Progressive Distributor - Assault on batteries

Assault on batteries

Lithium ion batteries are revolutionizing the power tool market. Superior run time and more power at a lighter weight mean higher productivity and greater job site efficiency.

by Paul Markgraff

Remember when cell phones were the size of a brick and were attached to batteries as big as a dictionary? Today, they are as thin as a pencil and weigh ounces.

Remember when laptops were heavy and awkward, with small screens and short battery life? That has changed too, due in large part to longer-lasting and better-performing lithium ion (Li-Ion) batteries.

Now, these advancements have come to power tools. In an industry where Nickel-Cadmium (NiCad) batteries ruled for 25 years, Li-Ion battery technology is beginning to make serious inroads.

Power tool manufacturers are investing heavily in Li-Ion research and development. They are working with battery cell manufacturers with names like A123 Systems, Molicel and Nanoexa to bring the next generation in cordless power to professional users.

“Li-Ion has the greatest energy density,” says Edwin Bender, Bosch group product manager for cordless power tools. “With Li-Ion, you can put more energy into a battery that’s the same size as an 18-volt NiCad. We have designed cells that can withstand the applications that we as power tool manufacturers have spec’d out, as well as producing run time and cycle life that far surpasses NiCad batteries.”

Basic battery benefits
Li-Ion is new to the cordless power tool market, whereas proven NiCad technology is currently the dominant force. And, Li-Ion power tool combo kits can cost hundreds of dollars more than their NiCad counterparts. So, when end-user customers ask why they should invest in Li-Ion powered tools, what is a distributor to say?

The main benefit is less weight. With lighter weight comes more power and longer run time.

“Lithium ion cell technology is essentially compact power. If you want a certain amount of voltage or run time, it gives you a smaller, lighter package than an equivalent NiCad battery,” says John Sara, Milwaukee Electric Tool senior product manager for cordless tools.

Weight
Simply put, the reason Li-Ion batteries weigh less than NiCad batteries is the element lithium weighs significantly less than the element nickel.

From an ergonomic perspective, Li-Ion batteries can make a big difference in worker fatigue. Milwaukee Electric Tool recently started shipping its V18 battery. This 18-volt battery weighs about half a pound less than the company’s current 18-volt NiCad battery and slightly less than the company’s 14.4-volt NiCad battery. As a side note, the new V18 battery also works with Milwaukee’s existing NiCad power tools.

Half a pound may not seem like a lot of weight, until you are forced to carry and use the tool for eight hours a day. Less weight means fewer mistakes, less waste on the job site.

Power
It’s important for distributors to remember that the term Li-Ion does not indicate power; 14.4-volt is still 14.4-volt and 18-volt is still 18-volt, regardless of battery technology, says Christine Potter, DeWalt group product manager for batteries/chargers and technologies. If lower voltages provide your customers with enough power to complete their job site applications, NiCad will provide more than enough power.

However, Li-Ion batteries provide even more power in a smaller, lighter package; 18-volt Li-Ion batteries weigh less than 14.4-volt NiCad batteries and 36-volt Li-Ion batteries weigh less than 24.4-volt NiCad batteries. Workers accustomed to a certain weight in the cordless power tools can now switch to a Li-Ion battery that is more powerful than the NiCad battery and the tool gets lighter.

“Li-Ion cells can either hold more power in the same size package or hold the same power in a smaller package,” says Bender. “A 36-volt Li-Ion battery offers twice the voltage capacity of an 18-volt NiCad battery for efficient high-amp draw tools, but weighs nearly the same.”

Sara also says Milwaukee’s version of Li-Ion provides fade-free power throughout the discharge cycle of the battery. During use, a typical NiCad battery gradually loses power and becomes frustrating to use toward the end of charge. “Our Li-ion packs avoid this power loss and it feels like a freshly charged battery until it stops,” he says.

“The fact that a Li-Ion battery will run at the same power until it dies makes a big difference for users of cordless power tools,” says Sara. “This helps when workers only have an hour left in the day. Users can charge the battery only 20 percent, and that battery will still perform at peak levels until the charge runs out.”

Run time
Milwaukee Electric Tool’s V28 Li-Ion batteries will provide longer run time than its 18-volt NiCad counterparts. DeWalt’s 36-volt technology and Bosch’s Litheon 36-volt technology will also provide longer run time than their lower-volt counterparts.

Any increase in voltage for any battery chemistry will increase run time, says Bender. However, like NiCad, run time increases and decreases relative to the power draw of any particular application.

“But overall, the larger the voltage, the more run time the user can expect,” says Bender. “Moving forward, 36-volt Li-Ion batteries are the highest voltage the market will likely see for power tools.”

The next generation
Many end-user customers are unaware that Li-Ion battery chemistries differ from battery to battery.

“There are hundreds of different formulas of Li-Ion,” says Potter. “DeWalt used a new, exclusive nano-phosphate Li-Ion battery to power its 36-volt platform.”

Mike Sinkula, director of business development for nanotechnology-based clean energy company Nanoexa Corp., says Li-Ion batteries have only been around for about 15 years. He says the majority of today’s lithium batteries are constructed using the same material used in the first lithium batteries.

Nanoexa and Decktron, a Li-Ion battery and display manufacturer, recently announced an agreement to develop and transfer into commercial use a new lithium battery technology originally developed at the U.S. Department of Energy’s Argonne National Laboratory.

The goal of the agreement is to commercialize the next generation of rechargeable Li-Ion batteries. The two companies will introduce batteries with increased power output, storage capacity, safety and lifetime that will be used in high-rate applications such as power tools.

Sinkula says Nanoexa’s batteries will offer improved lifetime and safety metrics. They will also have a 50 percent higher density and 50 percent higher power output than competitive lithium batteries in the power tool and transportation markets.

“This is an exciting time,” says Sinkula. “The battery market has been dominated by Asian manufacturers and so it’s exciting to have American companies step forward with new battery technology.”

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