO2 produced through the manufacturing process is balanced by removing equal or greater amounts from the environment.
Lead acid battery-powered forklifts are one of the most tried & true forklift power sources. The lead acid battery was first invented in 1860 by Gaston Plante. But the first battery-powered forklift didn’t hit the scene until 1906.
Today, it is one of the most commonly used power sources for forklifts. On average, you can get around 1500+ cycles out of a lead acid battery. The weight of a lead acid battery is more than that of a lithium-ion battery. This comes with both advantages and disadvantages. The extra weight of a lead acid battery can provide valuable ballast that can increase the load capacity of a forklift. This can also lead to a higher risk of ergonomic strains when swapping out the battery for charging purposes.
The internal chemistry of a lead acid battery comes with some major disadvantages. It requires less maintenance than an IC engine but lead acid batteries need to be regularly maintained to protect performance and lifespan.
Most lead acid batteries are flooded which means they require extra maintenance in the form of watering. They also require a cool down period before they can be used to help prevent thermal runaway during use. The ideal operating temperature is around 77 degrees Fahrenheit.
In extreme environments, wide fluctuations in ambient temperature not only degrades the time it takes to discharge, but it can also impact the lifespan of the battery. You will need dedicated space for storage and charging. That’s because lead acid batteries contain (and often discharge) toxic/hazardous chemicals and gasses that need to be isolated for safety reasons.
Unlike lithium-ion technology, they are slow to recharge and even if you are not using the battery, it needs to be charged every 30 days to avoid sulfation. Completely discharging a lead acid battery (i.e., deep cycling) can shorten its lifespan.
Forklift lead acid battery: A rechargeable type of battery that contains lead plates immersed in a sulfuric acid solution. The chemical reaction creates an electrical current used to power equipment.
Lead acid battery sulfation: The build-up of lead sulfate on the surface of a lead acid battery. Sulfation happens when a battery is not maintained. If left unattended, lead sulfate build-up can cause the battery to stop working.
Deep cycle battery: A lead acid battery that can sustain power over a long period of time until 80% discharged. “Deep cycle” means the level of discharge in comparison to other lead acid batteries that cannot sustain the same energy over a period of time.
Battery corrosion: The electrochemical reaction between metal and its environment that causes the battery material to deteriorate. Lead acid battery lead grids often corrode in service, which is an issue only lead acid batteries have. This usually leads to battery failure.
Positive plate growth: When materials build upon the positive electrode in the battery, causing them to expand and can result in deformation of the battery over time.
Lead acid battery operating temperature: Lead acid batteries run at the optimal level when operating between the range of -40oF – 120oF. The use of batteries outside of this temperature range could result in damage to the batteries.
Battery run time: The length of time a battery charge will last while the forklift is in use.
Voltage drop across battery: Voltage drop is the loss of voltage across part or all of the battery due to circuit limitations. Voltage drop can cause excessive wear on the battery and cause it to run at hotter temperatures than usual.
Battery watering: An important part of lead acid battery maintenance which is necessary to keep the battery functioning. Watering a battery, helps keep the electrolyte levels from overflowing after being charged. This helps prevent acid-related and overheating damages. Gassing also causes water loss which is why battery watering is necessary.
Battery charging hazards: The hazards of charging a battery consist of exposure to highly corrosive liquids, exposure to electrical circuits, and potential release of hydrogen gas.
Forklift battery safety: Guidelines and precautions operators and technicians must take to ensure they are handling battery systems carefully.
Industrial battery maintenance: The maintenance required to operate an industrial battery includes cooling, charging, equalizing charges to for equal charge voltage across all cells of a battery, watering the battery when low on electrolyte material to ensure the battery doesn't overheat and cleaning to remove corrosive material from the battery.
Forklift battery acid: Forklift battery acid is a combination of distilled water and sulfuric acid. This combination changes in concentration as the charge level of the battery changes.
Battery heat dissipation: The heat generated from a running battery dissipates in a range of many ways, from the heating of the battery pack and truck equipment, the use of fans, and the use of environmental cooling.
Wet cell battery: This traditional style lead acid battery operates where charged lead plates are suspended in an acidic electrolyte mixture. This type of battery technology requires extensive maintenance, safety equipment, and training to handle.
