Getting the most from high-powered drills

Cordless drills powered by nickel-cadmium (NiCd) batteries are still a good bet for such lighter-duty household tasks as assembling furniture, hanging shelves and installing blinds. But if your projects demand lots of torque and run time ? building a deck, for example ? consider a drill that runs on lithium-ion (Li-Ion) or nickel-metal-hydride (NiMH) cells.

MORE MUSCLE, HIGHER COST

Since these new batteries deliver more energy per ounce than NiCds, they often allow the drills to do more work for their weight. And they?re environmentally friendlier than their predecessors. While old NiCd cells should be recycled (lest their toxic cadmium leach out into the groundwater), you can toss spent Li-Ion and NiMH batteries in the trash without worry of hazard.

In fact, about the only thing keeping these dynamos from dominating the market is their price: At $200 and up, they often cost at least twice as much as conventional NiCd models. Replacement batteries, too, will drain your wallet. Many Li-Ion and NiMH cells cost $90 and more, compared with as little as $25 for a replacement NiCd pack. But all that could change as more of these new batteries hit the mainstream.

FEATURES THAT COUNT

Not everyone needs the extra oomph of a drill powered by a Li-Ion or NiMH battery. Nearly any model we tested will do for hanging pictures and other easy jobs. Assess your requirements before shopping for a new drill, and keep these other factors in mind:

Don?t choose by voltage. Although the more powerful models tended to lead our ratings, several 18-volt drills we tested were bested overall by models with 14.4 and 12 volts.

Put your hands on it. Apart from noting a drill?s weight, check its balance by gripping it firmly and then lifting it to the wall as if you were about to drive a screw. The drill?s chuck should point straight ahead and not tilt up or down.

Seek multiple speeds. A high-speed setting helps you drill holes more cleanly without letting the bit bog down, while a slower setting emphasizes twisting power for driving and removing stubborn screws and lag bolts. A useful feature found on most drills we tested.

Other features we recommend include a battery meter (found on a few of our tested models, it?s an LED gauge that shows remaining power), a 1/2-inch chuck (this can accept larger bits than a 3/8-inch chuck) and hammer mode (it pulses the chuck and bit forward and back to punch through masonry).

PICKS OF THE BATTERY-POWERED PACK

Our highest-scoring drills tended to be those with the higher-tech Ni-Ion and NiMH batteries. Top rated overall was the Hitachi DS18DMR ($240), an 18-volt model that also features quick recharging of its NiMH battery. (We bought our Hitachi at a hardware store. The version sold at Lowe?s costs roughly $25 less, but has a NiCd battery that ran only about 75 percent as long.)