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This class of drill/driver offers good power in a lightweight tool, and at a moderate price

by Clayton DeKorne and Pete Young
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In the maze of cordless tools, there are several different classes of drill/drivers. Those intended for professional use clearly set themselves apart from those intended for homeowners (the one homeowner-market 14.4-volt drill we tried out worked so poorly that we did not even include the results in this article). Professional cordless drills have standard features such as electric brakes and keyless chucks. They also have longer runtimes and higher durability. Tradespeople have largely migrated to 12-, 14.4-, and 18-volt power classes during the past few years. We are focusing this tool review on 14.4-volt drills because this class offers a practical compromise between performance, cost, and weight. We collected most of the latest models on the market and put them through some tough tests. The Panasonic 15.6-volt model was included in this tool class because Panasonic does not offer a 14.4-volt model.

NiCad vs NiMH Batteries

We also included new 14.4-volt nickel metal hydride (NiMH) batteries. NiMH batteries, which hit the market in 1998, provide longer runtimes than the more common nickel cadmium (NiCad) batteries. Makita is the only manufacturer that currently has NiMH batteries available on the market. Most other manufacturers plan to introduce NiMH at some point in 1999. We were able to test two drills using NiMH batteries — the Makita, with a 2.2 amp-hour (Ah) battery, and the Hitachi, with a prototype 3Ah battery (see Figure 1).

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Figure 1. Nickel metal hydride (NiMH) batteries like the 2.2Ah from Makita and 3Ah prototype from Hitachi increase runtimes for each charge. However, they are more expensive than more common NiCad batteries and cannot be charged as many times before wearing out. With the added runtime, though, manufacturers are claiming that NiMH total runtime over the life of the battery is still greater than with NiCads. Although the Hitachi prototype battery was the only 3Ah battery we tested, many NiMH batteries will show up for sale in 1999 with 3Ah ratings, which will increase runtimes. These new NiMH batteries set the standard in our tests. In each of our tests, we ranked all drill models relative to the top performing NiMH model. However, enhanced runtimes will come with added costs. Not only will this next generation of batteries cost more than NiCads, but their lifespans will be shorter by as much as 20% fewer charge cycles. Nevertheless, because you get more runtime between charge cycles, manufacturers claim that total runtime over the life of the battery will still greatly exceed that of NiCads.

Performance Testing

To get ready for testing, we first conditioned two batteries for each drill by draining them and charging them five times (believe us when we say that 12 drills can make quite a lot of noise when they’re all running together at full speed for an hour or so). Our tests were designed to objectively determine performance limits for both low- and high-torque applications. In the two high-speed tests, driving drywall screws and boring spade bit holes, we used plywood to provide a uniform base material. During both test runs, we also noted our subjective likes and dislikes. In the end, you should be able to find the information you need to make a good choice if you decide to shop for one of these 14.4-volt models.

Light Load Runtime

Our first test was designed to determine the runtime of the tools during a low-power application. We drove 1-1/4-inch drywall screws into two glued-together sheets of 3/4-inch plywood. We tested each drill twice, each time with a different battery, to see how many screws could be driven on one charge (see bar chart). Both of us had the chance to work with every drill and we took notes on how they felt during the task.