Cost And Safety Of Lithium Batteries

Although there are myriad of benefits from lithium batteries, they can come at a price. Lithium options are far more expensive than lead acid batteries, according to battery manufacturers.

Wittig estimates EnerSys’ lithium battery is three times the price of the company’s lead acid battery. However, customers need to consider the total cost of ownership when choosing between lithium and less-expensive alternatives.

“Lithium batteries are more expensive up front, but you have to look at the benefits and cost over the life of the product,” says Feodorov. “Lithium batteries can last up to 10 years, whereas lead acid batteries will need to be replaced every couple of years, depending on the application. There are also costs associated with maintaining lead acid batteries. So the lithium battery will be less expensive over the life of the product.”

In reality, a lithium battery with a 10-year warranty could outlast the autoscrubber that it powers.

“The life of [floor] equipment is about three years — and maybe an additional two years if it’s refurbished,” says Wittig. “So you’re looking at a five-year lifespan for an autoscrubber.”

While the battery could potentially power a new piece of equipment, Wittig believes batteries are becoming more like cell phones. The technology quickly becomes outdated and in 10 years, no one will want it.

This raises another concern about lithium batteries: Recyclability.

“Theoretically, lithium batteries are recyclable. The problem is it’s not economically feasible to recycle them,” says Wehmeyer. “If you look at lead recycling, not only are lead acid batteries 100 percent recyclable, but they’re close to 100 percent recycled — and that lead goes back into new batteries.”

As of now, questions about the feasibility of recycling lithium batteries — and whether or not recovered lithium can be used in new batteries — is a concern for the future, but a concern nonetheless. Currently, only a small percentage of lithium batteries are recycled; most end up in a landfill.

Another reason eco-conscious customers may avoid lithium is the controversy surrounding cobalt, a naturally occurring element found in the Earth’s crust that is essential for making lithium ion batteries. Cobalt is found in volatile areas and is difficult to retrieve from a virgin state.

“Most of the cobalt used in NMC [nickel-manganese-cobalt] products, which is the dominant chemistry, comes from the Congo,” says Wehmeyer. “Not only is there not enough of it, but it comes from parts of the world that are in conflict.”

Wired For Safety

Safety concerns can add fuel to the fire for end users who are already apprehensive about lithium batteries. If a lithium battery explodes or catches fire, nothing will put it out.

“There isn’t a fire extinguisher that you can hit a lithium battery with,” says Wittig. “You can’t put dirt on it and you can’t extinguish it with water. If one cell ruptures and catches fire, you’ll have a thermal runaway problem and all cells will catch fire.”

Despite the risk, manufacturers of lithium batteries insist their technology is safe.

“The kind we use — lithium iron phosphate — is an inherently safe chemistry,” says Feodorov. “It generates a fraction of the heat of other chemistries, and we’ve never had reports of a fire. Plus, we provide protection through a battery management system.”

The battery management system (BMS) protects and monitors the battery to optimize performance, maximize lifetime and ensure safe operation over a range of conditions.

EnerSys is on the brink of rolling out its lithium battery, which was designed first and foremost with safety in mind.

“We chose a nickel manganese cobalt chemistry that comes in prismatic cells,” says Wittig. “It’s the largest energy that you can buy, so when we link these cells together there are less points of failure. We’ve matched this with a BMS made up of redundant systems designed by two separate EnerSys groups working independently of each other. The batteries are also designed to exceed UL standards, so everything we’ve done is based on safety.”

Additionally, the onus is on end users to maintain the equipment and use it correctly. Fortunately, batteries — like cell phones — are getting smarter and can assist users with tasks like troubleshooting and checking charge status.

“Regardless of the battery type or application, there’s some complacency that takes place and users may start to take the batteries and chargers for granted,” says Wittig. “Education and ongoing training are necessary to ensure everyone knows how the battery works and how to use the equipment properly. If there’s a battery management system that’s giving a warning, they need to adhere to that.”

A maintenance-free experience, longer run times, and opportunity charging — that is, charging batteries at available opportunities throughout a shift — are the primary reasons customers use lithium batteries in autoscrubbers. Unfortunately, the battery’s hefty price tag and environmental impact can be deterrents for both customers and manufacturers.

U.S. Battery Manufacturing Co. does not make lithium batteries, but Wehmeyer says the company is looking into it.

“The real question is, ‘Does it make sense, and is the cost going to come down,”’ says Wehmeyer. “Until the industry comes up with a recycling structure, we’re dependent on the amount of known lithium worldwide. New mines are being discovered, but there is a theoretical shortage of lithium — particularly as the auto industry continues to move toward hybrid or pure electric vehicles.”

Meanwhile, manufacturers and distributors can educate customers on the pros and cons of lithium and help them choose the appropriate battery technology for their floor care needs

Kassandra Kania is a freelancer based in Charlotte, North Carolina. She is a frequent contributor to Sanitary Maintenance.