Cordless Drills & Impact Drivers

Battery type

The type of batteries provided with the drill. All are rechargeable. The more common type is denoted Li-Ion for Lithium-ion. Another common type is denoted NiCd, for its nickel-cadmium components. Lithium-ion batteries tend to deliver more power in a smaller size when compared to nickel-cadmium.

Battery recharge time

How long it takes to completely recharge a battery after it has properly cooled down. Most of the fast chargers have a built-in temperature sensor that delays the charging cycle, when the battery is too hot from recent heavy use, to when the battery has cooled.

Motor

This indicates whether the motor uses brushes or is brushless.

Speed ranges

Many cordless drills have two separate speed ranges, or gear ratios; some newer models have three. The slower speed range peaks at about 400 revolutions per minute (rpm) and provides increased torque (twisting force) for driving large screws. A higher speed range that reaches about 1,500 rpm or more is well suited for rapid drilling. Lower-priced drills usually have a single speed range that tops out at approximately 600 to 800 rpm, compromising both driving and drilling performance.

Maximum RPM

Two and three-speed cordless drills have a maximum speed of about 2000 revolutions per minute (rpm) or more and can easily handle rapid drilling. Many lower-priced, single-speed cordless drills can manage only about 600 to 800 rpm, compromising their performance.

Chuck capacity

Indicates the largest size full-shank tool (twist drill bits on power drills) that a drill's chuck can hold. Common sizes include .375 inch (3/8 inch) typically for general usage, and .5 inch (1/2 inch) for drill intended for heavy duty jobs. Fixed 1/4 inch hex chucks only accepts 1/4 inch screw bits or special drill bits.

Clutch settings

Virtually all cordless drills have settings that can limit maximum torque and so prevent the drill from driving a screw too far into soft wallboard, say, or mangling a screw's head or threads by continuing to turn after the screw is in. The more settings, the more precise the torque control.

Number of batteries included

A second battery lets you keep working while the first recharges, so that your work can continue. Most drills over $100 include two batteries.

Hammer mode

An additional selectable feature that pulses the chuck and drill bit back and forth to assist in drilling through masonry and similar hard materials.

LED work light

A small light, located on the body of the drill, to help in low-light job conditions.

Warranty

The length of the coverage, in years.