Many different factors can detract from lift truck battery performance—including a few you might not have thought of. Industry insiders tell us what to watch for.
Contributing Editor Toby Gooley is a writer and editor specializing in supply chain, logistics, and material handling, and a lecturer at MIT's Center for Transportation & Logistics. She previously was Senior Editor at DC VELOCITY and Editor of DCV's sister publication, CSCMP's Supply Chain Quarterly. Prior to joining AGiLE Business Media in 2007, she spent 20 years at Logistics Management magazine as Managing Editor and Senior Editor covering international trade and transportation. Prior to that she was an export traffic manager for 10 years. She holds a B.A. in Asian Studies from Cornell University.
In some warehouses and DCs, lift truck batteries are taken for granted. Much like car batteries, they're treated as something that can essentially be ignored until there's a problem. But a lift truck battery is not a "set it and forget it" piece of equipment. Rather, it's a complex device powered by electrochemical reactions; compromise the battery's ability to efficiently produce those reactions and you'll diminish its performance and lifespan. Indeed, the key to getting superior performance from a lift truck battery, says Harold Vanasse, vice president of sales and marketing for battery management systems supplier Philadelphia Scientific, is to understand the following fact: "The laws of physics can't be violated!"
Not everyone understands that, though. As a result, some of the many factors that can detract from battery performance tend to get overlooked. Want to know what you may be missing? Here's advice from industry insiders on what to watch for—including a few things you might never have thought of.
Temperature. Temperature—both high and low—has an enormous impact on battery performance. As you might expect, a battery can be destroyed if it should freeze. But even moderately low battery temperatures will decrease capacity. At 30 degrees F internal temperature, the available battery capacity is reduced by roughly 30 percent, says Bill Rubenzer, vice president, sales and marketing at industrial battery manufacturer Storage Battery Systems LLC. Even at 50 degrees internal temperature, a 1,000-ampere-hour battery will act more like a 600-700 amp-hour unit, according to Tony Amato, executive vice president of battery distributor Industrial Battery Products Inc.
When the battery temperature falls below 40, the voltage will appear artificially high and a battery discharge indicator (BDI) will show more power available than there actually is, says Steve Spaar, marketing director-Americas for the battery manufacturer EnerSys, which also owns Douglas brand batteries. At low temperatures, the charger will also see the voltage as artificially high and will shut off too soon, which leads to shorter battery life.
There are ways to counteract the effects of frosty temperatures. One option for extremely cold environments is to insulate the battery compartment. Another is to use a battery with a high amp-hour capacity. It's possible to raise that capacity in an existing battery by increasing the acid content in the electrolyte solution (the mix of water and acid that governs the battery's electrochemical reaction and thus, its voltage). However, Amato warns, there's a trade-off: You'll get more run time per shift, but you'll also be shortening the battery's useful life by potentially as much as two years.
A battery with tubular positive plates will have more usable capacity than an equivalent flat-plate-construction battery, and so should be considered for cold applications, Rubenzer says. Not just batteries but also chargers should be specifically designed for low temperatures, and battery discharge indicators should be adjusted for cold conditions.
Sustained high battery temperatures can do serious damage. Battery life can be reduced by as much as 50 percent for every 15-degree increase over 77, based on average temperatures. As a battery's sustained temperature increases, moreover, the loss of battery life accelerates.
Battery heating is caused by the resistance of the intercell connectors while a vehicle is in use, according to PowerDesigners, a manufacturer of battery chargers and monitoring systems. Additional heating due to this same effect occurs during charging, and the higher amperage used during opportunity and fast charging exacerbates the problem, the company says. Because there's no cooldown period following the charge, as in a conventional charging application, the battery remains hot.
Hot air temperatures can also lead to overheating, especially in fast and opportunity charging operations. Power Designers explains it this way: While it is in use (i.e., being discharged), a battery usually will be warmer than ambient temperatures. As the ambient temperature rises, the air becomes less effective in cooling the battery, and the battery's internal temperature will rise. Charging will further raise the battery's internal temperature—possibly to the point where the battery could suffer damage if you're not careful.
For example, discharging typically adds about 15 degrees to the battery temperature. At an ambient temperature of 75, then, discharging will add enough heat to raise the battery's temperature to 90. Charging will add another 10 degrees, bringing the battery's temperature to 100. When a battery reaches 130 degrees, the charger will issue a "battery over temp" fault and will stop the charge to prevent battery damage. In this case, the battery has a margin of 30 degrees before that happens. But at an ambient temperature of 90, the battery begins charging at 105 degrees (90 + 15). The added heat from charging (10 degrees) coupled with the reduced cooling effect of the higher ambient temperature could potentially cause the internal temperature to rise high enough to trigger a "battery over temp" fault.
