If you could have just one tool . . . choose the drill/driver

If you can afford only one power tool, it should be a battery-operated drill/driver. It is a good tool to have around whether you live in an apartment or a house, whether you are a do-it-yourselfer or prefer to have someone do it for you. You'll want a drill/driver that is easy to use right out of the box, will not tax your hand or arm muscles, and can recharge quickly. • Here's a caveat: Don't use a drill/driver for jobs for which old-fashioned, handheld equipment will do. There is always a good chance that you can damage the screw head by using too much power. • The chief advantage of a drill/driver in a lot of smaller jobs is the drill part, since being able to drill a pilot hole for a screw quickly and accurately is a plus, especially if you don't want to crack or damage wood.

Need to know

The power of the battery. Look for drill/drivers with batteries of 12, 14.4, 18, or 24 volts, which are appropriate for typical jobs around the house. But be sure you can handle the tool you buy; the greater the battery power, the heavier a drill/driver tends to be. Lift a few drills in the store; hold them up for a while. You'll want to be able to use the tool for prolonged periods without muscle strain.

Be sure to ask: Does the drill/driver have a keyless chuck? The chuck is the hole in which you put a drill bit, which then can be tightened or loosened. In the old days, a drill chuck had three holes; a key was used to loosen or tighten the chuck for drill-bit replacement. Today, what you want is a keyless chuck that allows you to change a drill bit with one hand, freeing the other to hold something else, such as a sheet of drywall.

Most jobs require a drill/driver that can hold bits up to ⅜ inch, but to be on the safe side, a chuck that can handle bits up to ½ inch is better. Such chucks are typically found in tools with higher voltages and are, therefore, more expensive.

Speed limit: Buy a drill/driver with two speed ranges. The lower speed will give you more power to turn screws; the higher speed will provide the power needed for drilling.

Don't do this: Don't buy a cordless drill for a big job that requires more power than a battery can provide. A 12-volt battery drill won't put holes in a concrete basement floor, for instance; you will need a drill you can plug into an electrical outlet.

Batteries: This is not the place to discuss the differences among NiCad (nickel cadmium), NiMH (nickel metal hydride) and lithium ion batteries. The problem with power tools is that batteries are not interchangeable among manufacturers, so if you have a DeWalt cordless drill/driver and a Ryobi, one battery doesn't fit the other. When the manufacturer switches from one type of battery to another, the old batteries often do not fit the new tool.

The one piece of advice I will give you is that if you are a serious do-it-yourselfer, make sure you have two batteries for each tool, with one always charging.

What it will cost: Depending on battery power and other features, a drill/driver can cost $50 to $400. If you are a do-it-yourselfer, something between $90 and $200 will likely meet your needs.