"If I could own just one cordless drill/driver," says the author, "it would be a full-size 18-volt lithium-ion model." A Bosch DDH 181-01 is pictured above, and there are many other choices within the class, including lighter-weight compact models.
Full-size 18-volt drill/drivers can be significantly bigger and more powerful than their compact 18-volt counterparts. For instance, DeWalt recommends using auger bits up to 1-1/4 inches and hole saws up to 4 inches in diameter with its premium 20V Max (right), but the numbers drop to 7/8 inches and 2 inches, respectively, for its compact 20V Max (left). That’s why most compacts don't have side handles.
To size up the balance between maximum torque and overload protection, the author drove four 1/2-inch by 8-inch Spax lags as deep as possible into a PSL beam with each tool, then compared the average depth of penetration.
The author tested for runtime by counting the number of holes each tool could drill through 2-by Douglas fir per charge in low gear with a 1-inch Irwin Speedbor solid-center auger bit. All of the drills averaged over 100 holes per charge.
Three-speed trannies. The DeWalt, Hilti, and Makita (left to right) have a three-speed — rather than the usual two-speed — transmission. Makita’s extra gear adds a second low-speed option for drilling big holes and other high-torque applications, while DeWalt’s and Hilti’s add a second high-speed option for less demanding applications like small-diameter drilling in metal.
Drill/drive switches. The Makita (shown), DeWalt, Festool, and Milwaukee allow you to switch between drilling and driving without losing your clutch setting.
Festool attachments. The complete Festool kit includes FastFix offset and rightangle attachments for working in tight quarters.
Headlights. All the tools except the Hilti have LED headlights, all of which illuminate the point of a standard spade bit with no shadows. From left: Bosch's trigger-activated light is in the base so the chuck won't cast a shadow on your target when you’re using short bits. Panasonic's basemounted light turns on and off with a push button and shuts itself off after the tool idles for five minutes. Hitachi's push-button amber light is built into the belt hook and requires separate batteries. It automatically shuts off in 15 minutes. Makita's topmounted, switch-activated light stays on for about 10 seconds after you release the trigger.
Battery gauges. Bosch, Festool, Hilti, Metabo, and Milwaukee have onboard battery gauges so they won’t quit right after you crawl into an attic. Festool’s gauge is located on the back of the tool, while the rest are located on the batteries so you can check their charge on or off the tool.
Chargers. All nine battery chargers are diagnostic, but some are faster and more sophisticated than others. Makita’s fancooled 30-minute charger indicates an 80 percent charge so you can finish a job without waiting unnecessarily, and you can select a beep or a ring tone that announces a full charge. A spring-loaded plastic cover protects the terminals.
Belt hooks. Only the Festool, Hitachi (left), and Makita (right) come with belt hooks; DeWalt and Milwaukee sell them separately.
Contractor bag. Hilti's kit includes either a plastic case or an optional contractor bag. The bag is roomy enough to store plenty of big drill bits and other tools, and it can hold the drill/driver with the side handle attached so you don't have to keep installing and removing it. You also don't have to waste time tucking in the charger cord, as you do with most plastic cases.