Page 58 - October 2015 Green Builder Magazine

INNOVATION UPDATE By Tim Truesdale

Breakthroughs in Sustainable Technology

56

Power Tool Batteries: A Technology Story

Lithium-ion batteries are the go-to power source for power tools, and wireless
charging is making battery-operated power tools even more efficient.

BATTERY POWER COULD
be thought of as the most
important yet least considered
element of power tool
operation. Great battery
power, runtime and longevity
are expected. But a lot of technology and
brainpower goes into the ongoing march
toward greater productivity. Here’s what
the landscape looks like today.

www.greenbuildermedia.com 10.2015 THE ADVANTAGES OF Superior Technology. Lighter weight combined with compact size, more power and
ROBERT BOSCH TOOL CORP.LITHIUM-ION TECHNOLOGY increased runtime make lithium-ion tools the workhorses of cordless technology.

Lithium-ion batteries make ultra-compact their lives. Only by engineering the battery application, resulting in less heat and
and heavy-duty tools the norm, not and its cells to resist these conditions are extended battery life.
an exception. And the three inherent manufacturers able to bring a lithium-
benefits—more power, runtime increase ion battery with acceptable life to the 2. Electronic Cell Protection (ECP)
and no weight penalty—are the basic professional market and not cost end located within the tool can manage
building blocks behind the technology. users significant investment and continual the battery’s activity to eliminate
battery replacement. overheating and extend battery life. Not
Lithium-ion cells can either hold more all manufacturers’ tool-based electronics
power in the same-size package (as tools There are three design steps that protect offer ECP, which is key to the long-term
change) or maintain the same power in and extend a lithium-ion battery’s battery battery life in professional applications.
a smaller package. The reason can be life, especially in heavy-duty applications: Other makers include their electronics
found at the basic chemistry level: A within the battery, which generates extra
single lithium-ion cell can hold and use 1. Higher-voltage batteries, such as heat and defeats the goal of ECP.
up to 3.6 volts, but weighs less than its 36 volts, reduce the overall strain on the
predecessor NiCad cell. As a result, a 36- individual lithium-ion cells and enable 3. The power tool industry’s best
volt lithium-ion battery offers twice the them to last longer. A larger battery batteries are made to stay cooler at all
voltage capacity of previous technologies, doesn’t need to work as hard as an 18- voltage levels. Battery housings should
even as it weighs about the same. volt battery in the same heavy-duty conduct heat away from battery core. For

Any increase in voltage will increase
runtime; consequently, users inherently
benefit with a runtime increase along with
the power advantages of increased voltage.

THE BATTERY LIFE CHALLENGE

How a manufacturer preserves its battery
products’ battery lives is important.
Similar to any engine or machinery,
extensive heat resulting from high
amp-draw applications can cause damage
to battery cells and drastically shorten