New battery technology a boon for cordless tools

Don your Tim Allen “tool guy” persona and imagine a cordless tool that lasts up to twice as long between charges and has the power of corded tools. How about a cordless tool that performs like a corded and has consistent, fade-free power throughout the discharge cycle, ensuring the last hole or cut is as powerful as the first?

That would be worthy of a primal whoo-oo-oo.

A power tool manufacturer has made that a reality.

After nearly a decade of research and development, Milwaukee Electric Tool Corporation recently unveiled a breakthrough technology that allowed it to introduce 28-volt versions of many of its products. The V28 system is based on a lithium-ion (Li-ion) battery developed by Milwaukee. Gary Meyer, the company’s manager of research and development, has been with the nine-year project since its inception and believes this approach to battery technology will cut the cord on many more tools in the future.

“About the only thing the new lithium-ion technology has in common with the old nickel-cadmium (NiCd) or nickel-metal hydride (NiMH) technology is that they are used to power cordless tools,” he says.

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. The results are large increases in power and run time and the ability to run power-hungry tools, such as a hammer-drill, reciprocating saw, circular saw, impact wrench and band saw. These tools can now run at faster speeds, with more power and for a longer time between charges.

“This technology can be adapted to many applications that were once untouchable by cordless tool power,” says Meyer.

During performance tests of cordless tools powered by the V28 Li-ion cell and standard 18-volt NiCd and NiMH cells, the benefits were clear.

Weight: While the new system provides heavy-duty power, “heavy” isn’t a major tool concern. The weight of a 3.0 amp-hour, 28-volt Li-ion battery is slightly less than a conventional 18-volt NiCd battery pack.

Run time: Take your average run time found with NiCd-powered tools and just about double it to see the Li-ion difference. In many applications, one battery charge per day is all that’s required.

Fade-free power: Instead of the gradual but noticeable power decline you expect as a NiCd or NiMH battery pack discharges, the lithium-ion cells maintain consistent power. Power doesn’t drop off drastically until the last hole or cut.

Battery fuel gauge: V28 offers a neat feature here. With its on-board fuel gauge, you don’t have to guess how much power is left in the battery. Before you climb a ladder to the top of a machine or get down into a tight space, you can check to be sure you’ll have the battery power to finish the job.

Corded tool power: The higher 3.0 amp-hour output and 28 volts of muscle mean you can use V28-powered tools that in the past were only available as corded. For example, the newly formatted hammer-drill puts out 600 inch-pounds of torque, and the circular saw cuts at 4,200 rpm, which is much closer to corded saw speeds than the 3,200 rpm found on NiCd models.

Charging: NiCd cells are finicky when hot, and, as a result, the NiCd charger waits for them to cool down. Once charged, they should cool before going back to work. This can add up to an extra hour for charging. The V28 charger, however, is a true one-hour charger. The battery pack begins to charge as soon as it is on the charger and, in an hour, is ready to go to work again.

The 28-volt Li-ion battery pack runs more efficiently than a traditional 18-volt pack, which helps prevent heat buildup during tool use. Often, this means the battery can begin charging immediately. Plus, the cells don’t heat up during charging and are ready to go right after the full charge light comes on.

Use life: Testing proved that the V28 battery packs can do up to twice the amount of work per charge as an 18-volt, 2.4 amp-hour NiCd battery pack. And, they can be charged an equal or greater number of times as a NiCd pack. Milwaukee estimates its battery will provide up to 2.5 times the amount of work over the life of the battery when compared with conventional NiCd.

Environmental plus: The composition of the lithium-ion battery contains no cadmium, making it more eco-friendly than other high-powered, rechargeable batteries currently used in power tools and, therefore, does not have to be recycled in many states.

Cold weather performance: Cordless tool users in cold climates know that NiCd and NiMH packs hate a chill and lose a substantial percentage of their charge in sub-freezing temperatures. The Performance Optimizing Circuit on the V28 monitors battery temperature, output and tool demand and makes adjustments so you can get full capacity even in very cold temperatures.

To learn more about the new battery technology, visit www.v28power.com.