Battery cool-down phase: The period in a charging cycle where the battery has to rest and reach ambient temperature before operating. Batteries generally require roughly 8 hours of cool-down after charging to allow them to return to optimal operating temperatures.
Capacity loss: The process rechargeable batteries experience where the charge capacity available to the battery diminishes as the battery experiences usage. Corrosion of internal battery components also plays a role in the loss of battery capacity.
Electrolyte levels: The measurement of electrolyte levels that are recommended when operating industrial lead acid batteries. These levels are used to ensure the protection of the battery plates and prevent overfill and leaking battery acid.
Battery voltage: The difference in electric potential between the positive and negative terminals of a battery.
Amp-hours: A measurement of energy capacity given a specified voltage. A 20 Amp-hour battery can provide 20 Amps for 1 hour, or 10 Amps for 2 hours, etc.
Power-to-weight ratio: This calculation is used to determine the ratio of how much power an object with an engine or power source produces divided by the mass of the object.
Motive batteries: Motive batteries are used to power electric vehicles. These batteries store energy that is later used to power the equipment and create motion.
Counterbalance: A type of forklift that uses counterweight on the backend of the equipment to offset any load being put on the front end of the lift. This is done to allow for the lifting of heavier loads.
Vent caps: A battery vent cap allows for harmful gasses internally built up in the battery to be released. This is done to prevent gas build-ups that could result in an explosion that is not vented.
Specific energy: Specific energy is another term for energy density. The measure of how much energy a battery contains in proportion to its weight. This measurement is typically presented in Watt-hours per kilogram (Wh/kg). A watt-hour is a measure of electrical energy that is equivalent to the consumption of one watt for one hour.
Battery recycling: When recycling batteries, they are broken down into various components ranging from plastic, lead, and electrolyte material. Each part gets treated through a specified recycling process to extract reusable parts for new batteries and alternative uses.
Battery change out: Lead acid batteries is removed when in need of charging. The battery is moved to a ventilated room to charge and cool off. A charged battery is put in place of the discharged battery to continue using the forklift.
TPPL battery technology is relatively new to the lead acid battery family. It is a more advanced variation on the traditional lead acid battery that offers some advantages.
They are a cousin to the AGM battery, which is also considered a variation on the traditional lead acid battery. The primary difference that sets TPPL batteries apart is that the grids on the TPPL batteries are pure lead. Having grids that are pure lead significantly reduces the internal resistance of the battery. As a result, the plate does not need to be as thick. Thicker plates slow the flow of current, and the greater internal resistance has a negative effect on the battery’s performance.
These two primary differences mean that the TPPL battery performs better over time than a standard lead acid or AGM battery. TPPL batteries are capable of tolerating high discharge/charge cycles better than standard lead acid batteries. But this comes with a cost. Extreme discharge/charge cycles will increase the internal temperature of the battery, which can lead to a shorter lifespan than an AGM battery with thicker plates.
Like other variations of lead acid batteries, they still need a full recharge to get the longest lifespan out of them. TPPL batteries can deliver 80% of their capacity up to 1200 cycles. TPPL batteries are more energy efficient than traditional lead acid batteries. You can expect to get around 85% energy efficiency vs the standard 60% for other lead acid batteries. TPPL may not be suitable for heavy duty applications because they tend to be more light weight. Therefore, you may need to add extra ballast plates to your lift trucks to increase your load capacity that is often compensated for by the heavier weight of traditional lead acid batteries. They may also struggle to maintain performance in extreme environments, which is consistent with other types of lead acid batteries.
TPPL battery: Thin Plate Pure Lead (TPPL) batteries are a type of lead acid battery which have electrodes that are thinner than traditional lead acid battery designs. TPPL batteries have a high rate of charge and discharge which increases the level of internal heat. This causes the life of a TPPL battery to deplete faster than other types of lead acid batteries.
Flooded battery: A flooded battery has plates, separators, and a high-density paste material. It uses a liquid electrolyte that submerges the plates. The liquid solution can be damaged in extreme temperatures due to evaporation or freezing. This requires watering and maintenance of the battery.
Battery anode: The anode is the negative electrode in the cell. It is very common, in lithium-ion batteries, for it to be composed of lithium and carbon, usually a graphite powder. The current can be collected due to the copper film that is combined with the electrode. The purity, particle size, and uniformity of the anode all contribute to the aging behavior and capacity.
