Lithium-ion (Li-Ion) batteries power more and more drills and drivers. Added power and run time per pound over the familiar nickel-cadmium (NiCd) cells are the major talking points. Greener design is also a plus, since Li-Ion batteries don't contain toxic cadmium, which can leach into ground water if spent NiCd batteries are thrown into the trash instead of recycled. But Li-Ion cells could die an early death if you aren't careful. Several lithium batteries from multiple brands couldn't be recharged after we ran them down to full discharge. That makes using every last minute of run time a potentially expensive mistake, since replacement Li-Ion cells can cost $100 or more.
Although all the advantages and added cost of Li-Ion batteries also apply to nickel-metal-hydride (NiMH) batteries, Li-Ion cells are quickly becoming the hot items in the industry. But NiCd-powered tools still make up most of the market, thanks to their lower cost and decent performance for most needs.
How to choose
Not everyone needs maximum power and run time. Nearly any drill will do for hanging pictures and other easy tasks. Decide how much speed and power you really need. And don't buy strictly by voltage. Some 14.4-volt and 15.6-volt models had more oomph and staying power than some 18-volt models.
Hold it in your hand
Besides checking the drill's weight, check its balance by gripping it firmly and lifting it to a wall as if to drive a screw. The drill's chuck should point straight ahead and not tilt up or down.
For kits, check all the tools
Most cordless tool kits include a drill, reciprocating saw, and circular saw for $300 to $500. But while cordless circular saws have improved, some of those and reciprocating versions have been unimpressive and proved to be slow and weak -- especially those in lower-priced kits.
Weigh the pros and cons of specialized drivers
You'll also see more Li-Ion impact drivers and small, lightweight cordless screwdrivers that weigh 1 pound or less. But our tests revealed some notable drawbacks.
Impact drivers add twisting power using an internal hammer that pulses the chuck and bit back and forth as it spins. But that process has made impact drivers loud enough to require hearing protection. And as appealing as a pocket-sized cordless screwdriver may be, most have been slow and shy on power. Our advice: Spend $10 or so for a good set of old-fashioned hand screwdrivers.
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