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If it’s been awhile since you picked up a cordless drill, you might be accused of having a screw or two loose. The battery-powered borers in CR's most recent ratings can drill holes and drive screws far longer—and with more power—than similar models did just a few years ago.
So whether you need to drive lag bolts into wall studs to mount a flat-screen TV, drill a hole in your front door to hang a holiday wreath, or install a new door lock, most any of the more than 30 models in our current cordless drill ratings will be a big step up from whatever old cordless drill you have in your toolbox or kitchen drawer.
In fact, in the five years since Consumer Reports last tested cordless drills, these power tools, as a class, have come so far that our lab had to upgrade its benchtop testing equipment to put them through their paces. They would have overpowered the dynamometer, or dyno, we've used for decades to measure a drill’s torque and RPM, the factors used to calculate power.
“There's no way we could have performed the tests on the old dyno with this new batch of drills,” says Frank Spinelli, the Consumer Reports engineer who oversees our cordless drill testing program.
That's why, for our latest tests, CR spent $23,000 on a new and larger dyno—one that measures as much torque as the average consumer would ever need. "Once you get to a certain point, the drill is really yanking on your arm," Spinelli says.
Much of the improvement in performance is due to advances in battery technology. “We’ve seen a 7 to 8 percent improvement in energy density in lithium-ion batteries every year over the past decade,” says Simon Mui, a lithium-ion battery expert at the Natural Resources Defense Council. That means a Li-ion battery today might power a drill 50 percent longer than a drill from seven years ago.
The evolution in Li-ion technology also allows cordless drills to “deliver longer run times in a lighter package,” Spinelli says. And now that the charger and motor-speed controller safeguard the Li-ion cells, you no longer have to worry about overcharging or fully draining your batteries.
“Older battery technologies were more finicky in terms of the conditions needed when charging and discharging to get peak performance and battery life,” Mui says.
A handful of drills in our ratings are still powered by nickel-cadmium batteries (the previous standard), but they tend to be lower-end models—and near the bottom of our ratings.
Many of today’s cordless drills also benefit from a motor makeover. Not long ago, brushless motors were reserved for contractor-oriented brands such as DeWalt, Makita, and Milwaukee, but now they’re available on modestly priced consumer drills from the likes of Kobalt, Porter Cable, and Ridgid.
Brushed motors run flat-out regardless of whether you’re drilling into a softwood, like pine, or a hardwood, like oak. Sometimes that's overkill, and it will drain the battery unnecessarily.
Brushless motors, on the other hand, operate with reduced friction, allowing them to spin faster and work more efficiently. They adjust to the level of resistance they encounter when drilling or driving, draining the battery more judiciously than motors with brushes. They also have fewer moving parts, and because they have no brushes, you never need to think about replacing them.
Testing the Limits
The bulk of CR’s testing for drills is conducted on a dynamometer, a calibrated machine with a spinning shaft and an electronic brake. We clamp the chuck of each drill onto the dyno’s shaft and spin the drill under a broad range of resistance settings. “After testing each drill on every speed under a variety of loads, we use those measurements to derive scores for power, speed, and run time,” Spinelli says.
The more power a drill has, the bigger screw it can drive and the bigger hole it can bore before the motor cuts out. That’s the Power score in CR’s ratings.
CR's Speed score reflects the time each drill would take to perform a given task; those models with higher scores can drive screws and drill holes faster than those with lower scores.
Run time is a reflection of how long each battery lasts on a single charge, assuming you used it to perform the same task over and over.
Our experts also assess qualities such as balance, trigger pull, and the feel of the handle to assign each model a score for Handling. “You really want something that feels good in your hand if you’re going to work with it all day,” Spinelli says.
Last, Spinelli's team measures decibels to capture a Noise-at-ear score for each tool. As it turns out, all but the smallest models require hearing protection for safe use.
Buying a Better Drill
When you go to buy your next cordless drill, you'll find that the first question you'll need to answer is what voltage drill you want. That's an indication of power. Though an 18- or 20-volt cordless drill should deliver more torque than a 12-volt model, it’s also bulkier. That central trade-off hasn't changed since CR's last cordless drill test, but what you can expect from each one has changed.
Today’s 12-volt drills, for instance, can easily drive a few hundred decking screws on a single charge and are probably all the power the typical homeowner needs. But they wouldn’t be your first choice for driving large lag bolts. For that you’d want a stout 18-volt model, which can also drill into brick or concrete block.
And if you run into a situation where a cordless drill won’t cut it, you can always rent a heavy-duty corded drill from a home center. Better to do that than invest in 20th-century technology—a power cord.
Check out CR’s buying guide and ratings of cordless drills.
Power Drill Challenge
Not all drills are created equal. Whether you're hanging pictures or building a house, Consumer Reports expert Eric Hagerman shows "Consumer 101" TV show host Jack Rico how to choose the best tool for the job.
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