Battery technology in the power tool world

In October 2005, Makita launched the market's first 18-volt lithium-ion cordless tool series, the LXT.

Battery technology in the power tool world
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Brad Wheeler, senior product marketing manager, Makita Cordless ToolsEducation is key to generating buyers of new technology
In October 2005, Makita launched the market's first 18-volt lithium-ion cordless tool series, the LXT. It offered more power, 40 percent less weight, better ergonomics and 2 to 3 times more cycle life than existing battery technology. Since then, Makita has brought 35 models to the market.
Lithium-ion will definitely enable engineers to offer a cordless option to tools previously available only with cords. The compact size of lithium technology also enables engineers to bring more comfort and control to the professional user by creating true ergonomic tools. Traditionally, some NiCad cells had to extend up into the tool's handle, keeping designers from making a grip that was truly contoured for a human hand. The best lithium-ion technology charging systems control temperature, voltage and current simultaneously, allowing leading manufacturers to offer fast charging systems that do not compromise battery life like the fast chargers of old. We are talking significantly faster charging for higher capacity batteries — try 25 minutes for a 3.0Ah lithium-ion battery!
Of course, innovations in motor design are also important, as they complement the more compact and lightweight improvements in battery technology. Creating smaller, more powerful 4-pole motors for the core set of tools in the driver-drill category was critical in marrying the best battery technology with solid power tool design. The result is more power, more work, lighter weight — equaling some 12-volt models — and compact size at a higher voltage (18-volt). The driver-drill and impact driver are hanging off the tool belt every day, so bringing the benefits of the latest lightweight motor and battery design was essential to reach the professional user.
An open, growing market
Lithium-ion power tools offer tremendous opportunities for additional sales, today and in the future. These tools are barely a year old, in terms of broad distribution, so most lithium-ion tools are priced at a premium due to the increased benefits over older battery technologies. Converting customers invested in NiMH/NiCad platforms is the sales opportunity. Not everyone is going to budge right away, but they will when they start to feel and understand the significant differences in power, comfort and run time. And, prices will start to fall as more brands start entering the lithium-ion power tool market. Selling up is often the hardest thing to do because there are so many manufacturers offering special deals. The best opportunity for distributors is to demand that the latest tools be prominently merchandised, so that their customers better understand what they are missing without the latest technologies.
As with any new technology, the older technology will lower in price a bit, keeping those tools around for a little longer than one might expect. There are many folks that don't yet know about the benefits of lithium-ion or don't want to abandon their current set of cordless tools. Converting these users will take time and education which should be a joint effort between the marketing teams of manufacturers and distributors to increase ad space and educational merchandising for lithium-ion tools. By default, there will be many professionals content to get a deal on old-school technology rather than step up into lithium-ion technology. They are not necessarily the target customer for the latest introduction of lithium-ion tools, but any user with NiCad/NiMH tools is an opportunity for a distributor to increase sales. It is essential for manufacturers and distributors to get in the field and get users onboard with this new technology to increase demand at the distributor and retailer level.
Mike Seaman, marketing director for Milwaukee Electric ToolGetting more from existing tools
As distributors cite end-user demand and manufacturer reputation as the top drivers behind the product lines they carry, Milwaukee has proven itsdedication to developing the high-quality, innovative products that are able to meet changing end-user requirements. After introducing the lithium-ion category for cordless power tools in 2005,we've seen the market quickly accept the performance capabilities of this new technology and ask for even more. This year we've combined power, run time and compatibility to introduce an 18-volt lithium-ion platform that offers interchangeability with older NiCad tools. The aspect of changing between battery systems creates a whole new world in battery technologies. The new V18 line is an example of how lithium-ion offers more than just run time and higher voltages; it now offers a way for end users to get more from their existingline of tools.
The best of both worlds
Interchangeable tools and batteries create opportunities for distributors to reach those seeking the latest technology without leaving NiCad customers behind. We expect the NiCad platform to be a viable category for several years — for price point considerations alone — and will continue to introduce tools compatible with all types of customer needs. To take advantage of the quickly-changing cordless market, in which lithium-ion tools will outsell NiCad tools within the next few years, distributors can provide real-world application and demo areas for these tools in their stores. Any new type of technology can take awhile to catch on, but lithium-ion is rapidly proving itself in the marketplace and demand will continue to increase as more end users become aware of its productivity benefits.
Doug Bock, group sales manager, PanasonicMarket may segment by price point and chemistry
The most meaningful advance in battery-operated power tool technology in recent years has been the introduction of lithium-ion batteries. Lithium-ion (Li-ion) offers several advances over the current battery chemistries of NiCad and NiMH.