Battery cathode: The cathode is the positive electrode. This is where all the different chemistries come into play. The cathode is what determines the overall lithium chemistry. Like the anode, a current collector is combined with the material so the flow of electrons can occur. The cathode is typically combined with an aluminum film. As shown above there are many different chemistries. The key differences between them is temperature at which they react with the electrolyte (thermal runaway) and the voltages they produce.
Battery degradation: The process that reduces the amount of energy a battery can store. Temperature, charge, and discharge voltage, current and the depth of charge and discharge can affect how much a battery’s capacity is reduced over time.
Battery round trip efficiency: The percentage of remaining energy stored after loss is accounted for throughout the storage process. This is the amount of energy remaining to operate the equipment after the battery has been fully charged.
Operational efficiency: The proportion of output gained compared to the resources expended to achieve the results. The focus of operational efficiency is to improve results using the existing resources available.
Nominal voltage: This is the normal electric voltage that we expect to flow through a circuit. The voltage of a battery pack is determined by the number of lithium-ion cells and how the cells are connected (series or parallel).
Charge cycle: A charge cycle is the complete charge and discharge of a battery used to operate forklift equipment. The battery continues through charging cycles until it has reached the end of its life.
Off gassing: A hazard of overcharging a battery. When a battery overcharges, the electrolyte solution can overheat cause hydrogen and oxygen gasses to form. This will increase pressure inside the battery leading to permanent damage.
Absorbent Glass Mat (AGM): batteries are a type of lead acid battery which contain a glass mat separator. This separator absorbs the electrolyte solution between the battery plates like a sponge which keeps the battery water levels down so you don’t have to water them as constant as other lead acid batteries. However, if the battery is overcharged, gas pressure builds within the cell and will cause the battery to dry out and fail.
Current peak: Current peak is the highest volume of current that is capable of being provided from a power source only for short periods. This is typically achieved upon the initial start-up of an electric device.
Cell pack compression: Cell pack compression is the process of applying compression to the outer walls of the calls through the use of a clamping fixture. The compression helps prevent swelling and potential damage to cells.
Vibration resistance: Vibration resistance is the maximum vibration frequency a battery can withstand without taking damage. Tests on industrial vibration tables are required for batteries to receive certifications such as UL listing and other similar safety tests.
Positive active material (PAM): Positive active material is the lead dioxide created through discharging the battery. This process is reversed when the battery is charging.
Lead oxide: Lead oxide is an inorganic compound that accelerates the speed at which combustible material burns. Lead oxide is produced as a battery is discharged.
Positive grid: Positive grids are used to help improve the lifespan of a battery by providing support to containing active material conducting current and transferring it to the terminals.
Float voltage: Float voltage is the voltage continually provided after a full charge has been completed. This continuous flow of current is to help maintain full capacity, as the battery naturally discharges when not in use.
State of Charge (SOC): A LED display that connects to the BMS, providing the end-user a measurement of how much energy is left in the battery.
Self-discharge rate: The self-discharge rate is the internal reaction that results in a loss of energy in a battery cell that sits unused. Self-discharge progressively gets worse as the battery ages having irreversible effects.
Battery operating cycle lifetime: The battery lifespan is the number of completed charge and discharge cycles a battery can withstand. The battery is considered inoperable when the capacity is too low and rendered useless.
Partial state of charge (PSOC): A partial state of charge is when a battery loses its capability to charge, requiring longer charging times. This happens when a battery is left partially discharged, causing lead sulfate to form on the plates that progressively grow larger over time.
Cyclic capability: The cyclic capability is a measurement of the capacity available to a battery compared to the levels at the first charge. The cyclic capability is affected by the chemistry used in a battery.
Overcharging: Overcharging a battery is charging a battery more than its designed capacity. This can create unstable conditions inside the battery, increase pressure, and cause thermal runaway. This can be damaging to the battery, the equipment, and the operator.
Stratification: Stratification is the process that occurs when the acid separates from the water and collects at the bottom of the battery pack. This causes parts of the plates to be exposed to concentrated levels of acid that cause damage.
Charge acceptance rate (CAR): A charge acceptance rate is the maximum allowed voltage that a battery will allow a charger to provide a charge. A battery will charge at its maximum allowed rate as long as the power supply equals the CAR.
Effective capacity: Effective capacity is the ratio between the true capacity a battery can reach and the rated capacity the battery is advertised for.