Tool Trends: Lithium-Ion

All lithium-ion batteries are not the same, and four toolmakers describe here what makes their batteries unique.


Hagen Dost, product manager—cordless power tools at Bosch Power Tools, said: “Professionals who use power tools look for increased battery power and run-time capabilities for power-hungry tools and all-day driving and drilling. Bosch’s 12V and 18V battery lines offer advanced lithium-­ion chemistry, which packs more energy per cell without increasing its size. 
Lithium-ion also offers users lower internal resistance and higher efficiency, which translates to increased productivity.


“Professionals want not only long run time but also exceptional recharge life, and that can be threatened by excessive heat. The Bosch 18V batteries address this need with proprietary CoolPack technology identified by its red heat-conductive housing, which extends inward and wraps around each cell to extract heat from within. With unique conductive properties and rib design, Bosch is the only battery manufacturer to integrate such advanced technology for longer recharge life—up to 100 percent longer versus similar packs without this feature.


“Bosch’s Flexible Power System for 12V or 18V tools allows users to select the battery that best meets their needs, whether that’s a smaller 2.0 Ah [ampere-hour] SlimPack for working overhead and in tight spaces or the more powerful FatPack for heavy-duty long run-time applications.


“To answer the need for power through continuous, all-day applications, we launched a 5.0-Ah battery. This new battery is the lightest, most compact and longest run time FatPack-style battery on the market. It is compatible with the complete line of Bosch 18V lithium-ion power tools.


“We built the Bosch BAT621 with state-of-the-art, high-capacity, low-resistance lithium-ion cells, which increase the overall capacity from the current 4.0-Ah batteries by 25 percent. This means improved run time and performance for all tools, especially system tools such as rotary hammers, impact drivers and reciprocating saws.


“Finally, all our battery packs are covered under our Pro­VANTAGE protection plan. This no-charge plan guarantees our batteries for two years. Once you sign up, if you have any issues with a pack in two years’ time, we will replace it.


“Bosch battery technology is on a steep growth curve. In the past three years, we have gone from 2.6-Ah packs to 5.0-Ah today. We always are looking for ways to increase professional productivity, whether it be new chemistries or configurations,” Dost said.


Ward Smith, product manager—batteries, chargers and cordless nailers at DeWalt, said: “Lithium-ion battery technology has provided multiple advancements for the power-tool market. For example, lithium-ion has virtually no self-discharge, which allows the user to work longer between charges. Unlike other chemistries, when the tool is not in use, the battery has minimal discharge, thus keeping more capacity within the pack for productive work. Lithium-ion technology has enabled tools to do more work in lighter weight packages compared to other chemistries. The design of the DeWalt 20V MAX system allows users to immediately upgrade their tools to better performance with higher capacity packs, such as the 5.0-Ah DCB205.


“Our world-class engineering team is focused on working with major cell suppliers to optimize power and run time within our 20V MAX system of cordless tools. DeWalt’s robust design is focused on the user’s productivity in order to minimize nuisance shutdowns. DeWalt designs for the long term to maintain compatibility with existing systems and also to implement new technologies that deliver more power without having to lock out batteries.


“For the future, there are various lithium-ion formats [prismatic, lithium polymer, etc.] in various adjacent markets. However, in terms of chemistry, lithium-ion will be the choice of chemistry for the immediate future. DeWalt will continue to develop more capability within the 20V MAX system in all components—battery, tool and charger—optimizing these three components to provide users the best system in terms of performance and durability,” Smith said.


Wayne Hart, communications manager at Makita, said: “Makita lithium-ion batteries have category-leading charge times, so the battery spends more time working and less time sitting on the charger. A Makita 18V lithium-ion 3.0-Ah battery will reach a full charge in 30 minutes; other 3.0-Ah batteries take up to an hour to reach a full charge. The new Makita 18V LXT lithium-ion 4.0-Ah battery will reach a full charge in only 40 minutes; other batteries take up to an hour and a half.


“The built-in fan on the Makita Rapid Optimum Charger forces air through the battery during the charging process to cool the battery for faster charging. The charger also communicates with the battery’s built-in chip throughout the charging process to optimize battery life by actively controlling current, voltage and temperature, resulting in faster charging and increased efficiency.


