By Thomas A. Westerkamp
Equipment Rental & Tools Article Use Policy
Power tools have long been the workhorses of maintenance and engineering departments in institutional and commercial facilities. Recent advances in batteries, cordless technology and horsepower have made them even more valuable.
Beyond these advances, essential power tools, including drill/drivers, wrenches and saws, have made strides in recent years related to equally important features and functions such as ergonomics and safety.
By staying up to speed on changes in these areas, managers can make smarter specification decisions that deliver improved safety, productivity, and long-term performance to technicians and projects.Eye on batteriesLithium ion batteries have gained rapidly in market share due to their high power-to-weight ratio, long performance life, and ability to take a partial charge without capacity loss. The 3.6 volt cells are combined to yield battery packs rated up to 36 volts and 500 watts — nearly two-thirds horsepower — to perform a range of drilling, driving, nailing, grinding, and cutting tasks.
Nickel cadmium batteries perform well in low temperatures and are rugged, but cadmium has negative environmental effects. Nickel metal hydride batteries perform well if tool users fully discharge them every month and follow other recommended periodic maintenance.
Since introduction of lithium ion batteries, nickel cadmium and nickel metal hydride batteries have remained popular for lighter-duty tasks because of their relatively low cost, but they have higher self-discharge rates when stored and are heavier, resulting in lower watt-hours per kilogram (watt-hour/kg).
Newer to the lithium ion family is the lithium ion polymer (LiPo) battery. It is used in electric bicycles, scooters, cell phones, and computers, and power tool manufacturers are now advertising it for tool applications. Like lithium ion batteries, LiPo batteries come in several formulations and formats.
One LiPo cell has a liquid electrolyte in a pouch format-type polymer laminate case that is 20 percent lighter than the rigid cylindrical lithium ion case. In addition to being one of the densest watt-hour/kg choices, it has one of the lowest self-discharge rates — 5 percent — in storage.
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Product Focus: Power Tools