Many 14.4 - volt drill/drivers pack all the power you need for a wide variety of chores. And higher-voltage drills can cost little more than less capable, lower-voltage models.

Battery packs with higher voltage and capacity allow today's cordless models to run longer and more powerfully per charge. The best can outperform corded drills and handle decks and other big jobs with minimum battery recharging.

While similar to conventional drill/drivers, Impact Drivers emphasize added tightening and loosening power, courtesy of a spinning internal hammer that strikes an anvil attached to the chuck to boost twisting force. Besides being lighter and smaller (most use 12- or 14.4- volt batteries), impact drivers don't twist in your hands under load. But they tend to be slower at drilling and require special drill bits for that task.