The most significant is a reduction in weight. A tool utilizing lithium-ion batteries will typically weigh 25 percent less than the same tool using NiCad or NiMH batteries.
Another advance of lithium-ion is more capacity which delivers more run time per charge. The highest capacity lithium-ion battery currently is 3.0 Ah. This represents a 25 percent increase versus the highest capacity NiCad available at 2.4 Ah. However, NiMH batteries offer a 3.5Ah capacity which means lithium-ion batteries will not necessarily deliver more run time than the highest capacity NiMH battery. Lithium-ion batteries have a more stable power delivery curve over the life of the charge than current battery chemistries, too. This means the power delivery will not deteriorate as the battery runs down, which is what typically happens with other batteries. And, Li-ion batteries will deliver more total performance over the life of the battery pack than current batteries.
At Panasonic we have found, through testing, that our lithium-ion batteries deliver at least twice the total lifetime performance versus our NiCad and NiMH batteries.
Slimming down
Yet, the most significant benefit of lithium-ion technology is a reduction in weight. It appears there are two schools of thought on how to utilize this new technology. The first group is utilizing the reduction in weight to build higher voltage tools (24-, 28-, 36-volt, for example) designed to deliver corded tool performance without the cord. With lithium- ion you can build higher voltage with less weight than in the past. The higher voltage tools are most practical for two-handed tools like a rotary hammer, recip saw or circular saw. However, they are less practical for the one-handed tools like a drill-driver, hammer drill and impact driver where the weight typically cannot exceed 6 pounds if the user is to work comfortably all day.
The second group is using the reduction in weight offered by lithium-ion to build tools in the traditional voltages (14.4- and 18-volt) that are more compact and lightweight than current models. At Panasonic we have always focused on building compact and lightweight tools. We are building 14.4-volt lithium-ion tools that weigh just a shade over 3 pounds but deliver 18-volt power and performance.
Keep in mind, the developments in battery technology will drive innovation in other components, too. With the ability to build higher voltage tools, you now need the development of higher voltage motors. With longer run time you now need motors that run longer and stay cooler and are more durable. This is also happening. Several manufacturers have introduced new motors along with the lithium-ion technology. Our new Li-ion impact driver, for example, uses a brushless motor that delivers twice the life of a brush motor.
You are also seeing the next generation of battery chargers that are designed to handle a wide range of voltages, from 7.2 to 24 volts, and several battery chemistries (NiCad, NiMH, Li-ion).
They feel right
Another area of continuous advances is ergonomics. The manufacturers today are using a variety of different materials to improve the grip, and the feel of the tool in the hand. In addition we are seeing the use of LED work lights on tools, and belt clips built onto tools. All these incremental developments are making the tools more practical and convenient to use.
What do all these developments mean for the distributor? Plenty. The tools today offer a terrific value to the end user in terms of the performance they get for the price they pay. It also gives the distributor the ability to better merchandise the cordless category. I believe as the market moves forward we will see it segment by price point and battery chemistry. Let's take the approach of offering good, better and best in each category. Good product with opening price points will continue to be current NiCad tools. Better product with mid-range price points will be NiMH tools. Best product with high-end price points will be Li-ion. If the end user wants reliable value, the current NiCad is a good bet. If the end user wants long run time the current NiMH is the best option. If the end user wants light weight or corded performance in a cordless, then Li-ion is the choice. As always qualifying the end user to identify their application and what tool works best for their budget will be a key element in making a sale.
Edwin Bender, group product manager, LITHEON cordless power tools, BoschLithium-ion is more than headlines
Lithium-ion is stealing headlines. It is the newest cordless battery technology and manufacturers, such as Bosch Power Tools and Accessories, believe it will eventually replace NiCad. For distributors, the new technology can seem complicated and daunting as NiCad comprises the majority of sales today. But for those who wish to stay on the leading edge of cordless technology, lithium-ion means long-awaited innovation and growth opportunities in areas never before possible.
When it comes to cordless, professionals continue to demand the same things year after year — more power, more run time, but not a heavier battery. Unfortunately, 18-volt is the pinnacle of power and run time at an acceptable weight for NiCad. But with lithium-ion technology, manufacturers can accomplish two things that change how we perceive battery technology:
Pack more power in the same size/weight battery pack, orFit the same power into a smaller battery pack.
While many different voltage platforms came to market in the past year following only one of these strategic design paths, Bosch Power Tools and Accessories took advantage of each by offering technology at both ends of the voltage spectrum with the Litheon 36-volt Flexible Power System (FPS) and 10.8-volt Ultra-compact System.