Making sure battery charging areas are well ventilated to provide good air movement will help to minimize average battery temperatures, according to Aerovironment, the manufacturer of PosiCharge fast charging systems. For battery changing systems, make sure there is a cooldown period after charging and use a first-in, first-out (FIFO) rotation. For opportunity charging, consider using ventilated battery trays or some type of active cooling, such as blowing air.
Temperature will affect cells differently depending on the battery layout or position in the lift truck, causing some cells to be overdischarged while others are underdischarged, notes Ken Sanders, director of motive power battery engineering for East Penn Manufacturing Co. Inc., maker of Deka brand batteries. A weekly equalizing charge—an extra-long charge that brings each cell in the battery up to the same, maximum capacity—will allow battery and cell temperatures to reach a state of equilibrium, thus minimizing cell-to-cell temperature variations and improving battery performance and longevity, he says.
Failing to equalize. Batteries should be equalized once a week, says Amato. Unfortunately, that doesn't always happen as scheduled, due to poor maintenance tracking or because with chargers that are set to automatically do an equalizing charge, users tend to assume that everything is happening as planned. But that's not always a safe assumption, Amato warns. In a facility that rotates multiple batteries, "the batteries don't always get on that charger the right day or time," he says. A battery tracking and monitoring system that alerts managers when a particular battery has not been equalized is one possible solution.
Improper watering. Overwatering, underwatering, or watering at the wrong time will lead to a host of problems that can shorten battery life. These include plate oxidation and capacity loss; inadequate electrolyte levels; drying out and overheating; reduced amp hours, which can lead to overcharging and overheating; and boilovers, resulting in acid damage to battery tops, equipment, and floors (and potentially personnel) and requiring a costly acid adjustment.
Battery manufacturers recommend filling after an equalizing charge. Because the electrolyte expands when the battery is in use, watering after a charge helps to prevent overfilling and boilovers, say the folks at Flow-Rite Controls, a supplier of battery watering systems. It's best to fill on a regular schedule: weekly for heavy-use applications and less frequently (perhaps as little as once a month) for light-use applications.
Manually filling individual cells correctly—adding neither too much nor too little—is not easy, and the process typically takes around 15 minutes. Single-point watering systems maintain reliable electrolyte levels and take less than a minute, according to Flow-Rite and other providers of watering systems. These systems consist of automatic shut-off valves connected to tubing, which replace the battery's vent caps. Once the tubing is connected to a water supply, water flows into each cell until it reaches the correct level. When using a single-point watering system, be sure to regularly check the system valves to prevent potential clogs.
Overdischarging. Regularly overdischarging—allowing a battery to dip below 20 percent state of charge—will damage the battery, causing premature capacity loss and shortening its lifespan. One increasingly common reason operators overdischarge batteries is that lift trucks are traveling faster and are lifting heavier loads higher and more quickly than in the past, which places greater demands on the battery. This is particularly true of trucks with the newer alternating current (AC) motors, which pull more current out of the battery than their direct current (DC) counterparts. "You're getting 10 to 15 percent more work out of [an AC] truck, but the battery technology is still the same," Amato says. "That means you're using 10 to 15 percent more power in the same time frame."
If the battery isn't sized to meet that extra demand, "the battery will draw down to a 20-percent charge sooner than you would see with a DC truck," says Spaar of EnerSys. "So if you're lifting high at the end of a shift, it could put you over the limit." Larger-capacity batteries designed for AC trucks and "lockout" systems that prevent lifting if the state of charge gets too close to 20 percent will help prevent overdischarging.
Overdischarging can also happen when lift truck operators in a facility that uses opportunity or fast charging cut short or skip scheduled breaks. Those breaks are essential windows for charging batteries; operators who miss some breaks are likely to run batteries down below the minimum before their shifts end, says Aerovironment. Making break schedules mandatory and using a properly sized charging system will help to prevent this problem.
Moisture. Moisture can cause corrosion on the battery connectors and tray, which allows voltage leakage from the battery to the frame of the lift truck—a situation that can cause the truck's electrical system to ground fault, says Sanders. Moisture, by the way, is not just a problem in hot, humid climates. It can also become a problem when batteries are overwatered or when the fans in high-frequency chargers draw in moist air and blow it over batteries and associated electrical components.
