Lithium Battery

Lead acid batteries have long been the gold standard in floor machines, but lithium batteries are beginning to infiltrate the marketplace. Their light weight makes them a viable option for backpack vacuums — and more recently they are finding their way into autoscrubbers, albeit for different reasons.

“Lithium is a buzzword in the industry right now,” says Tim Wittig, director of NexSys Products Americas at EnerSys, Reading, Pennsylvania. “People are asking for it by name, but what they’re really asking for is a maintenance-free experience.”

Indeed, one of the major selling points of lithium batteries is that they don’t require maintenance, unlike flooded lead acid batteries.

“The workhorse in the industry has always been the flooded lead acid battery,” says Fred Wehmeyer, senior vice president of engineering for U.S. Battery Manufacturing Co., Augusta, Georgia. “The downside is they have to be watered regularly, which can be time-consuming. So you have to consider the labor costs of watering these batteries.”

While zero maintenance is an attractive feature of lithium batteries, some argue customers can achieve similar benefits with alternative technologies.

Investing in a single-point watering system can reduce the time it takes to flood lead acid batteries from 30 minutes down to one or two minutes per battery. Sealed lead acid batteries are another option that doesn’t require maintenance; however, some cite the expense and shorter cycle life as drawbacks compared to their flooded counterparts.

Leading The Charge

RELiON Battery, Rock Hill, South Carolina, is seeing a growing interest in lithium batteries for autoscrubbers. Two U.S. manufacturers are beta testing the company’s 24-Volt lithium iron phosphate battery in their autoscrubbers. Another equipment manufacturer in Europe is successfully selling autoscrubbers equipped with RELiON’s lithium battery.

Lithium batteries are best suited for floor cleaning applications where cleanliness is critical, such as in cleanrooms. They also excel in high-demand applications where appearance is paramount, such as hotel lobbies and shopping malls. In these environments, lithium batteries have the advantages of longer run times and quicker recharge times compared to lead acid batteries.

One of RELiON’s beta test customers boasts run times of five hours with lithium iron phosphate batteries.

“Prior to using lithium, the original equipment manufacturer was lucky to get three-hour run times using the largest lead acid battery its machines could accommodate,” says Christine Feodorov, vice president of product management and strategy at RELiON Battery.

Another advantage of lithium batteries is that they can tolerate a partial state of charge, meaning that if the user leaves the battery in a discharged or partially charged state, it will not cause damage to the battery. On the other hand, lead acid batteries must be fully charged prior to use. Failure to do so could result in irreversible damage to the battery plates.

Manufacturers claim lithium batteries have a much longer cycle life than lead acid batteries — an estimated 2,000 cycles or more, versus 300 to 500 cycles for a lead acid battery. Furthermore, the battery maintains its power throughout the cycle, whereas lead acid batteries lose power quickly during discharge.

“As you use lead acid batteries, they get sluggish and in the last hour, you’ll notice [the autoscrubber] slow down,” says Feodorov. “With lithium, the machine is at full power the entire time.”

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Cost And Safety Of Lithium Batteries