The FPS offers the option of two different task-specific 36-volt battery packs. The 36-volt SlimPack weighs the same as a 14.4-volt NiCad, but delivers twice the voltage and 15 percent more run time than an 18-volt NiCad. Its lightweight design makes it perfect for one-handed and overhead applications with a drill-driver or hammer drill-driver and maximum power to run circular and reciprocating saws. And the 36-volt FatPack delivers twice the voltage, run time and the same weight of an 18-volt NiCad for those looking to tackle harder applications or extended usage projects, such as 45-degree bevel cuts or ripping plywood with a cordless circular saw or series drilling into concrete with a cordless rotary hammer. The FPS allows users to customize their 36-volt tool to the application based on weight and runtime, an option previously unavailable through NiCad.
Opening new tool opportunities
At the lower 10.8-volt end of the lithium-ion voltage spectrum, a completely new power tool category was born. Bosch developed 10.8-volt tools around the concept of "big power, small package." Put simply, these 10.8-volt tools have the power and capability to accomplish the majority of the daily work normally associated with larger high-voltage NiCad tools, but the system defies all previous compact design standards at a fraction of the size and weight. The first of these tools, the Pocket Driver and I-Driver, capable of driving 100 3-inch screws on a single charge and designed to complement larger drill-drivers, are an innovative new ultra-compact category and sales growth opportunity only made possible through lithium-ion technology.
While achieving more power and run time without additional weight is inherent to lithium-ion and conceivable for really any manufacturer applying the technology correctly, battery cycle-life, the number of times a battery can be charged and discharged before needing replacement, is the final essential part to any cordless battery technology. And while lithium-ion may be new, it is vital that cycle-life meet or exceed current NiCad standards. Specific design features, such as our Electronic Cell Protection, which specifically manages energy flow to prevent overheating of cells; designing to the highest voltage for the toughest applications (36-volt); additional cooling fins; vents and special heat conducting housings are the extra steps a manufacturer should take to ensure lithium-ion technology delivers the greatest return on investment for your customers.
As for tool development, in addition to the new ultra-compact category, corded tool replacements are another growth opportunity for distributors, and only lithium-ion makes it possible at an acceptable weight. An example includes the capability to offer a 36-volt a 1-inch cordless rotary hammer that drills faster and hits harder than most corded competitors. Furthermore, a 36-volt circular saw has more than enough power and run time to give corded tools a run for their money. And there will be more to come. New tools, whether 36-volt heavy-duty, or 10.8-volt ultra-compact, are new growth opportunities in cordless that were not possible with NiCad.
Overall, the industry is poised for growth. Most professionals are still heavily invested in NiCad to run their business, because it is a reliable and proven solution. But, as lithium-ion technology further develops and matures, manufacturers are confident that professionals will be captivated by the power, run time and weight benefits inherent in the technology. Meanwhile, professionals now have a choice at all ends of the voltage spectrum; a proven 18-volt NiCad solution for standard applications and a quickly growing and expanding lithium-ion solution making smaller tasks more efficient at the lower voltage end (10.8 volts) and heavy-duty tasks possible with cordless technology at the higher end (36 volts).
Christine Potter, group product manager, batteries, chargers and technologies, DeWaltFocused on efficiency
There have been many developments in cordless technology during the past years with lithium-ion, the most recent trend to take hold of the industry. We are laser-focused on developing innovative solutions that provide increased productivity and efficiency on the jobsite, and would not settle for a technology that did not meet professional user needs. To create the battery technology for the 36-volt platform, DeWalt partnered with A123Systems, a developer of a new generation of lithium-ion batteries that incorporate nanoscale technology developed at, and exclusively licensed from, Massachusetts Institute of Technology (MIT).
Despite some claims, the primary advantage of lithium-ion batteries is that they are smaller in size and weigh less than nickel cadmium (NiCad) and nickel-metal hydride (NiMH) batteries. It is important to understand that lithium-ion is not power, which is determined by voltage; it is not run time, which is determined by amp-hour rating; and it is not torque or speed, which is determined by the tool design.
Geared toward performance
The 36-volt platform was designed to provide professional contractors with the performance of a corded tool without the restriction of a power cord. During the research and development stage we conducted extensive field research to establish exactly how professional contractors use corded tools on the job. Sensors were attached to the tools to digitally record information. This information was collected electronically with data logger technology, which is a unique testing system developed and exclusively used by DeWalt, to determine the most effective high-voltage solution. As a result of this research, we determined 36 volts was the cordless platform with the capabilities that best matched or exceeded the performance of corded tools. The ergonomic benefit of lithium-ion provides a power-to-weight benefit, which allows users to utilize cordless tools for corded applications, and provides distributors opportunities for additional sales of cordless tools.
Where do older models fit in?