The best method of preventing humidity-related corrosion is a simple one: keeping the battery tops as clean and dry as possible. Rubenzer of Storage Battery Systems also recommends fully insulated, bolt-on cables, which are less susceptible to moisture-related corrosion. Be sure, too, to keep high-frequency chargers away from wet or washdown areas, he says.
"Parasitic" loads. Some integral devices and optional features, such as heaters, fans, and GPS, get their power from the same batteries that power the lift truck. While the energy draw of any one device may be low, a battery under such constant "parasitic" loads may require a refresh charge more frequently to counteract the higher battery self-discharge rate, says Sanders. This will negatively affect performance and life. To reduce or eliminate the need for refresh charges, be sure to use a battery with enough capacity to handle the total demand for an entire shift.
Outdated chargers. Technological advances mean that today's lift trucks—and the demands they place on batteries—are different from those of a decade ago. Yet many people who regularly update their forklifts have 10- or 15-year-old chargers, notes Amato. "Some of the outputs of those chargers have not kept up with the requirements of today's battery," he says. He recommends verifying that existing chargers are adequate for your current battery applications.
Pushing loads, driving uphill, and heavy lifting. Regularly driving up inclines, pushing loads (long frowned upon by lift truck manufacturers), and high lifting of heavy loads can quickly drain batteries while placing physical strain on trucks. There is no adverse effect on battery service life, but the kilowatt-hour consumption is higher and the battery should be sized accordingly, Rubenzer says. If those activities occur daily, consider using the highest ampere-hour-capacity battery available, he adds.
THE POWER OF PREVENTION
Lift truck batteries are designed to work for five years, or 1,500 to 1,800 cycles, assuming they are used and maintained correctly, says Vanasse. "If a battery doesn't last that long, then it's probably your own fault," he observes. That's why the experts we consulted for this article agree that regular preventive maintenance (PM) is a must for maximizing battery life and performance.
Even fleet managers who scrupulously follow a PM schedule for their lift trucks may not do the same for batteries. But batteries are costly and they're critical to an operation's productivity, so there should be a regular PM schedule in place to make sure they're getting cleaned, equalized, and watered appropriately, says Power Designers.
For many fleets, the most effective way to do that is to use a battery monitoring system that collects data, issues alerts, and creates reports on such things as cycles, equalization, watering, temperature, and state of charge. "In the past, you wouldn't recognize a problem with a battery until it was too late," says Spaar. "You could go a year or more before seeing a fall-off in performance. With the information systems available now, you can know the same day when somebody didn't water properly or overdischarged."
In Vanasse's view, monitoring systems are invaluable tools for both battery and fleet management. "If you don't measure and make use of that data, you can't improve anything," he says. Put that information together with a preventive maintenance program, and fleet managers can take a much more active role in extending the life of their batteries.
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There are hundreds of companies that design, manufacture, sell, and distribute lift truck batteries and related products in North America. Here are just some of those that we've run across.
Supply chain planning (SCP) leaders working on transformation efforts are focused on two major high-impact technology trends, including composite AI and supply chain data governance, according to a study from Gartner, Inc.
"SCP leaders are in the process of developing transformation roadmaps that will prioritize delivering on advanced decision intelligence and automated decision making," Eva Dawkins, Director Analyst in Gartner’s Supply Chain practice, said in a release. "Composite AI, which is the combined application of different AI techniques to improve learning efficiency, will drive the optimization and automation of many planning activities at scale, while supply chain data governance is the foundational key for digital transformation.”
Their pursuit of those roadmaps is often complicated by frequent disruptions and the rapid pace of technological innovation. But Gartner says those leaders can accelerate the realized value of technology investments by facilitating a shift from IT-led to business-led digital leadership, with SCP leaders taking ownership of multidisciplinary teams to advance business operations, channels and products.
“A sound data governance strategy supports advanced technologies, such as composite AI, while also facilitating collaboration throughout the supply chain technology ecosystem,” said Dawkins. “Without attention to data governance, SCP leaders will likely struggle to achieve their expected ROI on key technology investments.”
The British logistics robot vendor Dexory this week said it has raised $80 million in venture funding to support an expansion of its artificial intelligence (AI) powered features, grow its global team, and accelerate the deployment of its autonomous robots.
A “significant focus” continues to be on expanding across the U.S. market, where Dexory is live with customers in seven states and last month opened a U.S. headquarters in Nashville. The Series B will also enhance development and production facilities at its UK headquarters, the firm said.
