Once upon a time, power tools came with a cord and life was good. Then came cordless, and life got better. Today, as more manufacturers adopt and perfect lithium-ion battery technology, tool users can be downright giddy at the prospects.
The lithium-ion battery is perhaps the biggest development in cordless tools since, well, the cordless tool. It certainly is the most significant in the last 15 years, says Mike Sherriff, a senior product manager for professional cordless tools at Anderson, S.C.–based TTI North America, manufacturer of the RIDGID brand of power tools. And tool makers say the development of the technology has resulted in ancillary benefits that end users are sure to notice.
“It has the ability to deliver more voltage in a smaller package,” says Shane Moll, vice president of marketing for tools and equipment at Milwaukee Electric Tool Co. in Brookfield, Wis.
“The Li-ion technology uses a special molecule structure that allows current to flow three-dimensionally, instead of through two-dimensional layers in the cell,” Milwaukee's literature explains. This results in the ability to run power-hungry tools, such as a hammer-drill or a circular saw, the company says.
But lithium does not mean more power in the general sense. It offers a more efficient use of power, which results in a tool that is lighter in weight and runs longer between charges. “Lithium-ion provides an ergonomic benefit as the batteries offer a better power-to-weight ratio compared to other battery technologies,” Baltimore-based DeWalt Industrial Tool Co. says on its Web site.
For example, in order to increase the power of a tool using, say, a nickel-cadmium (NiCad) battery—which was the dominant player until now—the battery had to get bigger and the tool got heavier. Lithium-ion batteries do not have such limitations.
What lithium does mean, however, is more money. Some manufacturers say a lithium-ion tool will cost about twice as much as a comparable NiCad or a nickel-metal hydride (Ni-MH) tool, while others say the increase is not that significant. “In the retail environment, there is a minor cost increase,” says Moll, “but that is slowly going away. You are seeing a lot of the price points come down.”