All types of batteries have different benefits, and depending on the product and application, a different type of battery might suit the needs better than another. There is still a huge market for NiCd and NiMH. These battery technologies are going to be relevant as they provide the necessary amount of power and run time for most end users. There is a very large base of professional contractors out there have bought into NiCad tool platforms and trust its history of durability. NiCad-based sales are still growing and this technology continues to meet the user needs extremely well.
When a customer is looking for cordless tools, the best way for a distributor to promote the products is to provide the customer with information to help him/her select the best tool for their needs. For example, determine what type of tools are needed; do they only need a drill or would a four-tool combo kit be better? If the customer only needs a drill, a 14.4-volt offers a good balance of power and ergonomics. If cordless saws are desired, recommend 18- or 36-volt models — the harder the tasks the higher voltage. Also, let them know about the new features built into some of the new tools, not just the battery technology. For instance, drills with new self-tightening chucks, three-speed transmissions, better ergonomics providing balance and comfort and tool-less accessory changing.
What's next?
Over the past 15 years, almost all of the cordless growth has come from converting applications previously only possible with cords. Additionally, there have always been ongoing efforts to improve existing categories with performance, ergonomic and feature enhancements.
To take advantage of what's available today, consider selling a tool and not a battery. In the case of a 36-volt system, we didn't simply slap a new battery on an old tool. Instead we developed the tools from the ground up to accommodate this new level of cordless power. Customers should be aware of the value of buying into a system and consider all future purchases down the road that will allow them to expand on what they already have. Standardization can help to save time and money in the long run.
Terry Tuerk, product manager for Metabo CorporationHigh performance and environmentally friendly, too
We feel that by far the biggest advancement made in recent years concerning battery technology for power tools has been the development and employment of lithium-ion batteries.
Motivated in part by the European Environmental Bureau's push to phase out nickel cadmium (NiCad) batteries, the development of an environmentally friendly battery that could out-perform existing batteries became increasingly important, if not an urgent need, for power tool manufacturers.
The lithium-ion battery revolution has increasingly gained momentum because the new batteries are lighter weight, and provide more power in smaller cells than previous battery options. For example, our Li-Power line provides 40 percent more energy and weighs 40 percent less as the same size NiCad battery.
Lithium-ion batteries are currently available with cordless drill drivers, reciprocating saws, circular saws and our cordless rotary hammer. We chose to make these tools available with Li-ion power because they are our newest, most ergonomically designed tools with additional features, and we felt it was important to provide professional users with the best tool and battery combination available.
In addition, we chose our BSZ drill-driver line because the existing NiCad line already featured our air-cooled technology that is required to cool batteries for faster charging and for longer battery life. The lithium-ion batteries are interchangeable with the NiCad batteries in this line for added user convenience.
A safe lithium-ion program
One of the main problems that plagued early lithium-ion battery use was their instability and potential to cause fires or explosions. Through extensive R&D efforts, technology has been created to improve safety, increase performance and greatly extend the battery life. We have seven patents related to our lithium-ion batteries and charging technologies.
Safety features have been included in the multifunctional display on our batteries. The display includes overload warning, temperature monitoring, battery capacity monitoring and a low capacity warning. It also features over-discharge protection, electronic overcharge protection that stops the charging processes when it is complete, and an integrated temperature sensor that monitors each individual cell and shuts the battery down if it is too hot.
As we continue to enhance the safety features and overall usability of our lithium-ion tools, we also plan to make additional tools that will be powered by lithium-ion batteries. We expect continued developments will allow for higher capacity, higher power output batteries — without adding substantial weight. Our tools currently run on 18 volts or less, but we plan to release a lithium-ion powered 24-volt platform in the next six to eight months.
More options
Even though an increasing number of power tools are available with lithium-ion batteries, we do not believe corded tools will ever be completely replaced. A number of tools, such as angle grinders, operate at a high rpm and need the constant, large amounts of power that can only be supplied by corded tools. Running tools in a full production mode, over long periods of time, eliminates the viability of cordless power tools.
We will continue to produce both our corded tools and our NiCad lines because many users have owned and operated them for some time, and are satisfied with their performance. They might not be able to justify the additional cost of lithium-ion batteries or be able to give up the efficiency of corded power tools.
The benefits of lithium-ion powered tools can be easily demonstrated by displaying two models of the same tool, one with a NiCad battery and the other with Li-ion power. The weight difference speaks for itself, and is the greatest reason users choose lithium-ion batteries.
Power tool battery technology will continue to evolve beyond lithium-ion technology. The next step might be tools powered by fuel cells that run on methanol. The fuel cells will replenish the battery continually and will provide even more power than lithium-ion batteries in the same amount of space. Who knows?



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