August 1, 2007
equipment & applications | Batteries/Chargers

All charged up

all charged up

DC managers have plenty of tools at their disposal for keeping forklift batteries all charged up and ready to go. The trick is to select the right one for your particular operation.

By George Weimer

The premise is simple enough: if you want to keep your electric lift trucks in top operating condition, you'll need a system for maintaining and charging their batteries.But as many DC managers will attest, there's nothing simple about developing such a system. The days are long gone when keeping batteries charged was pretty much a matter of driving the truck to a battery room for overnight charging. Nowadays, DC managers have a far greater array of options when it comes to managing battery operations.

There's no one-size-fits-all solution. Each DC must determine for itself which types of equipment best suit its particular operation, factoring in such matters as labor costs and number of shifts. That requires a full understanding of the various charging and handling techniques and technologies, and how they work. It also calls for a clear-eyed assessment of an assortment of increasingly sophisticated battery management tools designed to ensure safety, efficient operations, and long battery life.

"Customers aren't looking for energy efficiency, productivity, low cost of ownership, service, turnkey maintenance, or reliability. They want all of the above," says Lisa Horiuchi Heiberg, director of marketing and venture development for AeroVironment in Monrovia, Calif.

The debate goes on
When it comes to charging systems, one of the first big decisions a fleet manager must make is whether to go with a fast-charging system or the more traditional battery exchange approach. What are the advantages of each? It depends on whom you ask.

Peter Michalski, managing director for fast-charging specialist Edison-Minit Charger, says one advantage of fast charging is that it eliminates the need for forklift operators to stop what they're doing and go change a battery. Multiply the time savings across several trucks and you've got a big boost in productivity, he says. Another plus is that fast charging doesn't require users to handle heavy, acid-filled batteries. "Safety considerations have become a leading reason for customers to switch to fast charging," he adds.

Michalski urges DC managers to investigate the quickcharge technology. "Evaluate fast charging as an alternative to battery changing," he advises. "Ask a fast charge representative or dealer to provide a facility assessment to learn how fast charging can 'fit' and the magnitude of the savings."

Heiberg, whose company produces the PosiCharge fastcharging system, contends that fast charging also has the economic edge over traditional battery exchange. "Imagine the quantifiable advantages of eliminating the battery room and the labor and capital-intensive changing regimen completely," she says. Those advantages, she adds, include reducing inventory carrying costs, increasing productivity, improving workplace safety, and decreasing ongoing operating expenses.

Not surprisingly, proponents of traditional battery handling systems see it differently. They dispute the notion that fast charging is the more economical alternative. Quickcharge technologies have gained popularity in industries with high labor costs, like the automotive business, acknowledges John Pratt, president of Multi-Shifter Inc., a manufacturer of industrial battery handling vehicles and storage systems. But when it comes to three-shift operations, he argues, battery changing systems are a better fit and offer a faster return on investment than costlier fastcharging systems.

Attention to the basics
Today's charging technologies may be more capable and powerful than ever, but DCs still have to follow the basic principles of sound battery maintenance and handling if they want to achieve top performance.With traditional battery charging, for example, it's essential to keep close track of each battery to ensure that it's properly charged and cooled. "Batteries that are fully charged and cooled will achieve maximum run time," says Terry Orf, vice president, global sales and marketing for St. Louis, Mo.-based BHS, a manufacturer of battery handling equipment and systems. "Run time [drops] as charge and cooling times are decreased when batteries are taken out of rotation." BHS, like other battery handling companies, offers software tools that monitor individual batteries to ensure that battery room workers or lift-truck operators select a battery that is fully charged and ready.

Pratt adds that when it comes to batteries, the rule of thumb is that you have to charge a battery for eight hours, work it for eight hours, and rest it for eight hours. That means that two-shift operations require two batteries per truck and three-shift operations, three batteries per truck. "Battery maintenance and battery handling equipment maintenance are crucial," he asserts.

Some have suggested that the introduction of fast-charging technology alters that equation by eliminating the need for spare batteries. That's not necessarily true, says Orf. "The main mistake that users of fast-charge technology make is to apply the [traditional guidelines for determining battery needs] to all applications. Using fast charge in applications where there is not adequate time for batteries to receive a full charge daily or an equalize charge on the weekends can have disastrous results."

Dean Portney, national accounts manager for industrial battery maker Hawker Powersource Inc., agrees that problems with fast charging occasionally crop up. Most of the time, he says, these problems are caused by forklift operators who forget to plug the batteries into rapid chargers during breaks or fail to equalize batteries weekly. "This causes batteries to not have enough amp hours returned, resulting in a deficit of amp hours for the operation," he says. "Not equalizing weekly causes a decay in battery performance and life."

Not surprisingly, advocates of fast charging dispute the assertion that the technology shortens battery life. With proper battery management, it's just not an issue, they say. "Despite many enterprise-wide installations of fast-charge systems by high-profile corporations, seven or eight years after the introduction of fast charging, this false perception remains," says Heiberg. "The key to long-term battery care is closed-loop charge algorithms that communicate with and monitor the battery—and ultimately control charge current and voltage according to a battery's temperature."

The case for automation
The fast-charging sector isn't the only part of the battery charging market that's gone high tech. The battery exchange business is seeing rapid technological advances as well. In recent years, players in this arena have introduced sophisticated battery management tools designed to promote operating efficiency and extend battery life.

Dan Dwyer, vice president and general manager of Sackett Systems, a Bensenville, Ill.-based producer of battery handling systems, says that DC managers have much to gain from today's automatic battery-changing systems. But all too often, he says, they fail to capitalize on those advantages because they don't look beyond the systems' initial capital cost. "Unfortunately, customers tend to look at the cost of the product, rather than the value that comes from it."

That becomes even more important as the cost of new batteries rises, according to Dwyer. "You need a disciplined way of rotating lift truck batteries and proper maintenance," he says. "This is especially true today with the increase in lead prices. Lead has doubled in the last eight months.

"There's a perception out there that there's not much to be gained in the way of efficiency," Dwyer continues. "That's not true." His advice? "Develop a battery management system if you don't have one. And if you do, move to as much automation as possible. The more automation, the better."

About the Author

George Weimer
Editor at Large
George Weimer has been covering business and industry for almost four decades, beginning with Penton Publishing's Steel Magazine in 1968 where his first "beat" was the material handling industry. He remained with Steel for two years and stayed for two more when it became Industry Week in 1970. He subsequently joined Iron Age, where he spent a dozen years as its regional and international machine tool editor. He then re-joined Penton Publishing as chief editor of Automation Magazine and in 1993 returned to Industry Week as executive editor. He has been a contributing editor for several publications, including Material Handling Management, where his columns and feature articles regularly generated lively discussion in the industry. He has won various awards from major journalism organizations. He has covered numerous trade shows here and abroad and has spoken to various industrial and trade groups on the current issues and events of the day as they impinge on business. He remains convinced that material handling technology and logistics are two of the major sources of productivity improvement today and in the future for all industries.

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