“Makita understands the importance of staying within the strongly preferred 18V lithium-ion platform and developed the 18V X2 rotary hammer powered by two 18V batteries for 36V power and run time. Since the release of this rotary hammer, we’ve delivered additional 18V X2 tools, including a cordless 7 ¼-inch circular saw, which delivers 36V power without leaving the 18V platform.


“The Makita 18V series is the world’s largest 18V cordless tool line powered by an 18V lithium-ion, slide-style battery,” he said. 


The combination of fast-charging 18V lithium-ion battery efficiency of brushless motors has resulted in new innovation and increased productivity. Hart gave the example of Makita’s 18V LXT lithium-ion, brushless 1-inch rotary hammer. The efficient brushless motor combined with the 18V lithium-ion battery allowed engineers to include a built-on HEPA vacuum with HEPA filtration system for improved dust containment. Even with the 18V battery powering both the rotary hammer and the vacuum, the brushless LXRH011 has up to 50 percent longer run time on a single charge than the nonbrushless 18V lithium-ion rotary hammer. Hart said it is the industry’s first 1-inch capacity, 18V cordless rotary hammer and also the first 18V brushless rotary hammer with a built-on vacuum attachment.


“With 80-plus tools powered by the fast-charging 18V battery and with the added convenience of using two 18V batteries on select 18V X2 tools, contractors get more solutions, unmatched breadth of line, a faster charging battery, and maximum convenience and efficiency,” Hart said.


Paul Fry, vice president of product marketing at Milwaukee Tool, said: “Lithium-ion has caused a fundamental shift in cordless tool technology. It is similar to the type of change users have seen in technology like flat-screen versus tube televisions. It is a massive change in form, features and function. Lithium-ion technology provides the opportunity for power tool manufacturers to create innovative new solutions and set new standards of performance and durability for electricians.


“Lithium-ion, along with advancements in motor technology and electronics, has allowed manufacturers to pack a massive amount of power and performance into a compact structure. Tools are getting smaller and lighter, and at the same time outperforming their predecessors.


“Lithium-ion batteries are not created equal. Milwaukee Tool has been leading the charge in advancements in lithium technology since it brought the technology to the power tool market. Milwaukee’s RedLithium battery technology provides up to two times more run time, 20 percent more power, and 50 percent more recharges than standard lithium products. This new technology will also operate in temperatures as low as 0°F/–18°C and will run 20 percent cooler with fade-free power and no memory effect. Milwaukee also offers industry- 
leading electronic features that optimize the performance of every tool and protect the user’s investment in abusive situations. Without these protections in place, a lithium-ion battery can be destroyed in as little as one use.


“These features allow us to broaden the possibilities in terms of the types of tools that can be viable cordless options. Lithium-ion will continue to drive the development of innovative products that redefine end-user productivity, and will continue to raise industry standards for cordless performance and reliability,” Fry said.


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In 2005, the Tool Trends report focused on Milwaukee Tool’s introduction of lithium-ion batteries to the cordless power tool market.


Observing that the development of battery-powered tools was one of the most significant technological advances in hand tools, the late Dennis Rhees, then national product specialist at Graybar, called Milwaukee Tool’s line of 28-volt (V) lithium-ion tools a cordless breakthrough.


“Lightweight lithium-ion battery technology increases productivity with more power and twice the run time of 18V battery-operated tools,” Rhees said. “It is the most important innovation in tool technology this year. 
Lithium-ion batteries provide maximum performance during the entire battery charge without the gradual decrease in power typical with nickel-cadmium [NiCd] batteries.”


Just a year later, Tool Trends reported entry by Bosch Power Tools, DeWalt, Makita and other major toolmakers into the lithium-ion tool market.


In addition to much lighter weight, longer run time at full power and quick charge times, lithium-ion power has brought significant changes in the tools they power with the introduction of cordless tools that previously had been available only in corded models (e.g., cordless band saws). In addition, tools, such as crimpers, are available with battery-­assist models, testers and job-site accessories, including lighting, wet-dry vacuums, radios and more.


The selection of lithium-ion tools and products for construction quickly multiplied, and manufacturers placed priority attention on improving the batteries that powered these tools.


About the Author

Jeff Griffin

Freelance Writer

Jeff Griffin, a construction and tools writer from Oklahoma City, can be reached at up-front@cox.net.

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