A look at the past, present and future of cordless tools

Manufacturers are constantly introducing new tools, but most of the time it’s just design and packaging updates rather than technological breakthroughs. And while the evolution of design constantly improves the way tools feel and fit our hands and job sites, what we’re really after is performance. That begins with the power source. And batteries can be confusing.

The sealed lead/acid batteries that started the whole cordless revolution are pretty much a thing of the past now. That’s because they’re so bulky and they run out of power so quickly. You can’t run them all the way down too often or they won’t take a charge as well as they should. And they are a significant groundwater and soil pollution risk.

The most common power tool batteries are still nickel-cadmium. These are tough, relatively impact-resistant, not too bothered by cold if they’re left in the truck overnight - and they’re fairly inexpensive. Many tool manufacturers are still sticking with nickel-cadmium because they have a long shelf life (they’ll accept a lot of recharging) and they deliver a lot of power. But they’re heavy (ask anyone hanging sheetrock on ceilings) and that burst of power doesn’t last too long. Plus, most tool manufacturers have rules about when and how long to charge them. And if you ignore those warnings the number of recharges can drop significantly. They’re also not terribly healthy. According to the U.S. Department of Health and Human Services, cadmium overexposure can be detrimental to our kidneys and bones.

Nickel/metal/hydride power packs deliver power for longer than nickel-cadmium between charges (as long as they’re being used and not just sitting around). They also weigh less, but we pay for that as their cost is significantly higher. Nickel/metal/hydride batteries aren’t as harmful to the environment when they go to the dump. That’s good, because a lot of them end up there as they fail quickly in subzero weather, lose their charge quickly if they’re not used often and have issues with deep discharges.

The game-changer

The new kids on the block are lithium-ion batteries and they are also the most expensive. They are very lightweight, which makes them a great choice for power tools that are used all day. They can also be left on the shelf for long periods of time and still deliver the goods when called upon. They’re cleaner, less vulnerable to deep discharge/recharge cycles and they can be physically shaped to fit the tool (most other batteries have constraints on shape, which is why they all seem to look alike). That last facet is important because the next generation of power tools will have almost invisible battery packs: lightweight and malleable, their shape will be able to flow through the tool, distributing weight and bulk in a way that makes drills and other tools feel lighter because they are far more balanced. Unfortunately, lithium-ion batteries do have a couple of shortfalls. They won’t accept as many recharges as most of the other types of power source. And they don’t handle heat very well. This has been a huge issue recently for the airline industry.

Advances in most other aspects of cordless power tools (beyond the actual battery) will be almost inextricably related to lithium-ion technology. As automobile industry engineers switch their focus from fossil fuels to electric propulsion, on-board power storage is the biggest challenge facing them. The drive in large industrial nations such as the U.S., Japan and Germany to become self-sufficient in energy production is perhaps based more on security issues rather than pure environmental ones. But emerging giants such as India and China are deeply concerned with pollution because it has already become a security issue for those governments. In recent months, there have been violent protests in Shifang and Qidong (a city just north of Shanghai) over environmental issues. The Internet has arrived in rural China and the sins of industrialization are becoming harder to hide.

New possibilities

A worldwide trend toward cleaner power has zoned in on the potential lithium-ion technology. And as these batteries become more stable and less vulnerable to heat buildup and other issues, woodshop workers everywhere are going to reap the rewards. Already we are seeing power tool manufacturers’ ads concentrate on their tools’ light weight or increased torque, better ergonomics and environmental benefits.

Perhaps the biggest shift we’ll see in the immediate future in the cordless tool culture is an expansion of the concept of power sharing. Most manufacturers already offer packages that include three or four tools that share the same battery packs. The trend seems to be fewer battery sizes with more tools to fit them, which definitely benefits woodworkers. Having several different types of tools all using the same interchangeable battery means that the transition from fabrication at the shop to installation at a job site will become easier. Charging tools will perhaps become as ubiquitous as charging our phones. Who knows? Maybe our electric pickup trucks will have universal tool chargers on board.

Having just one type of battery would positively affect the way we set up workstations in the woodshop. Centralized battery banks (instead of the current trend of having half a dozen different chargers cluttering up the bench outlets) could be time and space savers. Plus, it would be nice to be able to borrow a battery from your nearest neighbor and know it’ll fit every tool in your station.

One trend that woodworkers in advanced nations might soon borrow from people in emerging ones is the habit of plugging into small solar chargers. While it’s currently more comfortable for us to plug everything, including cordless chargers, into our vast and reliable power grid, non-governmental organizations around the Third World are daily discovering the wonder of bringing small solar cells to remote villages. These simple devices transform lives by delivering so much more than the miracle of having indoor light after dusk. Solar cells are making it possible for the most remote populations to share information and knowledge through satellite cellphones and the Internet. Without an electric grid, craftsmen in these areas have been limited to traditional hand tools. Now, they can charge lithium-ion batteries using donated active solar panels and enjoy an industrial revolution that is every bit as important as the information one.

That same technology is available here in the U.S. through the RV industry. Recreational vehicle factories and aftermarket customizing businesses sell small solar trickle chargers that pick up the slack if campers use their vehicle’s batteries to power computers and cellphone chargers when the rig isn’t running. Adding a small solar panel to the roof of a woodshop’s installation vehicle and then hooking up a lithium-ion charger for cordless tool batteries is already a viable option.

One trend that is bound to continue in the cordless power tool world is diversity. Visit the big-box websites and do a search for the word “cordless”. In addition to grid-free lawn mowers, trimmers, tillers and leaf blowers, you’ll find cordless screw guns, nail guns, reciprocating saws, impact drivers, circular saws, chainsaws, hammer drills, jigsaws, worklights, grinders, staplers, shears and more. Virtually anything you ever bought with a cord on it is now available without one.

Global manufacturing (that is, the availability of an inexpensive workforce) will probably ensure that cordless power tools continue to be affordable. Global markets (the continually increasing number of buyers) should theoretically contribute to economies of scale and this, too, might keep prices in check. As we move away from burning fossil fuels, the oil that is used to make plastics will hopefully become more abundant and help keep a lid on component prices, too.

Another constant trend in cordless tools is minimalizing. Everything is getting smaller, lighter and easier to carry around. You kids under 50 won’t remember this, but woodworkers used to haul huge radial-arm saws to kitchen installations 30 years ago. (Don’t laugh: we were very proud of the giant-wheeled stands that we built for them.) Now one can buy a cordless miter saw. With the versatility of shape that comes with lithium-ion, and constant increases in power, there is no doubt that cordless tools will continue to diminish in size while they grow in both function and efficiency. 

This article originally appeared in the March 2013 issue.