The “series B” funding round was led by DTCP, with participation from Latitude Ventures, Wave-X and Bootstrap Europe, along with existing investors Atomico, Lakestar, Capnamic, and several angels from the logistics industry. With the close of the round, Dexory has now raised $120 million over the past three years.
Dexory says its product, DexoryView, provides real-time visibility across warehouses of any size through its autonomous mobile robots and AI. The rolling bots use sensor and image data and continuous data collection to perform rapid warehouse scans and create digital twins of warehouse spaces, allowing for optimized performance and future scenario simulations.
Originally announced in September, the move will allow Deutsche Bahn to “fully focus on restructuring the rail infrastructure in Germany and providing climate-friendly passenger and freight transport operations in Germany and Europe,” Werner Gatzer, Chairman of the DB Supervisory Board, said in a release.
For its purchase price, DSV gains an organization with around 72,700 employees at over 1,850 locations. The new owner says it plans to investment around one billion euros in coming years to promote additional growth in German operations. Together, DSV and Schenker will have a combined workforce of approximately 147,000 employees in more than 90 countries, earning pro forma revenue of approximately $43.3 billion (based on 2023 numbers), DSV said.
After removing that unit, Deutsche Bahn retains its core business called the “Systemverbund Bahn,” which includes passenger transport activities in Germany, rail freight activities, operational service units, and railroad infrastructure companies. The DB Group, headquartered in Berlin, employs around 340,000 people.
“We have set clear goals to structurally modernize Deutsche Bahn in the areas of infrastructure, operations and profitability and focus on the core business. The proceeds from the sale will significantly reduce DB’s debt and thus make an important contribution to the financial stability of the DB Group. At the same time, DB Schenker will gain a strong strategic owner in DSV,” Deutsche Bahn CEO Richard Lutz said in a release.
Transportation industry veteran Anne Reinke will become president & CEO of trade group the Intermodal Association of North America (IANA) at the end of the year, stepping into the position from her previous post leading third party logistics (3PL) trade group the Transportation Intermediaries Association (TIA), both organizations said today.
Meanwhile, TIA today announced that insider Christopher Burroughs would fill Reinke’s shoes as president & CEO. Burroughs has been with TIA for 13 years, most recently as its vice president of Government Affairs for the past six years, during which time he oversaw all legislative and regulatory efforts before Congress and the federal agencies.
Before her four years leading TIA, Reinke spent two years as Deputy Assistant Secretary with the U.S. Department of Transportation and 16 years with CSX Corporation.
As the hours tick down toward a “seemingly imminent” strike by East Coast and Gulf Coast dockworkers, experts are warning that the impacts of that move would mushroom well-beyond the actual strike locations, causing prevalent shipping delays, container ship congestion, port congestion on West coast ports, and stranded freight.
However, a strike now seems “nearly unavoidable,” as no bargaining sessions are scheduled prior to the September 30 contract expiration between the International Longshoremen’s Association (ILA) and the U.S. Maritime Alliance (USMX) in their negotiations over wages and automation, according to the transportation law firm Scopelitis, Garvin, Light, Hanson & Feary.
The facilities affected would include some 45,000 port workers at 36 locations, including high-volume U.S. ports from Boston, New York / New Jersey, and Norfolk, to Savannah and Charleston, and down to New Orleans and Houston. With such widespread geography, a strike would likely lead to congestion from diverted traffic, as well as knock-on effects include the potential risk of increased freight rates and costly charges such as demurrage, detention, per diem, and dwell time fees on containers that may be slowed due to the congestion, according to an analysis by another transportation and logistics sector law firm, Benesch.
The weight of those combined blows means that many companies are already planning ways to minimize damage and recover quickly from the event. According to Scopelitis’ advice, mitigation measures could include: preparing for congestion on West coast ports, taking advantage of intermodal ground transportation where possible, looking for alternatives including air transport when necessary for urgent delivery, delaying shipping from East and Gulf coast ports until after the strike, and budgeting for increased freight and container fees.
Additional advice on softening the blow of a potential coastwide strike came from John Donigian, senior director of supply chain strategy at Moody’s. In a statement, he named six supply chain strategies for companies to consider: expedite certain shipments, reallocate existing inventory strategically, lock in alternative capacity with trucking and rail providers , communicate transparently with stakeholders to set realistic expectations for delivery timelines, shift sourcing to regional suppliers if possible, and utilize drop shipping to maintain sales.