Understanding Cordless Tools
More and more, cordless tools are becoming everyday fixtures in the woodworking shop. The most common of these is the drill, which you can see broken down to the right. Most cordless power tools have the same basic components, though, so once you understand how one tool works, you’ll be well on your way to understanding them all.
Volts vs Amp-Hours
The two numbers that appear on the sides of most tool batteries are volts (V) and amp-hours (Ah). So what’s the difference? If we were to use a car as an analogy, volts would be how much horsepower/torque your engine has, while amp-hours would be the size of the gas tank. (Before any battery engineers write us letters explaining how inaccurate that is, remember we’re a woodworking magazine, not a scientific publication.)
When comparing the different levels of voltage, it’s important to remember that this reflects the peak available power, not the amount of power a tool is constantly using. That’s why you don’t see any normal drills with 40V batteries—all that power just adds unnecessary weight to the tool. It’s also
